Sulfonium salt, chemically amplified resist composition, and pattern forming process

Abstract

a chemically amplified resist composition containing the sulfonium salt as a photoacid generator, and a pattern forming process using the chemically amplified resist composition. wherein Z- is an aromatic sulfonic acid anion having at least one cyclic structure.

Description

Technical Field

[0001] This invention relates to strontium salts, chemical amplification inhibitor compositions, and patterns forming methods. Prior Technology

[0002] In recent years, with the increasing integration and speed of LSI, there is a growing demand for finer pattern regularity. In terms of next-generation micro-processing technology, far-ultraviolet lithography and extreme ultraviolet (EUV) lithography have attracted much attention.

[0003] ArF lithography, using ArF excimer laser light, began with partial use in the fabrication of 130nm devices and became the primary lithography technology from the 90nm node. Regarding the next 45nm node lithography technology, while the initial use of 157nm F2 laser lithography attracted considerable attention, various issues led to development delays. Therefore, by inserting liquids with higher refractive indices than air, such as water, ethylene glycol, or glycerol, between the projection lens and the wafer, the aperture number (NA) of the projection lens could be designed to be 1.0 or higher, thus enabling the practical application of ArF immersion lithography, which achieves high resolution. 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 materials, a highly sensitive resist component that achieves sufficient resolution with low exposure is required. Generally, this component is chosen to be highly transparent at a wavelength of 193 nm. For example, for the base polymer, polyacrylic acid and its derivatives, norcamphene-maleic anhydride crosspolymers, polynorcamphene, ring-opening shift polymers, and ring-opening shift polymer hydrides have been proposed, achieving some success in improving the transparency of the resin monomer.

[0005] In recent years, positive tone resists developed using alkaline aqueous solutions and negative tone resists developed using organic solvents have also attracted attention. Since extremely fine aperture patterns that cannot be achieved with positive tone exposure will be resolved by exposure with negative tone, high-resolution positive resist compositions are used, and development with organic solvents is employed to form negative patterns. Furthermore, research is underway to achieve twice the resolution through a combination of alkaline aqueous solution development and organic solvent development. Regarding ArF resist compositions used for negative tone development with organic solvents, conventional positive ArF resist compositions can be used, and methods for pattern formation using these compositions are described in Patent Documents 1-3.

[0006] To adapt to the rapid miniaturization in recent years, processing technologies and the development of inhibitor compositions have also progressed daily. Various methods have been explored for photoacid generators, generally using strontium salts composed of triphenylstrontium cations and perfluoroalkane sulfonic acid anions. However, the perfluoroalkane sulfonic acids produced, particularly perfluorooctane sulfonic acid (PFOS), raise concerns about its poor biocompatibility, bioconcentration potential, and toxicity, leading to stringent requirements for its application in inhibitor compositions. Currently, photoacid generators that produce perfluorobutane sulfonic acid are used. However, when used in inhibitor compositions, the resulting acid diffuses significantly, making it difficult to achieve high resolution. To address this issue, partially fluorinated alkane sulfonic acids and their salts have been developed. For example, Patent Document 1 describes a photoacid generator that produces α,α-difluoroalkane sulfonic acid upon exposure, which is a prior art technique. Specifically, it is bis(4-tert-butylphenyl)zimonium 1,1-difluoro-2-(1-naphthyl)ethane sulfonate, a photoacid generator that produces α,α,β,β-tetrafluoroalkane sulfonic acid. However, although the fluorine substitution rate of these products is reduced, they lack substituents that can decompose, such as ester structures. Therefore, the environmental safety considerations for achieving easy decomposition are still insufficient. Furthermore, they are limited by molecular design that targets the size of the alkane sulfonic acid. In addition, there are issues such as the high cost of starting materials containing fluorine atoms.

[0007] Furthermore, with the reduction in circuit linewidth, the contrast degradation caused by acid diffusion in the resist composition becomes more severe. This is because the pattern size approaches the diffusion length of the acid, resulting in a larger dimensional deviation on the wafer relative to the mask size deviation (mask error factor (MEF)), leading to decreased mask fidelity and deterioration of pattern rectangularity. Therefore, to fully realize the advantages of shorter wavelength and higher NA of the light source, further increases in dissolution contrast or suppression of acid diffusion compared to conventional materials are needed. One improvement strategy is to lower the baking temperature, which reduces acid diffusion and improves MEF, but inevitably lowers sensitivity.

[0008] Introducing substituents or polar groups with large barriers to photoacid generation is effective in inhibiting acid diffusion. Patent Document 4 describes a photoacid generator containing 2-acryloxy-1,1,3,3,3-pentafluoropropane-1-sulfonic acid, which has excellent solubility and stability in solvents and high molecular design flexibility. In particular, the photoacid generator containing 2-(1-adamantoxy)-1,1,3,3,3-pentafluoropropane-1-sulfonic acid with large barriers to generation exhibits low acid diffusion. Furthermore, Patent Documents 5-7 describe photoacid generators incorporating condensed ring lactones, sulfonyl lactones, and thiolactones as polar groups. Although it has been confirmed that the introduction of polar groups results in an acid diffusion inhibition effect that improves performance to some extent, the degree of control over acid diffusion is still insufficient. Considering MEF, pattern shape, sensitivity, etc., the performance of photolithography is not yet satisfactory.

[0009] Inhibition of acid diffusion by anion introduction of polar groups in photoacid generators is effective, but becomes unfavorable in terms of solvent solubility. In patent literature 8 and 9, attempts were made to ensure solvent solubility by introducing an alicyclic group in the cationic part of the photoacid generating agent in order to improve the solvent solubility, specifically the cyclohexane ring and the amantane ring. Although the solubility is improved by the introduction of such alicyclic group groups, in order to ensure the solubility, some degree of carbon number is required, and as a result, the volume of the molecular structure of the photoacid generating agent becomes larger, so the microshape properties such as line width roughness (LWR) and size uniformity (CDU) are deteriorated during the formation of fine patterns.

[0010] Also, the patent literature 10 describes photoacid generating agents that will produce a fluoroalkyl sulfonic acid with an anion having a condensation ring from an aromatic group of anthracene. Thus, although some degree of improvement in microfilm performance was confirmed, the structure of alkane sulfonic acids lacks rigidity, and in recent years, the organofluorine compounds of PFAS objects have gradually been regulated, and the impact on the environment and human body is considered.

[0011] It was confirmed that the effect of producing secondary electrons from iodine atoms in exposure due to the extreme absorption of EUV with a wavelength of 13.5nm was noticed in EUV microphotography. Patent literature 11 describes photoacid-generating agents that introduce iodine atoms at anion, and patent literature 12 describes photoacid-generating agents with polymerizable groups introducing iodine atoms at anion. Patent literature 13 describes photoacid generators that introduce iodine atoms at both cations and anions. Thereby, although some degree of improvement in the microshaping performance was confirmed, the organic solvent solubility of the iodine atom was not high, and there was a risk of precipitation in the solvent.

[0012] Patent literature 14 describes photoacid generating agents that introduce multiple fluorine atoms at cations. Although the solvent solubility of photoacid generators was improved due to the introduction of multiple fluorine atoms, the view of considering the absorption of EUVs is still insufficient and improvement remains.

[0013] Patent literature 15~19 describes photoacid generators, quenchers (acid diffusion control agents) containing iodine atoms and fluorine atoms in cations. Patent literature 20 describes photoacid generating agents containing stannous cations introduced with iodine atoms and acid labile groups. By resorting to those developments, although improvements in the performance as resistor materials were confirmed, the view on acid diffusion control was not yet satisfied and the development of resistor materials more useful for fine pattern formation was needed. [Previous technical literature] [Patent Literature]

[0014] [Patent Document 1] Japanese Patent Application Publication No. 2008-281974 [Patent Document 2] Japanese Patent Application Publication No. 2008-281975 [Patent Document 3] Japanese Patent No. 4554665 [Patent Document 4] Japanese Patent Application Publication No. 2007-145797 [Patent Document 5] Japanese Patent No. 5061484 [Patent Document 6] Japanese Patent Application Publication No. 2016-147879 [Patent Document 7] Japanese Patent Application Publication No. 2015-63472 [Patent Document 8] Japanese Patent No. 5573098 [Patent Document 9] Japanese Patent No. 6461919 [Patent Document 10] Japanese Patent No. 7109178 [Patent Document 11] Japanese Patent No. 6720926 [Patent Document 12] Japanese Patent No. 6973274 [Patent Document 13] Japanese Patent No. 7041204 [Patent Document 14] Japanese Patent No. 7389562 [Patent Document 15] Japanese Patent Application Publication No. 2021-123579 [Patent Document 16] Japanese Patent Application Publication No. 2021-123580 [Patent Document 17] Japanese Patent Application Publication No. 2022-123839 [Patent Document 18] Japanese Patent Application Publication No. 2023-88869 [Patent Document 19] Japanese Patent Application Publication No. 2023-88870 [Patent Document 20] Japanese Patent No. 7367185 [Non-patent literature]

[0015] [Non-patent literature 1] Journal of Photopolymer Science and Technology, Vol. 17, No. 4, p. 587-601 (2004) Summary of the Invention

[0016] [The problem that the invention aims to solve] In response to the increasing demand for high-resolution resist patterns in recent years, conventional onium salt-type photoacid generator resist compositions have been used. However, these compositions cannot adequately suppress acid diffusion, resulting in occasional degradation of lithography performance such as contrast, LWR, CDU, MEF, exposure margin (EL), and depth of focus (DOF).

[0017] In view of the foregoing, the present invention aims to provide a strontium salt used in a chemical amplification inhibitor composition that exhibits excellent solvent solubility, high sensitivity, high contrast, and excellent lithography performance such as LWR, CDU, MEF, EL, and DOF, particularly in photolithography using high-energy rays such as KrF excimer laser, ArF excimer laser, electron beam (EB), and EUV; a chemical amplification inhibitor composition containing the strontium salt as a photoacid generator; and a patterning method using the chemical amplification inhibitor composition. [Methods for solving problems]

[0018] To achieve the aforementioned objectives, the inventors of this invention conducted repeated and in-depth research, and discovered that strontium salts, composed of an aromatic sulfonic acid anion having at least one ring structure and an acid-unstable group having an iodine atom and a tertiary / secondary ether structure, tertiary / secondary ester structure, tertiary / secondary carbonate structure, or acetal structure on the same aromatic ring, exhibit excellent solvent solubility. When used as a chemical amplification inhibitor for photoacid generation, it exhibits high sensitivity and high contrast, is extremely effective in suppressing acid diffusion, and demonstrates excellent photolithography properties such as LWR, CDU, MEF, EL, and DOF. It is highly effective in forming fine patterns, and thus became the basis of this invention.

