Resist composition and pattern forming method

Abstract

The invention relates to a resist composition and a pattern forming method. The present invention addresses the problem of providing: a resist composition having high sensitivity, high resolution, small edge roughness, small dimensional variation, and good pattern shape after exposure; and a pattern forming method. [Solution] A resist composition containing a resin (A) containing a repeating unit that is represented by formula (a1) and that generates an acid by exposure, a photodegradable quenching agent represented by formula (b1), and an organic solvent, the resin (A) being characterized in that at least one of M1 + in formula (a1) and M2 + in formula (b1) is a sulfonium cation represented by formula (1).

Description

Technical Field

[0001] This invention relates to a resist composition and a method for forming a pattern. Background Technology

[0002] With the increasing integration and speed of LSI (Lithium-ion Sensors), the miniaturization of patterning is rapidly advancing. This is because the growing prevalence of 5G high-speed communication and Artificial Intelligence (AI) necessitates high-performance devices to process them. As the most advanced miniaturization technology, 13.5nm extreme ultraviolet (EUV) lithography has enabled the mass production of 5nm node devices. Furthermore, research on the use of EUV lithography has been conducted in next-generation 3nm node devices and the next-next-generation 2nm node devices.

[0003] In recent years, the power of EUV sources used has been low. On the other hand, due to their short wavelength and high energy, the number of photons contained during exposure is very small. As a result, the amount of photoacid generator in EUV exposure is less than that in DUV exposure, resulting in an uneven distribution of acid in the resist film. Such photon shot noise is known to be a cause of reduced LWR performance (Non-Patent Literature 1).

[0004] To improve the performance degradation caused by such a low number of photons, adding a photoacid generator with high photosensitivity is effective. For example, onium salts of sulfonium cations substituted with fluorine atoms are proposed in Patent Documents 1 and 2.

[0005] As miniaturization progresses, image blurring caused by acid diffusion becomes a problem. To ensure the resolution of micropatterns with dimensions below 45 nm, it has been proposed that not only improving the previously proposed dissolution contrast but also controlling acid diffusion is important (Non-Patent Document 2). However, since chemically amplified resist materials improve sensitivity and contrast through acid diffusion, reducing the post-exposure baking (PEB) temperature or shortening the time to suppress acid diffusion to the limit significantly reduces sensitivity and contrast.

[0006] Sensitivity, resolution, and edge roughness illustrate the relationship between the triangular trade-offs. To improve resolution, acid diffusion needs to be suppressed, but if the acid diffusion distance becomes shorter, sensitivity decreases.

[0007] Adding an acid-generating agent that produces a large volume of acid is effective in suppressing acid diffusion. Therefore, it has been proposed to incorporate repeating units from onium salts with polymerizable unsaturated bonds into the polymer. In this case, the polymer also functions as an acid-generating agent (polymer-bonded acid-generating agent). Patent Document 3 proposes sulfonium salts and sulfonium salts with polymerizable unsaturated bonds that generate specific sulfonic acids. Patent Document 4 proposes sulfonium salts in which sulfonic acids are directly bonded to the main chain.

[0008] As acid diffusion control agents to suppress the diffusion of strong acid components generated by photoacid generators, onium salts of weak acids have been proposed. When a strong acid and a weak acid onium salt are mixed, ion exchange occurs, resulting in the replacement of the weak acid with the strong acid onium salt. The weak acid component replaced in this way does not cause acid decomposition reactions in the base polymer, thus the weak acid onium salt functions as a quencher. As weak acids, quenchers that generate carboxylic acids have been proposed, such as sulfonium salts of salicylic acid, β-hydroxycarboxylic acid (Patent Document 5), salicylic acid derivatives (Patent Documents 6, 7), iodinated salicylic acid (Patent Document 8), and α-fluorocarboxylic acid (Patent Documents 9, 10).

[0009] Thus, in the existing technology, in the mass production of 5nm node devices based on extreme ultraviolet (EUV) lithography that has been expected in recent years, there is a problem that there is no resist composition and patterning method that can simultaneously satisfy the three properties of sensitivity, resolution and edge roughness.

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: Japanese Patent No. 6442370

[0013] Patent Document 2: Japanese Patent No. 6586303

[0014] Patent Document 3: Japanese Patent Application Publication No. 2006-045311

[0015] Patent Document 4: Japanese Patent Application Publication No. 2006-178317

[0016] Patent Document 5: International Publication No. 2018 / 159560

[0017] Patent Document 6: Japanese Patent Application Publication No. 2020-203984

[0018] Patent Document 7: Japanese Patent Application Publication No. 2020-91404

[0019] Patent Document 8: Japanese Patent Application Publication No. 2022-77505

[0020] Patent Document 9: Japanese Patent Application Publication No. 2015-054833

[0021] Patent Document 10: Japanese Patent Application Publication No. 2021-91666

[0022] Non-patent literature

[0023] [Non-Patent Literature 1] SPIE Vol.3331p531(1998)

[0024] [Non-Patent Literature 2] SPIE Vol.6520 65203L-1(2007) Summary of the Invention

[0025] [The problem the invention aims to solve]

[0026] The present invention was made in view of the above circumstances, and its object is to provide a resist composition and a pattern forming method, wherein the aforementioned resist composition has higher sensitivity and higher resolution than conventional resist materials, and has small edge roughness and dimensional deviation, and the pattern shape after exposure is good.

[0027] [Methods used to solve problems]

[0028] To address the aforementioned issues, this invention provides a photoresist composition comprising a resin (A), a photodegradable quencher represented by formula (b1), and an organic solvent. The resin (A) contains a repeating unit represented by formula (a1) that generates acid upon exposure, wherein M1 in formula (a1)... + M2 in the above formula (b1) + At least one of them is a sulfonium cation as shown in formula (1).

[0029] [Chemistry 1]

[0030]

[0031] In the formula, R a1 Each can be independently a hydrogen atom or a methyl group. Z1 a1 It is a single bond or an ester bond. Z2 a1 It is a divalent organic group with 1 to 20 carbon atoms, consisting of a single bond or potentially including ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, or iodine atoms. Rf 1 ~Rf 4 Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom. But Rf 1 ~Rf 4 At least one of the atoms in M1 is a fluorine atom. + It is a sulfonium cation.

[0032] [Chemistry 2]

[0033]

[0034] In the formula, R b It can also be an organic group with 1 to 30 carbon atoms that has substituents. M2 + It is a sulfonium cation.

[0035] [Chemistry 3]

[0036]

[0037] In the formula, R 1 It can be a fluorine atom, an iodine atom, or a perfluoroalkyl group. R 2 R 3 Each is independently a fluorine atom or a perfluoroalkyl group. l is an integer from 0 to 3, m is an integer from 1 to 3, and n is an integer from 1 to 3. When l, m, and n are integers greater than 2, R... 1 R 2 R 3 They can be the same or different. However, the structure of formula (1) contains at least two or more fluorine atoms. Additionally, R... 2 Or R 3 When the atom is fluorine, at least one fluorine atom is meta-substituted relative to the sulfur atom.

[0038] If it is such a resist composition, it becomes a resist composition with high sensitivity, high resolution, small edge roughness, small dimensional deviation, and good pattern shape after exposure.

[0039] The photodegradable quencher shown in formula (b1) above is preferably the photodegradable quencher shown in formula (b1-1) below.

[0040] [Chemistry 4]

[0041]

[0042] In the formula, R b' It can be an organic group with 1 to 22 carbon atoms, which may also have substituents, and may include ester bonds, ether bonds, amide bonds, lactone rings, sulopentalide rings, aromatic cyclic groups, aliphatic cyclic groups, hydroxyl groups, alkoxy groups, fluoroalkyl groups, nitro groups, cyano groups, trifluoromethoxy groups, carbonyl groups, amino groups, alkylamino groups, fluorine atoms, bromine atoms, or iodine atoms. M2 + It is a sulfonium cation.

[0043] If the resist composition is such, it functions as an excellent (B1-1) quencher for suppressing the diffusion of strong acid components generated by photoacid generators. Through this action, it is possible to simultaneously improve exposure-based acid generation efficiency and shorten the acid diffusion distance to the limit, while achieving high sensitivity, excellent edge roughness (LWR), and dimensional tolerance.

[0044] The aforementioned resin (A) is preferably a resin that further contains repeating units as shown in the following formula (a2).

[0045] [Chemistry 5]

[0046]

[0047] In the formula, R A Each can be independently a hydrogen atom or a methyl group. Y 1It is a single bond, a phenylene or naphthylene group, or a linking group with 1 to 12 carbon atoms having an ester bond, an ether bond, or a lactone ring. R 11 It is an acid-labile group.

[0048] If this type of resin is used, the dissolution contrast is improved by the repeating unit in which the hydrogen atoms of the introduced carboxyl group are replaced by acid-instable groups, which can provide high sensitivity and significantly improve the contrast of alkali dissolution rate before and after exposure.

[0049] The repeating unit shown in the above formula (a1) is preferably the repeating unit shown in the following formula (a1-1).

[0050] [Chemistry 6]

[0051]

[0052] In the formula, R a1 Each can be independently a hydrogen atom or a methyl group. Z1 a1 It can be a single bond or an ester bond. L1 is a single bond or may also contain a divalent linker including an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom. L2 is a single bond or may also contain a divalent linker including an ester bond or an ether bond. Rf 1 ~Rf 4 Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom. But Rf 1 ~Rf 4 At least one of them is a fluorine atom. k is an integer from 0 to 4. M1 + It is a sulfonium cation.

[0053] If it is a repeating unit with such a structure, it will have high sensitivity, high resolution, small edge roughness and size deviation, and good pattern shape after exposure.

[0054] The repeating unit shown in the above formula (a1) is preferably the repeating unit shown in the following formula (a1-2).

[0055] [Chemistry 7]

[0056]

[0057] In the formula, R a1 Each is independently a hydrogen atom or a methyl group. L1 is a single bond or may contain a divalent linker including ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, or iodine atoms. L2 is a single bond or may contain a divalent linker including ester bonds and ether bonds. Rf 1 ~Rf 4 Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom. But Rf 1 ~Rf 4 At least one of them is a fluorine atom. k is an integer from 0 to 4. M1 + It is a sulfonium cation.

[0058] If the resin has a polymeric group of methacrylate, the polymer backbone becomes rigid, thus increasing the glass transition temperature. As a result, the thermal diffusion of the strong acid components generated by the photoacid generator is suppressed, and the resolution is improved.

[0059] The anionic portion of formulas (a1) and (b1) above preferably contains iodine atoms.

[0060] If the anion section contains iodine atoms, then because iodine atoms absorb EUV light extensively, the photons imparted by EUV exposure have a high ability to effectively generate secondary electrons, thus achieving high sensitivity and high resolution.

[0061] M1 of the above equation (a1) + M2 of formula (b1) + Sulfonium cations represented by formula (1) are preferred.

[0062] If it is a sulfonium cation, it can improve electron acceptability and efficiently convert secondary electrons generated by exposure into acid, thus achieving high sensitivity and high resolution.

[0063] In the above formula (1), l is preferably an integer from 1 to 3.

[0064] If it is such a sulfonium cation, the electron acceptability can be further improved, and the secondary electrons generated by exposure can be efficiently converted into acid, thus making it better for achieving high sensitivity and high resolution.

[0065] The cation shown in formula (1) above preferably contains iodine atoms.

