Polymer, resist composition and patterning method

Abstract

This invention provides a polymer, a resist composition, and a patterning method for forming patterns with high sensitivity, high resolution, high contrast, and low pattern width variation (LWR) and in-plane uniformity (CDU) under high-energy radiation. One polymer is a polymer that generates acid upon exposure, and whose solubility in a developer is altered by the acid, characterized by containing repeating units represented by formula (A-1) and repeating units represented by any one or more of formulas (B-1) to (B-4). Wherein, M... ‑ A is a non-nucleophilic relative ion. + For onium cations, n1 is an integer of 1 or 2, n2 is an integer of 0 to 2, n3 is an integer of 0 to 5, n4 is an integer of 0 to 2, and c is an integer of 0 to 3.

Description

Technical Field

[0001] This invention relates to a polymer, a resist composition, and a method for patterning using the resist composition. Background Technology

[0002] In recent years, with the increasing integration of integrated circuits, there has been a search for the formation of fine patterns. The processing of patterns below 0.2 μm mainly uses chemically amplified resists with acid as a catalyst. Furthermore, the exposure source at this time uses high-energy rays such as ultraviolet light, far-ultraviolet light, and electron beams (EB). However, as an important technology for electron beam lithography, especially for ultra-fine processing, the processing method of blank photomasks when fabricating photomasks for semiconductor manufacturing is indispensable.

[0003] Many polymers with aromatic backbones and acidic side chains, such as polyhydroxystyrene, are useful as photoresist materials for KrF excimer lasers. However, they exhibit significant absorption of light around 200 nm, making them unsuitable for use as photoresists for ArF excimer lasers. Nevertheless, they are important materials for EB lithography and EUV lithography, which are powerful techniques for forming patterns with smaller processing limits than those achieved with ArF excimer lasers, and for achieving high etch resistance.

[0004] The base polymers of photoresist compositions for positive EB lithography and EUV lithography primarily utilize acids generated from photoacid generators by irradiation with high-energy rays as catalysts. These acids deprotect the acidic functional groups of the phenol side chains on the base polymer, making the material soluble in alkaline developers. Furthermore, the aforementioned acid-degrading protective groups mainly use tert-alkyl, tert-butoxycarbonyl, and acetal groups. Using protective groups with lower activation energy, such as acetal groups, for deprotection yields a high-sensitivity photoresist film. However, if the diffusion of the generated acid is not sufficiently suppressed, even unexposed areas of the photoresist film will undergo deprotection, leading to deterioration of line edge roughness (LER) and a decrease in in-plane uniformity (CDU) of the pattern.

[0005] The sensitivity and pattern profile control of resists have been improved through various means, including the selection and combination of materials used in the resist composition and processing conditions. One such improvement addresses the issue of acid diffusion, which significantly affects the resolution of chemically amplified resist compositions. This acid diffusion problem has a major impact on both sensitivity and resolution, and has therefore been the subject of much research.

[0006] Furthermore, to improve sensitivity, some researchers have attempted to introduce multiple bonds or aromatic rings into the acid-labile groups of the base polymer of the resist composition. While the introduction of these substituents has resulted in some performance improvement, satisfactory results have not yet been achieved. The allyl and benzyl cations generated after the acid desorption reaction exhibit increased stability compared to typical carbocations. Therefore, some researchers have studied and designed base polymers that generate primary or secondary benzyl cations after the acid desorption reaction. However, due to insufficient reactivity with acids, satisfactory performance improvements have not been achieved. Conversely, the tertiary allyl and tertiary benzyl cations generated after the acid desorption reaction are highly reactive with acids, and it has been confirmed that a portion of the thermal desorption reaction occurs during the polymerization of the base polymer. Challenges remain in polymer manufacturing processes (Patent Documents 1-13).

[0007] [Existing Technical Documents]

[0008] [Patent Literature]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 2011-191262

[0010] [Patent Document 2] Japanese Patent Application Publication No. 2013-53196

[0011] [Patent Document 3] Japanese Patent Application Publication No. 2018-92159

[0012] [Patent Document 4] Japanese Patent Application Publication No. 2008-268741

[0013] [Patent Document 5] Japanese Patent Application Publication No. 2019-120759

[0014] [Patent Document 6] Japanese Patent Application Publication No. 2020-085917

[0015] [Patent Document 7] Japanese Patent No. 6782569

[0016] [Patent Document 8] Japanese Patent Application Publication No. 2019-214554

[0017] [Patent Document 9] Japanese Patent Application Publication No. 2002-156761

[0018] [Patent Document 10] Japanese Patent Application Publication No. 2006-030232

[0019] [Patent Document 11] Japanese Patent Application Publication No. 2019-008287

[0020] [Patent Document 12] Japanese Patent Application Publication No. 2019-038998

[0021] [Patent Document 13] Japanese Patent Application Publication No. 2019-074733 Summary of the Invention

[0022] [The problem the invention aims to solve]

[0023] In view of the foregoing, the present invention aims to provide polymer and resist compositions, and a method of pattern formation using the same composition, which are particularly sensitive, high-resolution, and high-contrast in high-energy radiation, and capable of forming patterns with low pattern width variation (LWR) and low in-plane uniformity (CDU).

[0024] [Methods for solving problems]

[0025] To address the aforementioned issues, the present invention provides a polymer that generates acid upon exposure, thereby altering its solubility in a developer solution due to the action of this acid. The polymer is characterized by containing repeating units represented by formula (A-1) and repeating units represented by any one or more of formulas (B-1) to (B-4).

[0026] [Chemistry 1]

[0027]

[0028] In the formula, R A Z is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. A For single bonds, (main chain)-C(=O)-OZ A1 - or may contain an alkoxy group with 1 to 10 carbon atoms containing fluorine atoms, or may contain a phenylene or naphthylene group containing halogen atoms, Z A1 R is a straight-chain, branched, or cyclic alkoxy group with 1 to 20 carbon atoms, consisting of a heteroatom, or may contain a fluorine atom, and may also contain a hydroxyl group, ether bond, ester bond, or lactone ring; or may contain a alkyldiyl, phenylene, or naphthyl group. B With R C Each is independently a linear, branched, or cyclic hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. B With R C They can also bond together to form a ring structure, R 1a Each of the following is independently a halogen atom, a cyano group, an acyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkoxy group having 1 to 5 carbon atoms; R 1b Each is an independent, linear, branched, or cyclic hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms; n1 is an integer of 1 or 2; n2 is an integer of 0 to 2; n3 is an integer of 0 to 5; and n4 is an integer of 0 to 2.

[0029] Z 1 It is a single bond or a phenylene.

[0030] Z 2 For single bonds, -C(=O)-OZ21 -、-C(=O)-NH-Z 21 -or-OZ 21 -, Z 21 It is a divalent group obtained by combining aliphatic hydrocarbon groups, phenylene groups, or combinations thereof with 1 to 6 carbon atoms, and may also contain carbonyl groups, ester bonds, ether bonds, or hydroxyl groups.

[0031] Z 3 It is a single bond, phenylene, naphthylene, or (main chain)-C(=O)-OZ 31 -, Z 31 It may also contain an aliphatic hydrocarbon group with 1 to 10 carbon atoms, or a phenylene or naphthylene group, which may contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring.

[0032] Z 4 For single bonds, methylene, or -Z 41 -C(=O)-O-,Z 41 It may also contain heteroatoms, ether bonds, or ester bonds, and be a hydrocarbon group with 1 to 20 carbon atoms.

[0033] Z 5 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, trifluoromethyl-substituted phenylene, -C(=O)-OZ 51 -、-C(=O)-NH-Z 51 -or-OZ 51 -, Z 51 It is an aliphatic alkylene group, phenylene, fluorinated phenylene, or trifluoromethyl-substituted phenylene, having 1 to 6 carbon atoms. It may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group.

[0034] R 21 and R 22 Each can be an independent hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. 21 With R 22 They can also bond to each other and form rings together with the sulfur atoms they are bonded to.

[0035] L 11 The bonds can be single bonds, ether bonds, ester bonds, carbonyl groups, sulfonate bonds, carbonate bonds, or carbamate bonds.

[0036] Rf 1 and Rf 2 Each is independently a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms.

[0037] Rf 3 and Rf 4 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 6 carbon atoms.

[0038] M - It is a non-nucleophilic relative ion.

[0039] A + It is a ium cation.

[0040] c is an integer from 0 to 3.

[0041] Such a polymer, due to the presence of repeating unit A containing acid-instable groups with phenolic hydroxyl groups, contributes to changes in developer solubility and simultaneously increases both acid-instable units and sensitizing units that generate secondary electrons in the base polymer. Furthermore, by utilizing repeating unit B, which generates acid due to exposure, excessive acid diffusion can be suppressed, as can the diffusion of secondary electrons generated at the sensitizing sites.

[0042] Therefore, such a polymer can provide a photoresist material that can simultaneously achieve high sensitivity, high resolution, and high contrast in high-energy radiation, and can form patterns with small LWR and CDU, as well as a pattern forming method using this material.

[0043] Furthermore, the repeating unit represented by the aforementioned formula (A-1) is preferably the repeating unit represented by the following formula (A-2).

[0044] [Chemistry 2]

[0045]

[0046] In the formula, R A Z A R B R C R 1a R 1b n1, n2, and n3 are as described above.

[0047] Such polymers can be obtained with good solvent solubility.

[0048] Furthermore, R in the aforementioned equation (A-1) 1a It is preferred to have any one of fluorine atom, trifluoromethyl, or trifluoromethoxy.

[0049] Such polymers are good for high-energy X-ray lithography.

[0050] Furthermore, A in the aforementioned equations (B-2) to (B-4) + A cation represented by the formula (cation-1) or (cation-2) is preferred.

[0051] [Chemistry 3]

[0052]

[0053] In the formula, R 11 R 12 and R 13Each can independently represent a straight-chain, branched, or cyclic monovalent hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. Also, R 11 R 12 and R 13 Any two atoms in the formula can also bond to each other and form a ring together with the sulfur atom in the formula. R 14 and R 15 Each can be an independent monovalent hydrocarbon group consisting of 1 to 20 carbon atoms in a straight-chain, branched, or cyclic form, or may contain heteroatoms.

[0054] Such polymers are good for high-energy X-ray lithography.

[0055] Furthermore, the aforementioned polymer preferably contains repeating units represented by formula (a-1) or (a-2).

[0056] [Chemistry 4]

[0057]

[0058] In the formula, R A Z A Same as above. Z B It is an alkyl diol with 1 to 10 carbon atoms, consisting of a single bond, (main chain)-C(=O)-O-, or possibly containing an ester group, ether group, or carbonyl group. R b It can be a straight-chain, branched, or cyclic hydrocarbon group with 1 to 20 carbon atoms, a halogen atom, or an alkoxy or cyano group containing fluorine. p is an integer from 0 to 4. X A and X B Each is an independent acid-instable group that does not contain a fluorinated aromatic ring.

[0059] Such polymers are good for high-energy X-ray lithography.

[0060] Furthermore, it is preferable that the aforementioned polymer contains repeating units represented by the following formula (C-1).

[0061] [Chemistry 5]

[0062]

[0063] In the formula, R A Same as above. Z B It is an alkyl diol with 1 to 10 carbon atoms, consisting of a single bond or (main chain)-C(=O)-O-, or may also contain an ester group, ether group, or carbonyl group. R b1It can be a halogen atom, a cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms containing heteroatoms. m is 1 to 4, k is 0 to 3, and m+k is an integer less than 4.

[0064] Such polymers are good for high-energy X-ray lithography.

[0065] Furthermore, it is preferable that the aforementioned polymer contains repeating units represented by the following formula (D-1).

[0066] [Chemistry 6]

[0067]

[0068] In the formula, R A Z A Same as above. Y A It is a hydrogen atom, or a polar group containing at least one of the following structures: hydroxyl, cyano, carbonyl, carboxyl, ether bond, ester bond, sulfonate bond, sulfonamide bond, carbonate bond, lactone ring, sulfonolactone ring, sulfur atom, and carboxylic anhydride.

[0069] Such polymers are good for high-energy X-ray lithography.

[0070] Furthermore, the present invention provides a resist composition containing the above-mentioned polymer.

[0071] Such a resist composition can provide a photoresist material with high sensitivity, high resolution, high contrast in high-energy rays and capable of forming patterns with small LWR and CDU.

[0072] Furthermore, it is preferable that the aforementioned resist composition contains more organic solvents.

[0073] Such a resist composition can be obtained as a good resist composition for high-energy X-ray lithography.

[0074] Furthermore, it is preferable that the aforementioned resist composition contains photoacid generating agents other than the aforementioned polymer chain-bonded photoacid generating agents.

[0075] Such a resist composition can be obtained as a good resist composition for high-energy X-ray lithography.

[0076] Furthermore, it is preferable that the aforementioned resist composition also contains a quenching agent.

[0077] Such a resist composition can be obtained as a good resist composition for high-energy X-ray lithography.

[0078] Furthermore, the aforementioned resist composition preferably contains a surfactant that is insoluble or poorly soluble in water but soluble in alkaline developer, and / or a surfactant that is insoluble or poorly soluble in both water and alkaline developer.

[0079] Such a resist composition can be obtained as a good resist composition for high-energy X-ray lithography.

[0080] Furthermore, the present invention provides a pattern forming method, comprising the following steps:

[0081] (i) A resist film is formed on a substrate using the aforementioned resist composition.

[0082] (ii) Expose the aforementioned resist film to high-energy rays.

[0083] (iii) The exposed resist film is developed with a developer.