[0019] That is, the present invention provides the following strontium salt, chemical amplification inhibitor composition and pattern formation method. 1. A strontium salt, represented by the following formula (1); [Chemistry 1] In the formula, n1 is 0 or 1; n2 is 1, 2, 3 or 4; n3 is 1 or 2; n4 is 0, 1 or 2; however, when n1 is 0, then 0 ≦ n2 + n3 + n4 ≦ 5, and when n1 is 1, then 0 ≦ n2 + n3 + n4 ≦ 7; n5 is 0 or 1; n6 is 1, 2, 3 or 4; n7 is 0, 1 or 2; however, when n5 is 0, then 0 ≦ n6 + n7 ≦ 5, and when n5 is 1, then 0 ≦ n6 + n7 + ≦ 7; n8 is 1 or 2; RF consists of a fluorine atom, a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon thio group with 1 to 6 carbon atoms, or a pentafluorothio group; when n6 is 2, 3, or 4, each RF can be the same or different from the others; R1 and R2 can each be a halogen atom other than fluorine, a nitro group, a cyano group, a hydroxyl group, a 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); when n4 is 2, each R1 can be the same or different, and two R1s can also be bonded to each other and form a ring together with the bonded carbon atoms; when n7 is 2, each R2 can be the same or different, and two R2s can also be bonded to each other and form a ring together with the bonded carbon atoms. LA-based ether, ester, or carbonate bonds; RAL series acid unstable groups; Furthermore, two of the three aromatic rings bonded to S+ can also bond to each other and form a ring together with the sulfur atoms of these bonds; Z-system aromatic sulfonic acid anions having at least one cyclic structure. 2. The strontium salt of 1. is represented by the following formula (1A); [Chemistry 2] In the formula, n2~n4, n6~n8, RF, R1, R2, LA, RAL and Z- are the same as those mentioned above. 3. A strontium salt as in 1. or 2, wherein the unstable group of the acid is represented by the formula (AL-1) or (AL-2); [Chemistry 3] In the formula, RL1 and RL2 are each independently a hydrocarbon group with 1 to 12 carbon atoms; RL3 is a hydrogen atom or a hydrocarbon group with 1 to 12 carbon atoms; the -CH2- portion of the hydrocarbon groups represented by RL1, RL2, and RL3 can also be replaced by -O- or -S-; when the hydrocarbon group contains an aromatic ring, part or all of the hydrogen atoms of the aromatic ring can also be replaced by a halogen atom, a cyano group, a nitro group, an alkyl group with 1 to 4 carbon atoms containing a halogen atom, or an alkoxy group with 1 to 4 carbon atoms containing a halogen atom; furthermore, RL1 and RL2 can also be bonded to each other and form a ring together with the bonded carbon atoms, and the -CH2- portion of the ring can also be replaced by -O- or -S-; however, when RL3 is a hydrogen atom, RL1 and RL2 are bonded to each other and form an alicyclic ring containing multiple bonds together with the bonded carbon atoms; furthermore, a portion of the hydrogen atoms of the alicyclic ring can also be replaced by a halogen atom; RL4 and RL5 are each independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms; RL6 is a hydrocarbon group having 1 to 20 carbon atoms, and a portion of the -CH2- group can be substituted with -O- or -S-; furthermore, RL5 and RL6 can also bond to each other and together with the bonded carbon atoms and LB to form a heterocyclic group having 3 to 20 carbon atoms, and a portion of the -CH2- group can also be substituted with -O- or -S-. LB series -O- or -S-; * indicates an atomic bond with LA. 4. A strontium salt as described in any of 1.~3, wherein Z- represents the anion of the following formula (Z); [Chemistry 4] In the formula, m1 is 0 or 1; m2 is 0, 1, 2, 3, 4 or 5; m3 is 0, 1, 2, 3, 4 or 5; m4 is 0, 1, 2, 3, 4 or 5; however, when m1 is 0, then 0 ≦ m2 + m3 + m4 ≦ 5, and when m1 is 1, then 0 ≦ m2 + m3 + m4 ≦ 7; The W-series contains a hydrocarbon group with 6 to 40 carbon atoms in at least one alicyclic or aromatic ring, and this hydrocarbon group may also contain heteroatoms; RF1 consists of a fluorine atom, a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon thio group with 1 to 6 carbon atoms, or a pentafluorothio group; when m2 is 2, 3, or 4, each RF1 may be the same or different from the others; R11 can be a halogen atom other than fluorine, a hydroxyl group, a nitro group, or a hydrocarbon group with 1 to 20 carbon atoms that is a heteroatom, or a hydrocarbon oxy group with 1 to 20 carbon atoms that is a heteroatom, or a hydrocarbon thio group with 1 to 20 carbon atoms that is a heteroatom; when m3 is 2, 3 or 4, each R11 can be the same or different from the others, and multiple R11s can also be bonded to each other and form a ring together with the carbon atoms of these bonds; LC and LD are each independently composed of single bonds, ether bonds, ester bonds, sulfonate bonds, amide bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds; XL1 series single bonds, or may also contain heteroatoms with 1 to 40 carbon atoms in the alkyl group. 5. As in 4. strontium salt, where W is represented by formula (W-1) or (W-2); [Chemistry 5] 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; m11 is 0, 1, 2, 3 or 4. R12 can be a halogen atom other than hydrogen or iodine, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms; R13 and R14 are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms; R15 to R19 are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group with 1 to 40 carbon atoms that may also contain heteroatoms; The atomic bonds of the dashed line system and LC. 6. Sulphur salts such as those in 4 or 5, wherein the anion is represented by the following formula (Z1); [Chemistry 6] In the formula, m1~m4, W, RF1, R11 and LC are the same as those mentioned above. 7. A photoacid generating agent, comprising a strontium salt of any one of 1. to 6. 8. A chemical amplification inhibitor composition comprising a photoacid generator as described in 7. 9. The chemical amplification inhibitor composition of 8. further comprises a base polymer containing at least one of the repeating units represented by formula (a1), formula (a2), and formula (a3); [Chemistry 7] In the formula, RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; X1 series consists of single bonds, pendiphenyl, pendinaphthyl, or *-C(=O)-O-X11-. The pendiphenyl or pendinaphthyl group may 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. X11 series consists of saturated pendialkyl groups with 1 to 10 carbon atoms, pendiphenyl, or pendinaphthyl groups. These saturated pendialkyl groups may also contain hydroxyl, ether bonds, ester bonds, or lactone rings. X2 series single bonds or *-C(=O)-O-; * indicates an atomic bond with a carbon atom in the main chain; R21 can be a halogen atom, cyano, hydroxyl, nitro, pentafluorothio, or may contain a hydrocarbon group with 1-20 carbon atoms, a hydrocarbon oxygen group with 1-20 carbon atoms, a hydrocarbon carbonyl group with 2-20 carbon atoms, a hydrocarbon carbonyl oxygen group with 2-20 carbon atoms, or a hydrocarbon oxygen carbonyl group with 2-20 carbon atoms; when a1 is 2, 3, or 4, each R21 can be the same or different from the others; AL1 and AL2 are each independently acid-labile groups; a1 series: 0, 1, 2, 3, or 4; [Chemistry 8] In the formula, b1 is 0 or 1; b2 is 0, 1, 2 or 3 when b1 is 0, and 0, 1, 2, 3, 4 or 5 when b1 is 1; RA series: hydrogen atom, fluorine atom, methyl or trifluoromethyl; X3 series single bonds, *-C(=O)-O- or *-C(=O)-N(H)-; * indicates an atomic bond with a carbon atom in the main chain; X4 group, aliphatic hydrocarbon group with 1 to 4 carbon atoms, carbonyl group, sulfonyl group, or group obtained by combination of these; X5 and X6 are each independently oxygen or sulfur atoms; however, X4 and X6 are bonded to adjacent carbon atoms in an aromatic ring. R22 and R23 are each independently hydrogen atoms, or may contain heteroatoms and be hydrocarbon groups with 1 to 20 carbon atoms; furthermore, R22 and R23 may also bond to each other and form a ring together with the bonded carbon atoms; R24 can be a halogen atom, hydroxyl group, cyano group, nitro group, pentafluorothio group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms, or -N(R24A)(R24B); R24A and R24B are each independently a hydrogen atom or a hydrocarbon group with 1 to 6 carbon atoms; when b2 is 2 or more, each R24 can be the same or different from each other, and multiple R24s can also be bonded to each other and form a ring together with the carbon atoms of the aromatic rings of these bonds. 10. A chemical amplification inhibitor composition as described in 9, wherein the polymer comprises a repeating unit represented by formula (b1) or (b2); [Chemistry 9] In the formula, RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; Y1 series single bonds or *-C(=O)-O-; * indicates an atomic bond with a carbon atom in the main chain; R31 refers to a hydrogen atom, or a group containing at least one of the following: 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)-). R32 can be a halogen atom, carboxyl, nitro, cyano, pentafluorothioyl, or may contain a hydrocarbon group with 1-20 carbon atoms, a hydrocarbon oxygen group with 1-20 carbon atoms, a hydrocarbon carbonyl group with 2-20 carbon atoms, a hydrocarbon carbonyl oxygen group with 2-20 carbon atoms, or a hydrocarbon oxygen carbonyl group with 2-20 carbon atoms; when c2 is 2, 3, or 4, each R32 can be the same or different. c1 is 1, 2, 3 or 4; c2 is 0, 1, 2, 3 or 4; however, 1 ≦ c1 + c2 ≦ 5. 11. A chemical amplification inhibitor composition as described in 9 or 10, wherein the polymer comprises at least one selected from the following formula (c1), the following formula (c2), the following formula (c3), the following formula (c4), and the following formula (c5); [Chemistry 10] In the formula, d1 and d2 are each independently 0, 1, 2 or 3; 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, then 0 ≦ e2 + e3 ≦ 4, and when e1 is 1, then 0 ≦ e2 + e3 ≦ 6; Each of RA can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; Z1 series single bonds or may also have substituents; Z2 series single bonds, **-C(=O)-O-Z21-, **-C(=O)-N(H)-Z21-, or **-O-Z21-; Z21 series aliphatic alkyl groups with 1 to 6 carbon atoms, phenyl groups, or divalent groups obtained by combining these, and may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups; Z3 series single bonds, ether bonds, ester bonds, sulfonate bonds, amide bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds; Z4 series single bonds, or aliphatic alkyl groups with 1 to 6 carbon atoms, phenyl groups, or divalent groups obtained by combining these, may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups; Z5 can be a single bond, or it can be a substituent phenyl group, a substituent naphthyl group, *-C(=O)-O-Z51-, or *-C(=O)-N(R)-Z51-; Z51 is an aliphatic alkyl group, phenyl group, or naphthyl group with 1 to 10 carbon atoms, which may also contain a halogen atom, hydroxyl group, ether bond, ester bond, or lactone ring; R is a hydrogen atom, or may also contain a heteroatom and be a hydrocarbon group with 1 to 10 carbon atoms; Z6 series single bonds, ether bonds, ester bonds, sulfonate bonds, amide bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds; Z7 can be a single bond, ***-Z71-C(=O)-O-, ***-C(=O)-N(R)-Z71-, or ***-O-Z71-; the Z71 series can also contain alkyl groups with 1 to 20 carbon atoms; R is the same as described above; Z8 can be a single bond, ****-Z81-C(=O)-O-, ****-C(=O)-N(R)-Z81-, or ****-O-Z81-; the Z81 series can also contain alkyl groups with 1 to 20 carbon atoms; R is the same as described above; Z9 refers to single bonds, methylene, ethyl, phenyl, fluorinated phenyl, trifluoromethyl-substituted phenyl, *-C(=O)-O-Z91-, *-C(=O)-N(R)-Z91-, or *-O-Z91-; Z91 refers to aliphatic phenyl groups, phenyl, fluorinated phenyl, or trifluoromethyl-substituted phenyl groups with 1 to 6 carbon atoms, and may also contain carbonyl groups, ester bonds, ether bonds, or hydroxyl groups; R is the same as described above; * indicates an atomic bond with a carbon atom in the main chain; ** indicates an atomic bond with Z1; *** indicates an atomic bond with Z6; **** indicates an atomic bond with Z7; L11 series single bonds, ether bonds, ester bonds, carbonyl groups, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds; Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; Rf5 and Rf6 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; however, not all Rf5 and Rf6 are hydrogen atoms simultaneously. Rf7 refers to fluorine atoms, fluorinated alkyl groups with 1 to 6 carbon atoms, fluorinated alkoxy groups with 1 to 6 carbon atoms, fluorinated alkylthio groups with 1 to 6 carbon atoms, or pentafluorothio groups; when e2 is 2, 3, or 4, each Rf7 can be the same or different from the others; R41 and R42 are each independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms; furthermore, R41 and R42 may also bond to each other and form a ring together with the sulfur atoms of such bonds; R43 is a halogen atom other than fluorine, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms; when e3 is 2, 3 or 4, each R43 may be the same or different from the others, and multiple R43s may also bond to each other and form a ring together with the carbon atoms of these bonds; M-series non-nucleophilic relative ions; A+ series onium cations. 12. Any chemical amplification inhibitor composition as described in any of items 8 to 11 further contains an organic solvent. 13. Any chemical amplification inhibitor composition as described in any of items 8 to 12 may further include a quencher. 14. Any chemical amplification inhibitor composition as described in any of 8 to 13, further includes photoacid generating agents other than those described in 7. 15. Any chemical amplification inhibitor composition as described in any of 8. to 14. further includes a surfactant. 16. A method for forming a pattern, comprising the following steps: A resist film is formed on a substrate using any one of the chemical amplification resist compositions described in 8 to 15, the resist film is exposed to high-energy rays, and the exposed resist film is developed using a developer. 17. The pattern forming method of 16, 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. [Effects of the Invention]

[0020] When patterning is performed using a chemical amplification resist composition containing strontium salt of the present invention as a photoacid generator, it exhibits high sensitivity, excellent acid diffusion inhibition capability, and improves the lithography performance of LWR, CDU, MEF, EL, DOF, etc., and can suppress the collapse of resist patterns during the formation of fine patterns. Implementation

[0021] 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, resulting in mirror-image isomers and non-mirror-image isomers. In such cases, a single formula is used to represent such isomers. These isomers may be used individually or as a mixture of two or more.

[0022] [Salt] The strontium salt system of the present invention is represented by the following formula (1). [Chemistry 11]

[0023] In formula (1), 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 1, 2, 3, or 4. Increasing the number of iodine atoms helps to improve EUV light absorption and increase sensitivity, but considering solvent solubility, the total number of iodine atoms in the strontium cation should be 1, 2, or 3. n3 is 1 or 2. n4 is 0, 1, or 2. However, when n1 is 0, then 0 ≤ n2 + n3 + n4 ≤ 5; when n1 is 1, then 0 ≤ n2 + n3 + n4 ≤ 7. 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 n1 of 0 is preferred. n6 is 1, 2, 3, or 4. n7 is 0, 1, or 2. However, when n5 is 0, then 0 ≦ n6 + n7 ≦ 5; when n5 is 1, then 0 ≦ n6 + n7 + ≦ 7. n8 is either 1 or 2.

[0024] In formula (1), RF refers to 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, a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms, or a pentafluorothio group. Among these, a fluorine atom, trifluoromethyl, trifluoromethoxy, trifluoromethylthio, or pentafluorothio group is preferred, with a fluorine atom being even more preferred. When n6 is 2, 3, or 4, each RF may be the same or different from the others.

[0025] In formula (1), R1 and R2 are each independently a halogen atom other than fluorine, a nitro group, a cyano group, a hydroxyl group, a 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. The aforementioned halogen atoms other than fluorine atoms can include chlorine atoms, bromine atoms, iodine atoms, etc. The hydrocarbon part of the aforementioned hydrocarbon group, hydrocarbon thio group, and hydrocarbon thio group 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, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecanyl, 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 these. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, the -CH2- portion of the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This results in the possible inclusion of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When n4 is 2, each R1 can be the same or different. Also, when n4 is 2, the two R1s can bond to each other and form a ring together with the carbon atoms of these bonds. The aforementioned ring is preferably a 5- to 8-membered ring. When n7 is 2, each R2 can be the same or different. Also, when n7 is 2, the two R2s can bond to each other and form a ring together with the carbon atoms of these bonds. The aforementioned rings should ideally consist of 5 to 8 members.

[0026] In formula (1), LA refers to ether, ester or carbonate bonds. Among these, ether and ester bonds are preferred.

[0027] In formula (1), RAL is an acid unstable group. It is preferred that the aforementioned acid unstable group is represented by the following formula (AL-1) or (AL-2). [Chemistry 12] In the formula, * represents the atomic bond with LA.

[0028] In formula (AL-1), RL1 and RL2 are each independently a hydrocarbon group having 1 to 12 carbon atoms. RL3 is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. The -CH2- portion of the hydrocarbon group represented by RL1, RL2, and RL3 may also be replaced by -O- or -S-. When the hydrocarbon group contains an aromatic ring, part or all of the hydrogen atoms in the aromatic ring may also be replaced by a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 4 carbon atoms containing a halogen atom, or an alkoxy group having 1 to 4 carbon atoms containing a halogen atom.

[0029] RL1, RL2, and RL3 represent hydrocarbon groups with 1 to 12 carbon atoms, which can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 12 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, tripentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, and n-dodecyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornel, norbornelmethyl, adamantyl, adamantylmethyl, tricyclic [5.2.1.02,6]decyl, tetracyclic [6.2.1] [13,6.02,7] Cyclic saturated hydrocarbon groups with 3 to 12 carbon atoms, such as dodecyl; alkenyl groups with 2 to 12 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, pentenyl, and hexenyl; alkynyl groups with 2 to 12 carbon atoms, such as ethynyl, propynyl, butynyl, pentynyl, and hexynyl; cyclic unsaturated aliphatic hydrocarbon groups with 3 to 12 carbon atoms, such as cyclopentenyl and cyclohexenyl; aryl groups with 6 to 12 carbon atoms, such as phenyl, naphthyl, and indanyl; aralkyl groups with 7 to 12 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and other alkyl groups obtained by combining these.