[0066] Iodine atoms have high absorption of EUV light, enabling them to effectively generate secondary electrons from photons imparted by EUV exposure, thus achieving high sensitivity and high resolution. Furthermore, by bonding with triarylsulfonium cations without a linking group, iodine atoms can efficiently undergo photochemical reactions.

[0067] In addition, the present invention provides a pattern forming method, which includes: a step of forming a resist film on a substrate using the resist composition described above; a step of exposing the resist film with high-energy rays; and a step of developing the exposed resist film using a developer.

[0068] Such a pattern forming method can provide a pattern forming method with high sensitivity, high resolution and low edge roughness (LWR) and dimensional deviation (CDU).

[0069] In this case, it is preferable to use i-rays, KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet light with wavelengths of 3 to 15 nm in the exposure step.

[0070] If such a patterning method is used, it can better simultaneously satisfy the three requirements of high sensitivity, high resolution, edge roughness (LWR), and dimensional deviation (CDU). It can be applied to the mass production of 5nm node devices with fine patterns that correspond to the high integration and high speed of LSI, as well as the mass production of next-generation 3nm node and the next-generation 2nm node devices.

[0071] [The effects of the invention]

[0072] As described above, the resist composition and patterning method according to the present invention can provide a resist composition and patterning method with high sensitivity and high resolution, and small edge roughness (LWR) and scale deviation (CDU). Furthermore, a resist composition with high sensitivity and significantly improved contrast between alkaline dissolution rates before and after exposure can be provided. Moreover, this enables the patterning method to be applied to the mass production of 5nm node devices with fine patterns corresponding to the high integration and high speed of LSI, as well as the mass production of next-generation 3nm node and the next-generation 2nm node devices. Detailed Implementation

[0073] As mentioned above, the aim is to develop resist compositions and patterning methods that offer the high sensitivity, high resolution, and low edge roughness (LWR) and dimensional deviation (CDU) that have been desired in recent years.

[0074] In order to obtain the resist composition with high sensitivity, high resolution, and low edge roughness (LWR) and dimensional deviation (CDU) that has been desired in recent years, the inventors have repeatedly conducted in-depth research and found that it is necessary to improve the acid generation efficiency based on exposure and shorten the acid diffusion distance to the limit. For this purpose, photosensitive resin containing sulfonium cations with specific structures and / or photodegradable quenchers containing sulfonium cations with specific structures are effective.

[0075] Furthermore, it was discovered that, in order to improve the dissolution contrast, repeating units formed by replacing the hydrogen atoms of the introduced carboxyl groups with acid-instable groups can obtain high sensitivity and a significant increase in the contrast of alkaline dissolution rates before and after exposure. This also results in high sensitivity and a high effect in suppressing acid diffusion, high resolution, and small and good deviations in the shape, edge roughness, and size of the exposed pattern. It is particularly suitable as a resist composition for the fabrication of ultra-LSI or for forming fine patterns in photomasks, thus completing the present invention.

[0076] That is, the present invention provides a resin composition comprising:

[0077] A photoresist composition comprising a resin (A), a photodegradable quencher represented by formula (b1), and an organic solvent, wherein the resin (A) contains a repeating unit represented by formula (a1) that generates acid upon exposure, wherein M1 in formula (a1) + M2 in the above formula (b1) + At least one of them is a sulfonium cation as shown in formula (1).

[0078] [Chemistry 8]

[0079]

[0080] In the formula, R a1 Each can be independently a hydrogen atom or a methyl group. Z1 a1 It is a single bond or an ester bond. Z2 a1 It is a divalent organic group with 1 to 20 carbon atoms, consisting of a single bond or potentially including ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, or iodine atoms. Rf 1 ~Rf 4 Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom. But Rf 1 ~Rf 4 At least one of the atoms in M1 is a fluorine atom. + It is a sulfonium cation.

[0081] [Chemistry 9]

[0082]

[0083] In the formula, R b It can also be an organic group with 1 to 30 carbon atoms that has substituents. M2 + It is a sulfonium cation.

[0084] [Chemistry 10]

[0085]

[0086] In the formula, R 1 It can be a fluorine atom, an iodine atom, or a perfluoroalkyl group. R 2 R 3 Each is independently a fluorine atom or a perfluoroalkyl group. l is an integer from 0 to 3, m is an integer from 1 to 3, and n is an integer from 1 to 3. When l, m, and n are integers greater than 2, R... 1 R 2 R 3 They can be the same or different. Among them, the structure of formula (1) contains at least two fluorine atoms. Additionally, R... 2 Or R 3 When the atom is fluorine, at least one fluorine atom is meta-substituted relative to the sulfur atom.

[0087] The present invention will now be described in detail, but it is not limited thereto.

[0088] [Basic Polymers]

[0089] (Repeating unit (a1))

[0090] The base polymer (A) (resin (A)) in the resist composition of the present invention contains repeating units of the following formula (a1) that generate acid upon exposure.

[0091] [Chemistry 11]

[0092]

[0093] In the formula, R a1 Each can be independently a hydrogen atom or a methyl group. Z1 a1 It is a single bond or an ester bond. Z2 a1 It is a divalent organic group with 1 to 20 carbon atoms, consisting of a single bond or potentially including ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, or iodine atoms. Rf 1 ~Rf 4 Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom. But Rf 1 ~Rf 4 At least one of the atoms in M1 is a fluorine atom. + It is a sulfonium cation.

[0094] Rf 1 ~Rf 4 Each atom can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom, but at least one of them must be a fluorine atom. Specifically, Rf... 3 and Rf 4 At least one of them is a fluorine atom, Rf 3 and Rf 4 Ideally, all atoms should be fluorine atoms.

[0095] The aforementioned repeating unit (a1) is a photoacid generator (PAG) composed of sulfonic acid anions and sulfonium cations. By embedding PAG as a repeating unit into the polymer, the diffusion distance of the strong acid component is reduced, thereby suppressing image blurring and improving resolution.

[0096] As the anionic portion of the aforementioned repeating unit (a1), examples can be given of those with a styrene structure as polymerizable groups. Specific examples of the anionic portion of the aforementioned repeating unit (a1) can be given as shown below, but are not limited to these.

[0097] [Chemistry 12]

[0098]

[0099] [Chemistry 13]

[0100]

[0101] [Chemistry 14]

[0102]

[0103] [Chemistry 15]

[0104]

[0105] In addition, the anionic portion of the repeating unit (a1) is preferably a polymerizable group having a methacrylate structure.

[0106] Specific examples of the anion portion of the aforementioned repeating unit (a1) can be listed below, but are not limited to these.

[0107] [Chemistry 16]

[0108]

[0109] [Chemistry 17]

[0110]

[0111] [Chemistry 18]

[0112]

[0113] [Chemistry 19]

[0114]

[0115] [Chemistry 20]

[0116]

[0117] [Chemistry 21]

[0118]

[0119] [Chemistry 22]

[0120]

[0121] [Chemistry 23]

[0122]

[0123] [Chemistry 24]

[0124]

[0125] [Chemistry 25]

[0126]

[0127] [Chemistry 26]

[0128]

[0129] When the polymeric group is methacrylate, the polymer backbone becomes rigid, thus increasing the glass transition temperature. As a result, the thermal diffusion of the strong acid component generated by the photoacid generator is suppressed, and the resolution is improved.

[0130] (M1 of repeating unit (a1)) + )

[0131] M1 in the aforementioned repeating unit (a1) + It is a sulfonium cation, preferably containing iodine atoms. Iodine atoms have high absorption of EUV light and can effectively generate secondary electrons from photons given by EUV exposure, thus promising high sensitivity and high resolution.

[0132] M1, as the aforementioned repeating unit (a1) + Specific examples can be given as shown below, but are not limited to these.

[0133] [Chemistry 27]

[0134]

[0135] [Chemistry 28]

[0136]

[0137] [Chemistry 29]

[0138]

[0139] [Chemistry 30]

[0140]

[0141] [Chemistry 31]

[0142]

[0143] [Chemistry 32]

[0144]

[0145] [Chemistry 33]

[0146]

[0147] [Chemistry 34]

[0148]

[0149] [Chemistry 35]

[0150]

[0151] [Chemistry 36]

[0152]

[0153] [Chemistry 37]

[0154]

[0155] [Chemistry 38]

[0156]

[0157] [Chemistry 39]

[0158]

[0159] [Chemistry 40]

[0160]

[0161] [Chemistry 41]

[0162]

[0163] M1 in the aforementioned repeating unit (a1) of the sulfonium cation represented by general formula (1) + Preferably, the sulfonium cation is represented by formula (1) below. [Chemistry 42]

[0164]

[0165] In the formula, R 1 It can be a fluorine atom, an iodine atom, or a perfluoroalkyl group. R 2 R 3 Each is independently a fluorine atom or a perfluoroalkyl group. l is an integer from 0 to 3, m is an integer from 1 to 3, and n is an integer from 1 to 3. When l, m, and n are integers greater than 2, R... 1 R 2 R 3 They can be the same or different. Among them, the structure of formula (1) contains at least two fluorine atoms. Additionally, R... 2 Or R 3 When the atom is fluorine, at least one fluorine atom is meta-substituted relative to the sulfur atom.

[0166] If it is such a sulfonium cation, it can improve electron acceptability and efficiently convert secondary electrons generated by exposure into acid, thus high sensitivity and high resolution can be expected.

[0167] In equation (1), l is an integer from 0 to 3, preferably an integer from 1 to 2, and more preferably l = 1. m is an integer from 1 to 3, preferably an integer from 1 to 2, and more preferably m = 2. n is an integer from 1 to 3, preferably an integer from 1 to 2, and more preferably n = 2.

[0168] The number of fluorine atoms contained in formula (1) is preferably three or more, and more preferably four or more.

[0169] R in equation (1) 2 R 3 Preferably, it is a fluorine atom or a trifluoromethyl atom, and even more preferably, it is a fluorine atom.

[0170] In addition, the sulfonium cation shown in formula (1) preferably contains more than one iodine atom, and more preferably contains only one.

[0171] R in equation (1) 1 Preferably, it is a fluorine atom or an iodine atom, and more preferably an iodine atom.

[0172] Iodine atoms have high absorption of EUV light and can effectively generate secondary electrons from photons imparted by EUV exposure, thus promising high sensitivity and high resolution. Furthermore, by bonding iodine atoms to triarylsulfonium cations without a linking group, highly efficient photochemical reactions are expected.

[0173] Generally speaking, compounds with multiple iodine atoms can improve the absorption of EUV light. On the other hand, due to the reduced solubility in casting solvents and developers, photolithography performance may be degraded.

[0174] If the compound has iodine atoms in both the anionic and cationic portions of the aforementioned repeating unit (a1), the EUV absorption efficiency can be improved without compromising solvent solubility, thus improving photolithography performance can be expected.

[0175] Specific examples of sulfonium cations represented by formula (1) can be listed below, but are not limited to these.

[0176] [Chemistry 43]

[0177]

[0178] [Chemistry 44]

[0179]

[0180] [Chemistry 45]

[0181]

[0182] Furthermore, the electron acceptability of triarylsulfonium cations can be estimated by calculating the LUMO (Lowest Unoccupied Molecular Orbital) energy level. The LUMO level can be calculated using DFT (Density Functional Theory). Examples of software capable of performing DFT calculations include Gaussian16.