[0084] Such a pattern forming method can provide a pattern forming method with high sensitivity, high resolution, high contrast and low LWR and CDU in high-energy rays.

[0085] Furthermore, the high-energy rays mentioned in step (ii) above are preferably i-rays, KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet rays with wavelengths of 3 to 15 nm.

[0086] The pattern forming method of the present invention can use such high-energy rays.

[0087] Alternatively, the developer in step (iii) can be an alkaline aqueous solution, which dissolves the exposed portion and obtains a positive pattern in which the unexposed portion does not dissolve.

[0088] Alternatively, the developer in step (iii) can be an organic solvent to dissolve the unexposed areas, thereby obtaining a negative pattern in which the exposed areas do not dissolve.

[0089] The resist composition of the present invention can form both positive and negative patterns by selecting the developer.

[0090] [The effects of the invention]

[0091] As described above, by using the polymer of the present invention, the resist composition containing the polymer, and the patterning method, it is possible to obtain resist patterns with high sensitivity, low LWR, low CDU, high contrast, excellent resolution, and wide processing tolerance. Detailed Implementation

[0092] As mentioned above, the aim is to develop chemically amplified resist compositions using acid as a catalyst that achieve higher sensitivity, higher resolution, and improved line LWR and pore CDU.

[0093] In order to achieve the aforementioned objective, the inventors of this application have made efforts in research and discovered that by using a photoresist material containing repeating units with phenolic hydroxyl groups containing acid-instable groups and repeating units that generate acid upon exposure, a pattern with high sensitivity and wide processing tolerance, capable of forming LWR with high contrast and excellent resolution, and CDU with excellent line patterns, is achieved.

[0094] In other words, the present invention is a polymer that generates acid upon exposure, and whose solubility in developer is altered by the action of this acid, containing repeating units represented by formula (A-1) and repeating units represented by any one or more of formulas (B-1) to (B-4).

[0095] [Chemistry 7]

[0096]

[0097] In the formula, R A Z is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. A For single bonds, (main chain)-C(=O)-OZ A1 - or may contain an alkoxy group with 1 to 10 carbon atoms containing fluorine atoms, or may contain a phenylene or naphthylene group containing halogen atoms, Z A1 R is a straight-chain, branched, or cyclic alkoxy group with 1 to 20 carbon atoms, consisting of a heteroatom, or may contain a fluorine atom, and may also contain a hydroxyl group, ether bond, ester bond, or lactone ring; or may contain a alkyldiyl, phenylene, or naphthyl group. B With R C Each is independently a linear, branched, or cyclic hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. B With R C They can also bond together to form a ring structure, R 1a Each of the following is independently a halogen atom, a cyano group, an acyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkoxy group having 1 to 5 carbon atoms; R 1b Each is an independent, linear, branched, or cyclic hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms; n1 is an integer of 1 or 2; n2 is an integer of 0 to 2; n3 is an integer of 0 to 5; and n4 is an integer of 0 to 2.

[0098] Z 1 It is a single bond or a phenylene.

[0099] Z 2 For single bonds, -C(=O)-OZ 21 -、-C(=O)-NH-Z 21 -or-OZ 21 -, Z21 It is a divalent group obtained by combining aliphatic hydrocarbon groups, phenylene groups, or combinations thereof with 1 to 6 carbon atoms, and may also contain carbonyl groups, ester bonds, ether bonds, or hydroxyl groups.

[0100] Z 3 It is a single bond, phenylene, naphthylene, or (main chain)-C(=O)-OZ 31 -, Z 31 It may also contain an aliphatic hydrocarbon group with 1 to 10 carbon atoms, or a phenylene or naphthylene group, which may contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring.

[0101] Z 4 For single bonds, methylene, or -Z 41 -C(=O)-O-,Z 41 It may also contain heteroatoms, ether bonds, or ester bonds, and be a hydrocarbon group with 1 to 20 carbon atoms.

[0102] Z 5 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, trifluoromethyl-substituted phenylene, -C(=O)-OZ 51 -、-C(=O)-NH-Z 51 -or-OZ 51 -, Z 51 It is an aliphatic alkylene group, phenylene, fluorinated phenylene, or trifluoromethyl-substituted phenylene, having 1 to 6 carbon atoms. It may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group.

[0103] R 21 and R 22 Each can be an independent hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. 21 With R 22 They can also bond to each other and form rings together with the sulfur atoms they are bonded to.

[0104] L 11 The bonds can be single bonds, ether bonds, ester bonds, carbonyl groups, sulfonate bonds, carbonate bonds, or carbamate bonds.

[0105] Rf 1 and Rf 2 Each is independently a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms.

[0106] Rf 3 and Rf 4 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 6 carbon atoms.

[0107] M - It is a non-nucleophilic relative ion.

[0108] A + It is a ium cation.

[0109] c is an integer from 0 to 3.

[0110] The present invention will be described in detail below, but the present invention is not limited thereto.

[0111] [Polymers (Basic Polymers)]

[0112] The polymer of the present invention contains repeating units having acid-instable groups containing phenolic hydroxyl groups, and repeating units that generate acid upon exposure.

[0113] [Repeating unit A containing an acid-labile group with a phenolic hydroxyl group]

[0114] The polymer (basic polymer) of the present invention contains repeating units (hereinafter also referred to as repeating unit A) having acid-instable groups containing phenolic hydroxyl groups. Repeating unit A is represented by the following formula (A-1).

[0115] [Chemistry 8]

[0116]

[0117] In equation (A-1), R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0118] Z A For single bonds, (main chain)-C(=O)-OZ A1 - or may contain an alkoxy group with 1 to 10 carbon atoms containing fluorine atoms, or may contain a phenylene or naphthylene group containing halogen atoms. A1 It is a straight-chain, branched, or cyclic alkoxy group with 1 to 20 carbon atoms, which may contain heteroatoms or fluorine atoms, alkoxy groups with 1 to 10 carbon atoms, or hydroxyl groups, ether bonds, ester bonds, or lactone rings, and may also contain alkyl diyl (aliphatic hydrocarbon group), phenylene, or naphthylene groups.

[0119] The aforementioned alkyl dienes can be saturated or unsaturated, and can be linear, branched, or cyclic. Specifically, examples include methane dienes, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, propane-2,2-diyl, butane-1,1-diyl, butane-1,2-diyl, butane-1,3-diyl, butane-2,3-diyl, butane-1,4-diyl, 1,1-dimethylethane-1,2-diyl, and pentane-1,5-diyl. Dialkyl groups such as 2-methylbutane-1,2-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, and decane-1,10-diyl; cycloalkyl dialkyl groups such as cyclopropane-diyl, cyclobutane-1,1-diyl, cyclobutane-diyl, cyclopentane-diyl, and cyclohexane-diyl; divalent polycyclic saturated hydrocarbon groups such as adamantane-diyl and norcamphene-diyl; and divalent groups obtained by combining them.

[0120] Z in equation (A-1) A The modified structures can be listed below, but are not limited to. Also, in the following formula, R... A As mentioned before, the dashed line represents R in the aforementioned equation (A-1). B With R C The bonds between the carbon atoms that are bonded.

[0121] [Chemistry 9]

[0122]

[0123] [Chemistry 10]

[0124]

[0125] In equation (A-1), R B With R C Each can be an alkyl group consisting of 1 to 10 carbon atoms in a straight-chain, branched, or cyclic form, which may also contain heteroatoms. Examples of such alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, dibutyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl, n-octyl, norbornel, tricyclodecyl, adamantyl, etc.

[0126] In equation (A-1), R B With R C They can also bond together to form ring structures. Specifically, examples include cyclopropane rings, cyclobutane rings, cyclopentane rings, and cyclohexane rings. Among these, cyclopentane and cyclohexane rings are preferred.

[0127] In equation (A-1), n1 represents an integer of 1 or 2. Among them, n1 = 1 is preferred.

[0128] In equation (A-1), R1a Each of the following is independently a halogen atom, a cyano group, an acyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkoxy group having 1 to 5 carbon atoms. Among these, a fluorine atom or a fluorinated alkoxy group having 1 to 5 carbon atoms is preferred, while a fluorine atom, trifluoromethyl, or trifluoromethoxy is even more ideal.

[0129] In equation (A-1), n2 represents an integer from 0 to 2.

[0130] In equation (A-1), R 1b Each can be independently a straight-chain, branched, or cyclic hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. Specifically, examples include R. B With R C The same example.

[0131] n3 represents an integer from 0 to 5, with 0 or 1 being preferred.

[0132] n4 represents an integer from 0 to 2. When n4 = 0, it represents a benzene ring; when n4 = 1, it represents a naphthalene ring; and when n4 = 2, it represents an anthracene ring. Considering solvent solubility, a benzene ring with n4 = 0 is preferable.

[0133] The repeating unit A represented by equation (A-1) is more preferably represented by the repeating unit represented by equation (A-2).

[0134] [Chemistry 11]

[0135]

[0136] In the formula, R A Z A R B R C R 1a R 1b n1, n2, and n3 are as described above.

[0137] [Synthesis of monomer A represented by formula (A-1)]

[0138] The repeating unit A represented by the above formulas (A-1) and (A-2) can be manufactured, for example, by monomer A-1 obtained by the following scheme. The following describes the synthesis of the monomer represented by the following formula (monomer A-1) as an example, but the synthesis method is not limited to this.

[0139] [Chemistry 12]

[0140]

[0141] In the formula, R A Z A R B R C R 1aR 1b n1, n2, n3, and n4 are as described above. H hal It consists of halogen atoms other than fluorine atoms.

[0142] Step 1 is to react a Grignard reagent or an organolithium reagent with a commercially available ketone compound (starting material 1) or a ketone compound that can be synthesized by a known synthetic method to obtain tert-benzyl alcohol (intermediate 1).

[0143] The reaction can be carried out using known organic synthesis methods. Specifically, a ketone compound (starting material 1) diluted with the solvent used is added dropwise to a commercially available Grignard reagent or an organolithium reagent prepared according to a known formulation. The reaction temperature is from room temperature to approximately the boiling point of the solvent used. From the viewpoint of yield, the reaction time should be monitored by gas chromatography (GC) or silica gel thin-layer chromatography (TLC) to ensure the reaction is complete, but it is typically about 30 minutes to 2 hours. Tertiary benzyl alcohol (intermediate 1) can be obtained from the reaction mixture using a conventional aqueous work-up. The obtained tertiary benzyl alcohol (intermediate 1) can be purified by conventional methods such as distillation, chromatography, and recrystallization if necessary.

[0144] Step 2 is to introduce a polymerizable group into the tert-benzyl alcohol (intermediate 1) obtained in step 1 via an ester bond to obtain intermediate 2.

[0145] The reaction can be carried out using well-known organic synthesis methods. Specifically, the tertiary alcohol of intermediate 1 is dissolved in solvents such as toluene, hexane, THF, and acetonitrile in the presence of organic bases such as triethylamine and pyridine, and the reaction is carried out by dropwise addition of acyl halides such as methacryloyl chloride and acryloyl chloride. To accelerate the reaction, 4-dimethylaminopyridine may also be added. The reaction is carried out at a temperature of 5°C or around the boiling point of the solvent used. From the perspective of yield, the reaction time should be monitored by gas chromatography (GC) or silica gel thin-layer chromatography (TLC) to ensure the reaction is complete, but it is usually about 1 hour to 24 hours. Intermediate 2 can be obtained from the reaction mixture using a conventional aqueous work-up. If necessary, intermediate 2 can be purified by conventional methods such as distillation, chromatography, and recrystallization.

[0146] Step 3 is to use a base to hydrolyze only the aromatic ester bonds of intermediate 2 obtained in step 2 to obtain monomer A-1.

[0147] The reaction can be carried out using well-known organic synthesis methods. Specifically, intermediate 2 is dissolved in 1,4-dioxane, THF, etc., and a base is added dropwise while the reaction proceeds. The base used in the reaction can be an aqueous solution of an inorganic base such as sodium hydroxide, potassium hydroxide, or potassium carbonate. The reaction is preferably carried out at a temperature ranging from ice-cold to 60°C. From the perspective of yield, the reaction time should be monitored by gas chromatography (GC) or silica gel thin-layer chromatography (TLC) to ensure the reaction is complete, but it is typically about 2 to 12 hours. After the reaction is complete, an acid is added to stop the reaction; the acid used can be an aqueous solution of hydrochloric acid, sulfuric acid, or nitric acid. The reaction is preferably stopped at ice-cold conditions. Monomer A-1 can be obtained from the reaction mixture using a conventional aqueous work-up. The obtained monomer A-1 can be purified by conventional methods such as distillation, chromatography, and recrystallization if necessary.

[0148] The specific structures of the repeating unit A represented by equations (A-1) and (A-2) above can be listed below, but are not limited to these examples. Furthermore, in the following equation, R... A As mentioned above.

[0149] [Chemistry 13]

[0150]

[0151] [Chemistry 14]

[0152]

[0153] [Chemistry 15]

[0154]

[0155] [Chemistry 16]

[0156]

[0157] [Chemistry 17]

[0158]

[0159] [Chemistry 18]

[0160]

[0161] [Chemistry 19]

[0162]

[0163] [Chemistry 20]

[0164]

[0165] [Chemistry 21]

[0166]

[0167] [Chemistry 22]

[0168]

[0169] [Chemistry 23]

[0170]

[0171] [Chemistry 24]

[0172]

[0173] [Chemistry 25]

[0174]

[0175] [Repeating unit B: Acid produced due to exposure]

[0176] The polymer of the present invention contains repeating units (hereinafter also referred to as repeating units B) that generate acid upon exposure. Repeating unit B is any one or more of the repeating units represented by formula (B-1) (hereinafter also referred to as repeating unit B1), repeating units represented by formula (B-2) (hereinafter also referred to as repeating unit B2), repeating units represented by formula (B-3) (hereinafter also referred to as repeating unit B3), and repeating units represented by formula (B-4) (hereinafter also referred to as repeating unit B4).