[0030] Furthermore, RL1 and RL2 can also bond to each other and form a ring together with the carbon atoms of these bonds, and the -CH2- portion of this ring can also be replaced by -O- or -S-. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, cycloheptane rings, cyclooctane rings, norcamphene rings, adamantane rings, tricyclic [5.2.1.02,6]decane rings, tetracyclic [6.2.1.13,6.02,7]dodecane rings, etc. Furthermore, the -CH2- portion of the aforementioned rings can also be replaced by -O- or -S-. However, when RL3 is a hydrogen atom, RL1 and RL2 bond to each other and form an alicyclic ring containing multiple bonds together with the carbon atoms of these bonds. Furthermore, a portion of the hydrogen atoms in this alicyclic ring can also be replaced by halogen atoms.

[0031] In formula (AL-2), RL4 and RL5 are each independently a hydrogen atom or a hydrocarbon group with 1 to 10 carbon atoms. The hydrocarbon groups with 1 to 10 carbon atoms represented by RL4 and RL5 can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed that are the same as those with 1 to 10 carbon atoms exemplified by the hydrocarbon groups represented by RL1, RL2, and RL3.

[0032] In formula (AL-2), RL6 refers to a hydrocarbon group with 1 to 20 carbon atoms, and part of the -CH2- group can be replaced by -O- or -S-. The aforementioned hydrocarbon group 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, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecyl, octadecyl, nonadecyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, norbornelmethyl, adamantyl, adamantylmethyl, tricyclo[5.2.1.02,6]decyl, and tetracyclo[6.2.1.13,6.02,7]dodecyl; vinyl, propenyl, and butene. Alkenyl groups with 2 to 20 carbon atoms, such as yl, pentenyl, and hexenyl; alkynyl groups with 2 to 20 carbon atoms, such as ethynyl, propynyl, butynyl, pentynyl, and hexynyl; cyclopentenyl, cyclohexenyl, and norbornenyl; aryl groups with 3 to 20 carbon atoms, such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, dibutylphenyl, tributylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, dibutylnaphthyl, and tributylnaphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl and phenethyl; and groups obtained by combining these. Furthermore, RL5 and RL6 can also bond to each other and together with the carbon atoms of these bonds and LB to form heterocyclic groups with 3 to 20 carbon atoms. A portion of the -CH2- of the heterocyclic group can also be replaced by -O- or -S-.

[0033] In formula (AL-2), LB is either -O- or -S-.

[0034] Specific examples of the unstable acid group represented by formula (AL-1) are shown below, but are not limited to these. * indicates an atomic bond with LA. [Chemistry 13]

[0035] [Chemistry 14]

[0036] [Chemistry 15]

[0037] [Chemistry 16]

[0038] [Chemistry 17]

[0039] [Chemistry 18]

[0040] [Chemistry 19]

[0041] [Chemistry 20]

[0042] [Chemistry 21]

[0043] [Chemistry 22]

[0044] [Chemistry 23]

[0045] [Chemistry 24]

[0046] [Chemistry 25]

[0047] [Chemistry 26]

[0048] [Chemistry 27]

[0049] [Chemistry 28]

[0050] [Chemistry 29]

[0051] [Chemistry 30]

[0052] [Chemistry 31]

[0053] [Chemistry 32]

[0054] [Chemistry 33]

[0055] [Chemistry 34]

[0056] Specific examples of acid-instable groups represented by formula (AL-2) are shown below, but are not limited to these. * indicates an atomic bond with LA. [Chemistry 35]

[0057] [Chemistry 36]

[0058] In formula (1), it is preferable for the iodine atom and the -LA-RAL bond to adjacent carbon atoms. Due to the electron-withdrawing property of the iodine atom, the acidity of the phenols and carboxylic acids generated by the deprotection of the -RAL will be increased, and the solubility contrast will be improved.

[0059] Furthermore, two of the three aromatic rings bonded to S+ can also bond to each other and form a ring together with the sulfur atoms of these bonds. In this case, specific examples of the aforementioned ring structures can be given by formulas such as the following. [Chemistry 37] In the formula, the dashed lines represent atomic bonds.

[0060] The strontium salt type monomer represented by formula (1) is preferably represented by formula (1A). [Chemistry 38] In the formula, n2~n4, n6~n8, RF, R1, R2, LA, and RAL are the same as those mentioned above. Z will be discussed later.

[0061] Specific examples of strontium salt cations represented by formula (1) are shown below, but are not limited to these. Furthermore, in the following formula, Me is a methyl group. Also, the substitution positions of the substituents on the aromatic ring are not limited to these. [Chemistry 39]

[0062] [Chemistry 40]

[0063] [Chemistry 41]

[0064] [Chemistry 42]

[0065] [Chemistry 43]

[0066] [Chemistry 44]

[0067] [Chemistry 45]

[0068] [Chemistry 46]

[0069] [Chemistry 47]

[0070] [Chemistry 48]

[0071] [Chemistry 49]

[0072] [Transformation 50]

[0073] [Chemistry 51]

[0074] [Chemistry 52]

[0075] [Chemistry 53]

[0076] [Chemistry 54]

[0077] [Chemistry 55]

[0078] [Chemistry 56]

[0079] [Chemistry 57]

[0080] [Chem.58]

[0081] [Chemistry 59]

[0082] [Transformation 60]

[0083] [Chemistry 61]

[0084] [Chemistry 62]

[0085] [Chemistry 63]

[0086] [Chemistry 64]

[0087] [Chemistry 65]

[0088] [Chemistry 66]

[0089] [Chemistry 67]

[0090] [Chemistry 68]

[0091] [Chemistry 69]

[0092] [Chemistry 70]

[0093] [Chemistry 71]

[0094] [Chemistry 72]

[0095] [Chemistry 73]

[0096] [Chemistry 74]

[0097] [Chemistry 75]

[0098] [Chemistry 76]

[0099] [Chemistry 77]

[0100] [Chemistry 78]

[0101] [Chemistry 79]

[0102] [Chemistry 80]

[0103] [Chemistry 81]

[0104] [Chemistry 82]

[0105] [Chemistry 83]

[0106] [Chemistry 84]

[0107] [Chemistry 85]

[0108] [Chemistry 86]

[0109] [Chemistry 87]

[0110] [Chemistry 88]

[0111] [Chemistry 89]

[0112] [Chemistry 90]

[0113] [Chemistry 91]

[0114] [Chemistry 92]

[0115] [Chemistry 93]

[0116] [Chemistry 94]

[0117] [Chemistry 95]

[0118] [Chemistry 96]

[0119] [Chemistry 97]

[0120] [Chem. 98]

[0121] [Chemistry 99]

[0122] [Chemistry 100]

[0123] [Chemistry 101]

[0124] [Chemistry 102]

[0125] [Chemistry 103]

[0126] [Chemistry 104]

[0127] [Chemistry 105]

[0128] [Chemistry 106]

[0129] [Chemistry 107]

[0130] [Chemistry 108]

[0131] [Chemistry 109]

[0132] [Chemical 110]

[0133] [Chemistry 111]

[0134] [Chemistry 112]

[0135] [Chemistry 113]

[0136] [Chemistry 114]

[0137] [Chemistry 115]

[0138] [Chemistry 116]

[0139] [Chemistry 117]

[0140] [Chemistry 118]

[0141] [Chemistry 119]

[0142] [Chemistry 120]

[0143] [Chemistry 121]

[0144] [Chemistry 122]

[0145] [Chemistry 123]

[0146] [Chemistry 124]

[0147] [Chemistry 125]

[0148] [Chemistry 126]

[0149] [Chemistry 127]

[0150] [Chemistry 128]

[0151] [Chemistry 129]

[0152] [Chemistry 130]

[0153] [Chemistry 131]

[0154] [Chemistry 132]

[0155] [Chemistry 133]

[0156] [Chemistry 134]

[0157] [Chemistry 135]

[0158] [Chemistry 136]

[0159] [Chemistry 137]

[0160] [Chemistry 138]

[0161] [Chemistry 139]

[0162] [Chemistry 140]

[0163] [Chemistry 141]

[0164] [Chemistry 142]

[0165] [Chemistry 143]

[0166] [Chemistry 144]

[0167] [Chemistry 145]

[0168] [Chemistry 146]

[0169] [Chemistry 147]

[0170] [Chemistry 148]

[0171] [Chemistry 149]

[0172] [Chemistry 150]

[0173] [Chemistry 151]

[0174] [Chemistry 152]

[0175] [Chemistry 153]

[0176] [Chemistry 154]

[0177] [Chemistry 155]

[0178] [Chemistry 156]

[0179] [Chemistry 157]

[0180] [Chemistry 158]

[0181] [Chemistry 159]

[0182] [Chemistry 160]

[0183] [Chemistry 161]

[0184] [Chemistry 162]

[0185] [Chemistry 163]

[0186] [Chemistry 164]

[0187] [Chemistry 165]

[0188] [Chemistry 166]

[0189] [Chemistry 167]

[0190] [Chemistry 168]

[0191] [Chemistry 169]

[0192] [Chemistry 170]

[0193] [Chemistry 171]

[0194] [Chemistry 172]

[0195] [Chemistry 173]

[0196] [Chemistry 174]

[0197] [Chemistry 175]

[0198] [Chemistry 176]

[0199] [Chemistry 177]

[0200] [Chemistry 178]

[0201] [Chemistry 179]

[0202] [Chemistry 180]

[0203] [Chemistry 181]

[0204] [Chemistry 182]

[0205] [Chemistry 183]

[0206] [Chemistry 184]

[0207] [Chemistry 185]

[0208] [Chemistry 186]

[0209] [Chemistry 187]

[0210] [Chem.188]

[0211] [Chemistry 189]

[0212] [Chemistry 190]

[0213] [Chemistry 191]

[0214] [Chemistry 192]

[0215] [Chemistry 193]

[0216] [Chemistry 194]

[0217] [Chemistry 195]

[0218] [Chemistry 196]

[0219] [Chemistry 197]

[0220] [Chemistry 198]

[0221] [Chemistry 199]

[0222] [Chemistry 200]

[0223] [Chemical Engineering 201]

[0224] [Chemical Engineering 202]

[0225] [Chemical Engineering 203]

[0226] [Chemical 204]

[0227] [Chemical Engineering 205]

[0228] [Chemical Engineering 206]

[0229] [Chemical 207]

[0230] [Chemical Engineering 208]

[0231] [Chemical Engineering 209]

[0232] [Chemical 210]

[0233] [Chemistry 211]

[0234] [Chemistry 212]

[0235] [Chemistry 213]

[0236] [Chemistry 214]

[0237] [Chemical 215]

[0238] [Chemistry 216]

[0239] [Chemistry 217]

[0240] [Chemistry 218]

[0241] [Chemistry 219]

[0242] [Chem.220]

[0243] [Chemistry 221]

[0244] [Chemistry 222]

[0245] [Chemistry 223]

[0246] [Chemistry 224]

[0247] [Chemistry 225]

[0248] [Chemistry 226]

[0249] [Chemistry 227]

[0250] [Chemistry 228]

[0251] [Chemistry 229]

[0252] [Chemistry 230]

[0253] [Chemistry 231]

[0254] [Chemistry 232]

[0255] [Chemistry 233]

[0256] [Chemistry 234]

[0257] [Chemistry 235]

[0258] [Chemistry 236]

[0259] [Chemistry 237]

[0260] [Chemistry 238]

[0261] [Chemistry 239]

[0262] [Chemistry 240]

[0263] [Chemistry 241]

[0264] [Chemistry 242]

[0265] [Chemistry 243]

[0266] [Chemistry 244]

[0267] [Chemistry 245]

[0268] [Chemistry 246]

[0269] [Chemistry 247]

[0270] [Chemistry 248]

[0271] [Chemistry 249]

[0272] [Chemistry 250]

[0273] [Chemistry 251]

[0274] [Chemistry 252]

[0275] [Chemistry 253]

[0276] [Chemistry 254]

[0277] [Chemistry 255]

[0278] [Chemistry 256]

[0279] [Chemistry 257]

[0280] [Chemistry 258]

[0281] [Chemistry 259]

[0282] [Chemistry 260]

[0283] [Chemistry 261]

[0284] [Chemistry 262]

[0285] [Chemistry 263]

[0286] [Chemistry 264]

[0287] [Chemistry 265]

[0288] [Chemistry 266]

[0289] [Chemistry 267]

[0290] [Chemistry 268]

[0291] [Chemistry 269]

[0292] [Chemistry 270]

[0293] [Chemistry 271]

[0294] [Chemistry 272]

[0295] [Chemistry 273]

[0296] [Chemistry 274]

[0297] [Chemistry 275]

[0298] [Chemistry 276]

[0299] [Chemistry 277]

[0300] [Chemistry 278]

[0301] [Chemistry 279]

[0302] [Chemistry 280]

[0303] [Chemistry 281]

[0304] [Chemistry 282]

[0305] [Chemistry 283]

[0306] [Chemistry 284]

[0307] [Chemistry 285]

[0308] [Chemistry 286]

[0309] [Chemistry 287]

[0310] [Chemistry 288]

[0311] [Chemistry 289]

[0312] [Chemistry 290]

[0313] [Chemistry 291]

[0314] In formulas (1) and (1A), Z- is an aromatic sulfonic acid anion having at least one cyclic structure. The aforementioned aromatic sulfonic acid anion is preferably represented by the following formula (Z). [Chemistry 292]

[0315] In formula (Z), m1 is 0 or 1. When m1 is 0, it is a benzene ring; when m1 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m1 of 0 is preferred. m2 is 0, 1, 2, 3, 4, or 5. Considering the availability of raw materials, m2 is 4 when m2 is 1 or higher. m3 is 0, 1, 2, 3, 4, or 5. m4 is 0, 1, 2, 3, 4, or 5. Considering acid diffusion control, m4 is 1 is preferred. However, when m1 is 0, then 0 ≤ m2 + m3 + m4 ≤ 5; when m1 is 1, then 0 ≤ m2 + m3 + m4 ≤ 7.