[0183] Using Gaussian16, DFT calculations were performed using B3LYP in the functional group and 6-31G(d) in the basis function. The resulting LUMO level of the triphenylsulfonium cation was -4.72 eV. Since the LUMO level of the sulfonium cation shown in equation (1) above is lower than -4.72 eV, it is considered to have high electron acceptability and improved acid production efficiency.

[0184] The LUMO energy level of the sulfonium cation shown in formula (1) above is below -4.72 eV, more preferably below -5.00 eV, more preferably below -5.10 eV, more preferably below -5.20 eV, and more preferably below -5.30 eV.

[0185] On the other hand, as the LUMO energy level decreases, the storage stability deteriorates. Therefore, the LUMO energy level of the sulfonium cation shown in the above formula (1) is preferably -5.50 eV or higher, more preferably -5.45 eV or higher, more preferably -5.40 eV or higher, and more preferably -5.35 eV or higher.

[0186] Regarding the sulfonium cation represented by equation (1) above, the following are examples of calculated LUMO levels, but preferred structures are not limited to these. Furthermore, the LUMO calculations use Gaussian16, with B3LYP as the functional group and 6-31G(d) as the basis function. For iodine atoms, the effective inner-shell potential approximation is applied, and LanL2DZ is used as the basis function.

[0187] [Chemistry 46]

[0188]

[0189] The repeating unit shown in the above formula (a1) is preferably the repeating unit shown in the following formula (a1-1).

[0190] [Chemistry 47]

[0191]

[0192] In the formula, R a1 Each can be independently a hydrogen atom or a methyl group. Z1 a1It can be a single bond or an ester bond. L1 is a single bond or may also contain a divalent linker including an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom. L2 is a single bond or may also contain a divalent linker including an ester bond or an ether bond. Rf 1 ~Rf 4 Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom. But Rf 1 ~Rf 4 At least one of them is a fluorine atom. k is an integer from 0 to 4. M1 + It is a sulfonium cation.

[0193] If it is a repeating unit with such a structure, it will have high sensitivity, high resolution, small edge roughness, small size deviation, and good pattern shape after exposure.

[0194] The repeating unit shown in the above formula (a1) is preferably the repeating unit shown in the following formula (a1-2).

[0195] [Chemistry 48]

[0196]

[0197] In the formula, R a1 Each is independently a hydrogen atom or a methyl group. L1 is a single bond or may contain a divalent linker including ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, or iodine atoms. L2 is a single bond or may contain a divalent linker including ester bonds and ether bonds. Rf 1 ~Rf 4 Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom. But Rf 1 ~Rf 4 At least one of them is a fluorine atom. k is an integer from 0 to 4. M1 + It is a sulfonium cation.

[0198] If the polymeric group is a methacrylate resin, the polymer backbone becomes rigid, thus increasing the glass transition temperature. As a result, the thermal diffusion of the strong acid components generated by the photoacid generator is suppressed, and the resolution is improved.

[0199] (The repeating unit represented by equation (a2))

[0200] The aforementioned base polymer preferably further comprises repeating units as shown in formula (a2) below.

[0201] [Chemistry 49]

[0202]

[0203] In the formula, R A Each can be independently a hydrogen atom or a methyl group. Y 1It is a single bond, a phenylene or naphthylene group, or a linking group with 1 to 12 carbon atoms having an ester bond, an ether bond, or a lactone ring. R 11 It is an acid-labile group.

[0204] If the base polymer contains repeating units represented by formula (a2) with hydrogen atoms of the carboxyl group replaced by acid-instable groups, the resist composition has high and excellent solubility contrast.

[0205] Specific examples of monomers providing (a2) include those shown below, but are not limited to these. Furthermore, in the following formula, R... A and R 11 It has the same meaning as defined in the aforementioned equation (a2).

[0206] [Transformation 50]

[0207]

[0208] [Chemistry 51]

[0209]

[0210] In addition, the aforementioned basic polymer may also contain repeating units (a2-2) in which the hydrogen atoms of the phenolic hydroxyl groups are replaced by acid-instable groups.

[0211] [Chemistry 52]

[0212]

[0213] In the above general formula (a2-2), R A R in equation (a2) A The meanings are the same. Their ideal examples are also the same. Y 2 It is a single bond or an ester bond. Y 3 It can be a single bond, an ether bond, or an ester bond. R 11 It is an acid-labile group. R 12 It is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 13 It is a single bond or an alkyldiyl group with 1 to 6 carbon atoms, some of which may be replaced by ether or ester bonds. a is 1 or 2. b is an integer from 0 to 4. Where 1 ≤ a + b ≤ 5.

[0214] Specific examples of monomers providing repeating units (a2-2) can be given as shown below, but are not limited to these. Furthermore, R in the following formula... A and R 11 R in equation (a2) A and R 11 Synonyms.

[0215] [Chemistry 53]

[0216]

[0217] R 11 The unstable acid group can be selected in various ways, for example, those represented by the following formulas (AL-1) to (AL-3) can be listed.

[0218] [Chemistry 54]

[0219]

[0220] In equation (AL-1), c is an integer from 0 to 6. R L1 It is a tertiary hydrocarbon group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, a trialkylsilyl group having each hydrocarbon group having 1 to 6 carbon atoms, a carbonyl group, a saturated hydrocarbon group having 4 to 20 carbon atoms containing an ether bond or an ester bond, or a group shown in formula (AL-3).

[0221] R L1 The tertiary hydrocarbon group can be saturated or unsaturated, and can be branched or cyclic. Specific examples include tert-butyl, tert-pentyl, 1,1-diethylpropyl, 1-ethylcyclopentyl, 1-butylcyclopentyl, 1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl, and 2-methyl-2-adamantyl. Examples of the aforementioned trialkylsilyl groups include trimethylsilyl, triethylsilyl, and dimethyl-tert-butylsilyl. The saturated hydrocarbon group containing carbonyl, ether, or ester bonds can be linear, branched, or cyclic, but is preferably cyclic. Specific examples include 3-oxocyclohexyl, 4-methyl-2-oxooxacyclohexane-4-yl, 5-methyl-2-oxooxacyclopentane-5-yl, 2-tetrahydropyranyl, and 2-tetrahydrofuranyl.

[0222] Examples of acid-instable groups represented by formula (AL-1) include: tert-butoxycarbonyl, tert-butoxycarbonylmethyl, tert-pentyloxycarbonyl, tert-pentyloxycarbonylmethyl, 1,1-diethylpropoxycarbonyl, 1,1-diethylpropoxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyloxycarbonylmethyl, 1-ethyl-2-cyclopentenyloxycarbonyl, 1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl, 2-tetrahydropyranyloxycarbonylmethyl, 2-tetrahydrofuranyloxycarbonylmethyl, etc.

[0223] Furthermore, as acid-instable groups represented by formula (AL-1), the groups represented by formulas (AL-1)-1 to (AL-1)-10 can also be listed below.

[0224] [Chemistry 55]

[0225]

[0226] In the formula, the dashed lines represent atomic bonds.

[0227] In equations (AL-1)-1 to (AL-1)-10, c is the same as above. R L8 Each is independently a saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. R L9 It consists of a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. R L10 It is a saturated hydrocarbon group with 2 to 10 carbon atoms or an aryl group with 6 to 20 carbon atoms. The above-mentioned saturated hydrocarbon group can be any of the following: straight-chain, branched, or cyclic.

[0228] In equation (AL-2), R L3 and R L4 Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10. Here, the saturated hydrocarbon group can be any of the following: straight-chain, branched, or cyclic. Specific examples include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl, n-octyl, etc.

[0229] In equation (AL-2), R L2 The hydrocarbon group may contain heteroatoms and has 1 to 18 carbon atoms, preferably 1 to 10. Here, the hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Examples of such hydrocarbon groups include saturated hydrocarbon groups with 1 to 18 carbon atoms, where a portion of the hydrogen atom may be replaced by a hydroxyl group, alkoxy group, oxo group, amino group, alkylamino group, etc. Specific examples of such substituted saturated hydrocarbon groups include the groups shown below.

[0230] [Chemistry 56]

[0231]

[0232] In the formula, the dashed lines represent atomic bonds.

[0233] R L2 and R L3 R L2 and R L4 Or R L3 and R L4 They can bond to each other and form rings together with the carbon atoms they are bonded to, or with carbon and oxygen atoms. In this case, R participates in the ring formation. L2 and R L3 R L2 and R L4 Or R L3 and R L4Each of the alkyl groups is independently an alkyldiyl group with 1 to 18 carbon atoms, preferably 1 to 10. The ring formed by their bonding preferably has 3 to 10 carbon atoms, more preferably 4 to 10.

[0234] Among the acid-instable groups represented by formula (AL-2), straight-chain or branched groups can be exemplified by examples represented by formulas (AL-2)-1 to (AL-2)-69, but are not limited thereto. Furthermore, in the following formulas, dashed lines represent atomic bonds.

[0235] [Chemistry 57]

[0236]

[0237] [Chem.58]

[0238]

[0239] [Chemistry 59]

[0240]

[0241] [Transformation 60]

[0242]

[0243] Among the acid-labile groups represented by formula (AL-2), those that are cyclic include: tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl, 2-methyltetrahydropyran-2-yl, etc.

[0244] Furthermore, groups represented by the following formulas (AL-2a) or (AL-2b) can be cited as acid-indestabilized groups. The base polymer can be cross-linked intermolecularly or intramolecularly via these acid-indestabilized groups.

[0245] [Chemistry 61]

[0246]

[0247] In the formula, the dashed lines represent atomic bonds.

[0248] In formula (AL-2a) or (AL-2b), R L11 and R L12 Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms. The aforementioned saturated hydrocarbon groups can be straight-chain, branched, or cyclic. Additionally, R... L11 and R L12 They can bond to each other and form a ring together with the carbon atoms they are bonded to; in this case, R L11 and R L12 Each is an alkyldiyl group having 1 to 8 carbon atoms. R L13Each is independently a saturated hydrocarbon group having 1 to 10 carbon atoms. The aforementioned saturated hydrocarbon group can be straight-chain, branched, or cyclic. d and e are each independently integers from 0 to 10, preferably integers from 0 to 5, and f is an integer from 1 to 7, preferably an integer from 1 to 3.

[0249] In formula (AL-2a) or (AL-2b), L A These are aliphatic saturated hydrocarbon groups with (f+1) valence carbons of 1–50, alicyclic saturated hydrocarbon groups with (f+1) valence carbons of 3–50, aromatic hydrocarbon groups with (f+1) valence carbons of 6–50, or heterocyclic groups with (f+1) valence carbons of 3–50. Furthermore, a portion of the carbon atoms in these groups may be replaced by groups containing heteroatoms, and a portion of the hydrogen atoms bonded to the carbon atoms of these groups may be replaced by hydroxyl, carboxyl, acyl, or fluorine atoms. A Preferably, the saturated hydrocarbon groups are saturated hydrocarbon groups with 1 to 20 carbon atoms, trivalent saturated hydrocarbon groups, tetravalent saturated hydrocarbon groups, or aryl hydrocarbon groups with 6 to 30 carbon atoms. The aforementioned saturated hydrocarbon groups can be straight-chain, branched, or cyclic. B It is -C(=O)-O-, -NH-C(=O)-O- or -NH-C(=O)-NH-.

