Sulfonium salt, chemically amplified resist composition and pattern forming method

Abstract

The invention relates to a sulfonium salt, a chemically amplified resist composition and a pattern forming method. The present invention addresses the problem of providing an optical lithography using high-energy rays, the present invention relates to an onium salt used in a chemically amplified resist composition having excellent solvent solubility, high sensitivity, high contrast, and excellent lithography performance such as LWR, CDU, MEF, EL, and DOF, a chemically amplified resist composition containing the onium salt as a photoacid generator, and a pattern forming method using the chemically amplified resist composition. [Solution] A sulfonium salt comprising an aromatic sulfonic acid anion represented by formula (1A) and a sulfonium cation represented by formula (1B).

Description

Technical Field

[0001] This invention relates to matte salts, chemically amplified resist compositions, and methods for pattern formation. Background Technology

[0002] In recent years, with the increasing integration and speed of LSI, there is a demand for miniaturized and regular patterns. Among these, far-ultraviolet lithography and extreme ultraviolet (EUV) lithography are considered promising for next-generation microfabrication technologies.

[0003] ArF lithography, using ArF excimer lasers, was partially adopted starting with the fabrication of devices at the 130nm node and became the mainstream lithography technology from the 90nm node. As a subsequent lithography technology for the 45nm node, lithography using the 157nm F2 laser was initially considered promising. However, due to numerous problems causing development delays and criticism, ArF immersion lithography was practically implemented by inserting liquids with higher refractive indices than air, such as water, ethylene glycol, or glycerol, between the projection lens and the wafer. This allowed for the design of projection lenses with an aperture number (NA) of 1.0 or higher. This enabled high-resolution ArF immersion lithography. This immersion lithography requires a resist composition that is not easily dissolved in water.

[0004] In ArF lithography, to prevent the degradation of delicate and expensive optical system materials, a high-sensitivity resist composition capable of achieving sufficient resolution with low exposure is required. As a method to achieve this, the most common approach, in terms of composition, is to choose a highly transparent resist at a wavelength of 193 nm. For example, some researchers have proposed base polymers such as polyacrylic acid and its derivatives, norcamphene-maleic anhydride crosspolymers, polynorcamphene, ring-opening metathesis polymers, and ring-opening metathesis polymer hydrides, which have achieved some success in improving the transparency of the resin monomers.

[0005] In recent years, along with positive tone resists developed using alkaline aqueous solutions, negative tone resists developed using organic solvents have also received attention. To resolve extremely fine aperture patterns that cannot be achieved with positive tone exposure, negative patterns are formed by using a high-resolution positive resist composition and developing it with an organic solvent. Furthermore, research is underway to achieve twice the resolution through a two-stage development process combining alkaline aqueous solution development and organic solvent development. Known positive ArF resist compositions can be used as negative tone development compositions using organic solvents, and pattern formation methods using these compositions are described in Patent Documents 1-3.

[0006] To keep pace with the rapid miniaturization and processing technology advancements in recent years, the development of photoresist compositions has also progressed significantly. Various studies are underway on photoacid generators, typically using sulfonium salts composed of triphenylsulfonium cations and perfluoroalkyl sulfonate anions. However, perfluoroalkyl sulfonates, particularly perfluorooctane sulfonate (PFOS), have concerns regarding their poor biocompatibility, bioconcentration potential, and toxicity, making them unsuitable for use in photoresist compositions. Currently, photoacid generators that produce perfluorobutane sulfonate are used. However, when used in photoresist compositions, the resulting acid diffuses significantly, making it difficult to achieve high resolution. To address this problem, various partially fluorinated alkyl sulfonic acids and their salts have been developed. For example, Patent Document 1 describes a photoacid generator that produces α,α-difluoroalkyl sulfonic acid upon exposure, specifically a photoacid generator that produces 1,1-difluoro-2-(1-naphthyl)ethanesulfonic acid di(4-tert-butylphenyl)monazine and α,α,β,β-tetrafluoroalkyl sulfonic acid. However, although these all involve a decrease in fluorine substitution rate, they lack decomposable substituents such as ester structures, making them unsatisfactory from the perspective of environmental safety due to their easy decomposition. Furthermore, they limit their use in molecular design to change the size of alkyl sulfonic acids, and they also encounter problems such as the high cost of starting materials containing fluorine atoms.

[0007] Furthermore, with the shrinking of circuit linewidths, the contrast degradation caused by acid diffusion in the resist composition becomes more severe. This is because the pattern size approaches the acid diffusion length, increasing the dimensional offset on the wafer relative to the mask size offset (mask error factor (MEF)). This leads to decreased mask fidelity and deterioration of pattern rectangularity. Therefore, to fully realize the advantages brought by shorter wavelengths and higher photosensitive elements (NAs) of the light source, it is necessary to significantly increase the dissolution contrast or suppress acid diffusion compared to known materials. As one improvement method, lowering the baking temperature reduces acid diffusion, thereby improving MEF, but inevitably leads to a decrease in sensitivity.

[0008] Introducing sterically hindered substituents and polar groups into photoacid generators is effective in suppressing acid diffusion. Patent Document 4 describes a photoacid generator containing 2-acyloxy-1,1,3,3,3-pentafluoropropane-1-sulfonic acid, which exhibits excellent solvent solubility and stability and allows for extensive molecular design. In particular, a photoacid generator containing 2-(1-adamantoxy)-1,1,3,3,3-pentafluoropropane-1-sulfonic acid with sterically hindered substituents exhibits low acid diffusion. Furthermore, Patent Documents 5-7 describe photoacid generators incorporating condensed ring lactones, sulfonyl lactones, and thiolactones as polar groups. While it has been confirmed that the acid diffusion suppression effect brought about by the introduction of polar groups has a certain degree of performance improvement, the control over the degree of acid diffusion is still insufficient. Considering factors such as MEF, pattern shape, and sensitivity, these generators are not suitable for photolithography performance.

[0009] Introducing polar groups into the anions of photoacid generators is effective in suppressing acid diffusion, but it becomes detrimental from the viewpoint of solvent solubility. Patent documents 8 and 9, in order to improve solvent solubility, attempts were made to introduce alicyclic groups into the cationic portion of the photoacid generator to ensure solvent solubility; specifically, cyclohexane rings and adamantane rings were introduced. While such introduction of alicyclic groups improves solubility, a certain number of carbon atoms is required to ensure solubility. As a result, the molecular structure of the photoacid generator becomes bulky, thus degrading photolithographic performance such as linewidth roughness (LWR) and dimensional uniformity (CDU) during fine pattern formation.

[0010] Furthermore, Patent Document 10 describes a photoacid generator that produces an anion of fluoroalkyl sulfonic acid having an aromatic condensation ring derived from anthracene. This confirms a certain degree of improvement in photolithography performance; however, the alkylsulfonic acid structure lacks rigidity, and in recent years, organofluorine compounds targeted by PFAS have been increasingly restricted, raising concerns about their environmental and human health impacts.

[0011] Iodine atoms exhibit significant absorption at EUV wavelengths of 13.5 nm, thus confirming the effect of generating secondary electrons from iodine atoms during exposure, which has attracted attention in EUV lithography. Patent Document 11 describes a photoacid generator in which iodine atoms are introduced into anions, and Patent Document 12 describes a photoacid generator containing polymerizable groups in which iodine atoms are introduced into anions. Patent Document 13 describes a photoacid generator in which iodine atoms are introduced into both cations and anions. This confirms a certain degree of improvement in photolithography performance, but the low solubility of iodine atoms in organic solvents raises concerns about precipitation in solvents.

[0012] Patent document 14 describes a photoacid generator in which multiple fluorine atoms are introduced into the cation. Due to the introduction of multiple fluorine atoms, the solvent solubility of the photoacid generator is improved, but it is not perfect from the viewpoint of EUV absorption and there is room for improvement.

[0013] Patent documents 15-19 describe photoacid generators and quenchers (acid diffusion control agents) containing iodine and fluorine atoms in their cations. It has been confirmed that these developments have improved the performance of photoresist materials, but from the viewpoint of acid diffusion control, they are not satisfactory, and further development of photoresist materials useful for forming fine patterns is needed.

[0014] Existing technical documents

[0015] Patent documents

[0016] [Patent Document 1] Japanese Patent Application Publication No. 2008-281974

[0017] [Patent Document 2] Japanese Patent Application Publication No. 2008-281975

[0018] [Patent Document 3] Japanese Patent No. 4554665

[0019] [Patent Document 4] Japanese Patent Application Publication No. 2007-145797

[0020] [Patent Document 5] Japanese Patent No. 5061484

[0021] [Patent Document 6] Japanese Patent Application Publication No. 2016-147879

[0022] [Patent Document 7] Japanese Patent Application Publication No. 2015-63472

[0023] [Patent Document 8] Japanese Patent No. 5573098

[0024] [Patent Document 9] Japanese Patent No. 6461919

[0025] [Patent Document 10] Japanese Patent No. 7109178

[0026] [Patent Document 11] Japanese Patent No. 6720926

[0027] [Patent Document 12] Japanese Patent No. 6973274

[0028] [Patent Document 13] Japanese Patent No. 7041204

[0029] [Patent Document 14] Japanese Patent No. 7389562

[0030] [Patent Document 15] Japanese Patent Application Publication No. 2021-123579

[0031] [Patent Document 16] Japanese Patent Application Publication No. 2021-123580

[0032] [Patent Document 17] Japanese Patent Application Publication No. 2022-123839

[0033] [Patent Document 18] Japanese Patent Application Publication No. 2023-88869

[0034] [Patent Document 19] Japanese Patent Application Publication No. 2023-88870

[0035] Non-patent literature

[0036] [Non-patent literature 1] Journal of Photopolymer Science and Technology, Vol.17, No.4, pp.587-601 (2004) Summary of the Invention

[0037] (The problem the invention aims to solve)

[0038] In response to the high resolution requirements of resist patterns in recent years, resist compositions using known onium salt-type photoacid generators cannot adequately suppress acid diffusion. As a result, lithographic performance such as contrast, LWR, CDU, MEF, exposure margin (EL), and depth of focus (DOF) is sometimes degraded.

[0039] In view of the foregoing, the present invention aims to provide an onium salt used in a chemical amplifying resist composition that exhibits excellent solvent solubility, high sensitivity, high contrast, and excellent lithographic performance such as LWR, CDU, MEF, EL, and DOF in optical lithography, particularly using high-energy rays such as KrF excimer lasers, ArF excimer lasers, electron beams (EB), and EUV; a chemical amplifying resist composition containing the onium salt as a photoacid generator; and a patterning method using the chemical amplifying resist composition.

[0040] (Methods for solving problems)

[0041] The inventors of this application have made repeated efforts to achieve the aforementioned objectives. As a result, they discovered that a sulfonate salt composed of an aromatic sulfonic acid anion substituted with a hydrocarbon group containing at least one aromatic ring and a sulfonate cation having a pentafluorosulfonium group and a hydrocarbon carbonyl group has excellent solvent solubility. When used as a photoacid generator, the chemical amplification resist composition has high sensitivity and high contrast, is extremely effective in suppressing acid diffusion, and exhibits excellent photolithography performance such as LWR, CDU, MEF, EL, and DOF. It is also extremely effective in forming fine patterns, thus completing this invention.

[0042] That is, the present invention provides the following matte salt, chemically amplified resist composition and pattern formation method.

[0043] 1. A sulfonium salt comprising an aromatic sulfonic acid anion represented by formula (1A) and a sulfonium cation represented by formula (1B),

[0044] [Chemistry 1]

[0045]

[0046] In the formula, m1 is 0 or 1, m2 is 0, 1, 2, 3 or 4, m3 is 0, 1, 2, 3 or 4, but when m1 is 0, 0 ≤ m2 + m3 ≤ 4, when m1 is 1, 0 ≤ m2 + m3 ≤ 6, and m4 is 0 or 1.

[0047] W is a hydrocarbon group with 6 to 40 carbon atoms containing at least one aromatic ring; this hydrocarbon group may also contain heteroatoms.

[0048] R F1When m2 is 2, 3, or 4, each R F1 They can be the same or different.

[0049] R 1 The R group can be a halogen atom other than fluorine, a nitro group, a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. When m3 is 2, 3, or 4, each R group... 1 They can be the same or different, multiple Rs 1 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0050] L A and L B Each bond can be independently a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond.

[0051] X L It can be a single bond, or it may contain a hydrocarbon group with 1 to 40 carbon atoms and heteroatoms.

[0052] [Chemistry 2]

[0053]

[0054] In the formula, n1 is 0 or 1, n2 is 0, 1 or 2, n3 is 0, 1 or 2, n4 is 0, 1 or 2, but when n1 is 0, 0 ≤ n2 + n3 + n4 ≤ 5, and when n1 is 1, 0 ≤ n2 + n3 + n4 ≤ 7; n5 is 0 or 1, n6 is 0, 1 or 2, n7 is 0, 1 or 2, and n8 is 0, 1 or 2, but when n5 is 0, 0 ≤ n6 + n7 + n8 ≤ 5. When n5 is 1, 0 ≤ n6 + n7 + n8 ≤ 7; n9 is 0 or 1; n10 is 0, 1, or 2; n11 is 0, 1, or 2; and n12 is 0, 1, or 2. However, when n9 is 0, 0 ≤ n10 + n11 + n12 ≤ 5; when n9 is 1, 0 ≤ n10 + n11 + n12 ≤ 7. Also, 1 ≤ n2 + n6 + n10 ≤ 6, and 1 ≤ n3 + n7 + n11 ≤ 6.

[0055] R 11 R 12 and R 13 Each can be an independent hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. When n3 is 2, each R 11 They can be the same or different. When n7 is 2, each R 12 They can be the same or different. When n11 is 2, each R 13 They can be the same or different.

[0056] R14 R 15 and R 16 Each can independently be a halogen atom, nitro group, hydroxyl group, carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms, and when n4 is 2, each R 14 They can be the same or different, 2 Rs 14 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When n8 is 2, each R 15 They can be the same or different, 2 Rs 15 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When n12 is 2, each R 16 They can be the same or different, 2 Rs 16 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0057] Furthermore, the bond is to S + Two of the three aromatic rings can also bond to each other and form a ring together with the sulfur atoms they are bonded to.

[0058] 2. As in 1., a sulfite salt, where W is represented by the formula (W-1) or (W-2).

[0059] [Chemistry 3]

[0060]

[0061] In the formula, m5 is 0 or 1, m6 is 0, 1, 2, 3 or 4, m7 is 1, 2, 3 or 4, m8 is 0 or 1, m9 is 0 or 1, m10 is 0, 1, 2, 3 or 4, and m11 is 0, 1, 2, 3 or 4.

[0062] R 2 Each is independently a halogen atom other than a hydrogen atom or an iodine atom, or may contain a hydrocarbon group with 1 to 20 carbon atoms and heteroatoms.

[0063] R 3 and R 4 Each is independently a hydrogen atom, a halogen atom, or may contain a hydrocarbon group with 1 to 20 carbon atoms and heteroatoms.

[0064] R 5 ~R 9 Each can be an independent hydrocarbon group consisting of hydrogen atoms, halogen atoms, or may contain heteroatoms and have 1 to 40 carbon atoms.

[0065] The dashed line represents L. A Atomic bonds.

[0066] 3. A sulfonium salt such as 1. or 2, wherein the anion is represented by the following formula (1A-1),

[0067] [Chemistry 4]

[0068]

[0069] In the formula, m1~m4, W, R F1 R 1 and L A As mentioned above.

[0070] 4. A sulfonium salt as described in any of 1. to 3, wherein the cation is represented by the following formula (1B-1).

[0071] [Chemistry 5]

[0072]

[0073] In the formula, n2~n4, n6~n8, n10~n12 and R 11 ~R 16 As mentioned above.

[0074] 5. A photoacid generator, comprising a sulfonium salt of any one of 1. to 4.

[0075] 6. A chemically amplified resist composition comprising, for example, a photoacid generator as described in 5.

[0076] 7. The chemically amplified resist composition as described in 6. further comprises a base polymer containing a polymer having repeating units represented by formula (a1) or (a2).

[0077] [Chemistry 6]

[0078]

[0079] In the formula, R A Each is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0080] X 1 It is a single bond, phenylene, naphthylene, or *-C(=O)-OX 11 - The phenylene or naphthylene group may also be replaced by a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbon group with 1 to 10 carbon atoms containing a fluorine atom, a saturated hydroxyl group with 1 to 10 carbon atoms containing a fluorine atom, or a halogen atom. X 11 It is a saturated hydrocarbon group, phenylene group, or naphthylene group having 1 to 10 carbon atoms. This saturated hydrocarbon group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring.

[0081] X 2 It is a single bond or *-C(=O)-O-.

[0082] * indicates an atomic bond with a carbon atom in the main chain.

[0083] R 21 The group can be a halogen atom, cyano group, hydroxyl group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms containing heteroatoms; or a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms containing heteroatoms. When a1 is 2, 3, or 4, each R... 21 They can be the same or different.

[0084] AL 1 and AL 2 Each is an independent acid-labile group.

[0085] a1 can be 0, 1, 2, 3 or 4.

[0086] 8. A chemically amplified resist composition as described in 7, wherein the polymer contains repeating units represented by the following formula (a3),

[0087] [Chemistry 7]

[0088]

[0089] In the formula, b1 is 0 or 1, and b2 is 0, 1, 2 or 3 when b1 is 0, and 0, 1, 2, 3, 4 or 5 when b1 is 1.

[0090] R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0091] X 3 It is a single bond, *-C(=O)-O- or *-C(=O)-NH-, where * indicates an atomic bond with a carbon atom in the main chain.

[0092] X 4 A group obtained by means of a single bond, an aliphatic alkylene group, a carbonyl group, a sulfonyl group, or a combination thereof, having 1 to 4 carbon atoms.