[0177] [Chemistry 26]

[0178]

[0179] In equations (B-1) to (B-4), R A Same as above. Z 1 It is a single bond or a phenylene oxide. Z 2 For single bonds, -C(=O)-OZ 21 -、-C(=O)-NH-Z 21 -or-OZ 21 -. Z 21 It is a divalent group consisting of an aliphatic hydrocarbon group, a phenylene group, or a combination thereof, having 1 to 6 carbon atoms; it may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 3 It is a single bond, phenylene, naphthylene, or (main chain)-C(=O)-OZ 31 -. Z 31 It may also contain an aliphatic hydrocarbon group with 1 to 10 carbon atoms, or a phenylene or naphthylene group, which may contain a hydroxyl group, an ether bond, an ester bond, or an lactone ring. 4 For single bonds, methylene, or -Z 41 -C(=O)-O-。 Z 41It can also contain heteroatoms, ether bonds, or ester bonds, and is a hydrocarbon group with 1 to 20 carbon atoms. 5 Single bond, methylene, ethylene, trifluoromethyl-substituted phenylene, phenylene, fluorinated phenylene, -C(=O)-OZ 51 -、-C(=O)-NH-Z 51 -or-OZ 51 -. Z 51 It is an aliphatic alkylene group, phenylene, fluorinated phenylene, or phenylene substituted with trifluoromethyl, having 1 to 6 carbon atoms, and may also contain carbonyl, ester, ether, or hydroxyl groups.

[0180] Z 21 Z 31 and Z 51 The aliphatic alkylene group can be linear, branched, or cyclic; specific examples can be listed and shown in formula (A-1) under Z. A1 The example shown is the same as the one used for illustration.

[0181] Z 41 The alkylene group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples are listed below, but are not limited to.

[0182] [Chemistry 27]

[0183]

[0184] In the formula, the dashed lines represent atomic bonds.

[0185] In equation (B-1), R 21 and R 22 Each can independently be a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. R 21 and R 22 The hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and tert-butyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclohexenyl and other cyclic unsaturated hydrocarbon groups; aryl groups such as phenyl, naphthyl, and thiophene; aralkyl groups such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining them, with aryl groups being preferred. Furthermore, a portion of the hydrogen atom in the aforementioned hydrocarbon group can also be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Groups containing heteroatoms such as oxygen, sulfur, or nitrogen can also be inserted between the carbon atoms of these groups, resulting in the presence of hydroxyl, cyano, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonolactone ring, carboxylic anhydride, or haloalkyl groups.

[0186] Also, R 21 With R 22 They can also bond to each other and form rings together with the sulfur atoms they are bonded to. Specifically, examples can be shown in the following formulas.

[0187] [Chemistry 28]

[0188]

[0189] The cations of repeating unit B1 can be listed below, but are not limited to. Also, in the following formula, R... A Same as above.

[0190] [Chemistry 29]

[0191]

[0192] [Chemistry 30]

[0193]

[0194] [Chemistry 31]

[0195]

[0196] [Chemistry 32]

[0197]

[0198] In equation (B-1), M - It is a non-nucleophilic relative ion. M - Examples of non-nucleophilic relative ions include halide ions such as chloride ions and bromide ions; fluoroalkyl sulfonate ions such as trifluoromethanesulfonate ions, 1,1,1-trifluoroethanesulfonate ions, and nonafluorobutanesulfonate ions; aryl sulfonate ions such as toluenesulfonate ions, benzenesulfonate ions, 4-fluorobenzenesulfonate ions, and 1,2,3,4,5-pentafluorobenzenesulfonate ions; alkyl sulfonate ions such as methanesulfonate ions and butanesulfonate ions; imine acid ions such as bis(trifluoromethanesulfonyl)imide ions, bis(perfluoroethylsulfonyl)imide ions, and bis(perfluorobutylsulfonyl)imide ions; and methylated acid ions such as tri(trifluoromethanesulfonyl)methylide ions and tri(perfluoroethylsulfonyl)methylide ions.

[0199] Furthermore, the aforementioned non-nucleophilic relative ions can be exemplified by the sulfonic acid anion represented by formula (B-1-1) with the α-position substituted by a fluorine atom and the sulfonic acid anion represented by formula (B-1-2) with the α-position substituted by a fluorine atom and the β-position substituted by a trifluoromethyl atom.

[0200] [Chemistry 33]

[0201] R23 -CF2-SO3 - (B-1-1)

[0202]

[0203] In equation (B-1-1), R 23 It consists of a hydrogen atom and a hydrocarbon group having 1 to 20 carbon atoms, and may also contain ether bonds, ester bonds, carbonyl groups, lactone rings, or fluorine atoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. A specific example can be cited from R in formula (3A'). 105 The hydrocarbons represented are based on the same examples described later.

[0204] In equation (B-1-2), R 24 It can be a hydrogen atom, a hydrocarbon group with 1 to 30 carbon atoms, a hydrocarbon carbonyl group with 2 to 30 carbon atoms, or an aryloxy group with 6 to 20 carbon atoms, and may also contain ether bonds, ester bonds, carbonyl groups, or lactone rings. The hydrocarbon group and hydrocarbon carbonyl group mentioned above can be saturated or unsaturated, and can be linear, branched, or cyclic. A specific example can be given by R in formula (3A'). 105 The hydrocarbons represented are based on the same examples described later.

[0205] Specific examples of sulfonic acid anions represented by the aforementioned non-nucleophilic relative ions are shown below, but are not limited to these. Furthermore, in the following formula, Q... 3 It is a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 6 carbon atoms, and Ac is an acetyl group.

[0206] [Chemistry 34]

[0207]

[0208] [Chemistry 35]

[0209]

[0210] [Chemistry 36]

[0211]

[0212] [Chemistry 37]

[0213]

[0214] [Chemistry 38]

[0215]

[0216] [Chemistry 39]

[0217]

[0218] [Chemistry 40]

[0219]

[0220] [Chemistry 41]

[0221]

[0222] In equation (B-2), L 11 The bonds can be single bonds, ether bonds, ester bonds, carbonyl bonds, sulfonate bonds, carbonate bonds, or carbamate bonds. Among these, from a synthetic point of view, ether bonds, ester bonds, and carbonyl bonds are more ideal, with ester bonds and carbonyl bonds being even more ideal.

[0223] In equation (B-2), Rf 1 and Rf 2 Each is independently a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms. Among them, Rf 1 and Rf 2 In order to increase the acid strength, it is preferable that all atoms be fluorine atoms. Rf 3 and Rf 4 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 6 carbon atoms. Among them, Rf is used to improve solvent solubility. 3 and Rf 4 At least one of them is preferably trifluoromethyl.

[0224] In equation (B-2), c is an integer from 0 to 3, but 1 is preferred.

[0225] The anions of the repeating units represented by equation (B-2) can be specifically listed below, but are not limited to. Furthermore, in the following equation, R... A Same as above

[0226] [Chemistry 42]

[0227]

[0228] [Chemistry 43]

[0229]

[0230] [Chemistry 44]

[0231]

[0232] [Chemistry 45]

[0233]

[0234] [Chemistry 46]

[0235]

[0236] In equation (B-3), L11 The bonds can be single bonds, ether bonds, ester bonds, carbonyl bonds, sulfonate bonds, carbonate bonds, or carbamate bonds. Among these, from a synthetic point of view, ether bonds, ester bonds, and carbonyl bonds are more ideal, with ester bonds and carbonyl bonds being even more ideal.

[0237] In equation (B-3), Rf 3 and Rf 4 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 6 carbon atoms. Among them, Rf is used to improve solvent solubility. 3 and Rf 4 At least one of them is preferably trifluoromethyl.

[0238] In equation (B-3), c is an integer from 0 to 3, but 1 is preferred.

[0239] The anions of the repeating units represented by equation (B-3) can be specifically listed below, but are not limited to. Furthermore, in the following equation, R... A Same as above

[0240] [Chemistry 48]

[0241]

[0242] [Chemistry 49]

[0243]

[0244] [Transformation 50]

[0245]

[0246] The anions of the repeating units represented by equation (B-4) can be specifically listed below, but are not limited to. Furthermore, in the following equation, R... A Same as above

[0247] [Chemistry 51]

[0248]

[0249] In equations (B-2) to (B-4), A + The cation is an onium cation. Examples of onium cations include ammonium cations, sulfonium cations, and monium cations, but sulfonium cations and monium cations are preferred, and sulfonium cations represented by formula (cation-1) and monium cations represented by formula (cation-2) are even more preferred.

[0250] [Chemistry 52]

[0251]

[0252] In equations (cation-1) and (cation-2), R 11 ~R15 Each group can be an independent hydrocarbon group containing 1 to 30 carbon atoms, or may contain heteroatoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and tert-butyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclohexenyl and other cyclic unsaturated hydrocarbon groups; aryl groups such as phenyl, naphthyl, and thiophene; aralkyl groups such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combinations thereof, but aryl groups are preferred. Furthermore, a portion of the hydrogen atom in the aforementioned hydrocarbon group may be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Groups containing heteroatoms such as oxygen, sulfur, or nitrogen may also be inserted between the carbon atoms of the group, resulting in the presence of hydroxyl, cyano, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonolactone ring, carboxylic anhydride, or haloalkyl groups.

[0253] Also, R 11 and R 12 They can also bond to each other and form rings together with the sulfur atoms they are bonded to. In this case, the sulfonium cation represented by formula (cation-1) can include sulfonium cations represented by the following formulas, etc.

[0254] [Chemistry 53]

[0255]

[0256] In the formula, the dashed line represents R. 13 Atomic bonds.

[0257] The sulfonium cations represented by formula (cation-1) can be listed below, but are not limited to.

[0258] [Chemistry 54]

[0259]

[0260] [Chemistry 55]

[0261]

[0262] [Chemistry 56]

[0263]

[0264] [Chemistry 57]

[0265]

[0266] [Chem.58]

[0267]

[0268] [Chemistry 59]

[0269]

[0270] [Transformation 60]

[0271]

[0272] [Chemistry 61]

[0273]

[0274] [Chemistry 62]

[0275]

[0276] [Chemistry 63]

[0277]

[0278] [Chemistry 64]

[0279]

[0280] [Chemistry 65]

[0281]

[0282] [Chemistry 66]

[0283]

[0284] [Chemistry 67]

[0285]

[0286] [Chemistry 68]

[0287]

[0288] [Chemistry 69]

[0289]

[0290] [Chemistry 70]

[0291]

[0292] [Chemistry 71]

[0293]

[0294] [Chemistry 72]

[0295]

[0296] The ferrocations represented by formula (cation-2) can be listed below, but are not limited to.

[0297] [Chemistry 73]

[0298]

[0299] The specific structure of the repeating unit represented by formulas (B-1) to (B-4) can be any combination of the aforementioned anions and cations.

[0300] Regarding repeating unit B, considering acid diffusion control, repeating units B2, B3, and B4 are more ideal; considering the acid strength of the generated acid, repeating units B2 and B4 are better; and considering solvent solubility, repeating unit B2 is more ideal.

[0301] The polymer of the present invention is characterized by repeating units comprising repeating units A having acid-instable groups containing phenolic hydroxyl groups and repeating units B that generate acid upon exposure. By including repeating units that generate acid upon exposure in the base polymer, especially when the acid generated after exposure is anionicly bonded to the main chain of the base polymer, excessive acid diffusion can be suppressed, and it is believed that the secondary electrons generated at the sensitizing sites do not diffuse, thus contributing to the decomposition of cations. Furthermore, repeating units having acid-instable groups containing phenolic hydroxyl groups contribute to changes in the solubility of the developer during the deprotection reaction after exposure, particularly contributing to the sensitizing effect of secondary electrons generated by EUV light. When acid-instable units and sensitizing units are introduced into the base polymer, to improve contrast, increasing the amount of acid-instable units reduces the amount of sensitizing units introduced, resulting in reduced secondary electron generation and decreased sensitivity. Conversely, increasing the amount of sensitizing units increases the amount of secondary electron generation, but decreases the amount of acid-instable units introduced into the base polymer, thus reducing the solubility contrast. Considering this perspective, by introducing repeating units with acid-indestabilized groups containing phenolic hydroxyl groups, it is possible to simultaneously increase both acid-indestabilized and sensitizing units in the base polymer. Through these synergistic effects, both high sensitivity and high contrast can be achieved simultaneously, resulting in line-patterned LWRs and hole-patterned CDUs with small patterns.

[0302] [Repeating units a1, a2]

[0303] The polymer of the present invention may further contain at least one of the repeating units represented by formula (a-1) (hereinafter also referred to as repeating unit a1) and the repeating units represented by formula (a-2) (hereinafter also referred to as repeating unit a2).

[0304] [Chemistry 74]

[0305]

[0306] In equations (a-1) and (a-2), R A Z A Z B R b Same as above. p is an integer from 0 to 4. X A and X B Each is an independent acid-instable group that does not contain a fluorinated aromatic ring.

[0307] In equations (a-1) and (a-2), X A and X B The acid-instable group is represented, for example, by Japanese Patent Application Publication No. 2013-80033 and Japanese Patent Application Publication No. 2013-83821.

[0308] Generally, the aforementioned unstable acid groups can be represented by the following formulas (AL-1) to (AL-3).