[0250] Examples of divalent linking groups represented by formula (AL-2a) or (AL-2b) include groups represented by formulas (AL-2)-70 to (AL-2)-77.

[0251] [Chemistry 62]

[0252]

[0253] In the formula, the dashed lines represent atomic bonds.

[0254] In equation (AL-3), R L5 R L6 and R L7 Each group is an independent hydrocarbon group having 1 to 20 carbon atoms and may contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine. These hydrocarbon groups can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups having 1 to 20 carbon atoms, cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms, and aryl groups having 6 to 10 carbon atoms. Additionally, R... L5 and R L6 R L5 and R L7 Or R L6 and R L7 They can bond to each other and together with the carbon atoms they are bonded to form alicyclic rings with 3 to 20 carbon atoms.

[0255] Examples of groups represented by formula (AL-3) include tert-butyl, 1,1-diethylpropyl, 1-ethylnorborneol, 1-methylcyclopentyl, 1-isopropylcyclopentyl, 1-ethylcyclopentyl, 1-methylcyclohexyl, 2-(2-methyl)adamantyl, 2-(2-ethyl)adamantyl, tert-pentyl, etc.

[0256] Furthermore, as a group represented by formula (AL-3), other examples include groups represented by formulas (AL-3)-1 to (AL-3)-19.

[0257] [Chemistry 63]

[0258]

[0259] In the formula, the dashed lines represent atomic bonds.

[0260] In formula (AL-3)-1~(AL-3)-19, R L14 Each is independently a saturated hydrocarbon group having 1 to 8 carbon atoms or an aryl group having 6 to 20 carbon atoms. R L15 and R L17 Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 20 carbon atoms. R L16 It is an aryl group with 6 to 20 carbon atoms. The aforementioned saturated hydrocarbon group can be straight-chain, branched, or cyclic. Furthermore, phenyl or the like is preferred as the aforementioned aryl group. R F It is a fluorine atom or a trifluoromethyl group. g is an integer from 1 to 5.

[0261] Furthermore, groups represented by formulas (AL-3)-20 or (AL-3)-21 can be listed as acid-indestructible groups. Through these acid-indestructible groups, the polymer can undergo intramolecular or intermolecular crosslinking.

[0262] [Chemistry 64]

[0263]

[0264] In the formula, the dashed lines represent atomic bonds.

[0265] In equations (AL-3)-20 and (AL-3)-21, R L14 Same as above. R L18 It is a (h+1) valence saturated alkylene group with 1 to 20 carbon atoms or a (h+1) valence arylene group with 6 to 20 carbon atoms, and may contain heteroatoms such as oxygen, sulfur, and nitrogen atoms. The aforementioned saturated alkylene group can be straight-chain, branched, or cyclic. h is an integer from 1 to 3.

[0266] As a monomer that provides a repeating unit containing an acid-instable group represented by formula (AL-3), examples include (meth)acrylates containing an exomeric structure represented by the following formula (AL-3)-22.

[0267] [Chemistry 65]

[0268]

[0269] In equation (AL-3)-22, R A Same as above. R Lc1 It is a saturated hydrocarbon group with 1 to 8 carbon atoms or an aryl group with 6 to 20 carbon atoms that can be substituted. The aforementioned saturated hydrocarbon group can be straight-chain, branched, or cyclic. R Lc2 ~R Lc11 Each group is a hydrocarbon group with 1 to 15 carbon atoms, and may also contain heteroatoms. Examples of heteroatoms include oxygen atoms. Examples of hydrocarbon groups include hydrocarbon groups with 1 to 15 carbon atoms and aryl groups with 6 to 15 carbon atoms. R Lc2 and R Lc3 R Lc4 and R Lc6 R Lc4 and R Lc7 R Lc5 and R Lc7 R Lc5 and R Lc11 R Lc6 and R Lc10 R Lc8 and R Lc9 Or R Lc9 and R Lc10 They can bond to each other and form a ring together with the carbon atoms they are bonded to. In this case, the groups involved in the bonding are hydrocarbon subgroups with 1 to 15 carbon atoms that may contain heteroatoms. Additionally, R Lc2 and R Lc11 R Lc8 and R Lc11 Or R Lc4 and R Lc6 The groups bonded to adjacent carbon atoms can bond to each other without any other groups, forming double bonds. Furthermore, according to this formula, it also represents a mirror image.

[0270] Here, monomers representing the repeating unit indicated by formula (AL-3)-22 can be exemplified by monomers described in Japanese Patent Application Publication No. 2000-327633. Specific examples include the compounds shown below, but the invention is not limited to these. Furthermore, in the following formula, R... A Same as above.

[0271] [Chemistry 66]

[0272]

[0273] As monomers providing repeating units containing acid-instable groups represented by formula (AL-3), examples also include (meth)acrylates containing furandiyl, tetrahydrofurandiyl, or oxanorbornenediyl groups, as represented by formula (AL-3)-23 below.

[0274] [Chemistry 67]

[0275]

[0276] In equation (AL-3)-23, R A Same as above. R Lc12 and R Lc13 Each is an independent hydrocarbon group having 1 to 10 carbon atoms. R Lc12 and R Lc13 They can bond to each other and form alicyclic rings together with the carbon atoms they are bonded to. R Lc14 It is furandiyl, tetrahydrofurandiyl, or oxanorbornenediyl. R Lc15 It is a hydrocarbon group consisting of 1 to 10 carbon atoms, which may contain hydrogen atoms or heteroatoms. The aforementioned hydrocarbon group can be straight-chain, branched, or cyclic. Specific examples include saturated hydrocarbon groups with 1 to 10 carbon atoms.

[0277] As specific examples of monomers providing repeating units represented by equation (AL-3)-23, the following monomers can be cited, but are not limited to these. Furthermore, in the following equations, R... A As above, Ac represents acetyl and Me represents methyl.

[0278] [Chemistry 68]

[0279]

[0280] [Chemistry 69]

[0281]

[0282] (Repeating unit d)

[0283] The aforementioned basic polymer may further comprise repeating units d having a close-knit group selected from hydroxyl, carboxyl, lactone ring, carbonate, thiocarbonate, carbonyl, cyclic acetal, hemiacetal, ether bond, ester bond, sulfonate bond, cyano, amide, -OC(=O)-S-, and -OC(=O)-NH-.

[0284] Specific examples of monomers providing repeating unit d can be given as shown below, but are not limited to these. Furthermore, in the following formula, R... A Same as above.

[0285] [Chemistry 70]

[0286]

[0287] [Chemistry 71]

[0288]

[0289] [Chemistry 72]

[0290]

[0291] [Chemistry 73]

[0292]

[0293] [Chemistry 74]

[0294]

[0295] [Chemistry 75]

[0296]

[0297] [Chemistry 76]

[0298]

[0299] [Chemistry 77]

[0300]

[0301] (Repeating unit e)

[0302] The aforementioned basic polymer may further comprise repeating units e that are amino-free and contain iodine atoms. Specific examples of monomers providing repeating units e include, but are not limited to, the monomers shown below. Furthermore, in the following formula, R... A Same as above.

[0303] [Chemistry 78]

[0304]

[0305] [Chemistry 79]

[0306]

[0307] (Repeating unit f)

[0308] The aforementioned base polymer may also contain repeating units f other than the aforementioned repeating units. Examples of repeating units f include repeating units from styrene, vinylnaphthalene, indene, acenaphthene, coumarin, benzofuran, etc.

[0309] In the aforementioned basic polymer, the content ratio of repeating units a1, a2, d, e, and f is preferably 0 ≤ a1 < 1.0, 0 ≤ a2 < 1.0, 0 ≤ d ≤ 0.8, 0 ≤ e ≤ 0.8, and 0 ≤ f ≤ 0.8; more preferably 0.001 ≤ a1 ≤ 0.8, 0.001 ≤ a2 ≤ 0.8, 0 ≤ d ≤ 0.5, 0 ≤ e ≤ 0.4, and 0 ≤ f ≤ 0.4; and even more preferably 0.005 ≤ a1 ≤ 0.7, 0.005 ≤ a2 ≤ 0.7, 0 ≤ d1 ≤ 0.4, 0 ≤ e ≤ 0.3, and 0 ≤ f ≤ 0.3. Wherein, a1 + a2 + d + e + f = 1.0.

[0310] To synthesize the above-mentioned basic polymer, for example, the monomer that provides the above-mentioned repeating unit can be polymerized by adding a free radical polymerization initiator to an organic solvent and heating.

[0311] Organic solvents used in polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, dioxane, propylene glycol monomethyl ether, γ-butyrolactone, and mixtures thereof. Polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid), benzoyl peroxide, and lauroyl peroxide. The preferred polymerization temperature is 50–80°C. The preferred reaction time is 2–100 hours, more preferably 5–20 hours.

[0312] In the case of copolymerizing monomers containing hydroxyl groups, the hydroxyl groups can be replaced with acetal groups such as ethoxyethoxy that are easily deprotected by acids during polymerization, and deprotection can be carried out using weak acids and water after polymerization. Alternatively, they can be replaced with acetyl, formyl, trimethylacetyl, etc., and alkaline hydrolysis can be carried out after polymerization.

[0313] In the case of copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, acetoxystyrene and acetoxyvinylnaphthalene can be used instead of hydroxystyrene and hydroxyvinylnaphthalene. After polymerization, the acetoxy groups are deprotected by alkaline hydrolysis to produce hydroxystyrene and hydroxyvinylnaphthalene.

[0314] Ammonia, triethylamine, etc., can be used as the base during alkaline hydrolysis. 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.

[0315] The equivalent weight-average molecular weight (Mw) of the polystyrene, determined by gel permeation chromatography (GPC) using THF as a solvent, is preferably 1,000 to 500,000, more preferably 2,000 to 30,000. If Mw is too small, the heat resistance of the resist material deteriorates; if it is too large, the alkali solubility decreases, and tailing is likely to occur after pattern formation.

[0316] Furthermore, the molecular weight distribution (Mw / Mn) of the aforementioned base polymer is preferably 1.0–2.0, more preferably 1.0–1.7, and even more preferably a narrow dispersion of 1.0–1.5. If the molecular weight distribution is within this range, there is no concern that the presence of low- or high-molecular-weight polymers may lead to the observation of foreign matter on the pattern after exposure or a deterioration in the shape of the pattern. Such a resist material is suitable for use with fine pattern sizes.

[0317] The aforementioned base polymer can comprise two or more polymers with different composition ratios, Mw, and Mw / Mn. Alternatively, polymers containing repeating unit a can be blended with polymers not containing repeating unit a.

[0318] [Photodegradable quenchers]

[0319] The resist material of the present invention contains a photodegradable quencher as shown in the following formula (b1).

[0320] [Chemistry 80]

[0321]

[0322] In the formula, R b It can also be an organic group with 1 to 30 carbon atoms that has substituents. M2 + It is a sulfonium cation.

[0323] (b1) is a sulfonium salt of carboxylic acid, which inhibits acid diffusion by ion exchange with the strong acid component generated by the photoacid generator.

[0324] In equation (b1), R b Preferably, it contains an aromatic cyclic group or a cyclic hydrocarbon group. More preferably, it contains an aromatic cyclic group.

[0325] In equation (b1), R b Preferably, it contains one or more iodine atoms, and more preferably, it contains two or more iodine atoms.

[0326] The photodegradable quencher shown in the aforementioned formula (b1) is a group represented by the following formula (b1-1).