[0316] In formula (Z), RF1 is a fluorine atom, a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon thio group with 1 to 6 carbon atoms, or a pentafluorothio group. RF1 is preferably a fluorine atom, trifluoromethyl, difluoromethyl, trifluoromethoxy, difluoromethoxy, trifluoromethylthio, or difluoromethylthio, with fluorine atom, trifluoromethyl, or trifluoromethoxy being more preferred. By including such substituents with fluorine atoms, the acid strength of the resulting acid will be increased due to the electron-withdrawing effect, thus the deprotection reaction of acid-unstable groups such as tertiary esters and tertiary ethers described later will proceed smoothly. When m2 is 2, 3, or 4, each RF1 can be the same or different.

[0317] In formula (Z), R11 refers to halogen atoms other than fluorine, hydroxyl groups, nitro groups, and may also include hydrocarbon groups with 1 to 20 carbon atoms (heteroatomic), hydroxyl groups with 1 to 20 carbon atoms (heteroatomic), or hydrocarbon thio groups with 1 to 20 carbon atoms (heteroatomic). Halogen atoms other than fluorine atoms can include chlorine atoms, bromine atoms, iodine atoms, etc., with iodine atoms being 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, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecanyl, 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 these. Of these, aryl is preferable. Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms; similarly, one part of the -CH2- group in the aforementioned hydrocarbon group may be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This results in the possible inclusion 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 R11 may be the same or different. Furthermore, when m3 is 2, 3, or 4, multiple R11s may also bond to each other and form a ring together with the bonded carbon atoms. The aforementioned ring is preferably a 5- to 8-membered ring.

[0318] In formula (Z), W contains at least one hydrocarbon group with 6 to 40 carbon atoms in an alicyclic or aromatic ring, and the hydrocarbon group may also contain heteroatoms.

[0319] In formula (Z), W should be the basis for the following formula (W-1) or (W-2). [Chemistry 293] In the formula, the dashed lines represent the atomic bonds between LC and the matrix.

[0320] In formula (W-1), m5 is 0 or 1. When m5 is 0, it represents a benzene ring; when m1 is 1, it represents 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 with 2, 3, or 4 is preferred. Considering EUV light absorption, m6 with 3 or 4 is preferred. m7 is 1, 2, 3, or 4. Considering raw material availability, m7 with 1, 2, or 3 is preferred. Considering acid diffusion control, m7 with 2 or 3 is preferred.

[0321] In formula (W-1), R12 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 include those similar to those exemplified by the hydrocarbon groups represented by R1 and R2 in the explanation of formula (1), but are not limited to these. R12 should preferably be a group with a branched or cyclic structure.

[0322] In formula (W-1), at least one of R12 and iodine atoms is preferably bonded to the carbon atom adjacent to the carbon atom of the LA bond. In this way, the rotation of the aromatic rings of these bonds and the aromatic rings of the sulfonic acid bonds is suppressed around the bond axis of -LC-XL1-LD- due to steric hindrance, which can reduce acid diffusion.

[0323] In formula (W-2), m8 is 0 or 1. When m8 is 0, it represents a benzene ring; when m7 is 1, it represents 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 represents a benzene ring; when m9 is 1, it represents 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 is preferably 0, 1, or 2. m11 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, m11 is preferably 0, 1, or 2.

[0324] In formula (W-2), R13 and R14 are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group with 1 to 20 carbon atoms that may 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 contain heteroatoms include those similar to those exemplified by the hydrocarbon groups represented by R1 and R2 in the explanation of formula (1), but are not limited to these. R13 and R14 are preferably groups with branched or cyclic structures.

[0325] In formula (W-2), R15 to R19 are each independently 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 atoms, with fluorine and iodine atoms being preferred. Specific examples of hydrocarbon groups with 1 to 20 carbon atoms that may contain heteroatoms include those similar to those exemplified by the hydrocarbon groups represented by R1 and R2 in the explanation of formula (1), but are not limited to these. R15 to R19 are preferably groups with branched or cyclic structures.

[0326] In formula (W-2), any two of R15 to R19 can bond to each other and form a ring together with the carbon atoms of these bonds. The aforementioned rings are preferably 5 to 8-membered rings.

[0327] In formula (Z), LC and LD are each 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.

[0328] In formula (Z), XL1 is a single bond, or may contain a heteroatom with 1 to 40 carbon atoms in an extended hydrocarbon group. The aforementioned extended hydrocarbon group can be straight-chain, branched, or cyclic; specific examples include alkane dimethyl, cyclic saturated extended hydrocarbon group, and extended aryl group. Specific examples of the aforementioned heteroatom include oxygen atoms, nitrogen atoms, and sulfur atoms.

[0329] XL1 can also include specific examples of hydrocarbon groups with 1 to 40 carbon atoms, as shown below, but is not limited to these. Furthermore, in the following formulas, * denotes atomic bonds with LC and LD, respectively. [Chemistry 294]

[0330] [Chemistry 295]

[0331] [Chemistry 296]

[0332] [Chemistry 297]

[0333] Among these, XL-0~XL-22, XL-29~XL-34 and XL-47~XL-61 are better.

[0334] The anion represented by formula (Z) should preferably be represented by formula (Z1). [Chemistry 298] In the formula, m1~m4, W, RF1, R11 and LC are the same as those mentioned above.

[0335] Specific examples of anions represented by formula (Z) may be listed in Japanese Patent Application Publication No. 2024-77330

[0229] ~

[0231] , Japanese Patent Application Publication No. 2024-177330

[0037] ~

[0060] , Japanese Patent No. 6248882

[0027] ~

[0029] , Japanese Patent No. 7067271

[0028] ~

[0029] , Japanese Patent No. 7032549

[0220] ~

[0225] , and Japanese Patent Application Publication No. 2023-177038

[0039] ~

[0057] , but are not limited to these.

[0336] Other specific examples of anions represented by formula (Z) are shown below, but are not limited to these. Furthermore, in the following formula, Me is a methyl group. [Chemistry 299]

[0337] [Chemical 300]

[0338] [Chemical Engineering 301]

[0339] [Chemical 302]

[0340] [Chemical 303]

[0341] [Chemical 304]

[0342] [Chemical 305]

[0343] [Chemical 306]

[0344] [Chemical 307]

[0345] [Chemical 308]

[0346] [Chemical 309]

[0347] [Chemical 310]

[0348] [Chemistry 311]

[0349] [Chemistry 312]

[0350] [Chemistry 313]

[0351] [Chemical 314]

[0352] [Chemical 315]

[0353] [Chemistry 316]

[0354] [Chemistry 317]

[0355] [Chemistry 318]

[0356] [Chemistry 319]

[0357] [Chemistry 320]

[0358] [Chemistry 321]

[0359] [Chemistry 322]

[0360] [Chemistry 323]

[0361] [Chemistry 324]

[0362] [Chemistry 325]

[0363] [Chemistry 326]

[0364] [Chemistry 327]

[0365] [Chemistry 328]

[0366] [Chemistry 329]

[0367] [Chemistry 330]

[0368] [Chemistry 331]

[0369] [Chemistry 332]

[0370] [Chemistry 333]

[0371] [Chemistry 334]

[0372] [Chemistry 335]

[0373] [Chemistry 336]

[0374] [Chemistry 337]

[0375] [Chemistry 338]

[0376] [Chemistry 339]

[0377] [Transformation 340]

[0378] [Chemistry 341]

[0379] [Chemistry 342]

[0380] [Chemistry 343]

[0381] [Chemistry 344]

[0382] [Chemistry 345]

[0383] [Chemistry 346]

[0384] [Chemistry 347]

[0385] [Chemistry 348]

[0386] [Chemistry 349]

[0387] [Chemical 350]

[0388] [Chemistry 351]

[0389] [Chemistry 352]

[0390] [Chemistry 353]

[0391] [Chemistry 354]

[0392] [Chemistry 355]

[0393] [Chemistry 356]

[0394] [Chemistry 357]

[0395] [Chemistry 358]

[0396] [Chemistry 359]

[0397] [Hua360]

[0398] [Chemistry 361]

[0399] [Chemistry 362]

[0400] [Chem.363]

[0401] [Chemical 364]

[0402] [Chemical 365]

[0403] [Chemical 366]

[0404] [Chemical 367] <​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

[0412] [Chemistry 375]

[0413] [Chemistry 376]

[0414] [Chemistry 377]

[0415] [Chemistry 378]

[0416] [Chemistry 379]

[0417] [Chemistry 380]

[0418] [Chemistry 381]

[0419] [Chemistry 382]

[0420] [Chemistry 383]

[0421] [Chem. 384]

[0422] [Chem.385]

[0423] [Chemistry 386]

[0424] [Chemistry 387]

[0425] [Chem.388]

[0426] [Chemistry 389]

[0427] [Chemistry 390]

[0428] [Chemistry 391]

[0429] [Chemistry 392]

[0430] [Chemistry 393]

[0431] [Chemistry 394]

[0432] [Chemistry 395]

[0433] [Chemistry 396]

[0434] [Chemistry 397]

[0435] [Chem.398]

[0436] [Chemistry 399]

[0437] [Chemical 400]

[0438] [Chemical Engineering 401]

[0439] [Chemical 402]

[0440] [Chemical 403]

[0441] [Chemical 404]

[0442] [Chemical 405]

[0443] [Chemical 406]

[0444] [Chemical 407]

[0445] [Chemical 408]

[0446] [Chemical 409]

[0447] [Chemical 410]

[0448] [Chemistry 411]

[0449] [Chemistry 412]

[0450] [Chemistry 413]

[0451] [Chemistry 414]

[0452] [Chemical 415]

[0453] [Chemistry 416]

[0454] [Chemistry 417]

[0455] [Chemistry 418]

[0456] [Chemistry 419]

[0457] [Chemistry 420]

[0458] [Chemistry 421]

[0459] [Chemistry 422]

[0460] [Chemistry 423]

[0461] [Chemistry 424]

[0462] [Chemical 425]

[0463] [Chemistry 426]

[0464] [Chemistry 427]

[0465] [Chemistry 428]

[0466] [Chemistry 429]

[0467] [Chemistry 430]

[0468] [Chemistry 431]

[0469] [Chemistry 432]

[0470] [Chemistry 433]

[0471] [Chemistry 434]

[0472] [Chemistry 435]

[0473] [Chemistry 436]

[0474] [Chemistry 437]

[0475] [Chemistry 438]

[0476] [Chemistry 439]

[0477] [Chemistry 440]

[0478] [Chemistry 441]

[0479] [Chemistry 442]

[0480] [Chemistry 443]

[0481] [Chemistry 444]

[0482] [Chemistry 445]

[0483] [Chemistry 446]

[0484] [Chemistry 447]

[0485] [Chemistry 448]

[0486] [Chemistry 449]

[0487] [Chemistry 450]

[0488] [Chemistry 451]

[0489] [Chemistry 452]

[0490] [Chemistry 453]

[0491] [Chemistry 454]

[0492] [Chemistry 455]

[0493] [Chemistry 456]

[0494] [Chemistry 457]

[0495] [Chemistry 458]

[0496] [Chemistry 459]

[0497] [Chemistry 460]

[0498] [Chemistry 461]

[0499] [Chemistry 462]

[0500] [Chemistry 463]

[0501] [Chemistry 464]

[0502] [Chemistry 465]

[0503] [Chemistry 466]

[0504] [Chemistry 467]

[0505] [Chemistry 468]

[0506] [Chemistry 469]

[0507] [Chemistry 470]

[0508] [Chemistry 471]

[0509] [Chemistry 472]

[0510] [Chemistry 473]

[0511] [Chemistry 474]

[0512] [Chemistry 475]

[0513] [Chemistry 476]

[0514] [Chemistry 477]

[0515] [Chemistry 478]

[0516] [Chemistry 479]

[0517] [Chemistry 480]

[0518] [Chemistry 481]

[0519] [Chemistry 482]

[0520] [Chemistry 483]

[0521] [Chemistry 484]

[0522] [Chemistry 485]

[0523] [Chemistry 486]

[0524] [Chemistry 487]

[0525] [Chemistry 488]

[0526] [Chemistry 489]

[0527] [Chemistry 490]

[0528] [Chemistry 491]

[0529] [Chemistry 492]

[0530] [Chemistry 493]

[0531] [Chemistry 494]

[0532] [Chemistry 495]

[0533] [Chemistry 496]

[0534] [Chemistry 497]

[0535] [Chemistry 498]

[0536] [Chemistry 499]

[0537] [Chemical 500]

[0538] [Chemical 501]

[0539] [Chemical 502]

[0540] [Chemical 503]

[0541] [Chemical 504]

[0542] [Chemical 505]

[0543] [Chemical 506]

[0544] [Chem. 507]

[0545] [Chem.508]

[0546] [Chemical 509]

[0547] [Chem.510]

[0548] [Chem.511]

[0549] [Chem.512]

[0550] [Chem.513]

[0551] [Chem.514]

[0552] [Chem.515]

[0553] [Chem.516]

[0554] Specific examples of the strontium salts of the present invention can be listed as any combination of the aforementioned anions and cations.

[0555] The method for synthesizing strontium salt of the present invention can be exemplified by methods described in Japanese Patent Application Publication No. 2010-155824 and Japanese Patent No. 7067271. The aforementioned manufacturing method is only one example, and the manufacturing method of strontium salt of the present invention is not limited to these.