[0309] [Chemistry 75]

[0310]

[0311] In the formula, the dashed lines represent atomic bonds.

[0312] In equations (AL-1) and (AL-2), R L1 and R L2 Each saturated hydrocarbon group is independently composed of 1 to 40 carbon atoms and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The aforementioned saturated hydrocarbon groups can be linear, branched, or cyclic. Those with 1 to 20 carbon atoms are preferred.

[0313] In formula (AL-1), a is an integer from 0 to 10, and an integer from 1 to 5 is preferred.

[0314] In equation (AL-2), R L3 and R L4 Each group is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The aforementioned hydrocarbon groups can be linear, branched, or cyclic. Furthermore, R... L2 R L3 and R L4 Any two of them can bond to each other and together with the carbon atoms they are bonded to, or carbon atoms and oxygen atoms, form a ring with 3 to 20 carbon atoms. The aforementioned rings with 4 to 16 carbon atoms are more ideal, especially alicyclic rings.

[0315] In equation (AL-3), R L5 R L6 and R L7Each group is an independent saturated hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The aforementioned hydrocarbon groups can be linear, branched, or cyclic. Furthermore, R... L5 R L6 and R L7 Any two of them can bond to each other and together with the carbon atoms they are bonded to form a ring with 3 to 20 carbon atoms. The aforementioned rings with 4 to 16 carbon atoms are more ideal, especially alicyclic rings.

[0316] Repeating unit a1 can be listed below, but is not limited to. Also, in the following formula, R... A and X A Same as above.

[0317] [Chemistry 76]

[0318]

[0319] [Chemistry 77]

[0320]

[0321] Repeating unit a2 can be listed below, but is not limited to. Also, in the following formula, R... A and X B Same as above.

[0322] [Chemistry 78]

[0323]

[0324] [Repeating unit C with phenolic hydroxyl group]

[0325] The polymer of the present invention contains repeating units having phenolic hydroxyl groups (hereinafter also referred to as repeating unit C). It is preferred that the repeating unit C is represented by the following formula (C-1).

[0326] [Chemistry 79]

[0327]

[0328] In equation (C-1), R A Same as above. Z B It is a single bond or (main chain) -C(=O)-O-. R b1 It can be a halogen atom, a cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms. m is 1 to 4, k is 0 to 3, and m+k is an integer less than 4.

[0329] Rb1 The hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated in formula (A-1) with R. 1b The examples given are the same. Furthermore, specific examples of the hydrocarbon groups of the aforementioned alkyloxy and hydrocarbon carbonyl groups can be listed and illustrated in R. 1b The examples provided are the same.

[0330] Repeating unit C can be listed below, but is not limited to. Also, in the following formula, R... A Same as above.

[0331] [Chemistry 80]

[0332]

[0333] [Chemistry 81]

[0334]

[0335] [Chemistry 82]

[0336]

[0337] [Repeating Unit D]

[0338] The polymer of the present invention may also contain repeating units represented by the following formula (D-1) (hereinafter also referred to as repeating unit D).

[0339] [Chemistry 83]

[0340]

[0341] In the formula, R A and Z A Same as above. Y A It is a hydrogen atom, or a polar group containing at least one of the following structures: hydroxyl, cyano, carbonyl, carboxyl, ether bond, ester bond, sulfonate bond, sulfonamide bond, carbonate bond, lactone ring, sulopentalide ring, sulfur atom, and carboxylic anhydride.

[0342] The above Y A It is a hydrogen atom, or a polar group containing at least one of the following structures: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulcinolone ring and carboxylic anhydride.

[0343] Repeating unit D can be listed as follows, but is not limited to. Also, in the following formula, R... A Same as above.

[0344] [Chemistry 84]

[0345]

[0346] [Chemistry 85]

[0347]

[0348] [Chemistry 86]

[0349]

[0350] [Chemistry 87]

[0351]

[0352] [Chemistry 88]

[0353]

[0354] [Chemistry 89]

[0355]

[0356] [Chemistry 90]

[0357]

[0358] [Chemistry 91]

[0359]

[0360] [Repeating Unit E]

[0361] The polymers of the present invention may further contain repeating unit E derived from indene, benzofuran, benzothiophene, vinylnaphthalene, crromone, coumarin, norcamphediene, or derivatives thereof. Monomers giving repeating unit E may be listed below, but are not limited thereto.

[0362] [Chemistry 92]

[0363]

[0364] [Repeating Unit F]

[0365] The polymers of the present invention may also contain repeating units F derived from dihydroindene, vinylpyridine, or vinylcarbazole.

[0366] In the polymer of the present invention, the content ratios of repeating units A, a1, a2, B, C, D, E, and F are preferably 0 < A < 1.0, 0 ≤ a1 ≤ 0.8, 0 ≤ a2 ≤ 0.8, 0 < B < 1.0, 0 ≤ C < 1.0, 0 ≤ D ≤ 0.8, 0 ≤ E ≤ 0.8, and 0 ≤ F ≤ 0.4, more preferably 0.05 ≤ A ≤ 0.9, 0 ≤ a1 ≤ 0.7, 0 ≤ a2 ≤ 0.7, 0 ≤ a1 + a2 ≤ 0.7, 0.01 ≤ B ≤ 0.4, 0.09 ≤ C ≤ 0.55, 0 ≤ D ≤ 0.7, 0 ≤ E ≤ 0.7, and 0 ≤ F ≤ 0.3, and even more preferably 0.1 ≤ A ≤ 0.8, 0 ≤ a1 ≤ 0.6, 0 ≤ a2 ≤ 0.6, 0 ≤ a1 + a2 ≤ 0.4, 0.1 ≤ B ≤ 0.45, 0.1 ≤ C ≤ 0.45, 0 ≤ D ≤ 0.6, 0 ≤ E ≤ 0.6, and 0 ≤ F ≤ 0.2.

[0367] Also, when the repeating unit B is at least one selected from repeating units B1 to B4, B = B1 + B2 + B3 + B4. Also, A + a1 + a2 + B + C + D + E + F = 1.

[0368] The weight average molecular weight (Mw) of the aforementioned polymer is preferably 1,000 to 500,000, and more preferably 3,000 to 100,000. If Mw is within this range, sufficient etching resistance can be obtained, and there is no concern about a decrease in resolution due to an inability to ensure a difference in dissolution rate before and after exposure. Also, Mw in the present invention is a polystyrene conversion measurement value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or N,N-dimethylformamide (DMF) as a solvent.

[0369] Also, when the molecular weight distribution (Mw / Mn) of the aforementioned polymer is broad, the influence of Mw / Mn tends to increase as the pattern rule is miniaturized. Therefore, in order to obtain a resist material suitable for use with a fine pattern size, a narrow dispersion with Mw / Mn of 1.0 to 2.0 is preferable. If it is within the above range, there are few low molecular weight and high molecular weight polymers, and there is no concern about foreign matter appearing on the pattern or deterioration of the pattern shape after exposure.

[0370] To synthesize the aforementioned polymer, for example, monomers that give the aforementioned repeating units are added with a radical polymerization initiator in an organic solvent, heated, and polymerized.

[0371] Organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, dioxane, cyclohexane, cyclopentane, methyl ethyl ketone (MEK), propylene glycol monomethyl ether acetate (PGMEA), and γ-butyrolactone (GBL). Polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, and lauroyl peroxide. The amount of initiator added relative to the total monomers to be polymerized is preferably 0.01–25 mol%. A reaction temperature of 50–150°C is ideal, with 60–100°C being more ideal. A reaction time of 2–24 hours is ideal; considering production efficiency, 2–12 hours is more ideal.

[0372] The aforementioned polymerization initiator can be added to the aforementioned monomer solution and supplied to the reactor, or a separate initiator solution can be prepared and supplied to the reactor independently. During the standby time, free radicals generated from the initiator may allow polymerization to proceed and generate ultrapolymers; therefore, from a quality control point of view, it is preferable that the monomer solution and initiator solution be prepared and added dropwise independently. Acid-labile groups can be used directly from those already introduced into the monomer, or they can be protected or partially protected after polymerization. Furthermore, for molecular weight adjustment, known chain transfer agents such as dodecyl mercaptan and 2-mercaptoethanol can be used concurrently. In this case, the amount of the chain transfer agent added relative to the total amount of monomers to be polymerized is preferably 0.01 to 20 mol%.

[0373] When the monomer contains hydroxyl groups, the hydroxyl groups can be replaced with acetal groups such as ethoxyethoxy, which are easily deprotected by acids, during polymerization. After polymerization, deprotection can be carried out with weak acid and water. Alternatively, acetyl, formyl, trimethylacetyl, etc., can be replaced first, and then alkaline hydrolysis can be carried out after polymerization.

[0374] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, hydroxystyrene or hydroxyvinylnaphthalene and other monomers can be added to an organic solvent, a free radical polymerization initiator can be added, and the mixture can be heated to polymerize. Alternatively, acetoxystyrene or acetoxyvinylnaphthalene can be used. After polymerization, the acetoxy groups can be deprotected by alkaline hydrolysis to obtain polyhydroxystyrene or hydroxyvinylnaphthalene.

[0375] The alkali used in alkaline hydrolysis can be ammonia, triethylamine, etc. Furthermore, the preferred reaction temperature is -20 to 100°C, more preferably 0 to 60°C. The preferred reaction time is 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0376] Furthermore, the amount of each monomer in the aforementioned monomer solution can be appropriately set to, for example, the ideal content ratio of the aforementioned repeating units.

[0377] The polymer obtained by the aforementioned manufacturing method can be used as the final product by using the reaction solution obtained from the polymerization reaction, or the polymer solution can be added to a poor solvent and the powder obtained by refining steps such as reprecipitation can be used as the final product. Considering the perspective of work efficiency and quality stabilization, it is better to use the polymer solution obtained by dissolving the powder obtained in the solvent as the final product.

[0378] Specific examples of solvents used at this time can be found in paragraphs

[0144] to

[0145] of Japanese Patent Application Publication No. 2008-111103, including ketones such as cyclohexanone and methyl-2-n-pentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; and propylene glycol monomethyl ether (PGME), ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, and propylene glycol dimethyl ether. Ethers such as diethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate; lactones such as GBL; alcohols such as diacetone alcohol (DAA); high-boiling-point alcohol solvents such as diethylene glycol, propylene glycol, glycerol, 1,4-butanediol, and 1,3-butanediol; and their mixed solvents.

[0379] In the aforementioned polymer solution, a polymer concentration of 0.01–30% by mass is ideal, and 0.1–20% by mass is even more ideal.

[0380] The aforementioned reaction solutions and polymer solutions are best filtered. Filtering removes foreign matter and gel that may cause defects, effectively stabilizing the quality.

[0381] The materials used in the aforementioned filter filtration can include fluorocarbon, cellulose, nylon, polyester, and hydrocarbon-based materials. However, for the filtration step involving the resist composition, it is preferable to use filters made of fluorocarbon (such as Teflon, a registered trademark), polyethylene, polypropylene, or nylon. The pore size of the filter can be appropriately selected according to the target cleanliness level, preferably below 100 nm, and more preferably below 20 nm. Furthermore, a single filter can be used, or multiple filters can be used in combination. The filtration method can allow the solution to pass through only once, but it is preferable to circulate the solution and perform multiple filtrations. The filtration steps can be performed in any order and number of times during the polymer manufacturing steps, but it is preferable to filter the reaction solution after the polymerization reaction, the polymer solution, or both.

[0382] The aforementioned polymer may also contain two or more polymers with different composition ratios, Mw, and molecular weight distributions.

[0383] Furthermore, the present invention provides a resist composition containing the above-mentioned polymer, specifically, a chemically amplified resist composition as shown below.

[0384] [Chemical amplification resist composition]

[0385] The chemically amplified resist composition of the present invention comprises

[0386] (P) Basic Polymer

[0387] (G) Quenching agent

[0388] (H) Organic solvent.

[0389] It may also contain selections from [sources], if necessary.

[0390] (I) Photoacid generators other than those with basic polymer chain bonds

[0391] (J) Nitrogen-containing quenchers, and

[0392] (K) at least one of the following: a surfactant that is insoluble or sparingly soluble in water but soluble in alkaline developing solution, and / or a surfactant that is insoluble or sparingly soluble in both water and alkaline developing solution.

[0393] Furthermore, it may contain, depending on the necessity.

[0394] (L) Other ingredients.

[0395] [(G) Quenching Agent]

[0396] (G) Quenching agents can be listed as onion salts represented by formula (1) or (2).

[0397] [Chemistry 93]

[0398]

[0399] In equation (1), R q1 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain hydrogen atoms or heteroatoms, except where the hydrogen atom bonded to the carbon atom at the α-position of the sulfonate group is replaced by a fluorine atom or a fluoroalkyl group. In formula (2), R q2 It consists of a hydrogen atom, or may contain a hydrocarbon group with 1 to 40 carbon atoms and heteroatoms.

[0400] R q1 Specifically, the hydrocarbon groups represented can be listed as methyl, ethyl, propyl, isopropyl, n-butyl, dibutyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, etc.; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclic [5.2.1.0] 2,6Decyl, adamantyl, and other cyclic saturated hydrocarbon groups; phenyl, naphthyl, anthracene, and other aryl groups, etc. Furthermore, some or all of the hydrogen atoms in these groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, or some of the carbon atoms in these groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, these groups may contain hydroxyl, cyano, carbonyl, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonyl lactone rings, carboxylic anhydrides, haloalkyl groups, etc.