[0327] [Chemistry 81]

[0328]

[0329] In the formula, R b' It can be an organic group with 1 to 22 carbon atoms, which may also have substituents, and may include ester bonds, ether bonds, amide bonds, lactone rings, sulopentalide rings, aromatic cyclic groups, aliphatic cyclic groups, hydroxyl groups, alkoxy groups, fluoroalkyl groups, nitro groups, cyano groups, trifluoromethoxy groups, carbonyl groups, amino groups, alkylamino groups, fluorine atoms, bromine atoms, or iodine atoms. M2 + It is a sulfonium cation.

[0330] In equation (b1-1), R b' Preferably, it contains aromatic cyclic groups.

[0331] In equation (b1-1), R b' Preferably, it contains one or more iodine atoms, and more preferably, it contains two or more iodine atoms.

[0332] Iodine atoms absorb EUV light strongly and can effectively generate secondary electrons from photons imparted by EUV exposure, thus promising high sensitivity and high resolution.

[0333] Specific examples of the anion portion of the aforementioned repeating units (b1) and (b1-1) can be listed below, but are not limited to these.

[0334] [Chemistry 82]

[0335]

[0336] [Chemistry 83]

[0337]

[0338] [Chemistry 84]

[0339]

[0340] [Chemistry 85]

[0341]

[0342] [Chemistry 86]

[0343]

[0344] [Chemistry 87]

[0345]

[0346] The cationic portion of the photodegradable quencher represented by the aforementioned formula (b1) may include the same cationic portion as the cationic portion exemplified as the cationic portion of the aforementioned repeating unit (a1), but is not limited to these.

[0347] M2 of the photodegradable quencher shown in the aforementioned formula (b1) + The sulfonium cation of the following formula is preferably represented by the following formula (1).

[0348] [Chemistry 88]

[0349]

[0350] In the formula, R 1 It can be a fluorine atom, an iodine atom, or a perfluoroalkyl group. R 2 R 3 Each is independently a fluorine atom or a perfluoroalkyl group. l is an integer from 0 to 3, m is an integer from 1 to 3, and n is an integer from 1 to 3. When l, m, and n are integers greater than 2, R... 1 R 2 R 3 They can be the same or different. Among them, the structure of formula (1) contains at least two fluorine atoms. Additionally, R... 2 Or R 3 When the atom is fluorine, at least one fluorine atom is meta-substituted relative to the sulfur atom.

[0351] As a photodegradable quencher as shown in the aforementioned formula (1), the sulfonium cation can be the same as the cation portion exemplified as the preferred cation portion of the repeating unit (a1) above, but is not limited to these.

[0352] Generally, compounds containing multiple iodine atoms can improve the absorption of EUV light. However, reduced solubility in casting solvents and developers can lead to deterioration of photolithography performance. If a compound contains iodine atoms in both the anionic and cationic portions of the aforementioned photodegradable quencher (b1), EUV absorption efficiency can be improved without compromising solvent solubility, thus improving photolithography performance can be expected.

[0353] The cationic portion M of the repeating unit (a1) contained in the resist composition of the present invention 1+ And the cationic portion M of the aforementioned photodegradable quencher (b1) 2+ It is preferred that all of them have the structure shown in the aforementioned formula (1). It is believed that if such a composition is used, it can increase the amount of secondary electrons generated based on EUV exposure, and can efficiently use the generated secondary electrons for acid generation, thereby improving the chemical contrast between the exposed and unexposed areas.

[0354] If the composition is like this, it becomes a resist with high sensitivity, high resolution, and small edge roughness and dimensional deviation.

[0355] [Acid generating agent]

[0356] The positive resist material of the present invention may further include an acid generator that generates a strong acid (hereinafter also referred to as an additive acid generator). The strong acid referred to herein is a compound having sufficient acidity to cause deprotection reactions of the acid-indestructible groups of the base polymer. Examples of such acid generators include, for instance, acid generators that generate acid in response to active light or radiation (photo-acid generators). Any acid generator that generates acid upon irradiation with high-energy rays can be used, but it is preferred to use an acid generator that generates sulfonic acid, imine acid, or methyl acid. Preferred photo-acid generators include sulfonium salts, sulfonyl diazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generators, etc. Specific examples of photo-acid generators include the photo-acid generators described in Japanese Patent Application Publication No. 2008-111103,

[0122] to

[0142] .

[0357] In addition, as photoacid generating agents, sulfonium salts shown in formula (1-1) and sulfonium salts shown in formula (1-2) can also be used appropriately.

[0358] [Chemistry 89]

[0359]

[0360] In equations (1-1) and (1-2), R 101 ~R 105 Each can be an independent monovalent hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms. Additionally, 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 above-mentioned monovalent hydrocarbon group can be any of the following: straight-chain, branched, or cyclic. As specific examples, groups similar to the above-mentioned groups can be given.

[0361] In equations (1-1) and (1-2), X - The anions are selected from the following formulas (1A) to (1D).

[0362] [Chemistry 90]

[0363]

[0364] In equation (1A), R fa It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain fluorine atoms or heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. As a specific example, R in formula (1A') can be cited. 107 The group that represents the hydrocarbon group and the group that is the same as the group described below.

[0365] The anion represented by formula (1A) is preferably the anion represented by formula (1A').

[0366] [Chemistry 91]

[0367]

[0368] In equation (1A'), R 106 It can be a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R 107 The hydrocarbon group may contain heteroatoms and has 1 to 38 carbon atoms. The aforementioned heteroatoms are preferably oxygen, nitrogen, sulfur, or halogen atoms, and more preferably oxygen. From the viewpoint of obtaining high resolution in the formation of fine patterns, a hydrocarbon group with 6 to 30 carbon atoms is particularly preferred.

[0369] R 107 The hydrocarbon group represented can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and eicosyl; cyclic saturated hydrocarbon groups such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornel, norbornelmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated 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.

[0370] Furthermore, some or all of the hydrogen atoms in these groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, some carbon atoms in these groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, they can contain hydroxyl, cyano, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulopentalide, carboxylic anhydride, or haloalkyl groups. Specific examples of hydrocarbon groups containing heteroatoms include tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetaminomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, and 3-oxocyclohexyl.

[0371] The synthesis of sulfonium salts containing anions represented by formula (1A') is described in detail in Japanese Patent Application Publications Nos. 2007-145797, 2008-106045, 2009-7327, and 2009-258695. Furthermore, the sulfonium salts described in Japanese Patent Application Publications Nos. 2010-215608, 2012-41320, 2012-106986, and 2012-153644 are also desirable.

[0372] As an anion represented by formula (1A), examples can be made of the same anion as the anion represented by formula (1A) in Japanese Patent Application Publication No. 2018-197853.

[0373] In equation (1B), R fb1 and R fb2 Each of the aforementioned hydrocarbon groups 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 straight-chain, branched, or cyclic. Specific examples include R in formula (1A'). 107 The same group as the one illustrated in the description. R fb1 and R fb2 Preferably, it is a fluorine atom or a straight-chain fluorinated alkyl group having 1 to 4 carbon atoms. Alternatively, R... fb1 and R fb2 They are bonded 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 and R fb2 The groups formed by mutual bonding are preferably fluorinated ethylidene or fluorinated propylene.

[0374] In equation (1C), R fc1 R fc2 and R fc3 Each of the aforementioned hydrocarbon groups 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 straight-chain, branched, or cyclic. Specific examples include R in formula (1A'). 107 The same group as the one illustrated in the description. R fc1 R fc2 and R fc3 Preferably, it is a fluorine atom or a straight-chain fluorinated alkyl group having 1 to 4 carbon atoms. Alternatively, R... fc1 and R fc2 They are bonded to each other and to the groups they are bonded to (-CF2-SO2-C) - -SO2-CF2-) together form a ring, at which point Rfc1 and R fc2 The groups formed by mutual bonding are preferably fluorinated ethylidene or fluorinated propylene.

[0375] In equation (1D), R fd It may be a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. As a specific example, R in formula (1A') can be cited. 107 The same group as the group illustrated in the description.

[0376] For details on the synthesis of sulfonium salts containing anions represented by formula (1D), please refer to Japanese Patent Application Publication Nos. 2010-215608 and 2014-133723.

[0377] As an anion represented by formula (1D), examples can be made of the same anion as the anion represented by formula (1D) in Japanese Patent Application Publication No. 2018-197853.

[0378] Furthermore, the photoacid generator containing the anion shown in formula (1D) does not contain fluorine at the α-position of the sulfonic acid group, but has two trifluoromethyl groups at the β-position, thus possessing sufficient acidity for cleaving acid-indestructible groups in the base polymer. Therefore, it can be used as a photoacid generator.

[0379] Furthermore, the substance shown in the following formula (2) can also be used as a photoacid generator.

[0380] [Chemistry 92]

[0381]

[0382] In equation (2), R 201 and R 202 Each can be an independent hydrocarbon group with 1 to 30 carbon atoms, and may also contain heteroatoms. R 203 It can also contain a hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. Additionally, R... 201 and R 202 Or R 201 and R 203 They can bond to each other and form rings together with the sulfur atoms they are bonded to. In this case, as the aforementioned ring, examples can be given of those that are represented as R in the description of equation (1-1). 101 and R 102 They can be the same rings exemplified by the rings formed by bonding and together with the sulfur atoms they are bonded to.

[0383] R 201 and R 202The hydrocarbon group represented can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, and tricyclic [5.2.1.0]. 2,6 Naphthyl, naphthylmethyl, naphthylethyl, naphthyl-n-propyl, naphthylisopropyl, naphthyl-n-butyl, naphthylisobutyl, naphthyl-sec-butyl, naphthyl-tert-butyl, anthracene, and other aryl groups are among the groups. 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. As a result, these groups can contain hydroxyl, cyano, carbonyl, ether bonds, ester bonds, sulfonate bonds, carbonate groups, lactone rings, sulfonyl lactone rings, carboxylic anhydrides, haloalkyl groups, etc.

[0384] R 203 The represented alkylene group can be saturated or unsaturated, and can be straight-chain, 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, and hexadecane-1,16-diyl. Alkyl groups such as heptadecanyl-1,17-diyl; cyclic saturated alkylene groups such as cyclopentanediyl, cyclohexanediyl, norcamphenediyl, and adamantanediyl; and aryl groups such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, sec-butylnaphthylene, and tert-butylnaphthylene. Furthermore, some or all of the hydrogen atoms in these groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms, and some of the carbon atoms in these groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, they can contain hydroxyl, cyano, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride, haloalkyl, etc. Oxygen atoms are preferred as the aforementioned heteroatoms.

[0385] In equation (2), L 1It is a hydrocarbon group with 1 to 20 carbon atoms, consisting of a single bond, an ether bond, or possibly a heteroatom. The hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include R... 203 The group represented by the alkylene group is the same group as the one exemplified by the alkylene group.

[0386] In equation (2), X A X B X C and X D Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom. Among them, X... A X B X C and X D At least one of them is a fluorine atom or a trifluoromethyl atom.

[0387] In equation (2), k is an integer from 0 to 3.

[0388] As the photoacid generator shown in formula (2), it is preferred to be the photoacid generator shown in formula (2') below.