[0556] The structural features of the strontium salt of this invention can be exemplified by a triarylstrontium cation comprising an aromatic sulfonic acid anion substituted with a hydrocarbon group containing at least one ring structure, and an acid-unstable group having an iodine atom and an acid-labile group having a tertiary / secondary ether structure, a tertiary / secondary ester structure, a tertiary / secondary carbonate structure, or an acetal structure on the same aromatic ring. It is known that irradiation of the base polymer with EUV light releases secondary electrons. Furthermore, regarding the iodine atom, especially in EUV lithography at a wavelength of 13.5 nm, due to the very large EUV absorption of the iodine atom, secondary electrons are generated from the iodine atom during exposure. It is known that the iodine atom bonded to the aromatic ring of the strontium cation has very large EUV absorption, therefore, secondary electrons are generated from the iodine atom during exposure, and it also exhibits electron-withdrawing properties due to the halogen atom. The acid-labile groups in the strontium cation, bonded to the same aromatic ring and possessing tertiary / secondary ether, tertiary / secondary ester, tertiary / secondary carbonate, or acetal structures, undergo deprotection reactions caused by the acids generated during exposure, resulting in the formation of corresponding phenols or carboxylic acids. This transformation from a lipid-soluble to a hydrophilic structure enhances the contrast between the exposed and unexposed areas. Furthermore, the presence of iodine atoms bonded to the carbon atoms adjacent to the phenolic hydroxyl or carboxyl groups formed during the deprotection reaction increases the acidity of the phenols or carboxylic acids due to the electron-withdrawing property of the iodine atoms. When developing the deprotected exposed areas with an alkaline developer, the increased acidity of the phenols enhances their solubility in the alkaline developer, thereby suppressing development residue. Additionally, the presence of fluorine-containing or fluorine-atom-containing substituents on the other aromatic rings of the triarylstrontium cation is preferable. It is believed that fluorine-containing atoms or fluorine-containing substituents have strong electron-withdrawing properties, which lowers the LUMO energy level of triarylstrom cations in the leading-edge orbital theory. Therefore, they become more receptive to secondary electrons generated by iodine atoms in the cations and anions, promoting the decomposition of the cations and efficiently producing acids.

[0557] The aforementioned hydrocarbon group containing at least one ring structure, being bulky, functions as a large substituent, effectively suppressing the diffusion of the generated acid. This effect is particularly pronounced when the aforementioned hydrocarbon group containing at least one aromatic ring is a substituent-containing aromatic ring structure as shown in formula (W-1) or a substituent-containing condensed ring structure as shown in formula (W-2). Furthermore, it exhibits resistance to alkaline developers, thus reducing film loss in unexposed areas. On the other hand, regarding aromatic sulfonic acid structures, the resulting acid has a rigid structure, exhibiting an effect of suppressing acid diffusion. In the aromatic ring forming the aromatic sulfonic acid structure, it is preferable to have a fluorine atom or an electron-withdrawing sulfonate bond as a linking group, thereby increasing the acidity of the generated acid and efficiently protecting the acid-indestructible groups of the base polymer. Furthermore, fluorine atoms are less numerous than iodine atoms, but their absorption of EUV light is still high. Therefore, by increasing the number of fluorine atoms, the generation of secondary electrons increases, promoting the decomposition of cations and contributing to higher sensitivity. Although Japanese Patent No. 7109178 discloses alkane sulfonic acid-type photoacid generators with 2 to 4 fluorine atoms, the acid diffusion is relatively large due to the alkane sulfonic acid, and it lacks solvent solubility, thus raising concerns about development defects. Through these additive effects, the inhibitor composition containing the strontium salt of this invention has high sensitivity and low acid diffusion, thus exhibiting excellent lithography performance in LWR, CDU, and other processes, and can form patterns resistant to pattern collapse, making it suitable for the formation of fine patterns.

[0558] The aforementioned strontium salt is suitable for use as a photoacid generator.

[0559] [Chemical Amplification Inhibitor Composition] [(A) Photoacid generator] The chemical amplification inhibitor composition of the present invention includes a photoacid generator composed of strontium salt represented by formula (A) as an essential component.

[0560] In the chemical amplification inhibitor composition of this invention, the content of component (A), which is the photoacid generator composed of strontium salt, is preferably 0.1 to 40 parts by mass, and more preferably 0.5 to 30 parts by mass, relative to 80 parts by mass of the base polymer described later. If the content of component (A) is within the aforementioned range, the sensitivity and resolution are good, and there is no concern about foreign matter problems arising after the inhibitor film is developed or peeled off, which is ideal. The photoacid generator (A) can be used alone or in combination of two or more.

[0561] [(B) Basic Polymer] The chemical amplification inhibitor composition of the present invention may also include a base polymer as component (B). The base polymer (B) is preferably composed of repeating units having acid-indestructible groups. The repeating units containing the aforementioned acid-indestructible groups may be used alone or in combination of two or more.

[0562] Specific examples of repeating units containing the aforementioned acid unstable groups can be listed as repeating units represented by the following formula (a1) (hereinafter also referred to as repeating unit a1.) and repeating units represented by the following formula (a2) (hereinafter also referred to as repeating unit a2.). [Chem.517]

[0563] In formulas (a1) and (a2), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0564] In formula (a1), X1 is a single bond, an phenyl group, a naphthyl group, or *-C(=O)-O-X11-. This phenyl or naphthyl group may be substituted with a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, a saturated hydrocarbon oxygen group containing fluorine atoms with 1 to 10 carbon atoms, or a halogen atom. X11 is a saturated hydrocarbon group with 1 to 10 carbon atoms, an phenyl group, or a naphthyl group. This saturated hydrocarbon group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * indicates an atomic bond with a carbon atom in the main chain.

[0565] In formula (a2), X2 represents a single bond or *-C(=O)-O-. * indicates an atomic bond with a carbon atom in the main chain. R21 represents a halogen atom, cyano group, hydroxyl group, nitro group, pentafluorothio group, or may contain a hydrocarbon group with 1-20 carbon atoms of a heteroatom, a hydrocarbon oxygen group with 1-20 carbon atoms of a heteroatom, a hydrocarbon carbonyl group with 2-20 carbon atoms of a heteroatom, a hydrocarbon carbonyl oxygen group with 2-20 carbon atoms of a heteroatom, or a hydrocarbon oxygen carbonyl group with 2-20 carbon atoms of a heteroatom. a1 is 0, 1, 2, 3, or 4, preferably 0 or 1. When a1 is 2, 3, or 4, each R21 can be the same or different.

[0566] In formulas (a1) and (a2), AL1 and AL2 are each independently acid-indestructible groups. Specific examples of the aforementioned acid-indestructible groups can be cited, for example, those described in Japanese Patent Application Publication Nos. 2013-80033 and 2013-83821.

[0567] Generally speaking, specific examples of the aforementioned unstable acid groups can be represented by the following formulas (AL-3) to (AL-5). [Chem.518] In the formula, * represents an atomic bond.

[0568] In formulas (AL-3) and (AL-4), RL11 and RL12 are each independently a 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 may be saturated or unsaturated, and may be linear, branched, or cyclic. Preferably, the aforementioned hydrocarbon groups have 1 to 20 carbon atoms.

[0569] In formula (AL-3), a2 is an integer from 0 to 10, and should preferably be 1, 2, 3, 4 or 5.

[0570] In formula (AL-4), RL13 and RL14 are each independently a hydrogen atom or a 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, any two of RL12, RL13, and RL14 can bond to each other and form a ring with 3 to 20 carbon atoms together with the bonded carbon atoms or carbon and oxygen atoms. The aforementioned rings are preferably rings with 4 to 16 carbon atoms, and especially alicyclic rings.

[0571] In formula (AL-5), RL15, RL16, and RL17 are each independently a 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, any two of RL15, RL16, and RL17 can bond to each other and together with the bonded carbon atoms to form a ring with 3 to 20 carbon atoms. The aforementioned ring is preferably a ring with 4 to 16 carbon atoms, and especially preferably an alicyclic ring.

[0572] Other specific examples of the aforementioned acid-indestructible groups can be cited 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 examples use the generation of conjugated olefins or acrylate derivatives after acid desorption reactions as the driving force for the reaction.

[0573] Specific examples of repeating unit a1 may be listed below, but are not limited to these. Furthermore, in the following formula, RA and AL1 are the same as those described above. [Chem.519]

[0574] [Chem.520]

[0575] [Chem.521]

[0576] [Chem.522]

[0577] Specific examples of repeating unit a2 may be listed below, but are not limited to these. Furthermore, in the following formula, RA and AL2 are the same as those described above. [Chem.523]

[0578] [Chem.524]

[0579] [Chem.525]

[0580] Other specific examples of repeating units containing acid-labile groups mentioned above can be listed as repeating units represented by the following formula (a3) ​​(hereinafter also referred to as repeating unit a3). [Chem.526]

[0581] In formula (a3), b1 is 0 or 1. When b1 is 0, it represents a benzene ring; when b1 is 1, it represents a naphthalene ring. Considering solvent solubility, a benzene ring with b1 of 0 is preferred. b2 represents 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 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0582] In formula (a3), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. It is preferable for RA to be a hydrogen atom or a methyl group, with hydrogen being even more preferred.

[0583] In formula (a3), X3 represents a single bond, *-C(=O)-O-, or *-C(=O)-N(H)-. * 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 even more preferred.

[0584] In formula (a3), X4 is a single bond, an aliphatic hydrocarbon group with 1 to 4 carbon atoms, a carbonyl group, a sulfonyl group, or a combination thereof. Among these, considering the availability of raw materials, a single bond, a carbonyl group, or a sulfonyl group is preferred; considering the polar group generated after the reaction, a single bond or a carbonyl group is even better.

[0585] In formula (a3), X5 and X6 are each independently an oxygen atom or a sulfur atom. However, X4 and X6 are bonded to adjacent carbon atoms of the aromatic ring. X5 and X6 can be the same or different. From the perspective of reactivity, it is better if X5 and X6 are both oxygen atoms.

[0586] In formula (a3), R22 and R23 are each independently hydrogen atoms, or may contain hydrocarbon groups with 1 to 20 carbon atoms containing heteroatoms. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may 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, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecanyl, 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 these. Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, one part of the -CH2- group in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, it can also contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulopentalide ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc.

[0587] Furthermore, R22 and R23 can also bond to each other and form rings together with the carbon atoms of these bonds. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Also, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms, and some of the -CH2- groups in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. The result is that the rings 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.

[0588] In formula (a3), R24 can be a halogen atom, hydroxyl group, cyano group, nitro group, pentafluorothio group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxycarbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms, or -N(R24A)(R24B). R24A and R24B are each independently a hydrogen atom or a hydrocarbon group with 1 to 6 carbon atoms. The aforementioned halogen atom is preferably a fluorine atom, chlorine atom, bromine atom, or iodine atom, with fluorine or iodine atom being more preferred. The hydrocarbon part of the aforementioned hydrocarbon group, hydrocarbon oxygen group, hydrocarbon oxycarbonyl group, and hydrocarbon thio group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon groups represented by R22 and R23. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, the -CH2- portion of the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This results in the possible inclusion 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 R24 can be the same or different.

[0589] Furthermore, when b2 is 2 or more, multiple R24 atoms can bond to each other and form a ring together with the carbon atoms of the aromatic rings formed by these bonds. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Also, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms, and some of the -CH2- groups in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. The result is that the rings 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.

[0590] Specific examples of repeating unit a3 may be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above, and Me is a methyl group. Also, the bonding positions of the various substituents on the aromatic ring can be interchanged. [Chem.527]

[0591] [Chem.528]

[0592] [Chem. 529]

[0593] [Chem.530]

[0594] [Chemistry 531]

[0595] [Chemistry 532]

[0596] [Chem.533]

[0597] [Chemistry 534]

[0598] [Chem.535]

[0599] [Chemistry 536]

[0600] [Chemistry 537]

[0601] [Chem.538]

[0602] [Chem.539]

[0603] [Chem.540]

[0604] [Chemistry 541]

[0605] [Chemistry 542]

[0606] [Chemistry 543]

[0607] [Chemistry 544]

[0608] [Chem.545]

[0609] [Chemistry 546]

[0610] [Chemistry 547]

[0611] [Chem.548]

[0612] [Chemical 549]

[0613] [Chemical 550]

[0614] [Chemical 551] <000414�> [Chemical 552]

[0616] [Chemical 553]

[0617] [Chemical 554]

[0618] [Chemical 555]

[0619] [Chemical 556]

[0620] [Chemical 557]

[0621] [Chemical 558]

[0622] [Chem.559]

[0623] [Transformation 560]

[0624] [Chem.561]

[0625] [Chem.562]

[0626] [Chem.563]

[0627] [Chem.564]

[0628] [Chem.565]

[0629] [Chem.566]

[0630] [Chem.567]

[0631] [Chem.568]

[0632] [Chem.569]

[0633] [Chemistry 570]

[0634] [Chemistry 571]

[0635] [Chemistry 572]

[0636] [Chem.573]

[0637] [Chemistry 574]

[0638] [Chem.575]

[0639] [Chemistry 576]

[0640] 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.). [Chemistry 577]

[0641] In formulas (b1) and (b2), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y1 is a single bond or *-C(=O)-O-. * indicates an atomic bond with a carbon atom in the main chain. R31 is a hydrogen atom, or a group with 1 to 20 carbon atoms containing at least one of the following: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulopentalide ring, and carboxylic anhydride (-C(=O)-OC(=O)-). R32 can be a halogen atom, carboxyl, nitro, cyano, pentafluorothio, or may contain a hydrocarbon group with 1-20 carbon atoms, a hydrocarbon oxygen group with 1-20 carbon atoms, a hydrocarbon carbonyl group with 2-20 carbon atoms, a hydrocarbon carbonyl oxygen group with 2-20 carbon atoms, or a hydrocarbon oxygen carbonyl group with 2-20 carbon atoms. When c2 is 2, 3, or 4, each R32 can be the same or different. c1 is 1, 2, 3, or 4. c2 is 0, 1, 2, 3, or 4. However, 1 ≤ c1 + c2 ≤ 5.

[0642] Specific examples of repeating unit b1 may be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chem.578]

[0643] [Chemistry 579]

[0644] [Chem.580]

[0645] [Chem.581]

[0646] [Chem.582]

[0647] [Chem.583]

[0648] [Chemical Formula 584]

[0649] [Chemical Formula 585]

[0650] [Chemical Formula 586]

[0651] [Chemical Formula 587]

[0652] [Chemical Formula 588]

[0653] [Chemical Formula 589]

[0654] [Chemical Formula 590] <​​​​​​​​​​​​​​​​​​​​​​​​​​

[0658] Specific examples of repeating unit b2 may be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chem. 594]

[0659] [Chem.595]

[0660] [Chem.596]

[0661] [Chem.597]

[0662] [Chem.598]

[0663] In ArF lithography, repeating units b1 or b2 are preferred, especially those with a lactone ring as a polar group; in KrF lithography, EB lithography, and EUV lithography, those with a phenolic site are preferred.