[0401] R q2 Specifically, the hydrocarbon groups represented can be listed as R. q1 Specific examples of substituents shown include fluorinated alkyl groups such as trifluoromethyl and trifluoroethyl, fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

[0402] The anions of the onium salts represented by formula (1) can be listed below, but are not limited to these.

[0403] [Chemistry 94]

[0404]

[0405] [Chemistry 95]

[0406]

[0407] The anions of the onium salts represented by equation (2) can be listed below, but are not limited to these.

[0408] [Chemistry 96]

[0409]

[0410] [Chemistry 97]

[0411]

[0412] In equations (1) and (2), Mq + The aforementioned onium cation is preferably an onium cation represented by the following formula (cation-1), (cation-2), or (cation-3).

[0413] [Chem. 98]

[0414]

[0415] For equations (cation-1) and (cation-2), we can list A in equations (B-2) to (B-4). + For the same example, in (cation-3), R 16 ~R 19 Each can independently be a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. Also, R16 With R 17 They can also bond to each other and form rings together with the nitrogen atoms they are bonded to. Examples of the aforementioned hydrocarbon groups include R in formulas (cation-1) and (cation-2). 11 ~R 15 The example shown is the same as the one used for illustration.

[0416] Mq + Among the onium cations represented, the ammonium cations represented by (cation-3) can be listed below, but are not limited to.

[0417] [Chemistry 99]

[0418]

[0419] Specific examples of onium salts represented by formula (1) or (2) can be listed as any combination of the aforementioned anions and cations. Furthermore, the onium salts can be easily prepared using ion exchange reactions employing known organic chemical methods. For example, Japanese Patent Application Publication No. 2007-145797 can be consulted regarding ion exchange reactions.

[0420] The onium salts represented by formula (1) or (2) act as quenchers in the chemically amplified resist composition of the present invention. This is because the relative anions of the aforementioned onium salts are conjugate bases of weak acids. Here, "weak acid" refers to an acid that exhibits an acidity that prevents the deprotection of acid-instable groups in units containing acid-instable groups used in the base polymer.

[0421] The onium salt represented by formula (1) or (2) acts as a quencher when used in conjunction with the conjugate base of a strong acid such as a sulfonic acid with α-fluorination as an onium salt-type photoacid generator with a relative anion. That is, when an onium salt that generates a strong acid such as a sulfonic acid with α-fluorination is mixed with an onium salt that generates a weak acid such as a sulfonic acid or carboxylic acid without fluorination, if the strong acid generated from the photoacid generator due to high-energy radiation irradiation collides with the onium salt with an anion of the unreacted weak acid, the weak acid is released due to salt exchange, and an onium salt with an anion of the strong acid is generated. In this process, the strong acid is exchanged for a weak acid with lower catalytic ability, so macroscopically, the acid is deactivated, and acid diffusion can be controlled.

[0422] Here, when the photoacid generator producing strong acids is an onium salt, as mentioned above, the strong acid produced by high-energy ray irradiation can be exchanged into a weak acid. However, it is believed that it is difficult for the weak acid produced by high-energy ray irradiation to undergo salt exchange through collision with the unreacted onium salt that produces strong acids. This is because onium cations more readily form ion pairs with the anions of strong acids.

[0423] Regarding the (G) onium salt type quencher, when it contains an onium salt represented by formula (1) or (2), its content is ideally 0.1 to 20 parts by mass relative to 80 parts by mass of the (P) base polymer, and even more ideally 0.1 to 10 parts by mass. If the onium salt type quencher of component (G) is within the aforementioned range, the resolution is good and the sensitivity does not decrease significantly, thus it is ideal. The onium salt represented by formula (1) or (2) can be used alone or in combination of two or more.

[0424] [(H) organic solvent]

[0425] The organic solvent for component (H) need only be able to dissolve the aforementioned components and the components described below, without any special restrictions. Such organic solvents include ketones such as cyclopentanone, cyclohexanone, and methyl-2-n-pentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; keto alcohols such as DAA; ethers such as PGME, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate; lactones such as GBL; and mixed solvents thereof.

[0426] When using polymers containing acid-labile acetal groups, high-boiling-point alcohol solvents can be added to accelerate the deprotection reaction of the acetal. Specifically, diethylene glycol, propylene glycol, glycerol, 1,4-butanediol, 1,3-butanediol, etc., can be added.

[0427] Among the organic solvents, 1-ethoxy-2-propanol, PGMEA, cyclohexanone, GBL, DAA, ethyl lactate, and mixed solvents thereof are preferred as they have particularly excellent solubility in the base polymer of component (P).

[0428] The amount of organic solvent used is ideally 200–5,000 parts by mass relative to the (P) base polymer 80, and even more ideally 400–3,000 parts by mass. (H) Organic solvents can be used alone or in combination of two or more.

[0429] [(I) Photoacid generators other than those with basic polymer chain bonds]

[0430] The chemically amplified resist composition of the present invention may also contain a photoacid generator other than a photoacid generator with a basic polymer chain bond as component (I). There are no particular limitations on the aforementioned photoacid generator as long as it is a compound that generates acid upon irradiation by high-energy rays. Ideal photoacid generators can be exemplified by the photoacid generator represented by the following formula (3).

[0431] [Chemistry 100]

[0432]

[0433] In equation (3), R 101 R 102 and R 103 Each can independently be a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. Also, R 101 R 102 and R 103 Any two of them can bond to each other and form a ring together with the sulfur atoms they are bonded to. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated in formulas (cation-1) and (cation-2) with R. 11 ~R 15 The examples given are the same. Furthermore, specific examples of sulfonium salt cations represented by formula (3) can be listed and are the same examples as those given by formula (cation-1).

[0434] In equation (3), X - The anions are selected from formulas (3A) to (3D).

[0435] [Chemistry 101]

[0436]

[0437] In equation (3A), R fa It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain fluorine atoms or heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and shown in formula (3A') under R. 105 The explanation in the following text is the same example.

[0438] The anion represented by formula (3A) is preferably represented by formula (3A').

[0439] [Chemistry 102]

[0440]

[0441] In equation (3A'), R 104 It can be a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R 105 Hydrocarbon groups with 1 to 38 carbon atoms that can also contain heteroatoms are preferred. Ideal heteroatoms include oxygen, nitrogen, sulfur, and halogen atoms, with oxygen atoms being even more desirable. Considering the need for high resolution when forming fine patterns, hydrocarbon groups with 6 to 30 carbon atoms are particularly advantageous.

[0442] R 105The hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, dibutyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and eicosyl; cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornel, norbornelmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups such as allyl and 3-cyclohexenyl; aryl groups such as phenyl, 1-naphthyl, and 2-naphthyl; and aralkyl groups such as benzyl and diphenylmethyl. Among these, R... 105 Aliphatic groups are preferred. Furthermore, some or all of the hydrogen atoms in these groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, some of the carbon atoms in these groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This can result in the presence of hydroxyl, cyano, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulopentalide, carboxylic anhydride, or haloalkyl groups. Examples of hydrocarbon groups containing heteroatoms include tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidemethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, and 3-oxocyclohexyl.

[0443] For the synthesis of sulfonium salts having anions represented by formula (3A'), please refer to Japanese Patent Application Publication Nos. 2007-145797, 2008-106045, 2009-7327, and 2009-258695. Furthermore, sulfonium salts described in Japanese Patent Application Publication Nos. 2010-215608, 2012-41320, 2012-106986, and 2012-153644 can also be ideally used.

[0444] The anions represented by formula (3A) can be listed as M in the aforementioned formula (B-1). - The examples listed are similar, but not limited to these.

[0445] In equation (3B), R fb1 and R fb2 Each hydrocarbon group consists independently of a fluorine atom or may contain heteroatoms and has 1 to 40 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated in formula (3A') with R. 105 The example provided is the same. fb1 and Rfb2 Preferably, it is a straight-chain fluorinated alkyl group having fluorine atoms or 1 to 4 carbon atoms. Also, R fb1 With R fb2 They can also bond to each other and to the groups they are bonded to (-CF2-SO2-N). - -SO2-CF2-) together form a ring, at which point R fb1 With R fb2 The groups obtained by mutual bonding are preferably fluorinated ethylidene or fluorinated propylene.

[0446] In equation (3C), R fc1 R fc2 and R fc3 Each hydrocarbon group consists independently of a fluorine atom or may contain heteroatoms and has 1 to 40 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated in formula (3A') with R. 105 The example shown is the same as the one used for illustration. R fc1 R fc2 and R fc3 Preferably, it is a straight-chain fluorinated alkyl group having fluorine atoms or 1 to 4 carbon atoms. Also, R fc1 With R fc2 They can also bond to each other and to the groups they are bonded to (-CF2-SO2-C). - -SO2-CF2-) together form a ring, at which point R fc1 With R fc2 The groups obtained by mutual bonding are preferably fluorinated ethylidene or fluorinated propylene.

[0447] In equation (3D), R fd It can also be a hydrocarbon group containing heteroatoms with 1 to 40 carbon atoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and shown in R in formula (3A'). 105 The example shown is the same as the one used for illustration.

[0448] For details on the synthesis of sulfonium salts having anions represented by formula (3D), please refer to Japanese Patent Application Publication Nos. 2010-215608 and 2014-133723.

[0449] Anions represented by formula (3D) can be listed below, but are not limited to.

[0450] [Chemistry 103]

[0451]

[0452] Furthermore, the photoacid generator with an anion represented by formula (3D) has no fluorine at the α-position of the sulfonium group, but has two trifluoromethyl groups at the β-position, thus possessing sufficient acidity to cleave the acid-unstable groups in the base polymer. Therefore, it can be used as a photoacid generator.

[0453] Furthermore, for photoacid generators other than those with photoacid generators based on polymer chain bonds of component (I), the following formula (4) is also ideal.

[0454] [Chemistry 104]

[0455]

[0456] In equation (4), R 201 and R 202 Each can independently be a hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. R 203 It can also contain a hydrocarbon group with 1 to 30 carbon atoms and a heteroatom. Also, R 201 R 202 and R 203 Any two of them can also bond to each other and form a ring together with the sulfur atoms they are bonded to. In this case, the aforementioned rings can be listed and described in the explanation of formula (B-1), R 21 and R 22 The same example is the rings that can be formed by mutual bonding and together with the sulfur atoms they are bonded to.

[0457] R 201 and R 202 The hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, dibutyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, and tricyclic [5.2.1.0]. 2,6 Decyl, adamantyl, and other cyclic saturated hydrocarbon groups; phenyl, naphthyl, anthracene, and other aryl groups. Furthermore, a portion of the hydrogen atoms in these groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and a portion of the carbon atoms in these groups can also be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, these groups may contain hydroxyl, cyano, carbonyl, ether bonds, ester bonds, sulfonate bonds, carbonate groups, lactone rings, sulfonyl lactone rings, carboxylic anhydrides, haloalkyl groups, etc.

[0458] R 203The alkylene group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include methylene, ethylene, 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, and so on. Heptadecane-1,17-diyl and other alkyl diyl groups; cyclopentane diyl, cyclohexane diyl, norcamphene diyl, adamantane diyl and other cyclic saturated alkylene groups; phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, dibutylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, dibutylnaphthylene, tert-butylnaphthylene and other aryl groups, etc. Furthermore, a portion of the hydrogen atoms in these groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms, and a portion of the carbon atoms in these groups can also be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. This can result in the presence of hydroxyl, cyano, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride, or haloalkyl groups. Oxygen atoms are preferred as the aforementioned heteroatoms.

[0459] In equation (4), L A It can be a single bond, an ether bond, or a carbon-10 alkylene group that may contain heteroatoms. The aforementioned alkylene groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and discussed in relation to R. 203 The example of the subhydrocarbon group is the same.

[0460] In equation (4), X a X b X c and X d Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. But X a X b X c and X d At least one of them is a fluorine atom or a trifluoromethyl group.

[0461] The photoacid generator represented by formula (4) is preferably represented by formula (4').

[0462] [Chemistry 105]

[0463]

[0464] In equation (4'), L A Same as above. X e It can be a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R 301 R 302 and R 303 Each hydrocarbon group consists independently of a hydrogen atom or may contain heteroatoms and has 1 to 20 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated in formula (3A') with R. 105 The example shown is the same. x and y are each independent integers from 0 to 5, and z is an integer from 0 to 4.

[0465] The photoacid generator represented by formula (4) can be exemplified by the same example as the photoacid generator represented by formula (4) in Japanese Patent Application Publication No. 2017-026980.

[0466] Among the aforementioned photoacid generators, those containing anions represented by formula (3A') or (3D) exhibit low acid diffusion and excellent solubility in resist solvents, making them particularly desirable. Furthermore, those containing anions represented by formula (4') exhibit extremely low acid diffusion, making them particularly desirable.

[0467] Furthermore, other acid-generating agents can also use onium salts represented by formulas (5-1) or (5-2).

[0468] [Chemistry 106]

[0469]

[0470] In equations (5-1) and (5-2), r is an integer satisfying 1 ≤ r ≤ 3. s and t are integers satisfying 1 ≤ s ≤ 5, 0 ≤ t ≤ 3, and 1 ≤ s + t ≤ 5. Ideally, s should be an integer satisfying 1 ≤ s ≤ 3, with 2 or 3 being even more desirable. Ideally, t should be an integer satisfying 0 ≤ t ≤ 2.

[0471] In equations (5-1) and (5-2), X BI When the atoms are iodine or bromine, and s is 2 or more, they can be the same or different.