[0389] [Chemistry 93]

[0390]

[0391] In equation (2'), L 1 Same as above. R HF 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 straight-chain, branched, or cyclic. Specific examples include R in formula (1A'). 107 The same groups are exemplified in the description. x and y are each independent integers from 0 to 5, and z is an integer from 0 to 4.

[0392] As the photoacid generator represented by formula (2), the same photoacid generator as the photoacid generator exemplified by formula (2) in Japanese Patent Application Publication No. 2017-026980 can be cited.

[0393] Among the aforementioned photoacid generators, those containing anions represented by formula (1A') or (1D) exhibit low acid diffusion and excellent solubility in resist solvents, making them particularly desirable. Furthermore, the photoacid generator represented by formula (2') exhibits extremely low acid diffusion, making it particularly desirable.

[0394] Furthermore, as the aforementioned photoacid generator, sulfonium salts or sulfonium salts having anions containing aromatic rings substituted with iodine or bromine atoms can also be used. Examples of such salts are those shown in formulas (3-1) or (3-2) below.

[0395] [Chemistry 94]

[0396]

[0397] In equations (3-1) and (3-2), p is an integer satisfying 1 ≤ p ≤ 3. q and r are integers satisfying 1 ≤ q ≤ 5, 0 ≤ r ≤ 3, and 1 ≤ q + r ≤ 5. Ideally, q should be an integer satisfying 1 ≤ q ≤ 3, preferably 2 or 3. Ideally, r should be an integer satisfying 0 ≤ r ≤ 2.

[0398] In equations (3-1) and (3-2), X BI The atoms are either iodine or bromine, and when q is 2 or more, they can be the same or different.

[0399] In equations (3-1) and (3-2), 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 an ether bond or ester bond. The aforementioned saturated hydrocarbon group can be any of the following: straight-chain, branched, or cyclic.

[0400] In equations (3-1) and (3-2), L 12 When p is 1, it is a single bond or a divalent linker with 1 to 20 carbon atoms; when p is 2 or 3, it is a trivalent or tetravalent linker with 1 to 20 carbon atoms. This linker may contain chlorine, bromine, iodine, oxygen, sulfur, or nitrogen atoms.

[0401] In equations (3-1) and (3-2), R 401 It can be a saturated hydrocarbon group with 1 to 20 carbon atoms, a saturated hydrocarbon oxy group with 1 to 20 carbon atoms, an unsaturated hydrocarbon oxy group with 2 to 20 carbon atoms, a saturated hydrocarbon oxy carbonyl group with 2 to 10 carbon atoms, a saturated hydrocarbon oxy carbonyl oxy group with 1 to 10 carbon atoms, a saturated hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms, an unsaturated hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms, or a saturated hydrocarbon sulfonyl oxy group with 1 to 20 carbon atoms, or -NR. It may also contain a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, a bromine atom, or an amino group, or may contain a fluorine atom, chlorine atom, bromine atom, hydroxyl group, amino group, carbonyl group, oxycarbonyl group, or ether bond. 401A -C(=O)-R 401B -NR 401A -C(=O)-OR 401B R 401A It is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and may also contain a halogen atom, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms. R 401BIt 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 a halogen atom, a hydroxyl group, a saturated alkyl group with 1 to 6 carbon atoms, a saturated alkyl carbonyl group with 2 to 6 carbon atoms, or a saturated alkyl carbonyl group with 2 to 6 carbon atoms. The aliphatic hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. The aforementioned saturated hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. When p and / or r is 2 or more, each R... 401 They can be the same or different.

[0402] Among them, as R 401 -NR is preferred 401A -C(=O)-R 401B -NR 401A -C(=O)-OR 401B Fluorine atoms, chlorine atoms, bromine atoms, methyl groups, methoxy groups, etc.

[0403] In equations (3-1) and (3-2), Rf 11 ~Rf 14 Each of them is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. Rf 11 、Rf 12 It can also be an oxygen atom, Rf 11 When it is an oxygen atom, Rf 12 It is also an oxygen atom, which, together with the bonded carbon atom, forms a carbonyl group. Specifically, Rf... 13 and Rf 14 Ideally, all atoms should be fluorine atoms.

[0404] In equations (3-1) and (3-2), R 402 R 403 R 404 R 405 and R 406 Each of these groups is an independent hydrocarbon group consisting of fluorine, chlorine, bromine, iodine, or possibly heteroatoms, with 1 to 20 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples can be listed and described in the explanations of formulas (1-1) and (1-2) regarding R. 101 ~R 105 The groups represented by the hydrocarbon group are the same as those exemplified by other groups. Furthermore, some or all of the hydrogen atoms in these groups may be replaced by hydroxyl, carboxyl, halogen, cyano, nitro, mercapto, sulfonyl, 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. Additionally, R... 402 and R 403They can bond to each other and form rings together with the sulfur atoms they are bonded to. In this case, as the aforementioned rings, for example, R in the description of equation (1-1) 101 and R 102 The same rings that are exemplified by the rings formed by the bonds and the sulfur atoms they are bonded to.

[0405] Furthermore, as a cation of the sulfonium salt represented by formula (3-1), examples can be given that are the same cations as those exemplified as cations of the sulfonium salt represented by formula (1-1). Additionally, as a cation of the zirconia salt represented by formula (3-2), examples can be given that are the same cations as those exemplified as cations of the zirconia salt represented by formula (1-2).

[0406] Specific examples of onium salt anions represented by formulas (3-1) or (3-2) are shown below, but are not limited to these. Furthermore, in the following formulas, X... BI Same as above.

[0407] [Chem. 95]

[0408]

[0409] [Chemistry 96]

[0410]

[0411] [Chemistry 97]

[0412]

[0413] [Chem. 98]

[0414]

[0415] [Chemistry 99]

[0416]

[0417] [Chemistry 100]

[0418]

[0419] [Chemistry 101]

[0420]

[0421] [Chemistry 102]

[0422]

[0423] [Chemistry 103]

[0424]

[0425] [Chemistry 104]

[0426]

[0427] [Chemistry 105]

[0428]

[0429] [Chemistry 106]

[0430]

[0431] [Chemistry 107]

[0432]

[0433] [Chemistry 108]

[0434]

[0435] [Chemistry 109]

[0436]

[0437] [Chemical 110]

[0438]

[0439] [Chemistry 111]

[0440]

[0441] [Chemistry 112]

[0442]

[0443] [Chemistry 113]

[0444]

[0445] [Chemistry 114]

[0446]

[0447] [Chemistry 115]

[0448]

[0449] [Chemistry 116]

[0450]

[0451] [Chemistry 117]

[0452]

[0453] [Organic solvents]

[0454] The corrosion resist material of the present invention can also be mixed with an organic solvent. As for the aforementioned organic solvent, it is not particularly limited as long as it can dissolve the above-mentioned components and the components described later. Examples of such organic solvents include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone as described in Japanese Patent Application Publication No. 2008-111103

[0144] to

[0145] ; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; and propylene glycol monomethyl ether, ethylene glycol monomethyl ether, etc. Ethers such as propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate; lactones such as γ-butyrolactone; and their mixed solvents.

[0455] In the resist material of the present invention, the content of the above-mentioned organic solvent is preferably 100 to 10,000 parts by weight, and more preferably 200 to 8,000 parts by weight, relative to 100 parts by weight of the base polymer.

[0456] [Other ingredients]

[0457] In addition to the above-mentioned components, surfactants, dissolution inhibitors, etc. can be appropriately combined and mixed according to the purpose to prepare a resist composition.

[0458] As the aforementioned surfactant, the surfactant described in paragraphs

[0165] to

[0166] of Japanese Patent Application Publication No. 2008-111103 can be cited as an example. By adding a surfactant, the coatability of the resist material can be further improved or controlled. One surfactant can be used alone or two or more surfactants can be used in combination. In the resist material of the present invention, the content of the above-mentioned surfactant is preferably 0.0001 to 10 parts by weight relative to 100 parts by weight of the base polymer.

[0459] By incorporating dissolution inhibitors, the difference in dissolution rates between the exposed and unexposed areas can be further increased, thereby further improving resolution.

[0460] Examples of the aforementioned dissolution inhibitors include compounds in which the hydrogen atoms of the phenolic hydroxyl groups of a compound having a molecular weight preferably of 100 to 1,000, more preferably 150 to 800, and containing two or more phenolic hydroxyl groups are replaced by acid-unstable groups at a ratio of 0 to 100 mol% on a total basis; or compounds in which the hydrogen atoms of the carboxyl groups of a compound containing carboxyl groups are replaced by acid-unstable groups at an average ratio of 50 to 100 mol% on a total basis. Specific examples include compounds in which the hydrogen atoms of the hydroxyl and carboxyl groups of bisphenol A, triphenol, phenolphthalein, cresol phenolic varnish, naphtholic acid, adamantane carboxylic acid, and cholic acid are replaced by acid-unstable groups, such as those described in Japanese Patent Application Publication Nos. 2008-122932,

[0155] to

[0178] .

[0461] The content of the above-mentioned dissolution inhibitor is preferably 0-50 parts by weight, more preferably 5-40 parts by weight, relative to 100 parts by weight of the base polymer. The above-mentioned dissolution inhibitor can be used alone or in combination of two or more.

[0462] In the resist composition of the present invention, a water-repellent enhancing agent for improving the water repellency of the resist surface after spin coating may also be incorporated. The aforementioned water-repellent enhancing agent can be used in immersion lithography without a top coating. Preferably, the aforementioned water-repellent enhancing agent is a polymer containing fluorinated alkyl groups, a polymer containing 1,1,1,3,3,3-hexafluoro-2-propanol residues with a specific structure, and more preferably, substances exemplified in Japanese Patent Application Publication No. 2007-297590 and Japanese Patent Application Publication No. 2008-111103. The aforementioned water-repellent enhancing agent needs to be dissolved in an organic solvent developer. The aforementioned water-repellent enhancing agent having specific 1,1,1,3,3,3-hexafluoro-2-propanol residues exhibits good solubility in the developer. As a water-repellent enhancing agent, polymers containing repeating units containing amino or amine salts are effective in preventing acid evaporation during post-exposure baking (PEB) to prevent opening defects in the hole pattern after development. The water-repellent agent can be used alone or in combination of two or more. In the corrosion-resistant material of the present invention, the content of the water-repellent agent is preferably 0 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, relative to 100 parts by weight of the base polymer.

[0463] Ethynyl alcohols may also be incorporated into the resist composition of the present invention. Examples of acetylenic alcohols include those described in Japanese Patent Application Publication No. 2008-122932,

[0179] to

[0182] . In the resist material of the present invention, the content of acetylenic alcohols is preferably 0 to 5 parts by mass relative to 100 parts by mass of the base polymer.

[0464] [Pattern Formation Method]

[0465] When the resist composition of the present invention is used in the manufacture of various integrated circuits, known photolithography techniques can be applied.

[0466] For example, the resist material of the present invention can be coated onto a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective film, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2) with a film thickness of 0.01 to 2 μm using appropriate coating methods such as spin coating, roll coating, flow coating, dip coating, spray coating, or blade coating. Pre-baking on a hot plate at 60 to 150°C for 10 seconds to 30 minutes, more preferably at 80 to 120°C for 30 seconds to 20 minutes, forms a resist film.