[0664] The aforementioned polymer may also include at least one of the repeating units represented by formula (c1) (hereinafter also referred to as repeating unit c1.), repeating units represented by formula (c2) (hereinafter also referred to as repeating unit c2.), repeating units represented by formula (c3) (hereinafter also referred to as repeating unit c3.), repeating units represented by formula (c4) (hereinafter also referred to as repeating unit c4.), and repeating units represented by formula (c5) (hereinafter also referred to as repeating unit c5.). [Chem.599]

[0665] In formulas (c1) to (c5), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z1 is a single bond or may be a phenyl group with substituents. Z2 is a single bond, **-C(=O)-O-Z21-, **-C(=O)-N(H)-Z21-, or **-O-Z21-. Z21 is an aliphatic alkyl group with 1 to 6 carbon atoms, a phenyl group, or a divalent group obtained by combining these, and may also contain a halogen atom, a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. Z3 is a single bond, an ether bond, an ester bond, a sulfonate bond, an amide bond, a sulfonamide bond, a carbonate bond, or a carbamate bond. Z4 is a single bond, or an aliphatic alkyl group with 1 to 6 carbon atoms, a phenyl group, or a divalent group obtained by combining these, and may also contain a halogen atom, a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. Z5 is independently a single bond, and may also contain substituents such as phenyl, naphthyl, *-C(=O)-O-Z51-, or *-C(=O)-N(R)-Z51-. Z51 is an aliphatic hydrocarbon group, phenyl, or naphthyl with 1 to 10 carbon atoms, which may also contain halogen atoms, hydroxyl groups, ether bonds, ester bonds, or lactone rings. R is a hydrogen atom, or may also contain heteroatoms and be a hydrocarbon group with 1 to 10 carbon atoms. Z6 is a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond. Z7 is independently a single bond, ***-Z71-C(=O)-O-, ***-C(=O)-N(R)-Z71-, or ***-O-Z71-. Z71 may also contain heteroatoms and be a hydrocarbon group with 1 to 20 carbon atoms. R is the same as described above. Z8 is independently a single bond, ****-Z81-C(=O)-O-, ****-C(=O)-N(R)-Z81-, or ****-O-Z81-. Z81 may also contain a heteroatom with 1 to 20 carbon atoms. R is the same as described above. Z9 is a single bond, methylene, ethyl, phenyl, fluorinated phenyl, trifluoromethyl-substituted phenyl, *-C(=O)-O-Z91-, *-C(=O)-N(R)-Z91-, or *-O-Z91-. Z91 is an aliphatic alkyl group with 1 to 6 carbon atoms, phenyl, fluorinated phenyl, or trifluoromethyl-substituted phenyl, and may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group. R is the same as described above. * indicates an atomic bond with a carbon atom in the main chain. ** indicates an atomic bond with Z1. *** indicates an atomic bond with Z6. **** indicates an atomic bond with Z7.

[0666] Z21, Z51, and Z91 represent aliphatic alkyl groups, which can be straight-chain, branched, or cyclic. Specific examples include methanediyl, 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, and 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, hexane-1,6-diyl and other alkane diyl groups; cyclopropane diyl, cyclobutane diyl, cyclopentane diyl, cyclohexane diyl and other cycloalkane diyl groups; and groups obtained by combining these.

[0667] Z71 and Z81 can also contain heteroatomic extended hydrocarbon groups, which can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples are shown below, but are not limited to these.

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

[0668] In formula (c1), R41 and R42 are each independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may 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, dibutyl, and tributyl; 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, naphthyl, and thiophene; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these, which should preferably be aryl groups. Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, one part of the -CH2- group in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, it can also contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc.

[0669] Furthermore, R41 and R42 can also bond to each other and form a ring together with the sulfur atoms of these bonds. In this case, specific examples of the aforementioned rings can be listed as follows. [Chemical 601] In the formula, the dashed lines represent the atomic bonds between Z4 and Z4.

[0670] Specific examples of the cations in repeating unit c1 may be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemical 602]

[0671] [Chemical 603]

[0672] [Chemical 604]

[0673] [Chemical 605]

[0674] [Chemical 606]

[0675] [Chem.607]

[0676] [Chemical 608]

[0677] [Chemical 609]

[0678] [Chemical 610]

[0679] [Chem.611]

[0680] In formula (c1), M- represents a non-nucleophilic relative ion. The aforementioned non-nucleophilic relative ions are preferably halide ions, sulfonic acid anions, aceimine anions, and methyl acid anions. Specific examples of the aforementioned halide ions include chloride ions, bromide ions, etc. Specific examples of the aforementioned 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, etc. Specific examples of the aforementioned aceimide acid anions (aceimide ions) include bis(trifluoromethylsulfonyl)aceimide ions, bis(perfluoroethylsulfonyl)aceimide ions, and bis(perfluorobutylsulfonyl)aceimide ions. Specific examples of the aforementioned methylated acid anions (methylated ions) include tris(trifluoromethylsulfonyl)methylated ions and tris(perfluoroethylsulfonyl)methylated ions.

[0681] Other examples of the aforementioned non-nucleophilic relative ions can be listed as anions represented by any of the following formulas (c1-1) to (c1-4). [Chem.612]

[0682] In formula (c1-1), Rfa is a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed as those illustrated by the hydrocarbon group represented by Rfa1 in formula (c1-1-1) described later. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This results in the possible inclusion of hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonyl lactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc.

[0683] The anion represented by formula (c1-1) should preferably be represented by the following formula (c1-1-1). [Chemistry 613]

[0684] In formula (c1-1-1), Q1 and Q2 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms. For improved solvent solubility, at least one of them is preferably trifluoromethyl. m is 0, 1, 2, 3, or 4, with 1 being particularly preferred. The Rfa1 system may also include a hydrocarbon group with 1 to 40 carbon atoms and heteroatoms. The aforementioned heteroatoms are preferably oxygen, nitrogen, sulfur, or halogen atoms, with oxygen atoms being even more preferred. Considering the need for high resolution in the formation of fine patterns, the aforementioned hydrocarbon groups with 6 to 30 carbon atoms are particularly preferred.

[0685] In formula (c1-1-1), Rfa1 represents a hydrocarbon group with 1 to 40 carbon atoms, which can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 40 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecayl, pentadecyl, heptadecayl, and icosyl; and cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornel, norbornelmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl, which are cyclic saturated hydrocarbon groups with 3 to 40 carbon atoms. Hydrocarbon groups; unsaturated aliphatic hydrocarbon groups with 2 to 40 carbon atoms, such as 2-propenyl and 3-cyclohexenyl; aryl groups with 6 to 40 carbon atoms, such as phenyl, 1-naphthyl, 2-naphthyl, and 9-enyl; aralkyl groups with 7 to 40 carbon atoms, such as benzyl and diphenylmethyl; polycyclic hydrocarbon groups containing aromatic rings with 7 to 40 carbon atoms, such as 9,10-ethylbridged-9,10-dihydroanthrayl and 6,13-ethylbridged-6,13-dihydropentaphenyl; hydrocarbon groups with 17 to 40 carbon atoms having a steroid skeleton; and groups obtained by combining the above.

[0686] Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, the -CH2- portion of the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This results in the possible inclusion 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, acetaminomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-sideoxypropyl, 4-sideoxy-1-adamantyl, 3-sideoxycyclohexyl, etc.

[0687] In formula (c1-1-1), the La1 series consists of 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 even better.

[0688] Specific examples of anions represented by formula (c1-1) are shown below, but are not limited to these. Furthermore, in the following formula, Q1 is the same as described above, and Ac is an acetyl group. [Chemical 614]

[0689] [Chemical 615]

[0690] [Chem.616]

[0691] [Chemistry 617]

[0692] [Chem.618]

[0693] [Chem.619]

[0694] [Chem.620]

[0695] [Chemistry 621]

[0696] [Chemistry 622]

[0697] [Chemistry 623]

[0698] [Chemistry 624]

[0699] [Chemical 625]

[0700] In formula (c1-2), Rfb1 and Rfb2 are each independently a fluorine atom, or may contain heteroatoms and be a hydrocarbon group with 1 to 40 carbon atoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon group represented by Rfa1 in formula (c1-1-1). Rfb1 and Rfb2 are preferably fluorine atoms or linear fluorinated alkyl groups with 1 to 4 carbon atoms. Furthermore, Rfb1 and Rfb2 may also be bonded to each other and form a ring together with the bonded group (-CF2-SO2-N--SO2-CF2-). In this case, the group obtained by the bonded Rfb1 and Rfb2 is preferably a fluorinated ethyl or fluorinated propyl group.

[0701] In formula (c1-3), Rfc1, Rfc2, and Rfc3 are each independently a fluorine atom, or may contain heteroatoms and be a hydrocarbon group with 1 to 40 carbon atoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon group represented by Rfa1 in formula (c1-1-1). Rfc1, Rfc2, and Rfc3 are preferably fluorine atoms or linear fluorinated alkyl groups with 1 to 4 carbon atoms. Furthermore, Rfc1 and Rfc2 can also be bonded to each other and form a ring together with the bonded group (-CF2-SO2-C--SO2-CF2-). In this case, the group obtained by the bonded Rfc1 and Rfc2 is preferably a fluorinated ethyl or fluorinated propyl group.

[0702] In formula (c1-4), the Rfd group may also include hydrocarbon groups with 1 to 40 carbon atoms. These hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed as those illustrated by the hydrocarbon group represented by Rfa1 in formula (c1-1-1). 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, the -CH2- portion of the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This results in the possible inclusion of hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc.

[0703] Specific examples of anions represented by formula (c1-4) are shown below, but are not limited to these. [Chemistry 626]

[0704] [Chemistry 627]

[0705] 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 represented by the following formula (c1-5). [Chemistry 628]

[0706] 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. It is preferable for y to be 1, 2, or 3, with 2 or 3 being even better. It is preferable for z to be 0, 1, or 2.

[0707] In formula (c1-5), XBI represents an iodine atom or a bromine atom. When x and / or y are 2 or more, each XBI may be the same or different.

[0708] In formula (c1-5), L11 is a single bond, ether bond, ester bond, sulfonate bond, carbonate bond, carbamate bond, or a saturated alkyl group with 1 to 6 carbon atoms. The -CH2- portion of this alkyl group can also be replaced by an ether bond or an ester bond. The aforementioned saturated alkyl group can be straight-chain, branched, or cyclic.

[0709] In formula (c1-5), L12 is a single bond when x is 1, or may contain a heteroatom with 1 to 20 carbon atoms and an extended hydrocarbon group. When x is 2 or 3, it may contain a heteroatom with 1 to 20 carbon atoms and an (x+1) valence hydrocarbon group.

[0710] L12 represents an alkyl group with 1 to 20 carbon atoms, which can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include dialkyl alkyl groups with 1 to 20 carbon atoms, such as 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, and dodecane-1,12-diyl; cyclopentanediyl, cyclohexanediyl, norcamphenediyl, etc. Cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as adamantanediyl and tricyclic [5.2.1.02,6]decanediyl; unsaturated aliphatic hydrocarbon groups with 2 to 20 carbon atoms, such as vinylene and propene-1,3-diyl; aryl groups with 6 to 20 carbon atoms, such as phenyl, naphthyl, and anthracenediyl; polycyclic hydrocarbon groups containing aromatic rings with 7 to 20 carbon atoms, such as 9,10-ethylbridged-9,10-dihydroanthracenediyl and 6,13-ethylbridged-6,13-dihydropentaphenyl; and groups obtained by combining these. L12 represents a (x+1) valence hydrocarbon group with 1 to 20 carbon atoms, which can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed as groups obtained by further removing one or two hydrogen atoms from the aforementioned examples of hydrocarbon groups with 1 to 20 carbon atoms.

[0711] Furthermore, one or all of the hydrogen atoms in the aforementioned extended hydrocarbon group and (x+1) valence hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. The -CH2- portion of the aforementioned extended hydrocarbon group and (x+1) valence hydrocarbon group can also be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it can 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.

[0712] In formula (c1-5), L13 series single bonds, ether bonds, ester bonds, sulfonate bonds, carbonate bonds or carbamate bonds.

[0713] In formula (c1-5), Rfe refers to hydroxyl, carboxyl, fluorine, chlorine, bromine, amino, hydrocarbon group with 1 to 20 carbon atoms, hydrocarbon oxy group with 1 to 20 carbon atoms, hydrocarbon thio group with 1 to 20 carbon atoms, hydrocarbon carbonyl group with 2 to 20 carbon atoms, hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms, or hydrocarbon sulfonyl oxy group with 1 to 20 carbon atoms, -N(RfeA)(RfeB), -N(RfeC)-C(=O)-RfeD or -N(RfeC)-C(=O)-O-RfeD. The hydrocarbon group, hydrocarbon oxy group, hydrocarbon thio group, hydrocarbon carbonyl group, hydrocarbon carbonyl oxy group, hydrocarbon carbonyl oxy group and hydrocarbon sulfonyl oxy group may also include at least one selected from fluorine atom, chlorine atom, bromine atom, iodine atom, hydroxyl group, amino group, ester bond and ether bond. RfeA and RfeB are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. RfeC 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 oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms. RfeD is an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 15 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. The aforementioned hydrocarbon groups, hydrocarbon oxy groups, hydrocarbon carbonyl groups, hydrocarbon oxycarbonyl groups, hydrocarbon carbonyloxy groups, and hydrocarbon sulfonyloxy groups may be linear, branched, or cyclic. When x and / or z are 2 or more, each Rfe can be the same or different from the others.

[0714] Among these, Rfe should preferably be a hydroxyl group, -N(RfeC)-C(=O)-RfeD, -N(RfeC)-C(=O)-O-RfeD, a fluorine atom, a chlorine atom, a bromine atom, a methyl group, a methoxy group, etc.

[0715] In formula (c1-5), Rf11 to Rf14 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, provided that at least one of them is a fluorine atom or a trifluoromethyl group. Furthermore, Rf11 and Rf12 can also form a carbonyl group together. In particular, it is preferable that both Rf13 and Rf14 are fluorine atoms.