[0472] In equations (5-1) and (5-2), L 11 It is a saturated hydrocarbon group with 1 to 6 carbon atoms, consisting of a single bond, ether bond, or ester bond, or may contain ether or ester bonds. The aforementioned saturated hydrocarbon group may be linear, branched, or cyclic.

[0473] In equations (5-1) and (5-2), L 12When r is 1, it is a single bond or a divalent linker with 1 to 20 carbon atoms; when r is 2 or 3, it is a trivalent or tetravalent linker with 1 to 20 carbon atoms. This linker may also contain oxygen, sulfur, or nitrogen atoms.

[0474] In equations (5-1) and (5-2), R 401 It may be a saturated hydrocarbon group with 1 to 20 carbon atoms, a saturated hydrocarbon oxygen group with 1 to 20 carbon atoms, a saturated hydrocarbon carbonyl group with 2 to 10 carbon atoms, a saturated hydrocarbon carbonyl group with 2 to 20 carbon atoms, or a saturated hydrocarbon sulfonyl group with 1 to 20 carbon atoms, or -NR, which may contain a hydroxyl, carboxyl, fluorine, chlorine, bromine, amino, or amino group, or may also contain a fluorine, chlorine, bromine, hydroxyl, amino, or ether bond. 401A -C(=O)-R 401B or -NR 401A -C(=O)-OR 401B .

[0475] R 401A It may contain hydrogen atoms or saturated hydrocarbon groups with 1 to 6 carbon atoms, or it may contain halogen atoms, hydroxyl groups, saturated hydrocarbon oxygen groups with 1 to 6 carbon atoms, saturated hydrocarbon carbonyl groups with 2 to 6 carbon atoms, or saturated hydrocarbon carbonyl groups with 2 to 6 carbon atoms.

[0476] R 401B It is an aliphatic hydrocarbon group with 1 to 16 carbon atoms or an aryl group with 6 to 12 carbon atoms, and may also contain halogen atoms, hydroxyl groups, saturated hydrocarbon oxygen groups with 1 to 6 carbon atoms, saturated hydrocarbon carbonyl groups with 2 to 6 carbon atoms, or saturated hydrocarbon carbonyl groups with 2 to 6 carbon atoms.

[0477] The aforementioned aliphatic hydrocarbon groups can be saturated or unsaturated, and can be chain-like, branched, or cyclic. The aforementioned saturated hydrocarbon groups, saturated hydrocarbon oxygen groups, saturated hydrocarbon carbonyl groups, saturated hydrocarbon carbonyl groups, and saturated hydrocarbon carbonyl oxygen groups can be any of the following: straight-chain, branched, or cyclic.

[0478] When t is 2 or more, each R 401 They can be the same or different.

[0479] Among them, R 401 Hydroxyl group, -NR 401A -C(=O)-R 401B -NR 401A -C(=O)-OR 401B Fluorine atoms, chlorine atoms, bromine atoms, methyl groups, and methoxy groups are preferred.

[0480] In equations (5-1) and (5-2), Rf 11 ~Rf 14 Each of these atoms can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them must be a fluorine atom or a trifluoromethyl group. Also, Rf 11 With Rf 12They can also combine to form carbonyl groups. Especially Rf 13 and Rf 14 Both are preferred if they contain fluorine atoms.

[0481] In equations (5-1) and (5-2), R 402 R 403 R 404 R 405 and R 406 Each of these can be an independent hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, cycloalkyl groups with 3 to 20 carbon atoms, alkenyl groups with 2 to 12 carbon atoms, alkynyl groups with 2 to 12 carbon atoms, aryl groups with 6 to 20 carbon atoms, and aralkyl groups with 7 to 12 carbon atoms.

[0482] Furthermore, some or all of the hydrogen atoms in these groups may be replaced by hydroxyl, carboxyl, halogen, cyano, nitro, mercapto, sulopentalide, sulfone, or sulfonate groups, and some of the carbon atoms in these groups may be replaced by ether, ester, carbonyl, amide, carbonate, or sulfonate bonds.

[0483] Also, R 402 R 403 and R 404 Any two of them can also bond to each other and form a ring together with the sulfur atoms they are bonded to. In this case, the aforementioned rings can be listed and described in the explanation of equation (3), regarding R 101 With R 102 Examples of the same kind of rings that can be formed by bonding and together with the sulfur atoms they are bonded to are shown below.

[0484] The cations of the sulfonium salt represented by formula (5-1) can be the same as those of the sulfonium cation represented by formula (cation-1). Similarly, the cations of the zirconia salt represented by formula (5-2) can be the same as those of the zirconia cation represented by formula (cation-2).

[0485] Examples of onium salt anions represented by formulas (5-1) and (5-2) can be cited in the Japanese Patent Application Publication No. 2018-197853, where the anions of onium salts represented by formulas (5-1) and (5-2) are also given. In addition, examples of anions in which the iodine atom is replaced by a bromine atom can also be cited.

[0486] When the photoacid generating agent other than the photoacid generating agent of the basic polymer chain bond of component (I) is present, its content is preferably 0.1 to 40 parts by mass, and more preferably 0.5 to 20 parts by mass, relative to 80 parts by mass of the basic polymer (P). If the amount of photoacid generating agent other than the photoacid generating agent of the basic polymer chain bond of component (I) is within the aforementioned range, the resolution is good, and there is no risk of foreign matter appearing after the resist film is developed or during peeling, which is ideal. The photoacid generating agent other than the photoacid generating agent of the basic polymer chain bond of component (I) can be used alone or in combination of two or more.

[0487] [(J) Nitrogen-containing quenchers]

[0488] The chemically amplified resist composition of the present invention may further contain a nitrogen-containing quencher. Furthermore, in the present invention, the nitrogen-containing quencher refers to a material used to form the desired pattern by capturing the acid generated by the photoacid generator in the chemically amplified resist composition to prevent the acid from diffusing to the unexposed areas.

[0489] Furthermore, nitrogen-containing quenchers of component (J) can be exemplified by first-, second-, or third-order amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Publication No. 2008-111103, particularly amine compounds having hydroxyl groups, ether bonds, ester bonds, lactone rings, cyano groups, or sulfonate bonds. Also, compounds such as those described in Japanese Patent No. 3790649, and compounds of primary or secondary amines protected by urethane groups can also be cited.

[0490] Alternatively, sulfonate sulfonates with nitrogen-containing substituents can be used as nitrogen-containing quenchers. Such compounds act as quenchers in the unexposed areas, but lose their quenching effect in the exposed areas due to neutralization with their own acidic components, thus acting as photodegrading bases. By using photodegrading bases, the contrast between the exposed and unexposed areas can be further enhanced. For examples of photodegrading bases, see, for instance, Japanese Patent Application Laid-Open Nos. 2009-109595 and 2012-46501.

[0491] When using nitrogen-containing quenchers containing component (J), an ideal content is 0.001–12 parts by mass relative to 80 parts by mass of the (P) base polymer, and even more ideal is 0.01–8 parts by mass. The aforementioned nitrogen-containing compounds can be used alone or in combination of two or more.

[0492] [(K) Surfactants that are insoluble or sparingly soluble in water but soluble in alkaline developing solutions, and / or surfactants that are insoluble or sparingly soluble in both water and alkaline developing solutions]

[0493] The chemically amplified resist composition of the present invention may further contain (K) a surfactant that is insoluble or sparingly soluble in water but soluble in alkaline developer, and / or a surfactant that is insoluble or sparingly soluble in both water and alkaline developer. Such surfactants can be referred to in Japanese Patent Application Publication Nos. 2010-215608 and 2011-16746.

[0494] Surfactants that are insoluble or poorly soluble in water and alkaline developing solutions are preferably those listed in the aforementioned publication, such as FC-4430 (manufactured by 3M), surflon (registered trademark) S-381 (manufactured by AGCSeimichemical), OLFINE (registered trademark) E1004 (manufactured by Nissin Chemical Industry), KH-20, KH-30 (manufactured by AGCSeimichemical), and oxobutane ring-opening polymers represented by the following formula (surf-1).

[0495] [Chemistry 107]

[0496]

[0497] Here, R, Rf, A, B, C, m, and n in the above formula (surf-1) are irrelevant to the foregoing description and only apply to formula (surf-1). R is an aliphatic group with 2 to 6 carbon atoms, ranging from 2 to 4 valent. Examples of the aforementioned aliphatic groups that are divalent include ethylene, 1,4-butylene, 1,2-propylene, 2,2-dimethyl-1,3-propylene, and 1,5-pentylene, while examples of trivalent or tetravalent groups include the following groups.

[0498] [Chemistry 108]

[0499]

[0500] In the formula, the dashed lines represent atomic bonds, each of which is a partial structure derived from glycerol, trimethylolethane, trimethylolpropane, and neopentyl tertrol.

[0501] Among them, 1,4-butylene and 2,2-dimethyl-1,3-propylene are preferred.

[0502] Rf is trifluoromethyl or pentafluoroethyl, preferably trifluoromethyl. m is an integer from 0 to 3, n is an integer from 1 to 4, and the sum of n and m is the valence of R, which is an integer from 2 to 4. A is 1. B is an integer from 2 to 25, preferably an integer from 4 to 20. C is an integer from 0 to 10, preferably 0 or 1. Furthermore, the arrangement of the constituent units in formula (surf-1) is not specified; they can be block bonds or random bonds. For details on the manufacture of surfactants based on partially fluorinated oxyheterocyclic butane ring-opening polymer systems, please refer to the specification in US Patent No. 5,650,483, etc.

[0503] Surfactants that are insoluble or sparingly soluble in water but soluble in alkaline developers can reduce water penetration and leaching when ArF wetted exposure is performed without a resist protective film. This is because they are aligned with the surface of the resist film. Therefore, inhibiting the leaching of water-soluble components from the resist film is useful in reducing damage to the exposure equipment. Furthermore, they are soluble in alkaline solutions after exposure and post-exposure baking (PEB), making them less likely to become foreign matter that causes defects. Such surfactants are polymeric surfactants that are insoluble or sparingly soluble in water but soluble in alkaline developers; they are also called hydrophobic resins, especially those with high water repellency that improve hydrophobic properties.

[0504] Such polymeric surfactants may include those containing at least one repeating unit selected from any of the following formulas (6A) to (6E).

[0505] [Chemistry 109]

[0506]

[0507] In equations (6A) to (6E), R B It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. W 1 It can be -CH2-, -CH2CH2-, -O-, or two separate -H groups. R s1 Each is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. R s2 It is a single bond, or a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms. R s3 Each is independently a hydrogen atom, a hydrocarbon group with 1 to 15 carbon atoms, a fluorinated hydrocarbon group, or an acid-labile group. R s3 When the group is a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond (-O-) or a carbonyl group (-C(=O)-) may also be inserted between the carbon-carbon bonds. s4 R is a hydrocarbon group or fluorinated hydrocarbon group with a valence of (u+1) and having 1 to 20 carbon atoms. u is an integer from 1 to 3. s5 Each is independently a hydrogen atom, or the formula -C(=O)-OR sa The group represented by R sa It is a fluorinated hydrocarbon group with 1 to 20 carbon atoms. R s6 It consists of a hydrocarbon group or a fluorinated hydrocarbon group with 1 to 15 carbon atoms, and an ether bond (-O-) or a carbonyl group (-C(=O)-) may also be inserted between carbon-carbon bonds.

[0508] R s1Ideally, the represented hydrocarbon group should be a saturated hydrocarbon group, and it can be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and cyclic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbenzene. Among these, those with 1 to 6 carbon atoms are preferred.

[0509] R s2 Ideally, the represented hydrocarbon group should be a saturated hydrocarbon group, which can be linear, branched, or cyclic. Specific examples include methylene, ethylene, propylene, butylene, and pentylene.

[0510] R s3 or R s6 The hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include saturated hydrocarbon groups, alkenyl groups, alkynyl groups, and other aliphatic unsaturated hydrocarbon groups, but saturated hydrocarbon groups are preferred. The aforementioned saturated hydrocarbon groups, except for R... s1 Besides the examples of hydrocarbon groups, other examples include n-undecyl, n-dodecyl, tridecyl, tetradecyl, and decadecyl. s3 or R s6 The fluorinated hydrocarbon group can be exemplified by fluorinated hydrocarbon groups in which some or all of the hydrogen atoms bonded to the carbon atoms of the aforementioned hydrocarbon group are replaced by fluorine atoms. As mentioned above, the carbon-carbon bonds may also contain ether bonds (-O-) or carbonyl groups (-C(=O)-).

[0511] R s3 The acid-unstable groups can be represented by groups represented by the aforementioned formulas (AL-1) to (AL-3), trialkylsilyl groups where each alkyl group has 1 to 6 carbon atoms, and alkyl groups containing oxygen groups with 4 to 20 carbon atoms.

[0512] R s4 The (u+1) valence hydrocarbon group or fluorinated hydrocarbon group can be straight-chain, branched, or cyclic. Specific examples can be listed as groups that have removed u hydrogen atoms from the aforementioned hydrocarbon group or fluorinated hydrocarbon group.

[0513] R saThe fluorinated hydrocarbon group represented should ideally be a saturated fluorinated hydrocarbon group, and can be linear, branched, or cyclic. Specific examples include those in which some or all of the hydrogen atoms of the aforementioned hydrocarbon group are replaced by fluorine atoms, such as trifluoromethyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoro-1-propyl, 3,3,3-trifluoro-2-propyl, 2,2,3,3-tetrafluoropropyl, 1,1,1,3,3,3-hexafluoroisopropyl, 2,2,3,3,4,4,4-heptafluorobutyl, 2,2,3,3,4,4,5,5-octafluoropentyl, 2,2,3,3,4,4,5,5,6,6,7,7-dodecylfluoroheptyl, 2-(perfluorobutyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorooctyl)ethyl, 2-(perfluorodecyl)ethyl, etc.