[0093] X 5 and X 6 Each can be independently an oxygen atom or a sulfur atom, but X 4 and X 6 It is an adjacent carbon atom bonded to the aromatic ring.

[0094] R 22 and R 23 Each is an independent hydrocarbon group consisting of 1 to 20 carbon atoms, or may contain heteroatoms; also, R 22 and R 23 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0095] R 24 It can be a halogen atom, hydroxyl group, cyano group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon oxycarbonyl group with 2 to 20 carbon atoms containing heteroatoms; or it can be a hydrocarbon thio group or -N(R) group with 1 to 20 carbon atoms containing heteroatoms. 24A (R) 24B ), R 24A and R 24B Each is independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms; when b2 is 2 or more, each R 24 They can be the same or different, multiple Rs 24 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0096] 9. A chemically amplified resist composition as described in 7 or 8, wherein the polymer contains repeating units represented by formula (b1) or (b2).

[0097] [Chemistry 8]

[0098]

[0099] In the formula, R A Each is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0100] Y 1 It represents a single bond or *-C(=O)-O-, where * indicates an atomic bond with a carbon atom in the main chain.

[0101] R 31 It is a hydrogen atom, or a group containing at least one of the following structures with 1 to 20 carbon atoms: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulcinolone ring, and carboxylic anhydride (-C(=O)-OC(=O)-).

[0102] R 32 The group can be a halogen atom, carboxyl group, nitro group, cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms containing heteroatoms; or a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms containing heteroatoms. When c2 is 2, 3, or 4, each R... 32 They can be the same or different.

[0103] c1 can be 1, 2, 3 or 4, and c2 can be 0, 1, 2, 3 or 4, but 1≤c1+c2≤5.

[0104] 10. A chemically amplified resist composition as described in any one of 7 to 9, wherein the polymer contains at least one selected from repeating units represented by formula (c1), formula (c2), formula (c3), formula (c4), and formula (c5).

[0105] [Chemistry 9]

[0106]

[0107] In the formula, d1 and d2 are each independently 0, 1, 2 or 3.

[0108] e1 can be 0 or 1, e2 can be 0, 1, 2, 3 or 4, and e3 can be 0, 1, 2, 3 or 4. However, when e1 is 0, 0 ≤ e2 + e3 ≤ 4, and when e1 is 1, 0 ≤ e2 + e3 ≤ 6.

[0109] R A Each is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0110] Z 1 It can be a single bond or may have substituents, phenylene

[0111] Z 2 For single bonds, **-C(=O)-OZ 21 -、**-C(=O)-NH-Z 21 -or**-OZ 21 -, Z 21 It is a divalent group obtained by aliphatic hydrocarbon groups, phenylene groups, or combinations thereof having 1 to 6 carbon atoms, and may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups.

[0112] Z 3 The bonds can be single bonds, ether bonds, ester bonds, sulfonate bonds, amide bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds.

[0113] Z 4 It is a single bond, or a divalent group obtained by aliphatic alkylene groups, phenylene groups, or combinations thereof having 1 to 6 carbon atoms. It may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups.

[0114] Z 5 Each can be a single bond, or may have substituents such as phenylene, naphthylene, or *-C(=O)-OZ. 51 -, Z 51 It is an aliphatic hydrocarbon group, phenylene group, or naphthylene group having 1 to 10 carbon atoms. This aliphatic hydrocarbon group may also contain a halogen atom, hydroxyl group, ether bond, ester bond, or lactone ring.

[0115] Z 6The bonds can be single bonds, ether bonds, ester bonds, sulfonate bonds, amide bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds.

[0116] Z 7 Each is independently a single bond, ***-Z 71 -C(=O)-O-、***-C(=O)-NH-Z 71 -or ***-OZ 71 -, Z 71 It can also contain a hydrocarbon group with 1 to 20 carbon atoms, which is a heteroatom.

[0117] Z 8 Each is independently a single key, ****-Z 81 -C(=O)-O-、****-C(=O)-NH-Z 81 -or ****-OZ 81 -, Z 81 It can also contain a hydrocarbon group with 1 to 20 carbon atoms, which is a heteroatom.

[0118] Z 9 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, trifluoromethyl-substituted phenylene, *-C(=O)-OZ 91 -、*-C(=O)-N(H)-Z 91 -or *-OZ 91 -, Z 91 It is an aliphatic alkylene group, phenylene, fluorinated phenylene, or trifluoromethyl-substituted phenylene, having 1 to 6 carbon atoms. It may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group.

[0119] * indicates an atomic bond with a carbon atom in the main chain, ** indicates an atomic bond with a Z atom. 1 atomic bonds, *** represents the bond between Z and Z 6 atomic bonds, **** represents the bond between Z and 7 atomic bonds,

[0120] L 1 The bonds can be single bonds, ether bonds, ester bonds, carbonyl groups, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds.

[0121] Rf 1 and Rf 2 Each is independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms.

[0122] Rf 3 and Rf 4 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms.

[0123] Rf 5 and Rf 6Each is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, but all Rf 5 and Rf 6 They are not both hydrogen atoms.

[0124] Rf 7 It is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkyl thio group having 1 to 6 carbon atoms.

[0125] R 41 and R 42 Each can independently be a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. Also, R 41 and R 42 They can also bond to each other and form rings together with the sulfur atoms they are bonded to.

[0126] R 43 The R group can be a halogen atom other than fluorine, or a hydrocarbon group containing heteroatoms with 1 to 20 carbon atoms. When e3 is 2, 3, or 4, each R... 43 They can be the same or different, multiple Rs 43 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0127] M - It is a non-nucleophilic relative ion.

[0128] A + It is a ium cation.

[0129] 11. A chemically amplified resist composition as described in any of 6 to 10, further comprising an organic solvent.

[0130] 12. The chemically amplified resist composition of any one of 6. to 11. further includes a quenching agent.

[0131] 13. A chemically amplified resist composition as described in any of 6 to 12, further comprising a photoacid generator other than the photoacid generator described in 5.

[0132] 14. Any chemically amplified resist composition as described in any of 6 to 13, further comprising a surfactant.

[0133] 15. A method for forming a pattern, comprising the following steps:

[0134] A resist film is formed on a substrate using a chemically amplified resist composition as described in any of 6. to 14, and the resist film is exposed to high-energy radiation.

[0135] The exposed resist film was developed using a developer.

[0136] 16. The pattern forming method of 15, wherein the high-energy ray is a KrF excimer laser, an ArF excimer laser, an electron beam, or extreme ultraviolet light with a wavelength of 3 to 15 nm.

[0137] (The effect of the invention)

[0138] When patterning is performed using a chemically amplified resist composition containing the matte salt of the present invention as a photoacid generator, it exhibits high sensitivity, excellent acid diffusion suppression capability, and superior photolithography performance such as LWR, CDU, MEF, EL, and DOF. Furthermore, it can suppress the collapse of the resist pattern during the formation of fine patterns. Detailed Implementation

[0139] The present invention will now be described in detail. Furthermore, in the following description, depending on the structure represented by the chemical formula, there may be asymmetric carbon and possibly mirror-image isomers and non-mirror-image isomers. In such cases, these isomers will be represented by a single formula. These isomers may be used individually or as a mixture of two or more.

[0140] [Sulfate]

[0141] The sulfonate salt of the present invention contains an aromatic sulfonic acid anion represented by the following formula (1A).

[0142] [Chemistry 10]

[0143]

[0144] In formula (1A), m1 is 0 or 1. When m1 is 0, it is a benzene ring; when m1 is 1, it is a naphthalene ring. However, from the viewpoint of solvent solubility, a benzene ring with m1 of 0 is preferred. m2 is 0, 1, 2, 3, or 4. From the viewpoint of obtaining raw materials, m2 of 4 with m2 of 1 or higher is preferred. m3 is 0, 1, 2, 3, or 4. However, when m1 is 0, 0 ≤ m2 + m3 ≤ 4; when m1 is 1, 0 ≤ m2 + m3 ≤ 6. m4 is 0 or 1, but from the viewpoint of acid diffusion control, m4 of 1 is preferred.

[0145] In equation (1A), R F1 It is a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms. R F1 Fluorine atoms, trifluoromethyl, difluoromethyl, trifluoromethoxy, difluoromethoxy, trifluoromethylthio, or difluoromethylthio are preferred, with fluorine atoms, trifluoromethyl, or trifluoromethoxy being even more ideal. These substituents containing or having fluorine atoms enhance the acid strength due to their electron-withdrawing effect, thus facilitating the deprotection reactions of unstable acid groups such as tertiary esters and tertiary ethers. When m2 is 2, 3, or 4, each R... F1 They can be the same or different.

[0146] In equation (1A), R 1 The halogen atom can be any halogen other than fluorine, a nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. Examples of halogen atoms other than fluorine include chlorine, bromine, and iodine atoms, but iodine atoms are preferred. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecyl, octadecyl, nonadecanyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclohexenyl and other cyclounsaturated hydrocarbon groups with 3 to 20 carbon atoms; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these. Among these, aryl groups are preferred. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. This can result in the presence of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When m3 is 2, 3, or 4, each R... 1 They can be the same or different. Also, when m3 is 2, 3, or 4, multiple R... 1 They can also bond to each other and form rings together with the carbon atoms they are bonded to. Five- to eight-membered rings are preferred.

[0147] In formula (1A), W is a hydrocarbon group with 6 to 40 carbon atoms containing at least one aromatic ring, and the hydrocarbon group may also contain heteroatoms.

[0148] In formula (1A), W is preferably a group represented by formula (W-1) or (W-2).

[0149] [Chemistry 11]

[0150]

[0151] In the formula, the dashed line represents L. A Atomic bonds.

[0152] In formula (W-1), m5 is 0 or 1. When m5 is 0, it is a benzene ring; when m5 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m5 of 0 is preferred. m6 is 0, 1, 2, 3, or 4. When m5 is 0, m6 is 2, 3, or 4, which is preferred. Considering EUV light absorption, m6 is 3 or 4, which is preferred. m7 is 1, 2, 3, or 4. Considering the availability of raw materials, m7 is 1, 2, or 3, which is preferred. Considering acid diffusion control, m7 is 2 or 3, which is preferred.

[0153] In equation (W-1), R 2 Each group can be a halogen atom other than a hydrogen atom or an iodine atom, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms. Examples of halogen atoms other than iodine atoms include fluorine, chlorine, and bromine atoms; fluorine atoms are preferred from the perspective of solvent solubility. Specific examples of hydrocarbon groups with 1 to 20 carbon atoms that may also contain heteroatoms can be given and are described in the explanation of formula (1A) regarding R. 1 The hydrocarbon groups represented are examples of the same, but are not limited to these. R 2 It is preferable to use groups with branched or cyclic structures.

[0154] In formula (W-1), the ingredients are selected from R. 2 and at least one of the iodine atoms and L A The carbon atoms adjacent to the bonded carbon atoms are more preferably bonded. This restricts the rotation of the aromatic rings bonded to by these atoms and the aromatic rings bonded to by the sulfonyl groups due to steric hindrance, thus limiting the rotation of the -L group. A -X L1 -L B Around the bond axis, acid diffusion can be reduced.

[0155] In formula (W-2), m8 is 0 or 1. When m8 is 0, it is a benzene ring; when m8 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m7 of 0 is preferred. m9 is 0 or 1. When m9 is 0, it is a benzene ring; when m9 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m9 of 0 is preferred. m10 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, m10 with 0, 1, or 2 is preferred. m11 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, m11 with 0, 1, or 2 is preferred.

[0156] In equation (W-2), R 3 and R 4 Each group is independently a hydrogen atom, a halogen atom, or a hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with fluorine and iodine atoms being preferred. Specific examples of hydrocarbon groups with 1 to 20 carbon atoms that may also contain heteroatoms can be given and are described in the explanation of formula (1A). 1 The hydrocarbon groups represented are examples of the same, but are not limited to these. R3 and R 4 It is preferable to use groups with branched or cyclic structures.

[0157] In equation (W-2), R 5 ~R 9 Each group can be a hydrogen atom, a halogen atom, or a hydrocarbon group with 1 to 40 carbon atoms that may contain heteroatoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine, but fluorine and iodine are preferred. Specific examples of hydrocarbon groups with 1 to 20 carbon atoms that may also contain heteroatoms can be given and are described in the explanation of formula (1A). 1 The hydrocarbon groups represented are examples of the same, but are not limited to these. R 5 ~R 9 It is preferable to use groups with branched or cyclic structures.

[0158] In equation (W-2), R 5 ~R 9 Any two of the atoms in the ring can also bond to each other and form a ring together with the carbon atoms they are bonded to. Five- to eight-membered rings are preferred.

[0159] In equation (1A), L A and L B Each bond can be independently a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond. Among these, single bonds, ether bonds, or ester bonds are preferred.

[0160] In equation (1A), X L1 It is a single bond, or may contain heteroatoms, of 1 to 40 carbon atoms. The aforementioned alkylene groups can be linear, branched, or cyclic; specific examples include alkyldiyl, cyclic saturated alkylene groups, and arylene groups. Specific examples of the aforementioned heteroatoms include oxygen atoms, nitrogen atoms, and sulfur atoms.

[0161] X L1 Examples of hydrocarbon groups containing 1 to 40 carbon atoms that can also represent heteroatoms are listed below, but are not limited to these. Furthermore, in the following formula, * respectively represent L. A and L B Atomic bonds.

[0162] [Chemistry 12]

[0163]

[0164] [Chemistry 13]

[0165]

[0166] [Chemistry 14]

[0167]

[0168] [Chemistry 15]

[0169]

[0170] Among these, X L -0~X L -22 and X L -47~X L -58 is the optimal value.

[0171] The anion represented by formula (1A) is preferably represented by formula (1A-1).

[0172] [Chemistry 16]

[0173]

[0174] In the formula, m1~m4, W, R F1 R 1 and L A As mentioned above.

[0175] Specific examples of anions represented by formula (1A) are listed below, but are not limited to these. Also, in the following formula, Me is a methyl group.

[0176] [Chemistry 17]

[0177]

[0178] [Chemistry 18]

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[0180] [Chemistry 19]

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[0721]

[0722] The sulfonium salt of the present invention contains a sulfonium cation represented by the following formula (1B).

[0723] [Chemistry 290]

[0724]

[0725] In formula (1B), n1 is 0 or 1. When n1 is 0, it is a benzene ring; when n1 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with n1 of 0 is preferred. n2 is 0, 1, or 2. n3 is 0, 1, or 2. n4 is 0, 1, or 2. Considering the availability of raw materials, n4 being 0 or 1 is preferred. However, when n1 is 0, 0 ≤ n2 + n3 + n4 ≤ 5; when n1 is 1, 0 ≤ n2 + n3 + n4 ≤ 7.

[0726] In formula (1B), n5 is 0 or 1. When n5 is 0, it is a benzene ring; when n5 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with n5 of 0 is preferred. n6 is 0, 1, or 2. n7 is 0, 1, or 2. n8 is 0, 1, or 2. Considering the availability of raw materials, n8 is 0 or 1 is preferred. However, when n5 is 0, 0 ≤ n6 + n7 + n8 ≤ 5; when n5 is 1, 0 ≤ n6 + n7 + n8 ≤ 7.

[0727] In formula (1B), n9 is 0 or 1. When n9 is 0, it is a benzene ring; when n9 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with n9 of 0 is preferred. n10 is 0, 1, or 2. n11 is 0, 1, or 2. n12 is 0, 1, or 2. Considering the availability of raw materials, n12 being 0 or 1 is preferred. However, when n9 is 0, 0 ≤ n10 + n11 + n12 ≤ 5; when n9 is 1, 0 ≤ n10 + n11 + n12 ≤ 7.

[0728] In formula (1B), the number of pentafluorosulfur groups is 1≤n2+n6+n10≤6, preferably 1≤n2+n6+n10≤3, and even more preferably 1≤n2+n6+n10≤2. When the number of pentafluorosulfur groups is 2 or more, each pentafluorosulfur group can be bonded to the same aromatic ring or to different aromatic rings.

[0729] In formula (1B), the number of alkyloxycarbonyl groups is 1≤n3+n7+n11≤6, preferably 1≤n3+n7+n11≤3, and even more preferably 1≤n3+n7+n11≤2. When the number of alkyloxycarbonyl groups is 2 or more, each alkyloxycarbonyl group can be bonded to the same aromatic ring or to different aromatic rings.

[0730] In equation (1B), R 11 R 12 and R 13Each of these groups can be an independent hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecyl, octadecyl, nonadecanyl, and icosyl; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; aryl groups with 6 to 20 carbon atoms such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these groups, but are not limited to these.

[0731] Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, it may contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride (-C(=O)-OC(=O)-), or haloalkyl groups. Specific examples of hydrocarbon groups containing heteroatoms include fluoroalkyl groups such as trifluoromethyl, 1,1,1-trifluoroethyl, 1,1,1,3,3,3-hexafluoroisopropyl, nonafluorobutyl, and octafluoropentyl; oxanorbenzyl, etc., but are not limited to these. It is preferred that the aforementioned fluoroalkyl groups have 1 to 6 carbon atoms.

[0732] When n3 is 2, each R 11 They can be the same or different. When n7 is 2, each R... 12 They can be the same or different. When n11 is 2, each R... 13 They can be the same or different.