[0467] Then, the resist film is exposed using high-energy radiation. Examples of such high-energy radiation include ultraviolet light, far-ultraviolet light, EUV, X-rays, soft X-rays, excimer lasers, gamma rays, and synchrotron radiation. When using ultraviolet light, far-ultraviolet light, EUV, X-rays, soft X-rays, excimer lasers, gamma rays, or synchrotron radiation, a mask used to form the target pattern is employed, with an exposure dose preferably between 1 and 200 mJ / cm². 2 Around 10-100 mJ / cm² is preferable. 2 Irradiate from both sides. When using EB as a high-energy ray, the optimal exposure dose is 0.1–100 μC / cm. 2 The optimal value is approximately 0.5–50 μC / cm. 2 The pattern can be drawn directly or using a mask to form the target pattern. Furthermore, the resist material of the present invention is particularly suitable for micro-patterning using i-rays, KrF excimer lasers, ArF excimer lasers, EB, EUV, X-rays, soft X-rays, gamma rays, and synchrotron radiation, especially for micro-patterning using EB or EUV.

[0468] After exposure, PEB can be applied on a hot plate at a temperature of 50–150°C for 10–30 seconds, or more preferably at 60–130°C for 30–20 seconds.

[0469] After exposure or PEB, a developer solution containing 0.1-10% by mass, preferably 2-5% by mass, of an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), or tetrabutylammonium hydroxide (TBAH) is used. The development is performed for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, using conventional methods such as dip, immersion, or spray. In this way, the light-exposed parts dissolve in the developer solution, while the unexposed parts do not dissolve, forming a positive pattern of the target on the substrate.

[0470] Alternatively, a positive resist material containing a base polymer with acid-inhibitory groups can be used for negative development to obtain a negative pattern by developing with an organic solvent. Examples of developers used in this process 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, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl valerate, methyl butenoate, and butenoic 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, benzoyl acetate, methyl phenyl acetate, benzoyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzoyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in mixtures of two or more.

[0471] At the end of development, rinsing is performed. The rinsing solution is preferably a solution miscible with the developer but not capable of dissolving the resist film. Preferably, such a solvent is an alcohol with 3 to 10 carbon atoms, an ether compound with 8 to 12 carbon atoms, an alkane, alkene, alkyne, or aromatic solvent with 6 to 12 carbon atoms.

[0472] Specifically, examples of alcohols with 3 to 10 carbon atoms include n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentanol, neopentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-2-butanol, and so on. Dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, 1-octanol, etc.

[0473] Examples of ether compounds with 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, disec-butyl ether, di-n-pentyl ether, diisopentyl ether, disec-pentyl ether, ditert-pentyl ether, and di-n-hexyl ether.

[0474] Examples of alkanes having 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, and cyclononane. Examples of alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Examples of alkynes having 6 to 12 carbon atoms include hexyne, heptyne, and octyne.

[0475] Examples of aromatic solvents include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, and mesitylene.

[0476] Rinsing can reduce the collapse of the resist pattern and the formation of defects. Furthermore, rinsing is not always necessary; by omitting rinsing, the amount of solvent used can be reduced.

[0477] The developed hole or trench pattern can also be shrunk by heat flow, RELACS, or DSA. A shrinking agent is applied to the hole pattern, and during baking, the shrinking agent cross-links on the surface of the resist through diffusion from the resist layer via an acid catalyst, causing the shrinking agent to adhere to the sidewalls of the hole pattern. The baking temperature is preferably 70–180°C, more preferably 80–170°C, and the baking time is preferably 10–300 seconds, removing excess shrinking agent and shrinking the hole pattern.

[0478] Example

[0479] The present invention will be specifically described below with examples and comparative examples, but the present invention is not limited to the following examples.

[0480] [1] Polymer synthesis

[0481] The PAG monomers 1 to 8, representing repeating units of formula (a1), and the acid-labile monomers (ALG monomers) 1 to 4, representing repeating units of formula (a2), used in the synthesis of the polymer are described below. Furthermore, the Mw of the polymer is a polystyrene equivalent value obtained using GPC with THF as a solvent.

[0482] [Chemistry 118]

[0483]

[0484] [Chemistry 119]

[0485]

[0486] [Synthesis Example 1-1] Synthesis of Polymer 1

[0487] A 2L flask was loaded with 6.0g of PAG monomer 1, 7.9g of ALG monomer 4, 5.2g of 4-hydroxystyrene (a monomer providing the structure corresponding to repeating unit d), and 40g of THF as solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and vacuum degassing and nitrogen purging were repeated three times. After raising the temperature to room temperature, 1.2g of AIBN was added as a polymerization initiator, the temperature was raised to 60°C, and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropanol, and the precipitated white solid was filtered. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer 1. The composition of polymer 1 was determined using... 13 C-NMR and 1 H-NMR confirmed Mw and Mw / Mn were confirmed using GPC.

[0488] [Chemistry 120]

[0489]

[0490] [Synthetic Examples 1-2] Synthesis of Polymer 2

[0491] In a 2L flask, 7.1g of PAG monomer 2, 7.3g of ALG monomer 2, 5.2g of 3-hydroxystyrene as a monomer providing the structure corresponding to repeating unit d, and 40g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and the process of degassing under reduced pressure and purging with nitrogen was repeated three times. After the temperature was raised to room temperature, 1.2g of AIBN was added as a polymerization initiator, the temperature was raised to 60°C, and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropanol, and the precipitated white solid was filtered. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer 2. The composition of polymer 2 was determined using... 13 C-NMR and 1H-NMR, Mw and Mw / Mn were confirmed using GPC.

[0492] [Chemistry 121]

[0493]

[0494] [Synthetic Examples 1-3] Synthesis of Polymer 3

[0495] 7.8 g of PAG monomer 3, 7.9 g of ALG monomer 3, 5.8 g of 4-hydroxy-3-methylstyrene (as a monomer providing the structure corresponding to repeating unit d), and 40 g of THF as a solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under a nitrogen atmosphere, and the process of degassing under reduced pressure and purging with nitrogen was repeated three times. After the temperature was raised to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 °C, and the reaction was carried out for 15 hours. This reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer 3. The composition of polymer 3 was determined using... 13 C-NMR and 1 H-NMR confirmed Mw and Mw / Mn were confirmed using GPC.

[0496] [Chemistry 122]

[0497]

[0498] [Synthetic Examples 1-4] Synthesis of Polymer 4

[0499] In a 2L flask, 9.8g of PAG monomer 4, 8.1g of ALG monomer 2, 4.4g of 3-hydroxystyrene as a monomer providing the structure corresponding to repeating unit d, and 40g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and the process of degassing under reduced pressure and purging with nitrogen was repeated three times. After the temperature was raised to room temperature, 1.2g of AIBN was added as a polymerization initiator, the temperature was raised to 60°C, and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropanol, and the precipitated white solid was filtered. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer 4. The composition of polymer 4 was determined using... 13 C-NMR and 1 H-NMR confirmed Mw and Mw / Mn were confirmed using GPC.

[0500] [Chemistry 123]

[0501]

[0502] [Synthetic Examples 1-5] Synthesis of Polymer 5

[0503] In a 2L flask, 9.1g of PAG monomer 5, 8.1g of ALG monomer 2, 5.2g of 4-hydroxy-3-methylstyrene (as a monomer providing the structure corresponding to repeating unit d), and 40g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and the process of degassing under reduced pressure and purging with nitrogen was repeated three times. After the temperature was raised to room temperature, 1.2g of AIBN was added as a polymerization initiator, the temperature was raised to 60°C, and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropanol, and the precipitated white solid was filtered. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer 5. The composition of polymer 5 was determined using... 13 C-NMR and 1 H-NMR confirmed Mw and Mw / Mn were confirmed using GPC.

[0504] [Chemistry 124]

[0505]

[0506] [Synthetic Examples 1-6] Synthesis of Polymer 6

[0507] In a 2L flask, 12.2g of PAG monomer 6, 10.7g of ALG monomer 1, 4.4g of 3-hydroxystyrene as a monomer providing the structure corresponding to repeating unit d, and 40g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and the process of degassing under reduced pressure and purging with nitrogen was repeated three times. After the temperature was raised to room temperature, 1.2g of AIBN was added as a polymerization initiator, the temperature was raised to 60°C, and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropanol, and the precipitated white solid was filtered. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer 6. The composition of polymer 6 was determined using... 13 C-NMR and 1 H-NMR confirmed Mw and Mw / Mn were confirmed using GPC.

[0508] [Chemistry 125]

[0509]

[0510] [Synthetic Examples 1-7] Synthesis of Polymer 7

[0511] 12.1 g of PAG monomer 7, 8.1 g of ALG monomer 2, 4.4 g of 3-hydroxystyrene (as a monomer providing the structure corresponding to repeating unit d), and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under a nitrogen atmosphere, and the process of degassing under reduced pressure and purging with nitrogen was repeated three times. After the temperature was raised to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 °C, and the reaction was carried out for 15 hours. This reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer 7. The composition of polymer 7 was determined using... 13 C-NMR and 1 H-NMR confirmed Mw and Mw / Mn were confirmed using GPC.

[0512] [Chemistry 126]

[0513]

[0514] [Synthetic Examples 1-8] Synthesis of Polymer 8

[0515] 12.2 g of PAG monomer 8, 8.1 g of ALG monomer 2, 4.4 g of 3-hydroxystyrene (as a monomer providing the structure corresponding to repeating unit d), and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under a nitrogen atmosphere, and the process of degassing under reduced pressure and purging with nitrogen was repeated three times. After the temperature was raised to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 °C, and the reaction was carried out for 15 hours. This reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer 8. The composition of polymer 8 was determined using... 13 C-NMR and 1 H-NMR confirmed Mw and Mw / Mn were confirmed using GPC.

[0516] [Chemistry 127]

[0517]

[0518] [Synthetic Examples 1-9] Comparative Synthesis of Polymer 1

[0519] Comparative polymer 1 was obtained by means of the same method as in Synthetic Examples 1-2, except that PAG monomer 2 was not used. The composition of comparative polymer 1 was determined using... 13 C-NMR and 1 H-NMR confirmed Mw and Mw / Mn were confirmed using GPC.

[0520] [Chemistry 128]

[0521]

[0522] [Examples 1-46, Comparative Examples 1-26]

[0523] In a solvent containing 50 ppm of Omnova's surfactant Polyfox636, each component was dissolved according to the compositions shown in Tables 1-5. The resulting solution was filtered through a 0.2 μm filter to prepare a positive resist material.

[0524] The components in Tables 1-5 are as follows.

[0525] Organic solvents: PGMEA (propylene glycol monomethyl ether acetate), DAA (diacetone alcohol)

[0526] EL (ethyl lactate)

[0527] Quenching agent: Q-1~12

[0528] • PAG: PAG-1

[0529] [Chemistry 129]

[0530]

[0531] [EUV Exposure Evaluation]

[0532] The photoresist materials shown in Tables 1 to 5 were spin-coated onto a Si substrate with a silicon-containing spin-coated hard mask SHB-A940 (Si content 43% by mass) with a film thickness of 20 nm. A 40 nm thick photoresist film was fabricated by pre-baking at 105°C for 60 seconds using a hot plate. An LS pattern with a pitch of 36 nm was exposed on the wafer using an ASML EUV scanner NXE34000 (NA 0.33, σ 0.9 / 0.6, dipole illumination). PEB was performed on the hot plate at the temperature specified in Table 1 for 60 seconds, followed by development with a 2.38% by mass TMAH aqueous solution for 30 seconds to form an 18 nm LS pattern. The resulting pattern was observed using a Hitachi Advanced Technology Co., Ltd. length measurement SEM (CG6300), and the sensitivity and LWR were evaluated according to the following methods.