[0514] The repeating units represented by equations (6A) to (6E) can be listed below, but are not limited to. Furthermore, in the following equations, R... B Same as above.

[0515] [Chemical 110]

[0516]

[0517] [Chemistry 111]

[0518]

[0519] [Chemistry 112]

[0520]

[0521] [Chemistry 113]

[0522]

[0523] [Chemistry 114]

[0524]

[0525] The aforementioned polymeric surfactants may also contain repeating units other than those represented by formulas (6A) to (6E). Examples of other repeating units include repeating units obtained from methacrylic acid, α-trifluoromethacrylic acid derivatives, etc. In polymeric surfactants, it is ideal for the content of repeating units represented by formulas (6A) to (6E) to be 20 mol% or more of all repeating units, more preferably 60 mol% or more, and more preferably 100 mol%.

[0526] For the aforementioned polymeric surfactants, a Mw of 1,000–500,000 is ideal, and 3,000–100,000 is even more ideal. An Mw / Mn ratio of 1.0–2.0 is ideal, and 1.0–1.6 is even more ideal.

[0527] Regarding methods for synthesizing the aforementioned polymeric surfactants, one method involves providing monomers containing unsaturated bonds, representing repeating units as shown in formulas (6A) to (6E), and other repeating units as needed, in an organic solvent, adding a free radical initiator, and heating to polymerize them. Examples of organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, and dioxane. Examples of polymerization initiators include AIBN, 2,2′-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid), benzoyl peroxide, and lauroyl peroxide. A reaction temperature of 50–100°C is preferred. A reaction time of 4–24 hours is preferred. Acid-labile groups can be used directly, or they can be protected or partially protected after polymerization.

[0528] When synthesizing the aforementioned polymeric surfactants, known chain-transfer agents such as dodecyl mercaptan and 2-mercaptoethanol can be used to adjust the molecular weight. In this case, the amount of the chain-transfer agent added is preferably 0.01 to 10 mol% relative to the total molar number of monomers to be polymerized.

[0529] When the surfactant contains (K) component, its content relative to 80 parts by weight of the (P) base polymer is ideally 0.1–50 parts by weight, and even more ideally 0.5–10 parts by weight. If the addition amount is 0.1 parts by weight or more, the receding contact angle between the resist film surface and water will be sufficiently increased; if it is less than 50 parts by weight, the dissolution rate of the resist film surface by the developer will be slow, and the height of the formed fine pattern can be fully maintained.

[0530] [(L) Other ingredients]

[0531] The chemically amplified resist composition of the present invention may also contain compounds that generate acid due to acid decomposition (acid-increasing compounds), organic acid derivatives, fluorinated alcohols, and compounds with an Mw of 3,000 or less that alter their solubility in the developer due to acid action (dissolution inhibitors) as other components in (L). The aforementioned acid-increasing compounds can be referred to in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608. When containing the aforementioned acid-increasing compounds, it is ideal for their content to be 0 to 5 parts by mass relative to 80 parts by mass of the (P) base polymer, and more ideally 0 to 3 parts by mass. If within the above range, diffusion is easily controlled, and resolution degradation and pattern shape degradation will not occur. The aforementioned organic acid derivatives, fluorinated alcohols, and dissolution inhibitors can be referred to in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608.

[0532] [Pattern Formation Method]

[0533] The pattern forming method of the present invention includes the following steps:

[0534] (i) A resist film is formed on a substrate using a resist composition containing the above-mentioned polymer.

[0535] (ii) Expose the above-mentioned resist film to high-energy rays.

[0536] (iii) The exposed resist film is developed with a developer.

[0537] In step (i) above, the aforementioned substrate may be, for example, a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective film, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.).

[0538] In step (i) above, the resist film is formed, for example, by coating the aforementioned resist composition by spin coating or other methods to make the film thickness 0.05 to 2 μm, and pre-baking it on a hot plate at 60 to 150°C for 1 to 10 minutes, more preferably at 80 to 140°C for 1 to 5 minutes.

[0539] In step (ii) above, the high-energy rays used for photoresist film exposure can include i-rays, KrF excimer lasers, ArF excimer lasers, electron beams (EB), extreme ultraviolet (EUV), etc., and extreme ultraviolet rays with wavelengths of 3–15 nm can also be used. When using KrF excimer lasers, ArF excimer lasers, or EUV for exposure, a mask for forming the desired pattern can be used, with an exposure dose preferably being 1–200 mJ / cm. 2 It is even better to achieve 10-100 mJ / cm 2 Irradiation is performed in a manner that allows for the formation of the desired pattern. When using EB, a mask can be used to form the desired pattern, or the exposure rate can be preferably 1–300 μC / cm. 2 It is better to achieve a temperature of 10–200 μC / cm 2 Exposure is achieved by irradiating the object in a certain way.

[0540] In addition to the usual exposure method, an immersion method can also be used, in which a liquid with a refractive index of 1.0 or higher is inserted between the resist film and the projection lens. In this case, a water-insoluble protective film can also be used.

[0541] The aforementioned water-insoluble protective film is used to prevent leaching from the resist film and to improve the hydrophobicity of the film surface. It can be broadly classified into two types. One type is an organic solvent-stripping type, which requires removal using an organic solvent that does not dissolve the resist film before alkaline aqueous solution development. The other type is an alkaline aqueous solution-soluble type, which is soluble in alkaline developing solution and removes the protective film simultaneously with the soluble portion of the resist film. The latter is particularly preferred as a material based on a polymer containing 1,1,1,3,3,3-hexafluoro-2-propanol residues that is water-insoluble but soluble in alkaline developing solution, and soluble in alcohol solvents with 4 or more carbon atoms, ether solvents with 8 to 12 carbon atoms, or mixtures thereof. Materials can also be prepared by dissolving the aforementioned water-insoluble but alkaline developing solution surfactant in alcohol solvents with 4 or more carbon atoms, ether solvents with 8 to 12 carbon atoms, or mixtures thereof.

[0542] PEB can also be performed after exposure if necessary. PEB can be performed, for example, by heating on a hot plate, preferably at 60–150°C for 1–5 minutes, and more preferably at 80–140°C for 1–3 minutes.

[0543] In step (iii) above, an alkaline aqueous solution can be used as the developer to dissolve the exposed areas while developing the unexposed areas without dissolving them, thus achieving positive tone development. This method can obtain a positive pattern.

[0544] In step (iii) above, the developer can be, for example, an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) at a concentration of 0.1–5% by mass, more preferably 2–3% by mass. Furthermore, development is preferably performed using conventional methods such as dip, immersion, or spray for 0.1–3 minutes, more preferably 0.5–2 minutes, to form the desired pattern on the substrate.

[0545] Furthermore, regarding the means of pattern formation, pure water postsoaking can be performed after the resist film is formed to extract acid-generating agents from the film surface, or microparticle washing can be performed, or postsoaking can be performed to remove water remaining on the film after exposure.

[0546] Patterns can also be formed using a double patterning method. Examples of double patterning methods include: the trench method, which processes a 1:3 trench pattern substrate by first exposure and etching, and then forms a 1:1 pattern by second exposure to offset the position; and the line method, which processes a 1:3 isolated residual pattern substrate by first exposure and etching, and then forms a 1:3 isolated residual pattern on a second substrate below the first substrate by second exposure to offset the position, thus forming a 1:1 pattern with half the pitch.

[0547] Furthermore, in the pattern forming method of the present invention, a negative tone development method can be used in step (iii) above, where an organic solvent is used instead of the aforementioned alkaline aqueous solution as the developer to dissolve and develop the unexposed portion. According to this method, a negative pattern can be obtained.

[0548] In this organic solvent development process, the developer may include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methyl acetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, methyl valerate, methyl valerate, methyl crotonate, and crotonic acid. Ethyl propionate, 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 phenyl acetate, benzyl formate, phenyl ethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. The organic solvents may be used alone or in combination.

[0549] [Example]

[0550] The following examples, embodiments, and comparative examples illustrate the present invention in detail, but the present invention is not limited to the following embodiments. Furthermore, the apparatus used is shown below.

[0551] •IR: Made by Thermofisher Scientific, NICOLET 6700

[0552] · 1 H-NMR: ECA-500 manufactured by Nippon Electronics Co., Ltd.

[0553] · 19 F-NMR: ECA-500 manufactured by Nippon Electronics Co., Ltd.

[0554] [1] Synthesis of monomers

[0555] [Synthesis of monomer A1]

[0556] [Chemistry 115]

[0557]

[0558] (1) Synthesis of intermediate 1

[0559] Under nitrogen atmosphere, in a solution of methylmagnesium chloride (800 ml of 3.0 M THF solution) diluted with THF (800 ml), maintaining an internal temperature below 45°C, a solution consisting of raw material 1 (136.1 g) and THF (150 ml) was added dropwise. After stirring at an internal temperature of 50°C for 2 hours, the reaction solution was cooled, and a mixed aqueous solution of ammonium chloride (240 g) and 3.0% hydrochloric acid (1200 g) was added dropwise to stop the reaction. Ethyl acetate (1000 mL) was added, and a standard aqueous work-up was performed. After distilling off the solvent, the solution was recrystallized from hexane to obtain 146.1 g of white crystalline intermediate 1 (yield 96%).

[0560] (2) Synthesis of intermediate 2

[0561] Under nitrogen atmosphere, methacryloyl chloride (240.8 g) was added dropwise in an ice bath to a solution of intermediate 1 (146.1 g), triethylamine (272 g), dimethylaminopyridine (11.7 g), and acetonitrile (450 mL). After addition, the internal temperature was raised to 50 °C and matured for 20 hours. The reaction solution was then cooled, and saturated sodium bicarbonate solution (300 mL) was added dropwise to stop the reaction. Extraction was performed with toluene (500 mL), followed by a standard aqueous work-up, solvent distillation, and purification by silica gel column chromatography to obtain 257.4 g of intermediate 2 as a colorless oil (93% yield).

[0562] (3) Synthesis of monomer A1

[0563] Intermediate 2 (257.4 g) was dissolved in THF (400 mL) under nitrogen atmosphere, and 25% (w / w) sodium hydroxide aqueous solution (171.4 g) was added dropwise in an ice bath. After the addition, the internal temperature was raised to 25 °C and matured for 15 hours. The reaction solution was then cooled, and 20% (w / w) hydrochloric acid aqueous solution (244.1 g) was added dropwise to stop the reaction. Extraction was performed with toluene (500 mL), followed by a standard aqueous work-up, solvent distillation, and purification by silica gel column chromatography to obtain 177 g of monomer A1 as a colorless oil (90% yield).

[0564] IR spectral data of monomer A1 and 1 The results of H-NMR are shown below.

[0565] IR (D-ATR): ν=3392, 2982, 2930, 1717, 1698, 1634, 1620, 1590, 1490, 1451, 1402, 1382, 1367, 1329, 1313, 1292, 1196, 1135, 1105, 1078, 1009, 941, 896, 867, 815, 784, 701, 652, 575, 475cm -1 .

[0566] 1 H-NMR (600MHz, in DMSO-d6): δ = 9.34 (1H, s), 7.10 (1H, t), 6.74 (2H, m), 6.62 (1H, d), 6.02 (1H, d), 5.64 (1H, d), 1.85 (3H, s), 1.69 (6H, s)ppm.

[0567] [Synthesis of monomer A2]

[0568] Instead of using raw material 1, raw material 2 was used, and otherwise the synthesis was carried out in the same manner as in (1) to (3) of Synthesis Example 1-1, to obtain monomer A2, which is a colorless and transparent oil (total yield 82%).

[0569] [Chemistry 116]

[0570]

[0571] IR spectral data of monomer A2 and 1 H-NMR, 19 The results of F-NMR are shown below.

[0572] IR (D-ATR): ν=3402, 2988, 2927, 1705, 1635, 1608, 1507, 1470, 1450, 1437, 1403, 1384, 1379, 1369, 1340 , 1327, 1313, 1277, 1213, 1190, 1136, 1119, 1087, 1013, 970, 949, 920, 866, 835, 812, 772, 715, 661, 551cm -1

[0573] 1 H-NMR (600MHz, in DMSO-d6): δ = 9.78 (1H, s), 7.05 (1H, dd), 6.93 (1H, dd), 6.74 (1H, m), 6.02 (1H, d), 5.65 (1H, d), 1.85 (3H, s), 1.68 (6H, s)ppm

[0574] 19 F-NMR (600 MHz, in DMSO-d6): δ = -140.41 (1F, m) ppm

[0575] [Synthesis of monomers A3 to A10]

[0576] Monomers A3 to A10 are synthesized using raw materials corresponding to monomers A3 to A10.

[0577] [Chemistry 117]

[0578]

[0579] [Comparative example: synthesis of monomers AX1 to AX8]

[0580] Using the raw materials corresponding to monomers AX1 to AX8, comparative example monomers AX1 to AX8 were synthesized as comparative example monomers for unit A.

[0581] [Chemistry 118]

[0582]

[0583] [2] Polymer synthesis

[0584] Among the monomers used in the synthesis of the polymer, the monomers other than monomers A1 to A10 and monomers AX1 to AX8 used in the comparative example are the following monomers.