[0733] In equation (1B), R 14 R 15 and R 16Each group can be independently a halogen atom, nitro group, hydroxyl group, carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. The hydrocarbon base of the aforementioned hydrocarbon, hydrocarbon oxy, and hydrocarbon thio groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecyl, octadecyl, nonadecanyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclohexenyl and other cyclounsaturated hydrocarbon groups with 3 to 20 carbon atoms; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these. Among these, aryl groups are preferred. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. This can result in the presence of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonyl lactone, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When n4 is 2, each R... 14 They can be the same or different. Also, when n⁴ is 2, there are 2 R... 14 They can also bond to each other and form rings together with the carbon atoms they are bonded to. Five- to eight-membered rings are preferred. When n8 is 2, each R... 15 They can be the same or different. Also, when n8 is 2, there are 2 R... 15 They can also bond to each other and form rings together with the carbon atoms they are bonded to. Five- to eight-membered rings are preferred. When n12 is 2, each R... 16 They can be the same or different. Also, when n12 is 2, there are 2 R... 16 They can also bond to each other and form rings together with the carbon atoms they are bonded to. Five- to eight-membered rings are preferred.

[0734] Furthermore, the bond is in S + Two of the three substituents can also bond to each other and form a ring together with the sulfur atoms they are bonded to. Specific examples of the aforementioned ring structure can be shown in the following formulas, etc.

[0735] [Chemistry 291]

[0736]

[0737] In the formula, the dashed lines represent atomic bonds.

[0738] The sulfonium cation represented by formula (1B) is preferably represented by formula (1B-1).

[0739] [Chemistry 292]

[0740]

[0741] In the formula, n2~n4, n6~n8, n10~n12 and R 11 ~R 16 As mentioned above.

[0742] Specific examples of sulfonium cations represented by formula (1B) are listed below, but are not limited to these.

[0743] [Chemistry 293]

[0744]

[0745] [Chemistry 294]

[0746]

[0747] [Chemistry 295]

[0748]

[0749] [Chemistry 296]

[0750]

[0751] [Chemistry 297]

[0752]

[0753] [Chemistry 298]

[0754]

[0755] [Chemistry 299]

[0756]

[0757] [Chemical 300]

[0758]

[0759] [Chemical Engineering 301]

[0760]

[0761] [Chemical 302]

[0762]

[0763] [Chemical 303]

[0764]

[0765] [Chemical 304]

[0766]

[0767] [Chemical 305]

[0768]

[0769] [Chemical 306]

[0770]

[0771] [Chemical 307]

[0772]

[0773] [Chemical 308]

[0774]

[0775] [Chemical 309]

[0776]

[0777] [Chemical 310]

[0778]

[0779] [Chemistry 311]

[0780]

[0781] [Chemistry 312]

[0782]

[0783] [Chemistry 313]

[0784]

[0785] [Chemical 314]

[0786]

[0787] [Chemical 315]

[0788]

[0789] [Chemistry 316]

[0790]

[0791] [Chemistry 317]

[0792]

[0793] [Chemistry 318]

[0794]

[0795] [Chemistry 319]

[0796]

[0797] [Chemistry 320]

[0798]

[0799] [Chemistry 321]

[0800]

[0801] [Chemistry 322]

[0802]

[0803] [Chemistry 323]

[0804]

[0805] [Chemistry 324]

[0806]

[0807] [Chemistry 325]

[0808]

[0809] [Chemistry 326]

[0810]

[0811] [Chemistry 327]

[0812]

[0813] [Chemistry 328]

[0814]

[0815] [Chemistry 329]

[0816]

[0817] [Chemistry 330]

[0818]

[0819] [Chemistry 331]

[0820]

[0821] [Chemistry 332]

[0822]

[0823] [Chemistry 333]

[0824]

[0825] [Chemistry 334]

[0826]

[0827] [Chemistry 335]

[0828]

[0829] [Chemistry 336]

[0830]

[0831] [Chemistry 337]

[0832]

[0833] [Chemistry 338]

[0834]

[0835] [Chemistry 339]

[0836]

[0837] Specific examples of the matte salts of the present invention can be any combination of the aforementioned anions and cations.

[0838] Examples of methods for synthesizing matte salts according to the present invention include those described in Japanese Patent Application Publication No. 2010-155824 and Japanese Patent No. 7067271, but the aforementioned manufacturing methods are merely examples, and the manufacturing methods of matte salts according to the present invention are not limited to these.

[0839] The structural features of the sulfonium salts of the present invention include aromatic sulfonic acid anions substituted with a hydrocarbon group containing at least one aromatic ring, and sulfonium cations containing a pentafluorosulfide group and a alkyloxycarbonyl group. It is known that secondary electrons are released when a base polymer is irradiated with EUV light. However, the pentafluorosulfide group of the aforementioned sulfonium cation, due to its electron-withdrawing effect, lowers the energy level of the lowest empty molecular orbital (LUMO) in the leading-edge orbital theory, making it more susceptible to accepting the generated secondary electrons. Therefore, the decomposition of the cation is promoted, effectively generating acid. Furthermore, the alkyloxycarbonyl group substituted on the aromatic ring of the sulfonium cation, having a lone pair of electrons from the ester bond, can also be expected to act as an acid diffusion inhibitor through proton interaction with the acid. Although not to the extent of the pentafluorosulfide group, it still has electron-withdrawing properties, thus a decrease in the energy level of the LUMO in the leading-edge orbital theory can be expected. Moreover, the alkyloxycarbonyl group is hydrolyzable to alkaline developers; therefore, in the exposure section, the decomposition products of the cation exhibit an affinity for alkaline developers, thereby suppressing development residue. On the other hand, the aforementioned hydrocarbon group containing at least one aromatic ring, being bulky, acts as a large substituent and thus significantly inhibits the diffusion of acid. This effect is particularly pronounced when the aforementioned hydrocarbon group containing at least one aromatic ring has an aromatic ring structure with substituents as shown in Formula (W-1) or a condensed ring structure with substituents as shown in Formula (W-2). Furthermore, it exhibits resistance to alkaline developers, thus reducing film loss in unexposed areas. On the other hand, aromatic sulfonic acid structures, with their rigid acid-generating structures, exhibit an effect of inhibiting acid diffusion. In the aromatic ring forming the aromatic sulfonic acid structure, fluorine atoms or electron-withdrawing sulfonate bonds are preferred as linking groups, thereby increasing the acidity of the generated acid and enabling efficient deprotection of acid-unstable groups in the base polymer. Moreover, although fluorine atoms are not as numerous as iodine atoms, they are still highly absorbent of EUV light; therefore, increasing the number of fluorine atoms increases the generation of secondary electrons, promotes cation decomposition, and contributes to higher sensitivity. Japanese Patent No. 7109178 discloses an alkylsulfonic acid type photoresist with 2 to 4 fluorine atoms. Because it is an alkylsulfonic acid, it has high acid diffusion and poor solvent solubility, raising concerns about development defects. Due to these synergistic effects, the resist composition containing the matte salt of this invention exhibits high sensitivity and low acid diffusion, thereby providing excellent photolithography performance for LWR, CDU, and other photolithography methods, enabling the formation of patterns resistant to pattern collapse, and making it suitable for micro-pattern formation.

[0840] The aforementioned sulfonium salt can be ideally used as a photoacid generator.

[0841] [Chemical amplification resist composition]

[0842] [(A) Photoacid generator]

[0843] The chemically amplified resist composition of the present invention includes a photoacid generator composed of (A) sulfonium salt as an essential component, wherein (A) sulfonium salt is composed of an aromatic sulfonic acid anion represented by formula (1A) and a sulfonium cation represented by formula (1B).

[0844] In the chemically amplified resist composition of the present invention, the content of the photoacid generating agent composed of the sulfonium salt of component (A) is ideally 0.1 to 40 parts by mass relative to 80 parts by mass of the base polymer described later, and more ideally 0.5 to 30 parts by mass. If the content of component (A) is within the aforementioned range, the sensitivity and resolution are good, and there is no risk of foreign matter occurring after the resist film is developed or peeled off, thus it is ideal. The photoacid generating agent (A) can be used alone or in combination of two or more.

[0845] [(B) Basic Polymer]

[0846] The chemically amplified resist composition of the present invention may also contain a base polymer as component (B). The base polymer (B) contains a repeating unit represented by formula (a1) (hereinafter also referred to as repeating unit a1.) or a repeating unit represented by formula (a2) (hereinafter also referred to as repeating unit a2.).

[0847] [Transformation 340]

[0848]

[0849] In equations (a1) and (a2), R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0850] In equation (a1), X 1 It is a single bond, phenylene, naphthylene, or *-C(=O)-OX 11 - The phenylene or naphthylene group may also be substituted with hydroxyl, nitro, cyano, or a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, or a saturated hydrocarbon oxygen group containing fluorine atoms with 1 to 10 carbon atoms, or a halogen atom. X 11 It is a saturated hydrocarbon group, phenylene group, or naphthylene group having 1 to 10 carbon atoms. This saturated hydrocarbon group may also contain a hydroxyl group, ether bond, ester bond, or lactone ring. * indicates an atomic bond with a carbon atom in the main chain.

[0851] In equation (a2), X 2 It represents a single bond or *-C(=O)-O-. * indicates an atomic bond with a carbon atom in the main chain. R 21It can be a halogen atom, cyano group, hydroxyl group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; or it can also be a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms containing heteroatoms. a1 is 0, 1, 2, 3 or 4, preferably 0 or 1. When a1 is 2, 3 or 4, each R 21 They can be the same or different.

[0852] In equations (a1) and (a2), AL 1 and AL 2 Each of these groups is an acid-indestructible group independently. Specific examples of the aforementioned acid-indestructible groups are, for example, those described in Japanese Patent Application Publication No. 2013-80033 and Japanese Patent Application Publication No. 2013-83821.

[0853] Generally speaking, specific examples of the aforementioned unstable acid groups can be represented by the formulas (AL-1) to (AL-3).

[0854] [Chemistry 341]

[0855]

[0856] In the formula, * represents an atomic bond.

[0857] In equations (AL-1) and (AL-2), R L1 and R L2 Each hydrocarbon group is an independent hydrocarbon group with 1 to 40 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Hydrocarbon groups with 1 to 20 carbon atoms are preferred.

[0858] In formula (AL-1), a2 is an integer from 0 to 10, and it is better to be 1, 2, 3, 4 or 5.

[0859] In equation (AL-2), R L3 and R L4 Each group is independently composed of a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Furthermore, R... L2 R L3 and R L4 Any two of them can bond to each other and together with the carbon atoms they are bonded to, or carbon atoms and oxygen atoms, form a ring with 3 to 20 carbon atoms. The aforementioned rings with 4 to 16 carbon atoms are more ideal, especially alicyclic rings.

[0860] In equation (AL-3), R L5 RL6 and R L7 Each group is an independent hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Furthermore, R... L5 R L6 and R L7 Any two of them can bond to each other and together with the carbon atoms they are bonded to form a ring with 3 to 20 carbon atoms. The aforementioned rings with 4 to 16 carbon atoms are more ideal, especially alicyclic rings.

[0861] Other specific examples of the aforementioned acid-indestructible groups can be found in paragraphs

[0064] to

[0068] of Japanese Patent Application Publication No. 2023-123222 and paragraphs

[0013] to

[0014] of Japanese Patent Publication No. 7492842. These groups generate conjugated olefins or acrylate derivatives after the acid desorption reaction, which serves as the driving force for the reaction.

[0862] Specific examples of repeated unit a1 can be listed below, but are not limited to these. Also, in the following formula, R... A and AL 1 As mentioned above.

[0863] [Chemistry 342]

[0864]

[0865] [Chemistry 343]

[0866]

[0867] [Chemistry 344]

[0868]

[0869] [Chemistry 345]

[0870]

[0871] Specific examples of repeated unit a2 can be listed below, but are not limited to these. Also, in the following formula, R... A and AL 2 As mentioned above.

[0872] [Chemistry 346]

[0873]

[0874] [Chemistry 347]

[0875]

[0876] [Chemistry 348]

[0877] The aforementioned polymer may also contain repeating units represented by the following formula (a3) ​​(hereinafter also referred to as repeating unit a3).

[0878] [Chemistry 349]

[0879]

[0880] In formula (a3), b1 is 0 or 1. When b1 is 0, it is a benzene ring; when b1 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with b1 of 0 is preferred. b2 is 0, 1, 2, or 3 when b1 is 0, and 0, 1, 2, 3, 4, or 5 when b1 is 1. Considering the availability of raw materials, b2 of 0, 1, 2, or 3 is preferred, with 0, 1, or 2 being even better.

[0881] In equation (a3), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R A Hydrogen atoms or methyl groups are preferred, with hydrogen atoms being even better.

[0882] In equation (a3), X 3 The bonds are single bonds, *-C(=O)-O-, or *-C(=O)-NH-. * indicates an atomic bond with a carbon atom in the main chain. Among these, single bonds and *-C(=O)-O- are preferred, with single bonds being the most ideal.

[0883] In equation (a3), X 4 A single bond, an aliphatic alkylene group having 1 to 4 carbon atoms, a carbonyl group, a sulfonyl group, or a combination thereof. Among these, considering the raw materials, a single bond, a carbonyl group, or a sulfonyl group is preferred; considering the polar groups formed after the reaction, a single bond or a carbonyl group is even better.

[0884] In equation (a3), X 5 and X 6 Each can be an oxygen atom or a sulfur atom independently. But X 4 and X 6 It is an adjacent carbon atom bonded to an aromatic ring. X 5 and X 6 They can be the same or different, taking into account the perspective of reactivity, X 5 and X 6 Both are better if they contain oxygen atoms.

[0885] In equation (a3), R 22 and R 23Each hydrocarbon group consists of 1 to 20 carbon atoms, and may also contain heteroatoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecyl, octadecyl, nonadecanyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclohexenyl and other cyclounsaturated hydrocarbon groups with 3 to 20 carbon atoms; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining them. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned hydrocarbon group may also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may also contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0886] Also, R 22 and R 23 They can also bond with each other and form rings together with the carbon atoms they are bonded to. Specific examples of rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, and adamantane rings. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, they may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0887] In equation (a3), R 24 It can be a halogen atom, hydroxyl group, cyano group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon oxycarbonyl group with 2 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon thio group with 1 to 20 carbon atoms or -N(R) 24A (R) 24B R 24A and R 24BEach group is independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. The aforementioned halogen atom is preferably a fluorine, chlorine, bromine, or iodine atom, with fluorine or iodine being more preferred. The hydrocarbon group, hydroxyl group, hydroxyl carbonyl group, and thiol group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given and discussed in relation to R. 22 and R 23 The alkyl group represented is an example of the same. Furthermore, some or all of the hydrogen atoms in the aforementioned alkyl group can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned alkyl group can be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This can result in the presence of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When b2 is 2 or more, each R... 24 They can be the same or different.

[0888] Furthermore, when b2 is 2 or more, multiple R 24 They can also bond with each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. Specific examples of rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and part of the -CH2- in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, etc. As a result, they may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0889] Specific examples of repeated unit a3 can be listed below, but are not limited to these. Also, in the following formula, R... A As mentioned earlier, Me is methyl. Furthermore, the bonding positions of the various substituents on the aromatic ring can also be interchanged.

[0890] [Chemical 350]

[0891]

[0892] [Chemistry 351]

[0893]

[0894] [Chemistry 352]

[0895]

[0896] [Chemistry 353]

[0897]

[0898] [Chemical Formula 354]

[0899]

[0900] [Chemical Formula 355]

[0901]

[0902] [Chemical Formula 356]

[0903]

[0904] [Chemical Formula 357]

[0905]

[0906] [Chemical Formula 358]

[0907]

[0908] [Chemical Formula 359]

[0909]

[0910] [Chemical Formula 360]

[0911]

[0912] [Chemical Formula 361]

[0913]

[0914] [Chemical Formula 362]

[0915]

[0916] [Chemical Formula 363]

[0917]

[0918] [Chemical Formula 364]

[0919]

[0920] [Chemical Formula 365]

[0921]

[0922] [Chemical Formula 366]

[0923]

[0924] [Chemical Formula 367]

[0925]

[0926] [Chem.368]

[0927]

[0928] [Chemistry 369]

[0929]

[0930] [Transformation 370]

[0931]

[0932] [Chemistry 371]

[0933]

[0934] [Chemistry 372]

[0935]

[0936] [Chemistry 373]

[0937]

[0938] [Chemistry 374]

[0939]

[0940] [Chemistry 375]

[0941]

[0942] [Chemistry 376]

[0943]

[0944] [Chemistry 377]

[0945]

[0946] [Chemistry 378]

[0947]

[0948] [Chemistry 379]

[0949]

[0950] [Chemistry 380]

[0951]

[0952] [Chemistry 381]

[0953]

[0954] [Chemistry 382]

[0955]

[0956] [Chemistry 383]

[0957]

[0958] [Chem. 384]

[0959]

[0960] [Chem. 385]

[0961]

[0962] [Chemistry 386]

[0963]

[0964] [Chemistry 387]

[0965]

[0966] [Chem.388]

[0967]

[0968] [Chemistry 389]

[0969]

[0970] [Chemistry 390]

[0971]

[0972] [Chemistry 391]

[0973]

[0974] [Chemistry 392]

[0975]

[0976] [Chemistry 393]

[0977]

[0978] [Chemistry 394]

[0979]

[0980] [Chemistry 395]

[0981]

[0982] [Chemistry 396]

[0983]

[0984] [Chemistry 397]

[0985]

[0986] [Chem.398]

[0987]

[0988] [Chemistry 399]

[0989]

[0990] The aforementioned polymer may also contain repeating units represented by formula (b1) (hereinafter also referred to as repeating unit b1.) or repeating units represented by formula (b2) (hereinafter also referred to as repeating unit b2.).

[0991] [Chemical 400]

[0992]

[0993] In equations (b1) and (b2), R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 It represents a single bond or *-C(=O)-O-. * indicates an atomic bond with a carbon atom in the main chain. R 31 It is a hydrogen atom, or a group containing at least one of the following structures with 1 to 20 carbon atoms: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulcinolone ring, and carboxylic anhydride (-C(=O)-OC(=O)-). R 32 It can be a halogen atom, carboxyl group, nitro group, cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; or it can be a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms containing heteroatoms. When c2 is 2, 3, or 4, each R 32 They can be the same or different. c1 can be 1, 2, 3 or 4. c2 can be 0, 1, 2, 3 or 4. But 1 ≤ c1 + c2 ≤ 5.