[0533] [Sensitivity Evaluation]

[0534] Find the optimal exposure E for obtaining an LS pattern with a linewidth of 18nm and a pitch of 36nm. op (mJ / cm 2 This value is used as the sensitivity. The smaller the value, the higher the sensitivity.

[0535] [LWR Evaluation]

[0536] For E op The LS pattern obtained by irradiation is used to measure the dimensions of 10 locations along the length of the line. The standard deviation (σ) of the results is calculated as three times the value (3σ) as the LWR. The smaller this value, the smaller the roughness and the more uniform the line width of the pattern.

[0537] [Table 1]

[0538]

[0539]

[0540] [Table 2]

[0541]

[0542]

[0543] [Table 3]

[0544]

[0545]

[0546] [Table 4]

[0547]

[0548]

[0549] [Table 5]

[0550]

[0551]

[0552] Based on the results in Tables 1-5, the resist compositions of Comparative Examples 1-26, which do not have the structure represented by Formula (1) in either the polymer portion or the quencher portion, are determined to be ×. On the other hand, the resist compositions of the present invention, which have the structure represented by Formula (1) in at least one of the polymer portion and the quencher portion, exhibit good sensitivity and LWR performance, showing that they are suitable as materials for EUV lithography. Furthermore, Examples 19-46, which have the structure represented by Formula (1) in both the polymer portion and the quencher portion, are determined to be ◎, showing particularly excellent performance.

[0553] This specification includes the following inventions.

[0554] [1]: A photoresist composition comprising a resin (A), a photodegradable quencher represented by formula (b1) below, and an organic solvent, wherein the resin (A) contains a repeating unit represented by formula (a1) that generates acid upon exposure, wherein M1 in formula (a1) + M2 in the above formula (b1) + At least one of them is a sulfonium cation as shown in formula (1) below.

[0555] [Chemistry 130]

[0556]

[0557] In the formula, R a1 Each is independently a hydrogen atom or a methyl group, Z1 a1 It is a single bond or an ester bond, Z2 a1 Rf is a divalent organic group with 1 to 20 carbon atoms, which may also include ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, or iodine atoms. 1 ~Rf 4 Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom, but Rf 1 ~Rf 4 At least one of them is a fluorine atom, M1 + It is a sulfonium cation.

[0558] [Chemistry 131]

[0559]

[0560] In the formula, R b M2 can also be an organic group with 1 to 30 carbon atoms that has substituents. + It is a sulfonium cation.

[0561] [Chemistry 132]

[0562]

[0563] In the formula, R 1 R is a fluorine atom, an iodine atom, or a perfluoroalkyl group. 2 R 3 Each is independently a fluorine atom or a perfluoroalkyl group, where l is an integer from 0 to 3, m is an integer from 1 to 3, and n is an integer from 1 to 3. When l, m, and n are integers greater than 2, R... 1 R 2 R 3 They can be the same or different, but the structure of formula (1) contains at least two fluorine atoms. In addition, R 2 Or R 3 When the atom is fluorine, at least one fluorine atom is meta-substituted relative to the sulfur atom.

[0564] [2]: The resist composition as in [1], wherein the photodegradable quencher shown in formula (b1) is the photodegradable quencher shown in formula (b1-1) below.

[0565] [Chemistry 133]

[0566]

[0567] In the formula, R b' It can be an organic group with 1 to 22 carbon atoms that may also have substituents, and may also include ester bonds, ether bonds, amide bonds, lactone rings, sulopentalide rings, aromatic cyclic groups, aliphatic cyclic groups, hydroxyl groups, alkoxy groups, fluoroalkyl groups, nitro groups, cyano groups, trifluoromethoxy groups, carbonyl groups, amino groups, alkylamino groups, fluorine atoms, bromine atoms, or iodine atoms, M2 + It is a sulfonium cation.

[0568] [3]: The resist composition as in [1] and [2], wherein the resin (A) is a resin that further contains repeating units as shown in the following formula (a2),

[0569] [Chemistry 134]

[0570]

[0571] In the formula, R A Each can be independently a hydrogen atom or a methyl group, Y 1 R is a single bond, a phenylene or naphthylene group, or a linking group having 1 to 12 carbon atoms, an ester bond, an ether bond, or a lactone ring. 11 It is an acid-labile group.

[0572] [4]: The resist composition of any one of [1] to [3], wherein the repeating unit shown in formula (a1) is the repeating unit shown in formula (a1-1) below.

[0573] [Chemistry 135]

[0574]

[0575] In the formula, R a1 Each is independently a hydrogen atom or a methyl group, Z1 a1 L1 is a single bond or an ester bond, which may also contain a divalent linker including an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom. L2 is a single bond or may also contain a divalent linker including an ester bond or an ether bond. Rf 1 ~Rf 4 Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom, but Rf 1 ~Rf 4 At least one of them is a fluorine atom, k is an integer from 0 to 4, M1 + It is a sulfonium cation.

[0576] [5]: The resist composition of any one of [1] to [4], wherein the repeating unit shown in formula (a1) is the repeating unit shown in formula (a1-2) below.

[0577] [Chemistry 136]

[0578]

[0579] In the formula R a1 Each is independently a hydrogen atom or a methyl group; L1 is a single bond or may contain a divalent linking group such as an ester bond, ether bond, lactone ring, aromatic ring, fluorine atom, bromine atom, or iodine atom; L2 is a single bond or may contain a divalent linking group such as an ester bond or ether bond; Rf 1 ~Rf 4 Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom, but Rf 1 ~Rf 4 At least one of them is a fluorine atom, k is an integer from 0 to 4, M1 + It is a sulfonium cation.

[0580] [6]: The resist composition of any one of [1] to [5], wherein the anionic part of formula (a1) and formula (b1) contains iodine atoms.

[0581] [7]: A resist composition as described in any of [1] to [6], wherein M1 of the above formula (a1) is... + M2 of formula (b1) + All are sulfonium cations as shown in formula (1).

[0582] [8]: The composition of the resist as in any of [1] to [7], wherein in formula (1), l is an integer from 1 to 3.

[0583] [9]: The resist composition of any one of [1] to [8], wherein the cation represented by formula (1) contains iodine atoms.

[0584]

[10] : A pattern forming method, characterized by comprising the following steps:

[0585] A resist film is formed on the substrate using a resist composition such as any one of [1] to [9];

[0586] The resist film was exposed to high-energy rays; and

[0587] The exposed resist film was developed using a developer.

[0588]

[11] : The pattern forming method as in

[10] , wherein the high-energy rays used in the exposure step are i-rays, KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet rays with wavelengths of 3 to 15 nm.

[0589] Furthermore, the present invention is not limited to the embodiments described above. The embodiments described above are illustrative examples, and any technical solutions having substantially the same structure and achieving the same effect as those described in the claims of the present invention are included within the technical scope of the present invention.

Claims

1. A resist composition comprising a resin (A) containing a repeating unit represented by the following formula (al) which generates an acid by exposure, a photodecomposable quencher represented by the following formula (bl), and an organic solvent, characterized in that: the formula (bl) is a photodecomposable quencher represented by the following formula (bl-1), at least one of M1in the formula (a1) + M2in the formula (b1) + is a sulfonium cation represented by the following formula (1), wherein R a1 each independently is a hydrogen atom or a methyl group, Z1 a1 is a single bond or an ester bond, Z2 a1 is a single bond or also can contain an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom of a divalent organic group having a carbon number of 1 to 20, Rf 1 ~ Rf 4 each independently is a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of Rf 1 ~ Rf 4 is a fluorine atom, M1 + is a sulfonium cation, wherein R b is an organic group having a carbon number of 1 to 30 which can also have a substituent, M2 + is a sulfonium cation, wherein R 1 is a fluorine atom, an iodine atom or a perfluoroalkyl group, R 2 , R 3 each independently is a fluorine atom or a perfluoroalkyl group, 1 is an integer of 0 to 3, m is an integer of 1 to 3, n is an integer of 1 to 3, and in the case where 1, m and n are integers of 2 or more, R 1 , R 2 , R 3 each can be the same or different, but the structure of formula (1) contains at least 2 or more fluorine atoms, and in addition, R 2 or R 3 is a fluorine atom, at least one fluorine atom is substituted in the meta position with respect to the sulfur atom.

2. The resist composition according to claim 1, wherein, the formula (bl) is a photodecomposable quencher represented by the following formula (bl-1), wherein R b' is an organic group having a carbon number of 1 to 22 which can also have a substituent, and can also contain an ester bond, an ether bond, an amide bond, a lactone ring, a sultone ring, an aromatic cyclic group, an aliphatic cyclic group, a hydroxyl group, an alkoxy group, a fluoroalkyl group, a nitro group, a cyano group, a trifluoromethoxy group, a carbonyl group, an amino group, an alkylamino group, a fluorine atom, a bromine atom, or an iodine atom, M2 + is a sulfonium cation.

3. The resist composition according to claim 1, wherein, the resin (A) is a resin further containing a repeating unit represented by the following formula (a2), wherein R A each independently is a hydrogen atom or a methyl group, Y 1 is a single bond, a phenylene group or a naphthylene group, or a linking group having a carbon number of 1 to 12 having an ester bond, an ether bond or a lactone ring, R 11 is an acid-labile group.

4. The resist composition according to claim 1, wherein, the formula (al) is a repeating unit represented by the following formula (al-1), in the formula, R a1 each independently is a hydrogen atom or a methyl group, Z1 a1 is a single bond or an ester bond, L1is a single bond or a divalent linking group which can also include an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom, L2is a single bond or a divalent linking group which can also include an ester bond, an ether bond, Rf 1 ~Rf 4 each independently is a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of Rf 1 ~Rf 4 is a fluorine atom, k is an integer of 0 to 4, M1 + is a sulfonium cation.

5. The resist composition according to claim 1, wherein, the formula (al) is a repeating unit represented by the following formula (al-2), wherein R a1 each independently is a hydrogen atom or a methyl group, L1is a single bond or a divalent linking group which can also include an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom, L2is a single bond or a divalent linking group which can include an ester bond, an ether bond, Rf 1 ~Rf 4 each independently is a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of Rf 1 ~Rf 4 is a fluorine atom, k is an integer of 0 to 4, M1 + is a sulfonium cation.

6. The resist composition according to claim 1, wherein, the anion part of the formula (al) and the formula (bl) contains an iodine atom.

7. The resist composition according to claim 1, wherein M1 of formula (a1) + and M2 of formula (b1) + are both sulfonium cations of formula (1).

8. The resist composition according to claim 1, wherein, in the formula (1), 1 is an integer of 1 to 3.

9. The resist composition according to claim 1, wherein, the cation represented by the formula (1) contains an iodine atom.

10. A pattern forming process characterized by comprising: a step of forming a resist film on a substrate using the resist composition according to any one of claims 1 to 9; a step of exposing the resist film to high-energy rays; and a step of developing the exposed resist film using a developer.

11. The pattern forming process according to claim 10, wherein the high-energy rays used in the exposing step are i-rays, a KrF excimer laser, an ArF excimer laser, an electron beam, or an extreme ultraviolet ray having a wavelength of 3 to 15 nm.

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