[0716] Specific examples of anions represented by equation (c1-5) are shown below, but are not limited to these. Furthermore, in the following equations, XBI is the same as described above. [Chemistry 629]

[0717] [Chemistry 630]

[0718] [Chemistry 631]

[0719] [Chemistry 632]

[0720] [Chemistry 633]

[0721] [Chemistry 634]

[0722] [Chemistry 635]

[0723] [Transformation 636]

[0724] [Chemistry 637]

[0725] [Chemistry 638]

[0726] [Chemistry 639]

[0727] [Transformation 640]

[0728] [Chemistry 641]

[0729] [Chemistry 642]

[0730] [Chemistry 643]

[0731] [Chemistry 644]

[0732] [Chemistry 645]

[0733] [Transformation 646]

[0734] [Chemistry 647]

[0735] [Chemistry 648]

[0736] [Chemistry 649]

[0737] [Chemical 650]

[0738] [Chemistry 651]

[0739] [Chemistry 652]

[0740] Other examples of anions represented by M- include paragraphs

[0076] and

[0106] of International Publication No. 2023 / 157455, paragraphs

[0111] of International Publication No. 2024 / 24801, paragraphs

[0253] to

[0256] of International Publication No. 2024 / 43121, paragraphs

[0044] to

[0045] of International Publication No. 2024 / 122423, paragraphs

[0205] to

[0220] of Japanese Patent Application Publication No. 2023-123183, and paragraphs

[0170] to

[0178] of Japanese Patent Application Publication No. 2024-62406.

[0028] , Paragraphs from Japanese Patent Application Publication No. 2024-62407

[0022] ~

[0025] , Paragraphs from Japanese Patent Application Publication No. 2024-62408

[0026] ~

[0028] , Paragraphs from Japanese Patent Application Publication No. 2024-68156

[0028] ~

[0030] , Paragraphs from Japanese Patent Application Publication No. 2024-68157

[0026] ~

[0028] , Paragraphs from Japanese Patent Application Publication No. 2024-68158

[0028] ~

[0030] , Paragraphs from Japanese Patent Application Publication No. 2024-68159

[0028] ~

[0030] , Paragraphs from Japanese Patent Application Publication No. 2024-72280

[0031] ~

[0033]

[0023] ~

[0025] , paragraphs of Japanese Patent Application Publication No. 2024-72281, paragraphs of Japanese Patent Application Publication No. 2024-77618, paragraphs of Japanese Patent Application Publication No. 2024-77619, paragraphs of Japanese Patent Application Publication No. 2024-80672, paragraphs of Japanese Patent Application Publication No. 2024-83303, paragraphs of Japanese Patent Application Publication No. 2024-83304, paragraphs of Japanese Patent Application Publication No. 2024-99500, paragraphs of Japanese Patent Application Publication No. 2024-99500, paragraphs of Japanese Patent Application Publication No. 2024-99500, paragraphs of Japanese Patent Application Publication No. 2024-92281, paragraphs of Japanese Patent Application Publication No. 2024-77618, paragraphs of Japanese Patent Application Publication No. 2024-77619, paragraphs of Japanese Patent Application Publication No. 2024-80672, paragraphs of Japanese Patent Application Publication No. 2024-83303, paragraphs of Japanese Patent Application Publication No. 2024-9950 ... Paragraphs

[0028] to

[0030] of Japanese Patent Application Publication No. 2024-99502,

[0030] to

[0032] of Japanese Patent Application Publication No. 2024-101557,

[0025] to

[0027] of Japanese Patent Application Publication No. 2024-102842,

[0033] to

[0035] of Japanese Patent Application Publication No. 2024-102843,

[0021] to

[0022] of Japanese Patent Application Publication No. 2024-127832,

[0169] to

[0172] of Japanese Patent Application Publication No. 2024-144354, and

[0178] to

[0181] of Japanese Patent Application Publication No. 2024-144356.The following are descriptions in paragraphs

[0040] to

[0143] of Japanese Patent Application Publication No. 2024-160436, paragraphs

[0157] to

[0158] of Japanese Patent Publication No. 7247732, paragraphs

[0227] to

[0238] of Japanese Patent Publication No. 7446352, paragraphs

[0253] to

[0256] of Japanese Patent Publication No. 7466597, and paragraphs

[0309] to

[0312] of Japanese Patent Publication No. 7466782.

[0741] The aforementioned non-nucleophilic relative ions may 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 a mechanism that decomposes by acid 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 described in Japanese Patent Application Publication No. 2018-92159.

[0742] The aforementioned non-nucleophilic relative ions may further include the anions of benzenesulfonic acid derivatives without fluorine atoms described in Japanese Patent Application Publication Nos. 2006-276759, 2015-117200, 2016-65016, 2019-202974, and 2024-104830; the benzenesulfonic acid anions and alkylsulfonic acid anions bonded to an aromatic group containing an iodine atom described in Japanese Patent No. 6645464; and the anions of benzenesulfonic acid without fluorine atoms bonded to an aromatic group containing an iodine atom described in Japanese Patent Application Publication No. 6645464. Furthermore, the anions described in paragraphs

[0229] to

[0231] of Japanese Patent Application Publication No. 2024-77330 and paragraphs

[0033] to

[0093] of Japanese Patent Application Publication No. 2024-140135 may also be used.

[0743] The aforementioned non-nucleophilic relative ions may also be the anions of disulfonic acid described in Japanese Patent Application Publication No. 2015-206932, the anions of sulfonic acid on one side and sulfenamide or sulfenimine on the other side as described in International Patent Application Publication No. 2020 / 158366, and the anions of sulfonic acid on one side and carboxylic acid on the other side as described in Japanese Patent Application Publication No. 2015-24989.

[0744] In equations (c2) and (c3), d1 and d2 are each independently 0, 1, 2 or 3, and should preferably be 1.

[0745] 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, then 0 ≦ e2 + e3 ≦ 4, and when e1 is 1, then 0 ≦ e2 + e3 ≦ 6.

[0746] In formulas (c2), (c3), and (c4), L11 represents single bonds, ether bonds, ester bonds, carbonyl groups, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Among these, from a synthetic point of view, ether bonds, ester bonds, and carbonyl groups are preferred, with ester bonds and carbonyl groups being even more preferred.

[0747] In formula (c2), Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Of these, for Rf1 and Rf2, it is preferable that both are fluorine atoms to improve the acid strength of the produced acid. Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Of these, it is preferable that at least one of Rf3 and Rf4 is trifluoromethyl to improve solvent solubility.

[0748] In formula (c3), Rf5 and Rf6 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. However, not all Rf5 and Rf6 are hydrogen atoms simultaneously. Among these, for the purpose of improving solvent solubility, it is preferable that at least one of Rf5 and Rf6 is a trifluoromethyl group.

[0749] In formula (c4), Rf7 is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a pentafluorothio group. Rf7 is preferably a fluorine atom, trifluoromethyl, difluoromethyl, trifluoromethoxy, difluoromethoxy, trifluoromethylthio, or difluoromethylthio, with fluorine atom, trifluoromethyl, or trifluoromethoxy being more preferred. When e2 is 2, 3, or 4, each Rf7 can be the same or different.

[0750] In formula (c4), R43 is a halogen atom other than a fluorine atom, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples may be listed as those exemplified by the hydrocarbon groups represented by R1 and R2 in the explanation of formula (1), but are not limited to these. Furthermore, when e3 is 2, 3, or 4, each R43 may be the same or different from the others.

[0751] Furthermore, when e3 is 2, 3, or 4, multiple R43 atoms can bond to each other and form a ring together with the carbon atoms of these bonds. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, and adamantane rings. Also, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, some of the -CH2- groups in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. The result is that the rings may contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulopentalide, carboxylic anhydride (-C(=O)-OC(=O)-), and haloalkyl groups.

[0752] Specific examples of the anion of repeating unit c2 may be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above, and Me is a methyl group. [Chemistry 653]

[0753] [Chem. 654]

[0754] [Chemistry 655]

[0755] [Chemistry 656]

[0756] [Chemistry 657]

[0757] [Chemistry 658]

[0758] [Chemistry 659]

[0759] [Chemical formula 660]

[0760] [Chemical formula 661]

[0761] [Chemical formula 662]

[0762] [Chemical formula 663]

[0763] [Chemical formula 664]

[0764] [Chemical formula 665]

[0765] Specific examples of the repeating unit c2 include those described in paragraphs

[0043] to

[0044] of International Publication No. 2024 / 176672, paragraphs

[0067] to

[0070] of International Publication No. 2024 / 176701, paragraphs

[0057] to

[0058] of International Publication No. 2024 / 190386, paragraphs

[0020] to

[0023] of Japanese Patent Application Laid-Open No. 2024-103465, paragraphs

[0067] to

[0070] of Japanese Patent Application Laid-Open No. 2024-120703, paragraphs

[0075] to

[0084] of Japanese Patent No. 7520258, etc.

[0766] Specific examples of the anion of the repeating unit c3 include those shown below, but are not limited thereto. Also, in the following formula, RA is the same as described above. [Chemical formula 666] <s

[0767] [Chemical Formula 667]

[0768] [Chemical Formula 668]

[0769] [Chemical Formula 669]

[0770] [Chemical Formula 670]

[0771] [Chemical Formula 671]

[0772] [Chemical Formula 672]

[0773] [[ID=¥52]] [Chemical Formula 673]

[0774] [Chemical Formula 674]

[0775] [Chemical Formula 675]

[0776] [Chemical Formula 676] Note: The "¥" in line 52 seems to be an incorrect symbol. It should be a normal digit or other correct character in the original text. This translation is based on the best understanding with the given content.

[0777] Specific examples of the anion of repeating unit c4 may be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Transformation 677]

[0778] [Transformation 678]

[0779] [Chemistry 679]

[0780] [Transformation 680]

[0781] [Chemistry 681]

[0782] [Chem. 682]

[0783] [Chem.683]

[0784] [Chem.684]

[0785] [Chem.685]

[0786] [Chemical Formula 686]

[0787] [Chemical Formula 687]

[0788] [Chemical Formula 688]

[0789] [Chemical Formula 689]

[0790] [Chemical Formula 690]

[0791] [Chemical Formula 691]

[0792] [Chemical Formula 692] <00�5254>

[0793] [Chemical Formula 693]

[0794] Specific examples of the anion of the repeating unit c5 include those shown below, but are not limited to these. Also, in the following formula, RA is the same as described above. [Chemical Formula 694] <□005272>

[0795] In formulas (c2) to (c5), A+ refers to onium cations. Examples of onium cations include strontium cations, ferromonium cations, and ammonium cations, with strontium cations and ferromonium cations being preferred. Specific examples of strontium cations include those exemplified by specific examples of strontium salt cations represented by formula (1), those described in paragraphs

[0102] to

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

[0044] to

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

[0035] to

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

[0796] Furthermore, among the aforementioned strontium cations, the strontium cation represented by the formula (sulfo-1) is also preferred. [Chemistry 695]

[0797] In formula (sulfo-1), f1 is either 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 either 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 f1 of 0 is preferred. f3 is either 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.

[0798] In formula (sulfo-1), f4 is 0, 1, 2, 3, or 4. The more iodine atoms in the cationic structure, the higher the absorption of EUV, but the less solvent-soluble it becomes, raising concerns about precipitation in the inhibitor composition. Therefore, f4 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0799] 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 even better. 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 even better. 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 even better.

[0800] In formula (sulfo-1), f8 is 0, 1, or 2. Considering the availability of raw materials, f8 is preferably 0 or 1. f9 is 0, 1, or 2. Considering the availability of raw materials, f9 is preferably 0 or 1. f10 is 0, 1, or 2. Considering the availability of raw materials, f10 is preferably 0 or 1.

[0801] In formula (sulfo-1), f11 is either 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.

[0802] In formula (sulfo-1), f12 is 0, 1, 2, 3, or 4. The more iodine atoms in the cationic structure, the higher the absorption of EUV, but the less solvent-soluble it becomes, raising concerns about precipitation in the inhibitor composition. Therefore, f12 of 0, 1, 2, or 3 is preferred, with 0, 1, or 2 being even better.

[0803] In formula (sulfo-1), f13 is 0, 1, or 2. From the perspective of raw material availability, f13 is preferably 0 or 1. f14 is 0, 1, or 2. From the perspective of synthesis, f14 is preferably 0 or 1.

[0804] However, when f1 is 0, then 0 ≦ f6 + f9 ≦ 4; when f1 is 1, then 0 ≦ f6 + f9 ≦ 6. When f2 is 0, then 0 ≦ f7 + f10 ≦ 4; when f2 is 1, then 0 ≦ f7 + f10 ≦ 6. When f3 is 0, then 1 ≦ f4 + f5 + f8 + f14 ≦ 4; when f3 is 1, then 1 ≦ f4 + f5 + f8 + f14 ≦ 6. When f11 is 0, then 0 ≦ f12 + f13 ≦ 4; when f11 is 1, then 0 ≦ f12 + f13 ≦ 6. Also, f4 + f12 ≧ 1.

[0805] In formula (sulfo-1), RF1 to RF3 are each 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 RF1 may be the same or different from the others. When f6 is 2, 3, 4, 5, or 6, each RF2 may be the same or different from the others. When f7 is 2, 3, 4, 5, or 6, each RF3 may be the same or different from the others.

[0806] In formula (sulfo-1), Rct1 to Rct4 are halogen atoms other than iodine and fluorine atoms, nitro groups, cyano groups, and may also include hydrocarbon groups with 1 to 20 carbon atoms (heteroatomic), hydroxyl groups with 1 to 20 carbon atoms (heteroatomic), or thiol groups with 1 to 20 carbon atoms (heteroatomic). The hydrocarbon groups, hydroxyl groups, and thiol groups mentioned above can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon groups represented by R1 and R2 in the explanation of formula (1). Furthermore, one or all of the hydrogen atoms in the hydrocarbon portion of the aforementioned hydrocarbon group, hydrocarbon oxygen group, and hydrocarbon sulfide group can be replaced by a group containing heteroatoms such as oxygen atom, sulfur atom, nitrogen atom, and halogen atom. The -CH2- portion of the aforementioned hydrocarbon group can also be replaced by a group containing heteroatoms such as oxygen atom, sulfur atom, and nitrogen atom. As a result, it can also contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulfonolactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc.