[0994] Specific examples of repeated unit b1 can be listed below, but are not limited to these. Also, in the following formula, R... A As mentioned above.

[0995] [Chemical Engineering 401]

[0996]

[0997] [Chemical 402]

[0998]

[0999] [Chemical 403]

[1000]

[1001] [Chemical 404]

[1002]

[1003] [Chemical 405]

[1004]

[1005] [Chemical 406]

[1006]

[1007] [Chemical 407]

[1008]

[1009] [Chemical 408]

[1010]

[1011] [Chemical 409]

[1012]

[1013] [Chemical 410]

[1014]

[1015] [Chemistry 411]

[1016]

[1017] [Chemistry 412]

[1018]

[1019] [Chemistry 413]

[1020]

[1021] [Chemistry 414]

[1022]

[1023] [Chemical 415]

[1024]

[1025] [Chemistry 416]

[1026]

[1027] Specific examples of repeated unit b2 can be listed below, but are not limited to these. Also, in the following formula, R... A As mentioned above.

[1028] [Chemistry 417]

[1029]

[1030] [Chemistry 418]

[1031]

[1032] [Chemistry 419]

[1033]

[1034] [Chemistry 420]

[1035]

[1036] [Chemistry 421]

[1037]

[1038] Regarding repeating units b1 or b2, in ArF lithography, those with lactone rings as polar groups are particularly ideal, while in KrF lithography, EB lithography, and EUV lithography, those with phenol sites are preferred.

[1039] The aforementioned polymer may also contain at least one selected from the following formula (c1) (hereinafter also referred to as repeating unit c1.), the following formula (c2) (hereinafter also referred to as repeating unit c2.), the following formula (c3) (hereinafter also referred to as repeating unit c3.), the following formula (c4) (hereinafter also referred to as repeating unit c4.), and the following formula (c5) (hereinafter also referred to as repeating unit c5.).

[1040] [Chemistry 422]

[1041]

[1042] In equations (c1) to (c5), R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1It is a single bond or may have substituents. Z 2 For single bonds, **-C(=O)-OZ 21 -、**-C(=O)-NH-Z 21 -or**-OZ 21 -. Z 21 It is a divalent group obtained by aliphatic hydrocarbon groups, phenylene groups, or combinations thereof having 1 to 6 carbon atoms, and may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups. 3 It can be a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. 4 It is a single bond, or a divalent group obtained by aliphatic alkylene groups, phenylene groups, or combinations thereof with 1 to 6 carbon atoms, and may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups. 5 Each can be a single bond, or may have substituents such as phenylene, naphthylene, or *-C(=O)-OZ. 51 -. Z 51 It is an aliphatic alkylene group, phenylene group, or naphthylene group having 1 to 10 carbon atoms. This aliphatic alkylene group may also contain a halogen atom, hydroxyl group, ether bond, ester bond, or lactone ring. 6 It can be a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. 7 Each is independently a single bond, ***-Z 71 -C(=O)-O-、***-C(=O)-NH-Z 71 -or ***-OZ 71 -. Z 71 It can also contain a hydrocarbon group with 1 to 20 carbon atoms, which may contain heteroatoms. Z 8 Each is independently a single key, ****-Z 81 -C(=O)-O-、****-C(=O)-NH-Z 81 -or ****-OZ 81 -. Z 81 It can also contain a hydrocarbon group with 1 to 20 carbon atoms, which may contain heteroatoms. Z 9 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, trifluoromethyl-substituted phenylene, *-C(=O)-OZ 91 -、*-C(=O)-N(H)-Z 91 -or *-OZ 91 -. Z 91 It is an aliphatic alkylene group, phenylene, fluorinated phenylene, or trifluoromethyl-substituted phenylene, having 1 to 6 carbon atoms. It may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group. * indicates an atomic bond with the carbon atom of the main chain. ** indicates a bond with Z. 1 The atomic bonds. *** indicates the relationship between Z and 6Atomic bonds. **** represents the bond between Z and Z. 7 Atomic bonds.

[1043] Z 21 Z 51 and Z 91 The aliphatic alkyl sub-groups can be linear, branched, or cyclic. Specific examples include alkyl diyl groups such as methane-diyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, propane-2,2-diyl, butane-1,1-diyl, butane-1,2-diyl, butane-1,3-diyl, butane-2,3-diyl, butane-1,4-diyl, 1,1-dimethylethane-1,2-diyl, pentane-1,5-diyl, 2-methylbutane-1,2-diyl, and hexane-1,6-diyl; cycloalkyl diyl groups such as cyclopropane-diyl, cyclobutane-diyl, cyclopentane-diyl, and cyclohexane-diyl; and groups obtained by combining them.

[1044] Z 71 and Z 81 The subhydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples are listed below, but are not limited to these.

[1045] [Chemistry 423]

[1046]

[1047] In the formula, the dashed lines represent atomic bonds.

[1048] In equation (c1), R 41 and R 42Each group can be an independent hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantylene; alkenyl groups with 2 to 20 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclohexenyl groups with 3 to 20 carbon atoms such as cyclohexenyl; aryl groups with 6 to 20 carbon atoms such as phenyl, naphthyl, and thiophene; aralkyl groups with 7 to 20 carbon atoms such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining them, but aryl groups are preferred. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned hydrocarbon group may also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may also contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[1049] Also, R 41 and R 42 They can also bond to each other and form rings together with the sulfur atoms they are bonded to. Specific examples of the aforementioned rings can be shown in the following formulas, etc.

[1050] [Chemistry 424]

[1051]

[1052] In the formula, the dashed line represents Z. 4 Atomic bonds.

[1053] Specific examples of the cations in repeating unit c1 can be listed below, but are not limited to these. Also, in the following formula, R... A As mentioned above.

[1054] [Chemical 425]

[1055]

[1056] [Chemistry 426]

[1057]

[1058] [Chemistry 427]

[1059]

[1060] [Chemistry 428]

[1061]

[1062] [Chemistry 429]

[1063]

[1064] [Chemistry 430]

[1065]

[1066] [Chemistry 431]

[1067]

[1068] [Chemistry 432]

[1069]

[1070] [Chemistry 433]

[1071]

[1072] [Chemistry 434]

[1073]

[1074] In equation (c1), M - These are non-nucleophilic relative ions. Preferred non-nucleophilic relative ions are halide ions, sulfonic acid anions, imide acid anions, and methylated acid anions. Specific examples of halide ions include chloride ions and bromide ions. Specific examples of sulfonic acid anions (sulfonate ions) include trifluoromethanesulfonate ions, 1,1,1-trifluoroethanesulfonate ions, nonafluorobutanesulfonate ions, and other fluoroalkyl sulfonate ions; toluenesulfonate ions, benzenesulfonate ions, 4-fluorobenzenesulfonate ions, 1,2,3,4,5-pentafluorobenzenesulfonate ions, and other aryl sulfonate ions; methanesulfonate ions, butanesulfonate ions, and other alkyl sulfonate ions. Specific examples of imide acid anions (imide ions) include (trifluoromethylsulfonyl)imide ions, bis(perfluoroethylsulfonyl)imide ions, and bis(perfluorobutylsulfonyl)imide ions. Specific examples of the aforementioned methylated acid anions (methylated ions) include tris(trifluoromethylsulfonyl) methylated ions and tris(perfluoroethylsulfonyl) methylated ions.

[1075] Other examples of the aforementioned non-nucleophilic relative ions can be exemplified by anions represented by any of the following formulas (c1-1) to (c1-4).

[1076] [Chemistry 435]

[1077]

[1078] In equation (c1-1), R fa It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain fluorine atoms or heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given by R in the following formula (c1-1-1). fa1 The hydrocarbon group shown is an example of the same.

[1079] The anion represented by formula (c1-1) is preferably represented by the following formula (c1-1-1).

[1080] [Chemistry 436]

[1081]

[1082] In equation (c1-1-1), Q 1 and Q 2 Each atom is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. To improve solvent solubility, at least one atom is preferably trifluoromethyl. m can be 0, 1, 2, 3, or 4, with 1 being particularly preferred. R fa1 Hydrocarbon groups with 1 to 35 carbon atoms that can also contain heteroatoms are preferred. Ideal heteroatoms include oxygen, nitrogen, sulfur, and halogen atoms, with oxygen atoms being even more desirable. From the viewpoint of achieving high resolution in the formation of fine patterns, hydrocarbon groups with 6 to 30 carbon atoms are particularly advantageous.

[1083] In equation (c1-1-1), R fa1 The hydrocarbon groups represented by carbon numbers 1 to 35 can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 35 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and icosyl; cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norcamphenyl, norcamphenylmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups with 2 to 35 carbon atoms, such as 2-propenyl and 3-cyclohexenyl; aryl groups with 6 to 35 carbon atoms, such as phenyl, 1-naphthyl, 2-naphthyl, and 9-fluorenyl; aralkyl groups with 7 to 35 carbon atoms, such as benzyl and diphenylmethyl; and groups obtained by combining them.

[1084] Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. This can result in the presence of hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulopentalide ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. Specific examples of hydrocarbon groups containing heteroatoms include tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidemethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, 3-oxocyclohexyl, etc.

[1085] In equation (c1-1-1), L a1 The bonds can be single bonds, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, or carbamate bonds. From a synthetic point of view, ether bonds or ester bonds are preferred, with ester bonds being more ideal.

[1086] Specific examples of anions represented by equation (c1-1) can be listed below, but are not limited to these. Furthermore, in the following equation, Q... 1 As mentioned above, Ac represents the acetyl group.

[1087] [Chemistry 437]

[1088]

[1089] [Chemistry 438]

[1090]

[1091] [Chemistry 439]

[1092]

[1093] [Chemistry 440]

[1094]

[1095] [Chemistry 441]

[1096]

[1097] [Chemistry 442]

[1098]

[1099] [Chemistry 443]

[1100]

[1101] [Chemistry 444]

[1102]

[1103] [Chemistry 445]

[1104]

[1105] [Chemistry 446]

[1106]

[1107] [Chemistry 447]

[1108]

[1109] [Chemistry 448]

[1110]

[1111] In equation (c1-2), R fb1 and R fb2 Each group consists of a fluorine atom or may contain heteroatoms and has 1 to 40 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given by R in formula (c1-1-1). fa1 The hydrocarbon group represented is an example of the same. R fb1 and R fb2 Preferably, it is a straight-chain fluorinated alkyl group having fluorine atoms or 1 to 4 carbon atoms. Also, R fb1 and R fb2 They can also bond to each other and to the groups they are bonded to (-CF2-SO2-N). - -SO2-CF2-) together form a ring, in which case R fb1 and R fb2 It is preferable that the groups obtained by mutual bonding are fluorinated ethylidene or fluorinated propyleneide.

[1112] In equation (c1-3), R fc1 R fc2 and R fc3 Each group consists of a fluorine atom or may contain heteroatoms and has 1 to 40 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given by R in formula (c1-1-1). fa1 The hydrocarbon group represented is an example of the same. R fc1 R fc2 and R fc3 Preferably, it is a straight-chain fluorinated alkyl group having fluorine atoms or 1 to 4 carbon atoms. Also, R fc1 and R fc2They can also bond to each other and to the groups they are bonded to (-CF2-SO2-C). - -SO2-CF2-) together form a ring, in which case R fc1 and R fc2 The groups obtained by mutual bonding are preferably fluorinated ethylidene or fluorinated propyleneide.

[1113] In equation (c1-4), R fd It can also be a hydrocarbon group with 1 to 40 carbon atoms containing heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given by R in formula (c1-1-1). fa1 The hydrocarbon group shown is an example of the same.

[1114] Specific examples of anions represented by formula (c1-4) are listed below, but are not limited to these.

[1115] [Chemistry 449]

[1116]

[1117] [Chemistry 450]

[1118]

[1119] The aforementioned examples of non-nucleophilic relative ions can be further illustrated by anions having aromatic rings substituted with iodine or bromine atoms. Specific examples of such anions can be exemplified by those represented by the following formula (c1-5).

[1120] [Chemistry 451]

[1121]

[1122] In equation (c1-5), x is 1, 2, or 3. y is 1, 2, 3, 4, or 5. z is 0, 1, 2, or 3. However, 1 ≤ y + z ≤ 5. y being 1, 2, or 3 is ideal, with 2 or 3 being even more ideal. z being 0, 1, or 2 is preferable.

[1123] In equation (c1-5), X BI It is an iodine atom or a bromine atom. When x and / or y are 2 or more, each X BI They can be the same or different.

[1124] In equation (c1-5), 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 also contain ether or ester bonds. The aforementioned saturated hydrocarbon group may be linear, branched, or cyclic.

[1125] In equation (c1-5), L 12When x is 1, it is a single bond or a divalent linker with 1 to 20 carbon atoms; when x is 2 or 3, it is a (x+1) valent linker with 1 to 20 carbon atoms. This linker may also contain oxygen, sulfur, or nitrogen atoms.

[1126] In equation (c1-5), R fe It can be a hydroxyl, carboxyl, fluorine, chlorine, bromine, or amino group, or may contain a fluorine, chlorine, bromine, hydroxyl, amino, or ether bond, and can be a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms, or a hydrocarbon sulfonyl group with 1 to 20 carbon atoms, or -N(R feA (R) feB ), -N(R feC )-C(=O)-R feD or -N(R) feC )-C(=O)-OR feD R feA and R feB Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R feC 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, a saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms. R feD It can be an aliphatic hydrocarbon group with 1 to 16 carbon atoms, an aryl group with 6 to 12 carbon atoms, or an aralkyl group with 7 to 15 carbon atoms. It may also contain a halogen atom, a hydroxyl group, a saturated alkyloxy group with 1 to 6 carbon atoms, a saturated alkylcarbonyl group with 2 to 6 carbon atoms, or a saturated alkylcarbonyloxy group with 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. The aforementioned hydrocarbon group, alkyloxy group, alkylcarbonyl group, alkyloxycarbonyl group, alkylcarbonyloxy group, and alkylsulfonyloxy group can be any of linear, branched, or cyclic. When x and / or z are 2 or more, each R... fe They can be the same or different.

[1127] Among these, R fe Hydroxyl group, -N(R) feC )-C(=O)-R feD -N(R) feC )-C(=O)-OR feD Fluorine atoms, chlorine atoms, bromine atoms, methyl groups, and methoxy groups are preferred.

[1128] In equation (c1-5), Rf 11 ~Rf 14 Each is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, at least one of which is a fluorine atom or a trifluoromethyl group. Also, Rf 11 With Rf 12 They can also combine to form carbonyl groups. Especially Rf13 and Rf 14 Both are preferred if they contain fluorine atoms.

[1129] Specific examples of anions represented by equation (c1-5) are listed below, but are not limited to these. Furthermore, in the following equation, X... BI As mentioned above.

[1130] [Chemistry 452]

[1131]

[1132] [Chemistry 453]

[1133]

[1134] [Chemistry 454]

[1135]

[1136] [Chemistry 455]

[1137]

[1138] [Chemistry 456]

[1139]

[1140] [Chemistry 457]

[1141]

[1142] [Chemistry 458]

[1143]

[1144] [Chemistry 459]

[1145]

[1146] [Chemistry 460]

[1147]

[1148] [Chemistry 461]

[1149]

[1150] [Chemistry 462]

[1151]

[1152] [Chemistry 463]

[1153]

[1154] [Chemistry 464]

[1155]

[1156] [Chemistry 465]

[1157]

[1158] [Chemistry 466]

[1159]

[1160] [Chemistry 467]

[1161]

[1162] [Chemistry 468]

[1163]

[1164] [Chemistry 469]

[1165]

[1166] [Chemistry 470]

[1167]

[1168] [Chemistry 471]

[1169]

[1170] [Chemistry 472]

[1171]

[1172] [Chemistry 473]

[1173]

[1174] [Chemistry 474]

[1175]

[1176] [Chemistry 475]

[1177]

[1178] The aforementioned non-nucleophilic relative ions can also include the fluorobenzenesulfonic acid anion bonded to an aromatic group containing an iodine atom as described in Japanese Patent No. 6648726, the anion with an acid decomposition mechanism as described in International Publication No. 2021 / 200056 and Japanese Patent Application Publication No. 2021-70692, the anion with a cyclic ether group as described in Japanese Patent Application Publication No. 2018-180525 and Japanese Patent Application Publication No. 2021-35935, and the anion as described in Japanese Patent Application Publication No. 2018-92159.

[1179] The aforementioned non-nucleophilic relative ions can also be further described in Japanese Patent Application Publication Nos. 2006-276759, 2015-117200, 2016-65016 and 2019-202974 as sterically hindered benzenesulfonic acid derivatives without fluorine atoms, or in Japanese Patent Application Publication No. 6645464 as benzenesulfonic acid anions and alkylsulfonic acid anions bonded to aromatic compounds containing iodine atoms without fluorine atoms.

[1180] The aforementioned non-nucleophilic relative ions may further include the anions of disulfonic acid as described in Japanese Patent Application Publication No. 2015-206932, the anions of sulfonamides and sulfonamides as described in International Publication No. 2020 / 158366, which are sulfonic acid on one side and different from that side on the other side, and the anions of sulfonic acid and carboxylic acid as described in Japanese Patent Application Publication No. 2015-24989.

[1181] In equations (c2) and (c3), d1 and d2 are each independently 0, 1, 2 or 3, with 1 being preferred.

[1182] In equation (c4), e1 is 0 or 1. e2 is 0, 1, 2, 3 or 4. e3 is 0, 1, 2, 3 or 4. However, when e1 is 0, 0 ≤ e2 + e3 ≤ 4, and when e1 is 1, 0 ≤ e2 + e3 ≤ 6.