[0585] [Single a1, a2]

[0586] [Chemistry 119]

[0587]

[0588] [Single B]

[0589] [Chemistry 120]

[0590]

[0591] [Single C]

[0592] [Chemistry 121]

[0593]

[0594] [Single D]

[0595] [Chemistry 122]

[0596]

[0597] [Synthesis of Polymer P-1]

[0598] Under nitrogen atmosphere, monomer A1 (50.1 g), monomer a1-1 (22.3 g), monomer B1 (48.7 g), 3.80 g of V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator, and 225 g of MEK were charged into a flask to prepare a monomer-polymerization initiator solution. In another flask under nitrogen atmosphere, 75 g of MEK was charged, and the mixture was heated to 80°C with stirring. The aforementioned monomer-polymerization initiator solution was then added dropwise over 4 hours. After the addition was complete, the polymerization solution was maintained at 80°C and stirred for another 2 hours, then cooled to room temperature. The obtained polymerization solution was added dropwise to 2,000 g of vigorously stirred hexane, and the precipitated polymer was filtered off. The obtained polymer was then washed twice with 600 g of hexane and vacuum dried at 50°C for 20 hours to obtain a white powder polymer P-1 (yield 98.1 g, 98% yield). The Mw of polymer P-1 is 10,000, and the Mw / Mn ratio is 2.03. Furthermore, Mw is a converted value of polystyrene obtained using GPC with DMF as the solvent.

[0599] [Chemistry 123]

[0600]

[0601] [Synthesis of polymers P-2 to P-20, and comparative examples using polymers CP-1 to CP-20]

[0602] By changing the type and blending ratio of each monomer, the polymers shown in Tables 1 and 2 are manufactured using the same method as polymer P-1.

[0603] [Table 1]

[0604]

[0605]

[0606] [Table 2]

[0607]

[0608] [3] Preparation of the resist composition

[0609] [Examples 1-1 to 1-20, Comparative Examples 1-1 to 1-20]

[0610] The polymers of the present invention (P-1 to P-20), the comparative example polymers (CP-1 to CP-20), the photoacid generators (PAG-1, PAG-2), and the quenchers (SQ-1 to SQ-3, AQ-1) were prepared according to the compositions shown in Tables 3 and 4 to form a solution containing 100 ppm of 3M FC-4430 as a surfactant. The solution was filtered through a 0.2 μm Teflon (registered trademark) filter to prepare a photoresist composition.

[0611] The components are shown in Tables 3 and 4 below.

[0612] Organic solvent 1: PGMEA (propylene glycol monomethyl ether acetate)

[0613] Organic solvent 2: DAA (diacetone alcohol)

[0614] • Photoacid generators: PAG-1, PAG-2

[0615] [Chemistry 124]

[0616]

[0617] Quenching agents: SQ-1~SQ-3, AQ-1

[0618] [Chemistry 125]

[0619]

[0620] [Table 3]

[0621]

[0622]

[0623] [Table 4]

[0624]

[0625]

[0626] [4] Evaluation of EUV lithography (1)

[0627] [Examples 2-1 to 2-20, Comparative Examples 2-1 to 2-20]

[0628] The chemically amplified resist compositions (R-1 to R-20, CR-1 to CR-20) listed in Tables 3 and 4 were spin-coated onto a Si substrate containing a silicon spin-coating hard mask (SHB-A940, 43% by mass) manufactured by Shin-Etsu Chemical Industry Co., Ltd., with a pre-baking time of 60 seconds at 100°C using a hot plate to produce a resist film with a thickness of 50 nm. This resist film was then exposed to extreme ultraviolet light (EUV) at a wavelength of 13.5 nm using an ASML NXE3300 scanning UV lithography machine (NA 0.33, σ 0.9 / 0.6, dipole illumination), with the exposure dose and focus (exposure pitch: 1 mJ / cm) varying. 2 An LS pattern with a focal pitch of 0.020 μm was exposed on the wafer at a size of 18 nm and a pitch of 36 nm. After exposure, PEB was performed for 60 seconds at the temperatures shown in Tables 5 and 6. Following this, the pattern was developed by immersion in a 2.38% (w / w) TMAH aqueous solution for 30 seconds, rinsed with a surfactant-containing rinsing material, and vortexed to obtain a positive pattern. The developed LS pattern was observed using a Hitachi Advanced Technology Co., Ltd. (GMT) CG6300 measuring SEM, and the sensitivity, EL, LWR, and DOF were evaluated according to the following methods. The results are shown in Tables 5 and 6.

[0629] [Sensitivity Evaluation]

[0630] Find the optimal exposure E for obtaining an LS pattern with a linewidth of 18nm and a pitch of 36nm. op (mJ / cm 2 ), defined as sensitivity.

[0631] [EL Review]

[0632] The exposure amount formed within ±10% (16.2–19.8 nm) of the aforementioned LS pattern's 18 nm spacing is calculated using the following formula for EL (unit: %). The larger this value, the better the performance.

[0633] EL(%)=(|E1-E2| / E op )×100

[0634] E1: Optimal exposure for an LS pattern with a linewidth of 16.2nm and a pitch of 36nm.

[0635] E2: Optimal exposure for an LS pattern with a linewidth of 19.8nm and a pitch of 36nm.

[0636] E op : Optimal exposure for an LS pattern with a linewidth of 18nm and a pitch of 36nm

[0637] [LWR Evaluation]

[0638] Determination with E opThe dimension of the LS pattern obtained by irradiation at a position 10 along the long side of the line is calculated as three times the standard deviation (σ) of the result (3σ), which is defined as LWR. The smaller this value, the smaller the roughness and the more uniform the linewidth of the pattern.

[0639] [DOF Rating]

[0640] For the evaluation of focal depth, the focal range is determined by considering the range of ±10% (16.2–19.8 nm) of the aforementioned LS pattern size of 18 nm. The larger this value, the wider the focal depth and the greater the processing tolerance of the resist pattern.

[0641] [Table 5]

[0642]

[0643]

[0644] [Table 6]

[0645]

[0646]

[0647] As shown in Tables 5 and 6, the resist compositions of the examples generally have larger EL and DOF values, and tend to have smaller optimal exposure and LWR values ​​compared to the comparative examples. Therefore, the resist compositions of the polymers of the present invention have good sensitivity and performance, and the resulting patterns have low roughness and wide focal depth, confirming excellent photolithography performance.

[0648] [5] Evaluation of EUV lithography (2)

[0649] [Examples 3-1 to 3-20, Comparative Examples 3-1 to 3-20]

[0650] The chemically amplified resist compositions (R-1 to R-20, CR-1 to CR-20) shown in Tables 3 and 4 were spin-coated onto a Si substrate containing a silicon spin-coated hard mask (SHB-A940, 43% by mass) manufactured by Shin-Etsu Chemical Industry Co., Ltd., with a pre-baking time of 60 seconds at 105°C using a hot plate to form a resist film with a thickness of 50 nm. This resist film was then exposed to extreme ultraviolet light at a wavelength of 13.5 nm using an ASML EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, wafer-scale hole pattern with a pitch of 46 nm and a deviation of +20%). PEB was performed for 60 seconds using a hot plate at the temperatures described in Tables 7 and 8, followed by development for 30 seconds with a 2.38% by mass TMAH aqueous solution to form a hole pattern with a size of 23 nm.

[0651] Using a Hitachi Advanced Technologies (AGT) CG6300 length measuring SEM, the exposure required to form holes at a size of 23 nm was measured and defined as the sensitivity (optimal exposure). Furthermore, the dimensions of 50 holes at this size were measured, and the standard deviation (σ) was calculated as three times the standard deviation (3σ), defined as the size variation (CDU). The results are shown in Tables 7 and 8.

[0652] [Table 7]

[0653]

[0654]

[0655] [Table 8]

[0656]

[0657]

[0658] As shown in Tables 7 and 8, the resist compositions of the examples tend to have lower optimal exposure and CDU values ​​overall compared to the comparative examples. Therefore, it is confirmed that the resist compositions using the polymers of the present invention have good sensitivity and excellent in-plane uniformity of the pattern.

[0659] As shown above, the present invention provides polymers, photoresist materials, and a method for forming resist patterns with high sensitivity, high resolution, high contrast, low pattern width variation (LWR), low in-plane uniformity (CDU), and wide processing tolerance in photolithography using high-energy ray ultra-micro processing technology.

[0660] Furthermore, the present invention is not limited to the embodiments described above. The embodiments described above are illustrative examples, and those that have substantially the same structure and perform the same function as the technical concept described in the claims of the present invention are all included within the technical scope of the present invention.

Claims

1. A polymer that generates acid upon exposure, and whose solubility in a developer is altered by the action of this acid, characterized by: It contains repeating units represented by the following formula (A-1), and repeating units represented by any one or more of the following formulas (B-2) to (B-3). In the formula, R A Z is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. A R is a single bond, or may contain a phenylene or naphthyl group with a halogen atom. B With R C Each is independently a linear, branched, or cyclic hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. B With R C They can also bond together to form a ring structure, R 1a Each of the following is independently a halogen atom, a cyano group, an acyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkoxy group having 1 to 5 carbon atoms; R 1b Each is an independent, linear, branched, or cyclic hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms; n1 is an integer of 1 or 2; n2 is an integer of 0 to 2; n3 is an integer of 0 to 5; and n4 is an integer of 0 to 2. Z 3 (Main chain)-C(=O)-OZ 31 -, Z 31 It may also contain an aliphatic hydrocarbon group with 1 to 10 carbon atoms, or a phenylene or naphthylene group, which may contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. Z 4 It is a single bond or a methylene group. L 11 The bonds can be ether bonds, ester bonds, carbonyl groups, sulfonate bonds, carbonate bonds, or carbamate bonds. Rf 1 and Rf 2 Each is independently a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms. Rf 3 and Rf 4 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 6 carbon atoms. A + It is a ium cation. c is an integer from 0 to 3; The polymer further contains repeating units represented by formula (a-1) or (a-2). In the formula, R A Z A As mentioned above, Z B R is an alkyl dieny with 1 to 10 carbon atoms, consisting of a single bond, (main chain)-C(=O)-O-, or possibly containing an ester group, ether group, or carbonyl group. b It may contain straight-chain, branched, or cyclic hydrocarbon groups with 1 to 20 carbon atoms, halogen atoms, and may also contain fluorine-containing alkoxy or cyano groups, p being an integer from 0 to 4, X A and X B Each is an independent acid-instable group that does not contain a fluorinated aromatic ring.

2. The polymer according to claim 1, wherein, The repeating unit represented by equation (A-1) is the same as the repeating unit represented by equation (A-2). In the formula, R A Z A R B R C R 1a R 1b n1, n2, and n3 are as described above.

3. The polymer according to claim 1 or 2, wherein, In equation (A-1), R 1a It is any one of fluorine atom, trifluoromethyl, or trifluoromethoxy.

4. The polymer according to claim 1 or 2, wherein, A in equations (B-2) to (B-3) + The cation is represented by the formula (cation-1) or (cation-2). In the formula, R 11 R 12 and R 13 Each can independently represent a straight-chain, branched, or cyclic monovalent hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. Furthermore, R... 11 R 12 and R 13 Either of the two atoms in R can bond to each other and form a ring together with the sulfur atom in the formula. 14 and R 15 Each can be an independent monovalent hydrocarbon group consisting of 1 to 30 carbon atoms in a straight-chain, branched, or cyclic form, or may contain heteroatoms.

5. The polymer according to claim 1 or 2, wherein, The polymer further contains repeating units represented by the following formula (C-1), In the formula, R A As mentioned above, Z B R is an alkyl diel with 1 to 10 carbon atoms, consisting of a single bond or (main chain) -C(=O)-O-, or may also contain an ester group, ether group, or carbonyl group. b1 It can be a halogen atom, a cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms containing heteroatoms, where m is 1 to 4, k is 0 to 3, and m+k is an integer less than 4.

6. The polymer according to claim 1 or 2, wherein, The polymer further contains repeating units represented by the following formula (D-1), In the formula, R A Z A Same as above, Y A It is a hydrogen atom, or a polar group containing at least one of the following structures: hydroxyl, cyano, carbonyl, carboxyl, ether bond, ester bond, sulfonate bond, sulfonamide bond, carbonate bond, lactone ring, sulopentalide ring, sulfur atom, and carboxylic anhydride.

7. A resist composition, characterized in that: Contains the polymer according to any one of claims 1 to 6.

8. The resist composition according to claim 7, wherein, The resist composition also contains organic solvents.

9. The resist composition according to claim 7 or 8, wherein, The resist composition further contains photoacid generators other than those linked by the polymer chain.

10. The resist composition according to claim 7 or 8, wherein, The resist composition also contains a quenching agent.

11. The resist composition according to claim 7 or 8, wherein, The resist composition further contains surfactants that are insoluble or poorly soluble in water but soluble in alkaline developing solutions, and / or surfactants that are insoluble or poorly soluble in both water and alkaline developing solutions.

12. A method for forming a pattern, characterized by comprising the following steps: (i) Forming a resist film on a substrate using the resist composition according to any one of claims 7 to 11. (ii) Expose the resist film to high-energy rays. (iii) The exposed resist film is developed with a developer.

13. The pattern forming method according to claim 12, wherein, The high-energy ray in step (ii) is i-ray, KrF excimer laser, ArF excimer laser, electron beam, or extreme ultraviolet light with a wavelength of 3 to 15 nm.

14. The pattern forming method according to claim 12 or 13, wherein, The developing solution in step (iii) is an alkaline aqueous solution, which dissolves the exposed portion and obtains a positive pattern in which the unexposed portion does not dissolve.

15. The pattern forming method according to claim 12 or 13, wherein, The developer in step (iii) is an organic solvent that dissolves the unexposed areas, resulting in a negative pattern where the exposed areas do not dissolve.

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