[1183] In equations (c2), (c3) and (c4), L 1 The bonds can be single bonds, ether bonds, ester bonds, carbonyl groups, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Among these, from a synthetic perspective, ether bonds, ester bonds, and carbonyl groups are more ideal, with ester bonds and carbonyl groups being even more desirable.

[1184] In equation (c2), Rf 1 and Rf 2 Each is independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Among these, Rf 1 and Rf 2 In order to increase the acid strength, fluorine atoms are preferred. Rf 3 and Rf 4Each is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Among these, Rf is used to improve solvent solubility. 3 and Rf 4 At least one of them is preferably trifluoromethyl.

[1185] In equation (c3), Rf 5 and Rf 6 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. However, all Rf... 5 and Rf 6 They are not all hydrogen atoms at the same time. Among these, in order to improve solvent solubility, Rf... 5 and Rf 6 At least one of them is preferably trifluoromethyl.

[1186] In equation (c4), Rf 7 It is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkyl thio group having 1 to 6 carbon atoms. Rf 7 The most desirable components are fluorine atom, trifluoromethyl, difluoromethyl, trifluoromethoxy, difluoromethoxy, trifluoromethylthio, or difluoromethylthio, with fluorine atom, trifluoromethyl, or trifluoromethoxy being even more desirable. When e2 is 2, 3, or 4, each Rf... 7 They can be the same or different.

[1187] In equation (c4), R 43 It is a halogen atom other than fluorine, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given and are described in the explanation of formula (1B) regarding R. 11 ~R 13 The examples representing hydrocarbon groups are the same, but not limited to these. Also, when e3 is 2, 3, or 4, each R... 43 They can be the same or different.

[1188] Furthermore, when e3 is 2, 3, or 4, multiple R... 43 They can also bond with each other and form rings together with the carbon atoms they are bonded to. Specific examples of rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, and adamantane rings. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, they may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[1189] Specific examples of the anion in repeating unit c2 can be listed below, but are not limited to these. Also, in the following formula, R... A As mentioned above, Me is a methyl group.

[1190] [Chemistry 476]

[1191]

[1192] [Chemistry 477]

[1193]

[1194] [Chemistry 478]

[1195]

[1196] [Chemistry 479]

[1197]

[1198] [Chemistry 480]

[1199]

[1200] [Chemistry 481]

[1201]

[1202] [Chemistry 482]

[1203]

[1204] [Chemistry 483]

[1205]

[1206] [Chemistry 484]

[1207]

[1208] [Chemistry 485]

[1209]

[1210] [Chemistry 486]

[1211]

[1212] [Chemistry 487]

[1213]

[1214] [Chemistry 488]

[1215]

[1216] Specific examples of the anion of repeating unit c3 can be listed below, but are not limited to these. Also, in the following formula, R... A As mentioned above.

[1217] [Chemistry 489]

[1218]

[1219] [Chemistry 490]

[1220]

[1221] [Chemistry 491]

[1222]

[1223] [Chemistry 492]

[1224]

[1225] [Chemistry 493]

[1226]

[1227] [Chemistry 494]

[1228]

[1229] [Chemistry 495]

[1230]

[1231] [Chemistry 496]

[1232]

[1233] [Chemistry 497]

[1234]

[1235] [Chemistry 498]

[1236]

[1237] [Chemistry 499]

[1238]

[1239] Specific examples of the anion in repeating unit c4 can be listed below, but are not limited to these. Also, in the following formula, R... A As mentioned above.

[1240] [Chemical 500]

[1241]

[1242] [Chemical 501]

[1243]

[1244] [Chemical 502]

[1245]

[1246] [Chemical 503]

[1247]

[1248] [Chemical 504]

[1249]

[1250] [Chemical 505]

[1251]

[1252] [Chemical 506]

[1253]

[1254] [Chemical 507]

[1255]

[1256] [Chem.508]

[1257]

[1258] [Chemical 509]

[1259]

[1260] [Chem.510]

[1261]

[1262] [Chem.511]

[1263]

[1264] [Chem.512]

[1265]

[1266] [Chem.513]

[1267]

[1268] [Chem.514]

[1269]

[1270] [Chem.515]

[1271]

[1272] [Chem.516]

[1273]

[1274] Specific examples of the anion in repeating unit c5 can be listed below, but are not limited to these. Also, in the following formula, R... A As mentioned above.

[1275] [Chem.517]

[1276]

[1277] In equations (c2) to (c5), A + The cation is a sulfonium cation. Examples of sulfonium cations include sulfonium cations, monium cations, and ammonium cations, but sulfonium cations and monium cations are preferred. Specific examples of the sulfonium cations mentioned above include those shown in Formula (1B), paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-3744, paragraphs

[0044] to

[0049] of International Publication No. 2024 / 128017, and paragraphs

[0035] to

[0046] of Japanese Patent Application Publication No. 7491173, but are not limited to these.

[1278] Furthermore, the aforementioned sulfonium cation represented by the formula (sulfo-1) is also ideal.

[1279] [Chem.518]

[1280]

[1281] In formula (sulfo-1), f1 is 0 or 1. When f1 is 0, it is a benzene ring; when f1 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with f1 of 0 is preferred. f2 is 0 or 1. When f2 is 0, it is a benzene ring; when f2 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with f2 of 0 is preferred. f3 is 0 or 1. When f3 is 0, it is a benzene ring; when f3 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with f3 of 0 is preferred.

[1282] In formula (sulfo-1), f4 is 0, 1, 2, 3, or 4. The more iodine atoms in the cationic structure, the higher the absorption for EUV, but the less solvent solubility there will be concerns about precipitation in the resist composition. Therefore, f4 is better if it is 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[1283] In formula (sulfo-1), f5 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, f5 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being more preferred. f6 is 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, f6 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being more preferred. f7 is 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, f7 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being more preferred.

[1284] In formula (sulfo-1), f8 is 0, 1, or 2. Considering the availability of raw materials, f8 being 0 or 1 is preferred. f9 is 0, 1, or 2. Considering the availability of raw materials, f9 being 0 or 1 is preferred. f10 is 0, 1, or 2. Considering the availability of raw materials, f10 being 0 or 1 is preferred.

[1285] In formula (sulfo-1), f11 is 0 or 1. When f11 is 0, it is a benzene ring; when f11 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with f11 of 0 is preferred.

[1286] In formula (sulfo-1), f12 is 0, 1, 2, 3, or 4. The more iodine atoms in the cationic structure, the higher the absorption, especially for EUV, but the less solvent solubility there will be concerns about precipitation in the resist composition. Therefore, f12 of 0, 1, 2, or 3 is preferred, with 0, 1, or 2 being even better.

[1287] In formula (sulfo-1), f13 is 0, 1, or 2. From the perspective of raw material availability, f13 being 0 or 1 is preferred. f14 is 0, 1, or 2. From a synthetic perspective, f14 being 0 or 1 is preferred.

[1288] However, when f1 is 0, 0 ≤ f6 + f9 ≤ 4; when f1 is 1, 0 ≤ f6 + f9 ≤ 6. When f2 is 0, 0 ≤ f7 + f10 ≤ 4; when f2 is 1, 0 ≤ f7 + f10 ≤ 6. When f3 is 0, 1 ≤ f4 + f5 + f8 + f14 ≤ 4; when f3 is 1, 1 ≤ f4 + f5 + f8 + f14 ≤ 6. When f11 is 0, 0 ≤ f12 + f13 ≤ 4; when f11 is 1, 0 ≤ f12 + f13 ≤ 6. Also, f4 + f12 ≥ 1.

[1289] In formula (sulfo-1), R F1 ~R F3 Each of these is independently a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms. Among these, trifluoromethyl, trifluoromethoxy, and trifluorothiomethoxy are preferred. When f5 is 2, 3, or 4, each R... F1 They can be the same or different. When f6 is 2, 3, 4, 5 or 6, each R F2They can be the same or different. When f7 is 2, 3, 4, 5 or 6, each R F3 They can be the same or different.

[1290] In formula (sulfo-1), R ct1 ~R ct4 The radical can be a halogen atom other than iodine or fluorine, a nitro group, a cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. The hydrocarbon group, hydrocarbon oxy group, and hydrocarbon thio group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given and described in the explanation of formula (1B) regarding R. 11 ~R 13 The examples of the hydrocarbon groups are the same. Furthermore, some or all of the hydrogen atoms in the hydrocarbon group, hydrocarbon oxygen group, and hydrocarbon sulfide group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned hydrocarbon group can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[1291] Also, when f8 is 2, there are 2 Rs. ct1 They can be the same or different, 2 Rs ct1 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When f9 is 2, there are 2 R atoms. ct2 They can be the same or different, 2 Rs ct2 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When f10 is 2, there are 2 R atoms. ct3 They can be the same or different, 2 Rs ct3 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When f13 is 2, there are 2 R atoms. ct4 They can be the same or different, 2 Rs ct4They can also bond with each other and form rings together with the carbon atoms they are bonded to. Specific examples of rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, and adamantane rings. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, they may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[1292] Furthermore, the sum of S in the sulfonium cation represented by formula (sulfo-1) + Directly bonded aromatic rings can also bond to each other and with S + Together they form a ring. Specific examples of the aforementioned ring structure can be represented by the following formulas, etc.

[1293] [Chem.519]

[1294]

[1295] In the formula, the dashed lines represent atomic bonds.

[1296] In formula (sulfo-1), L C and L D Each bond can be independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Among these, L... C Single bonds, ether bonds, ester bonds, or sulfonate bonds are preferred, with ester bonds or sulfonate bonds being even more preferred. L D Single bonds, ether bonds, or ester bonds are preferred, with single bonds being even better.

[1297] In formula (sulfo-1), X L2 It is a single-bonded or heteroatom-containing hydrocarbon group with 1 to 40 carbon atoms. The aforementioned hydrocarbon group can be linear, branched, or cyclic; specific examples include alkyldiyl, cyclic saturated hydrocarbon groups, and arylyl groups. Specific examples of the aforementioned heteroatom include oxygen, nitrogen, and sulfur atoms. X L2 Specific examples of hydrocarbon groups containing 1 to 40 carbon atoms, which may also represent heteroatoms, can be given and illustrated in the explanation of formula (1A) for X. L1 The example shown is X, which may also contain a heteroatom and a hydrocarbon group with 1 to 40 carbon atoms. L -0~X L -58. Among these, X L -0~X L -22, X L -29~X L-34, and X L -47~X L -58 is the optimal value.

[1298] The sulfonium cation represented by formula (sulfo-1) is preferably represented by formula (sulfo-1-1).

[1299] [Chem.520]

[1300]

[1301] In the formula, f4~f10, f12~f14, R F1 ~R F3 R ct1 ~R ct4 L C L D and X L2 As mentioned above.

[1302] The sulfonium cation represented by formula (sulfo-1-1) is preferably represented by formula (sulfo-1-2).

[1303] [Chem.521]

[1304]

[1305] In the formula, f4~f10, R F 1 ~R F3 and R ct1 ~R ct3 As mentioned above.

[1306] Specific examples of sulfonium cations represented by formula (sulfo-1) are listed below, but are not limited to these. Also, in the following formula, Me is a methyl group.

[1307] [Chem.522]

[1308]

[1309] [Chem.523]

[1310]

[1311] [Chem.524]

[1312]

[1313] [Chem.525]

[1314]

[1315] [Chem.526]

[1316]

[1317] [Chem.527]

[1318]

[1319] [Chem.528]

[1320]

[1321] [Chem. 529]

[1322]

[1323] [Chem.530]

[1324]

[1325] [Chemistry 531]

[1326]

[1327] [Chemistry 532]

[1328]

[1329] [Chem.533]

[1330]

[1331] [Chemistry 534]

[1332]

[1333] [Chem.535]

[1334]

[1335] [Chemistry 536]

[1336]

[1337] [Chem.537]

[1338]

[1339] [Chem.538]

[1340]

[1341] [Chemistry 539]

[1342]

[1343] [Chem.540]

[1344]

[1345] [Chemistry 541]

[1346]

[1347] [Chemistry 542]

[1348]

[1349] [Chem.543]

[1350]

[1351] [Chemistry 544]

[1352]

[1353] [Chem.545]

[1354]

[1355] [Chemistry 546]

[1356]

[1357] [Chemistry 547]

[1358]

[1359] [Chem.548]

[1360]

[1361] [Chemistry 549]

[1362]

[1363] Specific examples of the aforementioned citric acid can be found in paragraph

[0181] of Japanese Patent Application Publication No. 2024-259, but are not limited to these.

[1364] Specific examples of the aforementioned ammonium cations can be represented by the following formula (am-1).

[1365] [Chemical 550]

[1366]

[1367] In equation (am-1), R ct5 ~R ct8 Each can independently be a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. Also, R ct5 and R ct6They can also bond to each other and form rings together with the nitrogen atoms they are bonded to. Specific examples of the aforementioned hydrocarbon groups can be given and are described in the explanation of formula (1B) regarding R. 11 ~R 13 The hydrocarbon group shown is an example of the same.

[1368] Specific examples of ammonium cations represented by formula (am-1) are listed below, but are not limited to these.

[1369] [Chemistry 551]

[1370]

[1371] The specific structures of repeating units c1 to c5 can be exemplified by any combination of the aforementioned anions and cations.

[1372] Among the repeating units c1 to c5, considering the acid diffusion control, repeating units c2 to c5 are more ideal; considering the acid strength of the produced acid, repeating units c2, c4, and c5 are better; and considering the solvent solubility, repeating unit c2 is more ideal.

[1373] The aforementioned polymer may also contain repeating units (hereinafter also referred to as repeating units d) that have a structure in which hydroxyl groups are protected by acid-indestructible groups. Repeating units d are not particularly limited as long as they have a structure in which one or more hydroxyl groups are protected and the protecting groups are decomposed by acid to generate hydroxyl groups. However, those represented by the following formula (d1) are preferred.

[1374] [Chem.552]

[1375]

[1376] In equation (d1), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 41 It can also contain a (g+1) valence hydrocarbon group with 1 to 30 carbon atoms, which may contain heteroatoms. R 42 It is an acid-labile group. g can be 1, 2, 3, or 4.

[1377] In equation (d1), R 41 The acid-unstable group can be any group that undergoes deprotection and generates a hydroxyl group due to acid action. R 41 The structure is not particularly limited, but acetal, ketal, hydrocarbon carbonyl, and hydrocarbon oxymethyl represented by formula (d2) are more ideal, especially hydrocarbon oxymethyl represented by formula (d2).

[1378] [Chem.553]

[1379]

[1380] In the formula, * represents an atomic bond. R43 is a hydrocarbon group having 1 to 15 carbon atoms.

[1381] R 43 Specific examples of the acid-labile group represented by, the hydroxymethyl group represented by formula (d2), and the repeating unit d can be the same as those exemplified in the description of the repeating unit d described in JP-A-2020-111564.

[1382] The aforementioned polymer may also contain a repeating unit e derived from indene, benzofuran, benzothiophene, vinylnaphthalene, chromone, coumarin, norbornadiene or their derivatives. Specific examples of the monomer providing the repeating unit e are listed below, but are not limited to these.

[1383] [Chemical formula 554]

[1384]

[1385] The aforementioned polymer may also contain a repeating unit f derived from indan, vinylpyridine or vinylcarbazole.

[1386] In the aforementioned polymer, the content ratios of the repeating units a1, a2, a3, b1, b2, c1 to c5, d, e and f are preferably 0 < a1 ≤ 0.8, 0 ≤ a2 ≤ 0.8, 0 ≤ a3 ≤ 0.6, 0 ≤ b1 ≤ 0.6, 0 ≤ b2 ≤ 0.6, 0 ≤ c1 ≤ 0.4, 0 ≤ c2 ≤ 0.4, 0 ≤ c3 ≤ 0.4, 0 ≤ c4 ≤ 0.4, 0 ≤ c5 ≤ 0.4, 0 ≤ d ≤ 0.5, 0 ≤ e ≤ 0.3 and 0 ≤ f ≤ 0.3, more preferably 0 < a1 ≤ 0.7, 0 ≤ a2 ≤ 0.7, 0 ≤ a3 ≤ 0.5, 0 ≤ b1 ≤ 0.5, 0 ≤ b2 ≤ 0.5, 0 ≤ c1 ≤ 0.3, 0 ≤ c2 ≤ 0.3, 0 ≤ c3 ≤ 0.3, 0 ≤ c4 ≤ 0.3, 0 ≤ c5 ≤ 0.3, 0 ≤ d ≤ 0.3, 0 ≤ e ≤ 0.3 and 0 ≤ f ≤ 0.3. However, a1 + a2 + a3 + b1 + b2 + c1 + c2 + c3 + c4 + d + e + f ≤ 1.0.

[1387] The weight average molecular weight (Mw) of the aforementioned polymer is preferably 1000 to 500000, more preferably 3000 to 100000. If Mw is within this range, sufficient etching resistance can be obtained, and there is no concern about a decrease in resolution due to the inability to ensure the difference in dissolution rate before and after exposure. Also, in the present invention, Mw is a polystyrene conversion measurement value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or N,N-dimethylformamide (DMF) as a solvent.

[1388] Regarding the aforementioned polymer molecular weight distribution (Mw / Mn), considering that the influence of Mw / Mn tends to increase as the pattern becomes more regular and refined, a narrow dispersion of Mw / Mn of 1.0 to 2.0 is preferable to obtain a resist composition suitable for fine pattern sizes. If it falls within the aforementioned range, there will be fewer low-molecular-weight and high-molecular-weight polymers, and there is no risk of foreign matter appearing on the pattern or the pattern shape deteriorating after exposure.

[1389] The aforementioned polymer synthesis method, for example, involves placing the monomer to which the aforementioned repeating unit is given in an organic solvent, adding a free radical polymerization initiator, and heating to polymerize it.

[1390] Specific examples of organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, dioxane, cyclohexane, cyclopentane, methyl ethyl ketone (MEK), propylene glycol monomethyl ether acetate (PGMEA), and γ-butyrolactone (GBL). Specific examples of polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylpentanonitrile), 2,2-azobis(2-methylpropionic acid) dimethyl ester, 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, and lauroyl peroxide. The optimal amount of these initiators relative to the total monomers to be polymerized is 0.01–25 mol%. A reaction temperature of 50–150°C is ideal, with 60–100°C being more ideal. A reaction time of 2–24 hours is ideal; considering production efficiency, 2–12 hours is more ideal.

[1391] The aforementioned polymerization initiator can be added to the monomer solution and supplied to the reactor, or a separate initiator solution can be prepared and supplied to the reactor independently. During the standby time, free radicals generated from the initiator may cause the polymerization reaction to proceed, potentially forming ultra-high molecular weight polymers. Therefore, from a quality control perspective, it is preferable to prepare and add the monomer solution and initiator solution independently. Acid-labile groups can be used directly from the monomer, or they can be protected or partially protected after polymerization. Furthermore, to adjust the molecular weight, known chain transfer agents such as dodecyl mercaptan and 2-mercaptoethanol can be used. In this case, the amount of these chain transfer agents added relative to the total amount of monomers to be polymerized is preferably 0.01 to 20 mol%.

[1392] When the monomer contains hydroxyl groups, the hydroxyl groups can be replaced with acetal groups such as ethoxy-ethoxy, which are easily deprotected by acids, before polymerization. After polymerization, deprotection can be carried out using weak acids and water. Alternatively, acetyl, formyl, neopentyl, etc., can be replaced first, and alkaline hydrolysis can be performed after polymerization.

[1393] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, hydroxystyrene or hydroxyvinylnaphthalene and other monomers can be added to an organic solvent with a free radical polymerization initiator and then heated for polymerization. Alternatively, acetoxystyrene or acetoxyvinylnaphthalene can be used, and after polymerization, the acetoxy groups can be deprotected by alkaline hydrolysis to become polyhydroxystyrene or hydroxypolyvinylnaphthalene.

[1394] Specific examples of alkalis used in alkaline hydrolysis include ammonia and triethylamine. Furthermore, the preferred reaction temperature is -20 to 100°C, more preferably 0 to 60°C. The preferred reaction time is 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[1395] Furthermore, the amount of each monomer in the aforementioned monomer solution can be appropriately set to the ideal content ratio of the aforementioned repeating units.

[1396] The polymer obtained by the aforementioned manufacturing method can be treated as a final product by either the reaction solution obtained from the polymerization reaction or by the powder obtained through refining steps such as adding the polymer liquid to a poor solvent and obtaining powder by reprecipitation. Considering the perspectives of work efficiency and quality stabilization, it is better to treat the polymer solution obtained by dissolving the powder obtained in the refining step into the solvent as the final product.

[1397] Specific examples of solvents used at this time can be found in paragraphs

[0144] to

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

[1398] In the aforementioned polymer solution, a polymer concentration of 0.01–30% by mass is ideal, and 0.1–20% by mass is even more ideal.

[1399] It is preferable to filter the aforementioned reaction solutions and polymer solutions using a filter. By filtering, foreign matter and gel that may cause defects can be removed, which is effective in stabilizing the quality.

[1400] The materials used in the aforementioned filters include fluorocarbon, cellulose, nylon, polyester, and hydrocarbon-based materials. For the filtration step involving the resist composition, filters made of fluorocarbon materials such as Teflon (a registered trademark), or hydrocarbon materials such as polyethylene or polypropylene, or nylon, are preferred. The pore size of the filter can be appropriately selected according to the target cleanliness level, preferably below 100 nm, and more preferably below 20 nm. Furthermore, these filters can be used individually or in combination. The filtration method can involve passing the solution through only once, but multiple filtrations with solution circulation are preferable. The filtration steps in the polymer manufacturing step can be performed in any order and number of times, but filtering the reaction solution, polymer solution, or both after the polymerization reaction is preferred.

[1401] (B) A single base polymer may be used alone, or two or more polymers with different composition ratios, Mw and / or Mw / Mn ratios may be used in combination. Furthermore, (B) the base polymer may contain hydrides of ring-opening metathesis polymers in addition to the aforementioned polymers; in this regard, the polymer disclosed in Japanese Patent Application Publication No. 2003-66612 may be used.

[1402] [(C) Organic solvent]

[1403] The chemically amplified resist composition of the present invention may also contain an organic solvent as component (C). There are no particular limitations on the organic solvent (C), as long as it can dissolve the aforementioned components and the components described below. Specific examples of such organic solvents include ketones such as cyclopentanone, cyclohexanone, and methyl-2-n-pentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ketols such as DAA; ethers such as PGME, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate; lactones such as GBL; and mixed solvents thereof.

[1404] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, cyclohexanone, GBL, ethyl lactate, DAA, and their mixtures are preferred as they exhibit particularly excellent solubility in the base polymer of component (B).

[1405] In the chemically amplified resist composition of the present invention, the content of (C) organic solvent is ideally 200-5000 parts by mass relative to 80 parts by mass of (B) base polymer, and more ideally 400-3500 parts by mass. (C) Organic solvent can be used alone or in combination of two or more.

[1406] [(D) Quencher]

[1407] The chemically amplified resist composition of the present invention may also contain a quencher as the component (D). Further, in the present invention, the quencher refers to a material that prevents the acid generated from the photoacid generator in the chemically amplified resist composition from diffusing into the unexposed portion and is used to form a desired pattern.

[1408] (D) The quencher may include an onium salt represented by the following formula (2) or (3).

[1409] [Chemical formula 555]

[1410]

[1411] In formula (2), R q1 is a hydrogen atom, or a hydrocarbon group having 1 to 40 carbon atoms that may also contain heteroatoms, excluding the hydrogen atom bonded to the α-position carbon atom of the sulfonyl group that is substituted by a fluorine atom or a fluoroalkyl group. In formula (3), R q2 is a hydrogen atom, or a hydrocarbon group having 1 to 40 carbon atoms that may also contain heteroatoms.

[1412] The hydrocarbon group represented by R q1 Specific examples include alkyl groups having 1 to 40 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, etc.; cycloaliphatic saturated hydrocarbon groups having 3 to 40 carbon atoms such as cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6 decyl, adamantyl, etc.; aryl groups having 6 to 40 carbon atoms such as phenyl, naphthyl, anthryl, etc. Further, a part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing heteroatoms such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, etc., and a part of -CH2- of the aforementioned hydrocarbon group may also be substituted by a group containing heteroatoms such as an oxygen atom, a sulfur atom, a nitrogen atom, etc. As a result, it may also contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-O-C(=O)-), a fluoroalkyl group, etc.

[1413] The hydrocarbon group represented by R q2 Specific examples include the substituents exemplified for the specific examples of R q1 , and in addition, fluorinated saturated hydrocarbon groups such as trifluoromethyl, trifluoroethyl, etc., and fluorinated aryl groups such as pentafluorophenyl, 4-trifluoromethylphenyl, etc. may also be mentioned.

[1414] Specific examples of the anion of the onium salt represented by formula (2) are listed below, but are not limited to these.

[1415] [Chem.556]

[1416]

[1417] [Chem.557]

[1418]

[1419] [Chem.558]

[1420]

[1421] [Chem.559]

[1422]

[1423] [Transformation 560]

[1424]

[1425] Specific examples of onium salt anions represented by equation (3) are listed below, but are not limited to these.

[1426] [Chem.561]

[1427]

[1428] [Chem.562]

[1429]

[1430] [Chem.563]

[1431]

[1432] [Chem.564]

[1433]

[1434] [Chem.565]

[1435]

[1436] In equations (2) and (3), Mq +The aforementioned onium cations include sulfonium cations, monium cations, and ammonium cations. Specific examples of the aforementioned sulfonium cations include those represented by formula (1B), paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-3744, paragraphs

[0044] to

[0049] of International Publication No. 2024 / 128017, paragraphs

[0035] to

[0046] of Japanese Patent Application Publication No. 7491173, and those represented by formula (sulfo-1), but are not limited to these. Specific examples of monium cations include those represented by paragraph

[0181] of Japanese Patent Application Publication No. 2024-259, but are not limited to these. Specific examples of the aforementioned ammonium cations include those represented by the formula (am-1).

[1437] Specific examples of onium salts represented by formula (2) or (3) can be any combination of the aforementioned anions and cations. Furthermore, these onium salts can be easily prepared using ion exchange reactions employing known organic chemical methods. For example, Japanese Patent Application Publication No. 2007-145797 can be consulted regarding ion exchange reactions.

[1438] The onium salts represented by formula (2) or (3) act as quenchers in the chemically amplified resist composition of the present invention. This is because the relative anions of the aforementioned onium salts are conjugate bases of weak acids. Here, a weak acid is defined as an acid that exhibits an acidity that cannot deprotect the acid-instable group of a unit containing an acid-instable group used in the base polymer. The onium salts represented by formula (2) or (3) act as quenchers when used in combination with a conjugate base of a strong acid, such as sulfonic acid with α-fluorination, as an onium salt-type photoacid generator with a relative anion. That is, when an onium salt that generates a strong acid, such as sulfonic acid with α-fluorination, is used in combination with an onium salt that generates a weak acid, such as unfluorinated sulfonic acid or carboxylic acid, the strong acid generated from the photoacid generator due to high-energy radiation irradiation collides with the onium salt having unreacted weak acid anions, resulting in the release of weak acid and the generation of an onium salt having strong acid anions due to salt exchange. In this process, the strong acid is exchanged for a weak acid with lower catalytic ability, so the acid appears to be deactivated and the diffusion of acid can be controlled.

[1439] Furthermore, the quenching agent for component (D) may be an onium salt having a sulfonium cation and a benzene oxide anion site in the same molecule as disclosed in Japanese Patent No. 6848776, an onium salt having a sulfonium cation and a carboxylate anion site in the same molecule as disclosed in Japanese Patent No. 6583136 and Japanese Patent Application Publication No. 2020-200311, and an onium salt having a monazine cation and a carboxylate anion site in the same molecule as disclosed in Japanese Patent No. 6274755.

[1440] Here, when the photoacid generator producing a strong acid is an onium salt, as mentioned above, the strong acid produced by high-energy ray irradiation can be exchanged for a weak acid. However, on the other hand, the weak acid produced by high-energy ray irradiation is considered unlikely to collide with the unreacted onium salt that produces the strong acid, thus avoiding salt exchange. This is because onium cations readily form ion pairs with the anions of stronger acids.

[1441] When the chemically amplified resist composition of the present invention contains an onium salt represented by formula (2) or (3) as a quencher in (D), its content is ideally 0.1 to 20 parts by mass relative to 80 parts by mass of the base polymer in (B), and even more ideally 0.1 to 10 parts by mass. If the content of the aforementioned onium salt-type quencher is within the aforementioned range, the resolution is good and the sensitivity will not decrease significantly, thus it is ideal. The onium salt represented by formula (2) or (3) can be used alone or in combination of two or more.

[1442] The chemically amplified resist composition of the present invention may also contain a nitrogen-containing compound as a (D) quencher. Specific examples of the aforementioned nitrogen-containing compounds include primary, secondary, or tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Publication No. 2008-111103, particularly amine compounds having hydroxyl groups, ether bonds, ester bonds, lactone rings, cyano groups, or sulfonate bonds. Furthermore, compounds such as those described in Japanese Patent No. 3790649, which are compounds in which a primary or secondary amine is protected with a carbamate group, may also be cited.

[1443] Furthermore, nitrogen-containing compounds can also be sulfonate sulfonates with nitrogen-containing substituents. Such compounds act as quenchers in the unexposed areas, but lose their quenching ability in the exposed areas due to neutralization with their own generated acid, thus acting as so-called photodegrading bases. By using photodegrading bases, the contrast between the exposed and unexposed areas can be enhanced. For example, Japanese Patent Application Publication Nos. 2009-109595 and 2012-46501 can be found on photodegrading bases.

[1444] When the chemically amplified resist composition of the present invention contains a nitrogen-containing compound as a quencher in component (D), its content is preferably 0.001 to 12 parts by mass relative to 80 parts by mass of the base polymer (B), and more preferably 0.01 to 8 parts by mass. The aforementioned nitrogen-containing compound may be used alone or in combination of two or more.

[1445] [(E) Other photoacid generating agents]

[1446] The chemically amplified resist composition of the present invention may also contain a photoacid generator (hereinafter also referred to as other photoacid generators) other than component (A) as component (E). There are no particular limitations on the aforementioned other photoacid generators as long as they are compounds that generate acid due to high-energy radiation. Ideal other photoacid generators can be represented by the following formula (4) or (5).

[1447] [Chem.566]

[1448]

[1449] In equation (4), R 101 ~R 105 Each group consists independently of a halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 20 carbon atoms. Also, R 101 R 102 and R 103 Any two of them can also bond to each other and form a ring together with the sulfur atoms they are bonded to. Specific examples of the aforementioned hydrocarbon groups can be given and explained in the description of formula (1B) regarding R. 11 ~R 13 The hydrocarbon group shown is an example of the same.

[1450] Specific examples of sulfonium salt cations represented by formula (4) may include those represented by formula (1B), paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-3744, paragraphs

[0044] to

[0049] of International Publication No. 2024 / 128017, paragraphs

[0035] to

[0046] of Japanese Patent Application Publication No. 7491173, and specific examples of sulfonium cations represented by formula (sulfo-1), but are not limited to these. Specific examples of ferrous salt cations represented by formula (5) may include those represented by paragraph

[0181] of Japanese Patent Application Publication No. 2024-259, but are not limited to these.

[1451] In equations (4) and (5), Xa - It is the anion of a strong acid. Specific examples of the anions of the aforementioned strong acids can be represented by any one of the formulas (c1-1) to (c1-5).

[1452] Furthermore, it is also ideal for other photoacid generators of component (E) to be represented by the following formula (6).

[1453] [Chem.567]

[1454]

[1455] In equation (6), R 201 and R 202 Each can independently be a hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. R 203 It can also contain a hydrocarbon group with 1 to 30 carbon atoms and a heteroatom. Also, R 201 R 202 and R 203 Any two of them can also bond to each other and form a ring together with the sulfur atoms they are bonded to.

[1456] R 201 and R 202 The hydrocarbon groups representing 1 to 30 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornel, oxanorbornel, and tricyclic [5.2.1.0]. 2,6 ] Decyl, adamantyl, and other cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms; phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl, anthracene, and other aryl groups with 6 to 30 carbon atoms; groups obtained by combining them, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned hydrocarbon group may also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[1457] R 203The alkylene groups representing carbon atoms from 1 to 30 can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, and hexadecane-1,16-diyl. Alkyl groups with 1 to 30 carbon atoms, such as heptadecanyl-1,17-diyl; cyclopentanediyl, cyclohexanediyl, norcamphenediyl, adamantanediyl, and other cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms; 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 the aforementioned alkylene group can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned alkylene group can be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This can result in the presence of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), or haloalkyl groups. Oxygen atoms are preferred as the aforementioned heteroatom.

[1458] In equation (6), L 21 It is a hydrocarbon group with 1 to 20 carbon atoms, which can be a single bond, an ether bond, or may contain heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given in R. 203 The examples representing the alkylene groups are the same.

[1459] In equation (6), X a X b X c and X d Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. But X a X b X c and X d At least one of them is a fluorine atom or a trifluoromethyl group.

[1460] The photoacid generator represented by formula (6) is preferably represented by formula (6').

[1461] [Chem.568]

[1462]

[1463] In equation (6'), L 21 As mentioned before. X e It can be a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R 301 R 302 and R 303 Each hydrocarbon group consists independently of a hydrogen atom, or may contain heteroatoms, and has 1 to 20 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given by R in formula (c1-1-1). fa1 The hydrocarbon groups represented are examples of the same. p and q are each independently 0, 1, 2, 3, 4 or 5, and r is 0, 1, 2, 3 or 4.

[1464] Specific examples of photoacid generators represented by formula (6) are the same as those represented by formula (2) in Japanese Patent Application Publication No. 2017-26980.

[1465] Among the aforementioned photoacid generators, those containing anions represented by formula (c1-1-1) or (c1-4) exhibit low acid diffusion and excellent solvent solubility, making them particularly desirable. Furthermore, those represented by formula (6') exhibit extremely low acid diffusion, making them particularly desirable.

[1466] When the chemically amplified resist composition of the present invention contains other photoacid generating agents (E), the content of which is preferably 0.1 to 40 parts by mass relative to 80 parts by mass of the base polymer (B), and more preferably 0.5 to 20 parts by mass. If the amount of photoacid generating agent (E) added is within the aforementioned range, the resolution is good, and there is no risk of foreign matter occurring after development or during peeling of the resist film, thus it is ideal. Other photoacid generating agents (E) can be used alone or in combination of two or more.

[1467] [(F) Surfactant]

[1468] The chemically amplified resist composition of the present invention may also contain a surfactant as component (F). The surfactant (F) is preferably a surfactant that is insoluble or sparingly soluble in water but soluble in alkaline developer, or a surfactant that is insoluble or sparingly soluble in both water and alkaline developer. Such surfactants can be referred to in Japanese Patent Application Publication Nos. 2010-215608 and 2011-16746.

[1469] Among the surfactants described in the aforementioned publication, those that are insoluble or poorly soluble in water and alkaline developing solutions are preferred, including FC-4430 (manufactured by 3M), surflon (registered trademark) S-381 (manufactured by AGC Seimichemical), OLFINE (registered trademark) E1004 (manufactured by Nissin Chemical Industry), KH-20, KH-30 (manufactured by AGC Seimichemical), and oxobutane ring-opening polymers represented by the following formula (surf-1).

[1470] [Chem.569]

[1471]

[1472] Here, R, Rf, A, B, C, m, and n are not limited to the foregoing description, but only apply to formula (surf-1). R is an aliphatic group with 2 to 5 carbon atoms in a 2 to 4-valent configuration. Examples of 2-valent aliphatic groups include ethylene, 1,4-butylene, 1,2-propylene, 2,2-dimethyl-1,3-propylene, and 1,5-pentylene, while examples of 3- or 4-valent groups include the following.

[1473] [Chemistry 570]

[1474]

[1475] In the formula, the dashed lines represent atomic bonds, each of which is a partial structure derived from glycerol, trimethylolethane, trimethylolpropane, and neopentyl tertrol.

[1476] Among these, 1,4-butylene and 2,2-dimethyl-1,3-propylene are preferred.

[1477] Rf is trifluoromethyl or pentafluoroethyl, preferably trifluoromethyl. m is an integer from 0 to 3, n is an integer from 1 to 4, and the sum of n and m is the valence of R, which is an integer from 2 to 4. A is 1. B is an integer from 2 to 25, preferably an integer from 4 to 20. C is an integer from 0 to 10, preferably 0 or 1. Furthermore, the arrangement of the constituent units in formula (surf-1) is not specified; they can be block bonds or random bonds. For details on the manufacture of surfactants based on partially fluorinated oxyheterocyclic butane ring-opening polymer systems, please refer to the specification in US Patent No. 5,650,483, etc.

[1478] Surfactants that are insoluble or sparingly soluble in water but soluble in alkaline developers can reduce water penetration and leaching when used in ArF photolithography without a resist protective film, by aligning with the surface of the resist film. Therefore, they inhibit the leaching of water-soluble components from the resist film and reduce damage to the exposure equipment, making them useful. Furthermore, they are soluble in alkaline solutions after exposure or post-exposure baking (PEB) and are less likely to become foreign matter causing defects, making them useful as well. Such surfactants, possessing properties of being insoluble or sparingly soluble in water but soluble in alkaline developers, are polymeric surfactants, also known as hydrophobic resins. Those with high water repellency and improved hydrophobicity are particularly desirable.

[1479] Specific examples of such polymeric surfactants include those containing at least one repeating unit selected from any of the following formulas (7A) to (7E).

[1480] [Chemistry 571]

[1481]

[1482] In equations (7A) to (7E), R B It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. W 1 It can be -CH2-, -CH2CH2-, -O-, or two separate -H groups. R s1 Each is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. R s2 It is a single bond, or a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms. R s3 Each is independently a hydrogen atom, a hydrocarbon group with 1 to 15 carbon atoms, a fluorinated hydrocarbon group, or an acid-labile group. R s3 When the group is a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond or a carbonyl group may also be inserted between the carbon-carbon bonds. s4 It is a (u+1) valence hydrocarbon group or a fluorinated hydrocarbon group with 1 to 20 carbon atoms. u can be 1, 2, or 3. R s5 Each is independently a hydrogen atom, or -C(=O)-OR sa The group indicated by R. sa It is a fluorinated hydrocarbon group with 1 to 20 carbon atoms. R s6 It is a hydrocarbon group or fluorinated hydrocarbon group with 1 to 15 carbon atoms, and an ether bond or carbonyl group may be inserted between the carbon-carbon bonds.

[1483] R s1Ideally, the hydrocarbon group representing 1 to 10 carbon atoms should be a saturated hydrocarbon group, and it can be any of the following: linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and cyclic saturated hydrocarbon groups with 3 to 10 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornel. Among these, those with 1 to 6 carbon atoms are preferred.

[1484] R s2 Ideally, the represented hydrocarbon group should be a saturated hydrocarbon group, which can be linear, branched, or cyclic. Specific examples include methylene, ethylene, propylene, butylene, and pentylene.

[1485] R s3 or R s6 The hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include saturated hydrocarbon groups, alkenyl groups, alkynyl groups, and other aliphatic unsaturated hydrocarbon groups, but saturated hydrocarbon groups are preferred. Specific examples of the aforementioned saturated hydrocarbon groups include R... s1 Examples of hydrocarbon groups that can be represented include undecyl, dodecyl, thiol, tetradecyl, and decadecyl groups. s3 or R s6 Examples of fluorinated hydrocarbon groups include those in which some or all of the hydrogen atoms bonded to the carbon atoms of the aforementioned hydrocarbon groups are replaced by fluorine atoms. As mentioned above, ether bonds or carbonyl groups may also be inserted between these carbon-carbon bonds.

[1486] R s3 Specific examples of acid-instable groups include groups represented by the aforementioned formulas (AL-3) to (AL-5), trialkylsilyl groups where each alkyl group has 1 to 6 carbon atoms, and alkyl groups containing oxygen substituents with 4 to 20 carbon atoms.

[1487] R s4 The (u+1) valence hydrocarbon group or fluorinated hydrocarbon group can be straight-chain, branched, or cyclic. Specific examples include groups obtained by further removing u hydrogen atoms from the aforementioned hydrocarbon group or fluorinated hydrocarbon group.

[1488] R saIdeally, the fluorinated hydrocarbon group should be saturated; it can be linear, branched, or cyclic. Specific examples include hydrocarbon groups in which some or all of the hydrogen atoms are replaced by fluorine atoms. Examples include trifluoromethyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoro-1-propyl, 3,3,3-trifluoro-2-propyl, 2,2,3,3-tetrafluoropropyl, 1,1,1,3,3,3-hexafluoroisopropyl, 2,2,3,3,4,4,4-heptafluorobutyl, 2,2,3,3,4,4,5,5-octafluoropentyl, 2,2,3,3,4,4,5,5,6,6,7,7-dodecylheptyl, 2-(perfluorobutyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorooctyl)ethyl, 2-(perfluorodecyl)ethyl, etc.

[1489] Specific examples of repeating units represented by any of equations (7A) to (7E) are listed below, but are not limited to these. Furthermore, in the following equation, R... B As mentioned above.

[1490] [Chemistry 572]

[1491]

[1492] [Chem.573]

[1493]

[1494] [Chemistry 574]

[1495]

[1496] [Chem.575]

[1497]

[1498] [Chemistry 576]

[1499]

[1500] [Chemistry 577]

[1501]

[1502] The aforementioned polymeric surfactants may also contain repeating units other than those represented by formulas (7A) to (7E). Specific examples of other repeating units include repeating units obtained from methacrylic acid, α-trifluoromethacrylic acid derivatives, etc. In polymeric surfactants, it is ideal for the content of repeating units represented by formulas (7A) to (7E) to be 20 mol% or more of all repeating units, more preferably 60 mol% or more, and more preferably 100 mol%.

[1503] For the aforementioned polymeric surfactants, a Mw of 1,000–500,000 is ideal, and 3,000–100,000 is even more ideal. An Mw / Mn ratio of 1.0–2.0 is ideal, and 1.0–1.6 is even more ideal.

[1504] One method for synthesizing the aforementioned polymeric surfactants includes polymerizing a monomer containing unsaturated bonds, comprising repeating units represented by formulas (7A) to (7E) and other repeating units as needed, in an organic solvent by adding a free radical initiator and heating. Examples of organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, and dioxane. Examples of polymerization initiators include AIBN, 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid), benzoyl peroxide, and lauroyl peroxide. A reaction temperature of 50–100°C is preferred. A reaction time of 4–24 hours is preferred. Acid-labile groups can be directly used from monomers, or they can be protected or partially protected after polymerization.

[1505] When synthesizing the aforementioned polymeric surfactants, known chain-transfer agents such as dodecyl mercaptan and 2-mercaptoethanol can be used to adjust the molecular weight. In this case, the amount of these chain-transfer agents added relative to the total molar percentage of the monomers to be polymerized is preferably 0.01 to 10 mol%.

[1506] When the chemically amplified resist composition of the present invention contains (F) surfactant, its content is ideally 0.1 to 50 parts by mass relative to 80 parts by mass of the (B) base polymer, and more ideally 0.5 to 10 parts by mass. If the content of (F) surfactant is 0.1 parts by mass or more, the receding contact angle between the resist film surface and water will be sufficiently increased; if it is 50 parts by mass or less, the dissolution rate of the resist film surface to the developer is low, and the height of the formed fine pattern can be sufficiently maintained. (F) Surfactant can be used alone or in combination of two or more.

[1507] [(G) Other ingredients]

[1508] The chemically amplified resist composition of the present invention may also contain compounds that decompose due to acid and produce acid (acid-increasing compounds), organic acid derivatives, fluorinated alcohols, and compounds with a Mw of 3000 or less that cause changes in solubility in the developer due to acid action (dissolution inhibitors) as other components (G). The aforementioned acid-increasing compounds can refer to the compounds described in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608. When containing the aforementioned acid-increasing compounds, an amount of 0 to 5 parts by mass relative to 80 parts by mass of the base polymer (B) is ideal, and 0 to 3 parts by mass is more ideal. If the amount is too high, acid diffusion control becomes difficult, and sometimes degradation of resolvability and pattern shape may occur. The aforementioned organic acid derivatives, fluorinated alcohols, and dissolution inhibitors can refer to the compounds described in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608.

[1509] [Pattern Formation Method]

[1510] The pattern forming method of the present invention includes the following steps: forming a resist film on a substrate using the aforementioned chemically amplified resist composition, exposing the aforementioned resist film to high-energy rays, and developing the aforementioned exposed resist film using a developing solution.

[1511] The aforementioned substrate can be, for example, a substrate used for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective film, etc.) or a substrate used for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.).

[1512] The resist film can be formed by coating the aforementioned chemically amplified resist composition onto a substrate by methods such as spin coating, with a film thickness preferably being 0.05 to 2 μm, and then pre-baking it on a hot plate, preferably at 60 to 150°C for 1 to 10 minutes, more preferably at 80 to 140°C for 1 to 5 minutes.

[1513] High-energy rays used for photoresist film exposure include KrF excimer lasers, ArF excimer lasers, EB, and EUV with wavelengths of 3–15 nm. When using KrF excimer lasers, ArF excimer lasers, or EUV, a mask used to form the desired pattern can be used to achieve an optimal exposure dose of 1–200 mJ / cm². 2 The optimal value is 10–100 mJ / cm³. 2 Irradiation is performed in a specific manner. When using EB, a mask is used to form the desired pattern, or direct irradiation is employed, with the optimal exposure level being 1–300 μC / cm. 2 It is better to achieve a temperature of 10–200 μC / cm 2 .

[1514] In addition to the usual exposure method, exposure can also be achieved by immersion, in which a liquid with a refractive index of 1.0 or higher is inserted between the resist film and the projection lens. In this case, a water-insoluble protective film can also be used.

[1515] The aforementioned water-insoluble protective film is used to prevent leaching from the resist film and to improve the hydrophobicity of the film surface. It is broadly classified into two types. One type is an organic solvent-stripping type, which must be stripped with an organic solvent that does not dissolve the resist film before alkaline aqueous solution development. The other type is an alkaline aqueous solution-soluble type, which is soluble in alkaline developer and removes the protective film simultaneously with the soluble portion of the resist film. The latter is particularly preferred because it is based on a polymer containing 1,1,1,3,3,3-hexafluoro-2-propanol residues, which is insoluble in water but soluble in alkaline developer, and is dissolved in alcohol solvents with 4 or more carbon atoms, ether solvents with 8 to 12 carbon atoms, or mixtures thereof. Materials containing surfactants that are insoluble in water but soluble in alkaline developer, dissolved in alcohol solvents with 4 or more carbon atoms, ether solvents with 8 to 12 carbon atoms, or mixtures thereof, can also be prepared.

[1516] PEB can also be performed after exposure. PEB can be performed, for example, on a hot plate, preferably at 60-150°C for 1-5 minutes, more preferably at 80-140°C for 1-3 minutes.

[1517] Developing is performed, for example, by using a developing solution of an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) at 0.1-5% by mass, more preferably 2-3% by mass, for 0.1-3 minutes, more preferably 0.5-2 minutes, using conventional methods such as dip, immersion, or spray, thereby dissolving the exposed portion and forming the desired pattern on the substrate.

[1518] Furthermore, after the resist film is formed, pure water rinsing can be used to extract or wash away particles such as acid-generating agents from the film surface, or to remove water remaining on the film after exposure.

[1519] Furthermore, pattern formation can also be achieved using a double patterning method. Examples of double patterning methods include the trench method, which processes a substrate with a 1:3 trench pattern by first exposure and etching, then offsets the position and forms a 1:3 trench pattern and a 1:1 pattern by second exposure; and the line method, which processes a first substrate with a 1:3 isolated residual pattern by first exposure and etching, then offsets the position and processes a second substrate with a 1:3 isolated residual pattern already formed under the first substrate by second exposure, forming a 1:1 pattern with half the pitch.

[1520] In the pattern forming method of the present invention, a negative tone development method in which an organic solvent is used to dissolve the unexposed portion, instead of the aforementioned alkaline aqueous solution, can also be used as the developing solution.

[1521] In the aforementioned organic solvent development, the developing solution may include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methyl acetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butenyl acetate, isopentyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isopentyl formate, methyl valerate, methyl valerate, methyl crotonate, croton... Ethyl lactate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, ethyl formate, phenyl ethyl formate, methyl 3-phenylpropionate, benzyl propionate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in combination.

[1522] Example

[1523] The following examples, embodiments, and comparative examples are provided to specifically illustrate the present invention, but the present invention is not limited to the following embodiments. Furthermore, the apparatus used is shown below.

[1524] MALDI TOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[1525] [1] Synthesis of sulfonium salts

[1526] [Example 1-1] Synthesis of Sulfonium Salt PAG-1

[1527] [Chem.578]

[1528]

[1529] (1) Synthesis of intermediate In-1

[1530] Under a nitrogen atmosphere, starting materials SM-1 (25.0 g), SM-2 (43.5 g), DMAP (1.2 g), and dichloromethane (150 g) were added to a reaction vessel and cooled in an ice bath. While maintaining the temperature inside the reaction vessel below 20°C, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (24.9 g) was added in powder form. After addition, the mixture was heated to room temperature and allowed to mature for 12 hours. After maturation, water was added and the reaction was stopped. A standard aqueous work-up was performed, the solvent was distilled off, diisopropyl ether was added, and the residue was washed to obtain 57.7 g of intermediate In-1 in oily form (92% yield).

[1531] (2) Synthesis of PAG-1

[1532] Under nitrogen atmosphere, intermediate In-1 (12.6 g), raw material SM-3 (10.6 g), dichloromethane (50 g), and water (30 g) were added. After stirring for 15 minutes, the organic layer was separated and washed with water, followed by concentration under reduced pressure. Methyl isobutyl ketone (50 g) was added to the concentrate and azeotropically dehydrated. Diisopropyl ether was then added, and the residue was washed away to obtain 17.4 g of the target compound PAG-1 in oily form (yield 94%).

[1533] MALDI TOF-MS: POSITIVE M + 447 (equivalent to C) 20 H 16 F5O2S2 + )

[1534] NEGATIVE M - 477 (equivalent to C) 23 H 13 F4O5 S - )

[1535] [Examples 1-2 to 1-9] Synthesis of Sulfonium Salts PAG-2 to PAG-9

[1536] Using the corresponding raw materials and known organic synthesis reactions, the sulfonium salts PAG-2 to PAG-9 represented by the following formulas were synthesized.

[1537] [Chemistry 579]

[1538]

[1539] [Chem.580]

[1540]

[1541] [2] Synthesis of basic polymers

[1542] [Synthetic Example] Synthesis of basic polymers (P-1 to P-5)

[1543] The monomers were combined and copolymerized in MEK as a solvent. The reaction solution was added to hexane, and the precipitated solid was washed with hexane, isolated, and dried to obtain the base polymers (P-1 to P-5) with the compositions shown below. The composition of the obtained base polymers was utilized... 1 H-NMR confirmed Mw and Mw / Mn using GPC (solvent: THF, standard: polystyrene).

[1544] [Chem.581]

[1545]

[1546] [3] Preparation of chemically amplified resist composition

[1547] [Examples 2-1 to 2-30, Comparative Examples 1-1 to 1-20]

[1548] The photoacid generators (PAG-1 to PAG-9) composed of the sulfonium salts of the present invention, the comparative photoacid generators (PAG-A to PAG-E), other photoacid generators (PAG-X, PAG-Y), the base polymer (P-1 to P-5), and the quencher (Q-1 to Q-4) were dissolved in a solvent containing 0.01% by mass of surfactant A (Omnova) according to the compositions shown in Tables 1 and 2 to prepare a solution. The solution was then filtered through a 0.2 μm Teflon (registered trademark) type filter to prepare chemically amplified resist compositions (R-1 to R-30 and CR-1 to CR-20).

[1549] [Table 1]

[1550]

[1551] [Table 2]

[1552]

[1553]

[1554] In Tables 1 and 2, the solvent, other photoacid generator PAG-X, comparative photoacid generators PAG-A to PAG-E, quenchers Q-1 to Q-4, and surfactant A are shown below.

[1555] Solvent: PGMEA (Propylene Glycol Monomethyl Ether Acetate)

[1556] DAA (diacetone alcohol)

[1557] Other photoacid generators: PAG-X

[1558] [Chem.582]

[1559]

[1560] • Comparison of photoacid generating agents: PAG-A to PAG-E

[1561] [Chem.583]

[1562]

[1563] Quenching agents: Q-1 to Q-4

[1564] [Chem.584]

[1565]

[1566] Surfactant A: 3-methyl-3-(2,2,2-trifluoroethoxymethyl)oxetane / tetrahydrofuran / 2,2-dimethyl-1,3-propanediol copolymer (manufactured by Omnova).

[1567] [Chem.585]

[1568]

[1569] a : (b + b') : (c + c') = 1 : 4 ~ 7 : 0.01 ~ 1 (molar ratio)

[1570] Mw = 1500

[1571] [4] Evaluation of EUV lithography (1)

[1572] [Examples 3-1 to 3-30, Comparative Examples 2-1 to 2-20]

[1573] The chemically amplified resist compositions (R-1 to R-30, CR-1 to CR-20) shown in Tables 1-3 were spin-coated onto a Si substrate with a 20 nm thick silicon-containing spin-coated hard mask SHB-A940 (43% by mass silicon) manufactured by Shin-Etsu Chemical Industry Co., Ltd. The substrate was pre-baked at 100°C for 60 seconds using a hot plate to obtain a 50 nm thick resist film. The resist film was then processed using an ASML EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9 / 0.6, dipole illumination), while varying the exposure and focus (exposure pitch: 1 mJ / cm). 2 LS patterns with a size of 18 nm and a pitch of 36 nm were exposed on the wafer at a focal pitch of 0.020 μm. After exposure, PEB was performed for 60 seconds at the temperatures shown in Tables 4 and 5. Subsequently, immersion development was performed for 30 seconds with a 2.38% by mass TMAH aqueous solution, followed by rinsing with a surfactant-containing washing material and swirl drying to obtain a positive pattern.

[1574] LS patterns were observed using a Hitachi Advanced Technology Co., Ltd. measuring SEM (CG6300), and sensitivity, EL, LWR, depth of focus (DOF), and collapse limit were evaluated according to the following methods. Furthermore, development defects of the obtained LS patterns were evaluated. The results are shown in Tables 3 and 4.

[1575] [Sensitivity Evaluation]

[1576] Find the optimal exposure Eop (mJ / cm) for obtaining an LS pattern with a linewidth of 18nm and a pitch of 36nm. 2 This value is defined as sensitivity. The smaller the value, the higher the sensitivity.

[1577] [EL Review]

[1578] The exposure amount that can be formed in the aforementioned LS pattern within a range of ±10% (16.2~19.8nm) of a spacing width of 18nm is used to calculate the EL (unit: %). The larger this value, the better the performance.

[1579] EL(%)=(|E1-E2| / Eop)×100

[1580] E1: Optimal exposure for an LS pattern with a linewidth of 16.2nm and a pitch of 36nm.

[1581] E2: Optimal exposure for an LS pattern with a linewidth of 19.8nm and a pitch of 36nm.

[1582] Eop: Optimal exposure for LS patterns with a linewidth of 18nm and a pitch of 36nm.

[1583] [LWR Evaluation]

[1584] For the LS pattern obtained by Eop irradiation, the dimensions at 10 points along the longitudinal direction are measured. The standard deviation (σ) of the results is calculated as three times the value (3σ), which is defined as LWR. The smaller this value, the smaller the roughness and the more uniform the line width of the pattern.

[1585] [DOF Rating]

[1586] In terms of depth of focus evaluation, the focal range formed in the aforementioned LS pattern within ±10% (16.2–19.8 nm) of a size of 18 nm is calculated. The larger this value, the wider the focal depth.

[1587] [Collapse Limit Assessment of Line Patterns]

[1588] For the aforementioned LS pattern, the line dimensions at various exposure levels under the optimal focal point were measured at 10 points along the longitudinal direction. The finest line dimension obtained without collapse is defined as the collapse limit dimension. The smaller this value, the better the collapse limit.

[1589] [Evaluation of Development Defects]

[1590] For an LS pattern with a linewidth of 18nm and a pitch of 36nm formed using the aforementioned optimal exposure, a defect inspection device KLA2360 (trade name) manufactured by KLA TENCOR was used. The pixel size of the defect inspection device was set to 0.16μm and the threshold to 20. The comparison image was overlaid with the pixel unit, and the defects (number / cm) extracted from the resulting differences were detected. 2 ), calculate the number of defects per unit area (defects / cm²) 2 Next, a defect inspection is performed. Development defects are classified and extracted from all defects, and the number of development defects per unit area (defects / cm²) is calculated. 2 Values ​​below 0.5 are rated A, values ​​above 0.5 but below 1.0 are rated B, values ​​above 1.0 but below 5.0 are rated C, and values ​​above 5.0 are rated D. Lower values ​​indicate better performance.

[1591] [Table 3]

[1592]

[1593] [Table 4]

[1594]

[1595]

[1596] As shown in Tables 3 and 4, the chemically amplified resist composition containing the photoacid generator composed of the sulfonium salt of the present invention exhibits good sensitivity and excellent EL, LWR, and DOF. Furthermore, it was confirmed that the collapse limit is small, and fine pattern formation is resistant to pattern collapse. Additionally, development defects are also suppressed. Therefore, the chemically amplified resist composition of the present invention is suitable as a material for EUV lithography.

[1597] [5] Evaluation of EUV lithography (2)

[1598] [Examples 4-1 to 4-30, Comparative Examples 3-1 to 3-20]

[1599] The chemically amplified resist compositions (R-1 to R-30, CR-1 to CR-20) shown in Tables 1 to 3 were spin-coated onto a Si substrate with a 20 nm thick silicon-containing spin-coated hard mask SHB-A940 (43% by mass silicon) manufactured by Shin-Etsu Chemical Industry Co., Ltd. The resist film was pre-baked at 105°C for 60 seconds using a hot plate to create a 50 nm thick resist film. The resist film was then exposed using an ASML EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9 / 0.6, quadruple illumination, 46 nm pitch, +20% bias hole pattern mask on wafer). PEB was performed for 60 seconds at the temperatures described in Tables 5 and 6 using a hot plate, followed by 30 seconds of development with a 2.38% by mass TMAH aqueous solution to form a 23 nm hole pattern.

[1600] Using a Hitachi Advanced Technologies (AG) CG6300 length measuring SEM, the exposure was measured when the aperture size was 23 nm and defined as the sensitivity. Furthermore, the dimensions of 50 apertures were measured at this time, and the standard deviation (σ) was calculated as three times the standard deviation (3σ), defined as the CDU. The results are shown in Tables 5 and 6.

[1601] [Table 5]

[1602]

[1603] [Table 6]

[1604]

[1605] The results shown in Tables 5 and 6 confirm that the chemically amplified resist composition containing the photoacid generator composed of the sulfonium salt of the present invention has good sensitivity and excellent CDU.

Claims

1. A sulfonium salt comprising an aromatic sulfonic acid anion represented by formula (1A) and a sulfonium cation represented by formula (1B), In the formula, m1 is 0 or 1, m2 is 0, 1, 2, 3 or 4, m3 is 0, 1, 2, 3 or 4, but when m1 is 0, 0 ≤ m2 + m3 ≤ 4, when m1 is 1, 0 ≤ m2 + m3 ≤ 6, and m4 is 0 or 1. W is a hydrocarbon group with 6 to 40 carbon atoms containing at least one aromatic ring; this hydrocarbon group may also contain heteroatoms. R F1 When m2 is 2, 3, or 4, each R F1 They can be the same or different. R 1 The R group can be a halogen atom other than fluorine, a nitro group, a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. When m3 is 2, 3, or 4, each R group... 1 They can be the same or different, multiple Rs 1 They can also bond to each other and form rings together with the carbon atoms they are bonded to. L A and L B Each bond can be independently a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond. X L It can be a single bond, or it may contain a hydrocarbon group with 1 to 40 carbon atoms and heteroatoms. In the formula, n1 is 0 or 1, n2 is 0, 1 or 2, n3 is 0, 1 or 2, n4 is 0, 1 or 2, but when n1 is 0, 0 ≤ n2 + n3 + n4 ≤ 5, and when n1 is 1, 0 ≤ n2 + n3 + n4 ≤ 7; n5 is 0 or 1, n6 is 0, 1 or 2, n7 is 0, 1 or 2, and n8 is 0, 1 or 2, but when n5 is 0, 0 ≤ n6 + n7 + n8 ≤ 5. When n5 is 1, 0 ≤ n6 + n7 + n8 ≤ 7; n9 is 0 or 1; n10 is 0, 1, or 2; n11 is 0, 1, or 2; and n12 is 0, 1, or 2. However, when n9 is 0, 0 ≤ n10 + n11 + n12 ≤ 5; when n9 is 1, 0 ≤ n10 + n11 + n12 ≤ 7. Also, 1 ≤ n2 + n6 + n10 ≤ 6, and 1 ≤ n3 + n7 + n11 ≤ 6. R 11 R 12 and R 13 Each can be an independent hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. When n3 is 2, each R 11 They can be the same or different. When n7 is 2, each R 12 They can be the same or different. When n11 is 2, each R 13 They can be the same or different. R 14 R 15 and R 16 Each can independently be a halogen atom, nitro group, hydroxyl group, carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxy group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. When n4 is 2, each R 14 They can be the same or different, 2 Rs 14 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When n8 is 2, each R 15 They can be the same or different, 2 Rs 15 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When n12 is 2, each R 16 They can be the same or different, 2 Rs 16 They can also bond to each other and form rings together with the carbon atoms they are bonded to. Furthermore, the bond is to S + Two of the three aromatic rings can also bond to each other and form a ring together with the sulfur atoms they are bonded to.

2. The matte salt according to claim 1, wherein, W is represented by the formula (W-1) or (W-2). In the formula, m5 is 0 or 1, m6 is 0, 1, 2, 3 or 4, m7 is 1, 2, 3 or 4, m8 is 0 or 1, m9 is 0 or 1, m10 is 0, 1, 2, 3 or 4, and m11 is 0, 1, 2, 3 or 4. R 2 Each is independently a halogen atom other than a hydrogen atom or an iodine atom, or may contain a hydrocarbon group with 1 to 20 carbon atoms and heteroatoms. R 3 and R 4 Each can be independently a hydrogen atom, a halogen atom, or a hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms. R 5 ~R 9 Each can be an independent hydrocarbon group consisting of hydrogen atoms, halogen atoms, or may contain heteroatoms and have 1 to 40 carbon atoms. The dashed line represents L. A Atomic bonds.

3. The matte salt according to claim 1, wherein, The anion is represented by the following formula (1A-1). In the formula, m1~m4, W, R F1 R 1 and L A As mentioned above.

4. The matte salt according to claim 1, wherein, The cation is represented by the following formula (1B-1), In the formula, n2~n4, n6~n8, n10~n12 and R 11 ~R 16 As mentioned above.

5. A photoacid generator comprising a sulfonium salt according to any one of claims 1 to 4.

6. A chemically amplified resist composition comprising the photoacid generator according to claim 5.

7. The chemically amplified resist composition according to claim 6 further comprises a base polymer containing a polymer having repeating units represented by formula (a1) or (a2). In the formula, R A Each is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X 1 It is a single bond, phenylene, naphthylene, or *-C(=O)-OX 11 - The phenylene or naphthylene group may also be replaced by a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbon group with 1 to 10 carbon atoms containing a fluorine atom, a saturated hydroxyl group with 1 to 10 carbon atoms containing a fluorine atom, or a halogen atom. X 11 It is a saturated hydrocarbon group, phenylene group, or naphthylene group having 1 to 10 carbon atoms. This saturated hydrocarbon group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. X 2 It is a single bond or *-C(=O)-O-. * indicates an atomic bond with a carbon atom in the main chain. R 21 The group can be a halogen atom, cyano group, hydroxyl group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms containing heteroatoms; or a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms containing heteroatoms. When a1 is 2, 3, or 4, each R... 21 They can be the same or different. AL 1 and AL 2 Each is an independent acid-labile group. a1 can be 0, 1, 2, 3 or 4.

8. The chemically amplified resist composition according to claim 7, wherein, The polymer contains repeating units represented by the following formula (a3). In the formula, b1 is 0 or 1, and b2 is 0, 1, 2 or 3 when b1 is 0, and 0, 1, 2, 3, 4 or 5 when b1 is 1. R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X 3 It is a single bond, *-C(=O)-O- or *-C(=O)-NH-, where * indicates an atomic bond with a carbon atom in the main chain. X 4 A group obtained by means of a single bond, an aliphatic alkylene group, a carbonyl group, a sulfonyl group, or a combination thereof, having 1 to 4 carbon atoms. X 5 and X 6 Each can be independently an oxygen atom or a sulfur atom, but X 4 and X 6 It is an adjacent carbon atom bonded to the aromatic ring. R 22 and R 23 Each is an independent hydrocarbon group consisting of 1 to 20 carbon atoms, or may contain heteroatoms; also, R 22 and R 23 They can also bond to each other and form rings together with the carbon atoms they are bonded to. R 24 It can be a halogen atom, hydroxyl group, cyano group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon oxycarbonyl group with 2 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon thio group with 1 to 20 carbon atoms or -N(R) 24A (R) 24B ), R 24A and R 24B Each is independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms; when b2 is 2 or more, each R 24 They can be the same or different, multiple Rs 24 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

9. The chemically amplified resist composition according to claim 7, wherein, The polymer contains repeating units represented by formula (b1) or (b2). In the formula, R A Each is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y 1 It represents a single bond or *-C(=O)-O-, where * indicates an atomic bond with a carbon atom in the main chain. R 31 It is a hydrogen atom, or a group containing at least one of the following structures with 1 to 20 carbon atoms: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulcinolone ring, and carboxylic anhydride (-C(=O)-OC(=O)-). R 32 The group can be a halogen atom, carboxyl group, nitro group, cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms containing heteroatoms; or a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms containing heteroatoms. When c2 is 2, 3, or 4, each R... 32 They can be the same or different. c1 can be 1, 2, 3 or 4, and c2 can be 0, 1, 2, 3 or 4, but 1≤c1+c2≤5.

10. The chemically amplified resist composition according to claim 7, wherein, The polymer contains at least one of the repeating units represented by formula (c1), formula (c2), formula (c3), formula (c4), and formula (c5). In the formula, d1 and d2 are each independently 0, 1, 2 or 3. e1 can be 0 or 1, e2 can be 0, 1, 2, 3 or 4, and e3 can be 0, 1, 2, 3 or 4. However, when e1 is 0, 0 ≤ e2 + e3 ≤ 4, and when e1 is 1, 0 ≤ e2 + e3 ≤ 6. R A Each is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z 1 It can be a single bond or may have substituents, phenylene Z 2 For single bonds, **-C(=O)-OZ 21 -、**-C(=O)-NH-Z 21 -or**-OZ 21 -, Z 21 It is a divalent group obtained by aliphatic hydrocarbon groups, phenylene groups, or combinations thereof having 1 to 6 carbon atoms, and may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups. Z 3 The bonds can be single bonds, ether bonds, ester bonds, sulfonate bonds, amide bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Z 4 It is a single bond, or a divalent group obtained by aliphatic alkylene groups, phenylene groups, or combinations thereof having 1 to 6 carbon atoms, and may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups. Z 5 Each can be a single bond, or may have substituents such as phenylene, naphthylene, or *-C(=O)-OZ. 51 -, Z 51 It is an aliphatic hydrocarbon group, phenylene group, or naphthylene group having 1 to 10 carbon atoms. This aliphatic hydrocarbon group may also contain a halogen atom, hydroxyl group, ether bond, ester bond, or lactone ring. Z 6 The bonds can be single bonds, ether bonds, ester bonds, sulfonate bonds, amide bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Z 7 Each is independently a single bond, ***-Z 71 -C(=O)-O-、***-C(=O)-NH-Z 71 -or ***-OZ 71 -, Z 71 It can also contain a hydrocarbon group with 1 to 20 carbon atoms, which is a heteroatom. Z 8 Each is independently a single key, ****-Z 81 -C(=O)-O-、****-C(=O)-NH-Z 81 -or ****-OZ 81 -, Z 81 It can also contain a hydrocarbon group with 1 to 20 carbon atoms, which is a heteroatom. Z 9 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, trifluoromethyl-substituted phenylene, *-C(=O)-OZ 91 -、*-C(=O)-N(H)-Z 91 -or *-OZ 91 -, Z 91 It is an aliphatic alkylene group, phenylene, fluorinated phenylene, or trifluoromethyl-substituted phenylene, having 1 to 6 carbon atoms. It may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group. * indicates an atomic bond with a carbon atom in the main chain, ** indicates an atomic bond with a Z atom. 1 atomic bonds, *** represents the bond between Z and 6 atomic bonds, **** represents the bond between Z and 7 atomic bonds, L 1 The bonds can be single bonds, ether bonds, ester bonds, carbonyl groups, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Rf 1 and Rf 2 Each is independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Rf 3 and Rf 4 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Rf 5 and Rf 6 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, but all Rf 5 and Rf 6 They are not both hydrogen atoms. Rf 7 It is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkyl thio group having 1 to 6 carbon atoms. R 41 and R 42 Each can independently be a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. Also, R 41 and R 42 They can also bond to each other and form rings together with the sulfur atoms they are bonded to. R 43 The R group can be a halogen atom other than fluorine, or a hydrocarbon group containing heteroatoms with 1 to 20 carbon atoms. When e3 is 2, 3, or 4, each R... 43 They can be the same or different, multiple Rs 43 They can also bond to each other and form rings together with the carbon atoms they are bonded to. M - It is a non-nucleophilic relative ion. A + It is a ium cation.

11. The chemically amplified resist composition according to claim 6, further comprising an organic solvent.

12. The chemically amplified resist composition according to claim 6, further comprising a quenching agent.

13. The chemically amplified resist composition according to claim 6, further comprising a photoacid generator other than the photoacid generator according to claim 5.

14. The chemically amplified resist composition according to claim 6, further comprising a surfactant.

15. A method for forming a pattern, comprising the following steps: A resist film is formed on the substrate using the chemically amplified resist composition according to claim 6. The resist film was exposed to high-energy rays, and The exposed resist film was developed using a developer.

16. The pattern forming method according to claim 15, wherein, The high-energy rays are KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet rays with wavelengths of 3–15 nm.

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