[0807] Furthermore, when f8 is 2, the two Rct1s can be the same or different, and the two Rct1s can also bond to each other and form a ring together with the carbon atoms of these bonds. When f9 is 2, the two Rct2s can be the same or different, and the two Rct2s can also bond to each other and form a ring together with the carbon atoms of these bonds. When f10 is 2, the two Rct3s can be the same or different, and the two Rct3s can also bond to each other and form a ring together with the carbon atoms of these bonds. When f13 is 2, the two Rct4s can be the same or different, and the two Rct4s can also bond to each other and form a ring together with the carbon atoms of these bonds. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norcamphene rings, adamantane rings, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned ring can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Similarly, some of the -CH2- in the aforementioned ring can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it can 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.

[0808] Furthermore, the aromatic rings of S+ directly bonded to each other in the sulfonium cation represented by formula (sulfo-1) can also bond to each other and form a ring together with S+. In this case, specific examples of the aforementioned ring structures can be listed in the following formulas, etc. [Transformation 696] In the formula, the dashed lines represent atomic bonds.

[0809] In formula (sulfo-1), LE and LF are each independently a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond. Of these, LC is preferably a single bond, ether bond, ester bond, or sulfonate bond, with ester or sulfonate bond being more preferred. LD is preferably a single bond, ether bond, or ester bond, with single bond being more preferred.

[0810] In formula (sulfo-1), XL2 is a single bond, or may contain a heteroatom and be a carbon group with 1 to 40 carbon atoms. The aforementioned carbon group can be straight-chain, branched, or cyclic; specific examples include alkane dimethyl, cyclic saturated carbon group, and carbonyl group. Specific examples of the aforementioned heteroatom include oxygen, nitrogen, and sulfur atoms. Specific examples of carbon groups with 1 to 40 carbon atoms represented by XL2, which may also contain heteroatoms, include XL-0 to XL-61, as illustrated in the description of formula (Z) where XL1 represents carbon groups with 1 to 40 carbon atoms. Among these, XL2 is preferably XL-0 to XL-22, XL-29 to XL-34, and XL-47 to XL-61.

[0811] The strontium cation represented by formula (sulfo-1) is preferred over the one represented by formula (sulfo-1-1). [Chemistry 697] In the formula, f4~f10, f12~f14, RF1~RF3, Rct1~Rct4, LE, LF and XL2 are the same as those mentioned above.

[0812] The strontium cation represented by formula (sulfo-1-1) is preferred over the strontium cation represented by formula (sulfo-1-2). [Transformation 698] In the formula, f4~f10, RF1~RF3 and Rct1~Rct3 are the same as those mentioned above.

[0813] Specific examples of strontium cations represented by formula (sulfo-1) are shown below, but are not limited to these. Furthermore, in the following formula, Me is a methyl group. [Transformation 699]

[0814] [Chemical 700]

[0815] [Chemical 701]

[0816] [Chemical 702]

[0817] [Chemical 703]

[0818] [Chemical 704]

[0819] [Chemical 705]

[0820] [Chemical 706]

[0821] [Chem.707]

[0822] [Chem.708]

[0823] [Chem. 709]

[0824] [Chem.710]

[0825] [Chemical formula 711]

[0826] [Chemical formula 712]

[0827] [Chemical formula 713]

[0828] [Chemical formula 714]

[0829] [Chemical formula 715]

[0830] [Chemical formula 716]

[0831] [Chemical formula 717]

[0832] [Chemical formula 718]

[0833] [Chemical formula 719]

[0834] [Chemical formula 720]

[0835] [Chemistry 721]

[0836] [Chem.722]

[0837] [Chem.723]

[0838] [Chem. 724]

[0839] [Chem. 725]

[0840] [Chemistry 726]

[0841] Specific examples of the aforementioned cations can be found in paragraph

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

[0842] Specific examples of the aforementioned ammonium cations can be represented by the following formula (am-1). [Chem.727]

[0843] In formula (am-1), Rct5 to Rct8 are each independently an hydrocarbon with 1 to 40 carbon atoms, which may also contain heteroatoms. Furthermore, Rct5 and Rct6 may bond to each other and form a ring together with the nitrogen atoms of these bonds. Specific examples of the aforementioned hydrocarbons can be given as those exemplified by the hydrocarbons represented by R1 and R2 in the explanation of formula (1).

[0844] Specific examples of ammonium cations represented by formula (am-1) are shown below, but are not limited to these. [Chem.728]

[0845] The specific structures of repeating units c1 to c5 can be listed as any combination of the aforementioned anions and cations.

[0846] Among the repeating units c1 to c5, considering the control of acid diffusion, repeating units c2 to c5 are preferable. Considering the acid strength of the produced acid, repeating units c2, c4, and c5 are even better. Considering the solvent solubility, repeating unit c2 is even better.

[0847] The aforementioned polymer may also contain repeating units (hereinafter also referred to as repeating units d) having a structure in which hydroxyl groups are protected by acid-insecure 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 decompose and generate hydroxyl groups due to the action of acid, and are preferably represented by the following formula (d1). [Chemistry 729]

[0848] In formula (d1), RA refers to hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups. R51 may also contain heteroatoms with a carbon number of 1 to 30 and a (g+1) valence hydrocarbon group. R52 refers to acid-labile groups. g refers to 1, 2, 3, or 4.

[0849] In formula (d1), R52 represents an acid-insecure group, which can be deprotected by the acid to form a hydroxyl group. The structure of R52 is not particularly limited, but it is preferable to have an acetal structure, a ketal structure, a hydroxyl group, or a hydroxyl group represented by formula (d2), especially a hydroxyl group represented by formula (d2). [Chemistry 730] In the formula, * represents an atomic bond. R53 refers to hydrocarbon groups with 1 to 15 carbon atoms.

[0850] R52 represents an acid-instable group, formula (d2) represents an alkyloxymethyl group, and specific examples of repeating unit d can be listed as those illustrated in the description of repeating unit d in Japanese Patent Application Publication No. 2020-111564.

[0851] The aforementioned polymer may also contain repeating unit e derived from indene, benzofuran, benzothiophene, acenaphthylene, chromone, coumarin, norbornadiene or derivatives thereof. Specific examples of the monomer providing repeating unit e are as shown below, but are not limited thereto. [Chemical formula 731]

[0852] The aforementioned polymer may also contain repeating unit f derived from indan, vinylpyridine or vinylcarbazole.

[0853] In the aforementioned polymer, the content ratios of 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.

[0854] The weight average molecular weight (Mw) of the aforementioned polymer is preferably 1,000 to 500,000, more preferably 3,000 to 100,000. If Mw is within this range, sufficient etching resistance can be obtained without fear of a decrease in resolution due to an inability to ensure a difference in dissolution rate before and after exposure. In addition, in the present invention, Mw is a polystyrene equivalent measurement value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or N,N-dimethylformamide (DMF) as a solvent.

[0855] The molecular weight distribution (Mw / Mn) of the aforementioned polymers tends to increase with the refinement of the pattern. Therefore, to obtain a resist composition suitable for fine pattern sizes, a narrow dispersion of Mw / Mn of 1.0 to 2.0 is preferable. Within this range, there are fewer low- and high-molecular-weight polymers, and after exposure, there is no concern about foreign matter being observed on the pattern or the pattern shape deteriorating.

[0856] For example, a method for synthesizing the aforementioned polymer can be described as a method in which a monomer providing the aforementioned repeating unit is added to an organic solvent, a free radical polymerization initiator is added, and the mixture is heated to carry out polymerization.

[0857] Specific examples of organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, dialkylene, 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(methyl 2-methylpropionate), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, and lauryl peroxide. The amount of these initiators added relative to the total monomers to be polymerized should preferably be 0.01~25 moles. The reaction temperature should preferably be 50~150℃, and more preferably 60~100℃. A reaction time of 2 to 24 hours is preferable, but from the perspective of production efficiency, 2 to 12 hours is even better.

[0858] The aforementioned polymerization initiator can be added to the monomer solution and supplied to the reactor, or the monomer solution and initiator solution can be prepared separately and supplied to the reactor independently. During the standby time, there is a possibility that polymerization may occur due to free radicals generated by the initiator, resulting in ultra-high molecular weight polymers. Therefore, from a quality management perspective, it is preferable to prepare the monomer solution and initiator solution independently and add them dropwise. Acid-labile groups can be used directly introduced into 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 concurrently. In this case, the amount of such chain transfer agents added relative to the total amount of monomers to be polymerized should preferably be 0.01~20 mol%.

[0859] When monomers contain hydroxyl groups, the hydroxyl groups can be replaced with acetal groups such as ethoxy or ethoxy, which are easily deprotected by acids, during polymerization. After polymerization, the hydroxyl groups can be deprotected with weak acids and water. Alternatively, they can be replaced with acetyl, methyl, or neopentyl groups before polymerization and then subjected to alkaline hydrolysis.

[0860] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, hydroxystyrene or hydroxyvinylnaphthalene can be copolymerized with other monomers in an organic solvent, with the addition of a free radical polymerization initiator and heating. Alternatively, acetoxystyrene or acetoxyvinylnaphthalene can be used, and after polymerization, the acetoxy group can be deprotected by alkaline hydrolysis to become polyhydroxystyrene or hydroxyvinylnaphthalene.

[0861] Specific examples of alkali used in alkaline hydrolysis include ammonia and triethylamine. Furthermore, the reaction temperature should preferably be -20 to 100°C, more preferably 0 to 60°C. The reaction time should preferably be 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0862] Furthermore, the amount of each monomer in the aforementioned monomer solution can be appropriately set, for example, in a manner that results in a preferred content ratio for the aforementioned repeating unit.

[0863] The polymer obtained by the aforementioned manufacturing method can be used as the final product, either as the reaction solution obtained by polymerization or as the final product, which is obtained by purification steps such as adding the polymer solution to a lean solvent to obtain the powder and then reprecipitating it. Considering the efficiency of operation and the stability of quality, it is better to use the polymer solution in which the powder obtained by purification steps is dissolved in the solvent as the final product.

[0864] Specific examples of solvents used at this time can be cited from paragraphs

[0144] to

[0145] of Japanese Patent Application Publication No. 2008-111103, including ketones such as cyclohexanone and methyl-2-n-pentanone; 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, propylene glycol dimethyl ether, and dimethyl propylene glycol monomethyl ether. Ethers such as ethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tributyl acetate, tributyl propionate, and propylene glycol monoterbutyl 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 mixed solvents thereof.

[0865] In the aforementioned polymer solution, the polymer concentration is preferably 0.01~30% by mass, and more preferably 0.1~20% by mass.

[0866] The aforementioned reaction solutions and polymer solutions are best filtered. Filtering removes foreign matter and colloids that may cause defects, thus effectively stabilizing the quality.

[0867] The materials used in the aforementioned filters include fluorocarbon-based, cellulose-based, nylon-based, polyester-based, and hydrocarbon-based materials. For filtration steps involving inhibitor components, filters made of fluorocarbon-based materials such as Teflon (registered trademark), polyethylene, 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 preferably involve passing the solution through only once, or circulating the solution for multiple filtrations. The filtration steps can be performed in any order and number of times during the polymer manufacturing process, preferably filtering the reaction solution, polymer solution, or both after the polymerization reaction.

[0868] (B) The base polymer may be used alone or in combination with two or more polymers having different composition ratios, Mw and / or Mw / Mn. Furthermore, (B) the base polymer may include, in addition to the aforementioned polymers, hydrides of ring-opening shift polymers; in this case, those described in Japanese Patent Application Publication No. 2003-66612 may be used.

[0869] [(C) Organic solvent] The chemical amplification inhibitor composition of the present invention may also include an organic solvent as component (C). As for the organic solvent (C), it is not particularly limited 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-pentanone; 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, tributyl acetate, tributyl propionate, and propylene glycol monotert-butyl ether acetate; lactones such as GBL; and mixed solvents of these.

[0870] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, cyclohexanone, GBL, ethyl lactate, DAA, and mixed solvents thereof are preferred, as they have particularly good solubility in component (B), i.e., the base polymer.

[0871] In the chemical amplification inhibitor composition of the present invention, the content of (C) organic solvent relative to 80 parts by mass of (B) base polymer is preferably 200-5000 parts by mass, and more preferably 400-3500 parts by mass. (C) organic solvent can be used alone or in combination with two or more.

[0872] [(D) Quenching agent] The chemical amplification inhibitor composition of the present invention may also include a quencher as component (D). Furthermore, the quencher in the present invention is a material used to prevent diffusion towards the unexposed area by capturing the strong acid generated by the photoacid generator in the chemical amplification inhibitor composition, thereby forming a desired pattern. Moreover, the term "strong acid" refers to an acid with sufficient acidity to cause deprotection reactions of unstable acid groups.

[0873] (D) Specific examples of quenching agents can be listed as onion salts represented by formula (2) or (3). [Chemistry 732]

[0874] In formula (2), Rq1 is a hydrogen atom, or may contain a hydrocarbon group with 1 to 40 carbon atoms of heteroatoms, except that the hydrogen atom at the α-position of the sulfonic acid group is replaced by a fluorine atom or a fluoroalkyl group. In formula (3), Rq2 is a hydrogen atom, or may contain a hydrocarbon group with 1 to 40 carbon atoms of heteroatoms.

[0875] Rq1 represents hydrocarbon groups with 1 to 40 carbon atoms. Specifically, examples include alkyl groups with 1 to 40 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, tripentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclo[5.2.1.02,6]decyl, and adamantylalkyl; and aryl groups with 6 to 40 carbon atoms such as phenyl, naphthyl, and anthracene. Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Similarly, one part of the -CH2- group in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it can 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, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0876] Specifically, the hydrocarbon group represented by Rq2, in addition to the substituents exemplified in the specific examples of Rq1, can also include fluorinated saturated hydrocarbon groups such as trifluoromethyl and trifluoroethyl, and fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

[0877] Specific examples of the anions of the onium salts represented by equation (2) are shown below, but are not limited to these. [Chemistry 733]

[0878] [Chemistry 734]

[0879] [Chemistry 735]

[0880] [Chemistry 736]

[0881] [Chemistry 737]

[0882] Specific examples of the anions of the onium salts represented by equation (3) are shown below, but are not limited to these. [Chemistry 738]

[0883] [Chemistry 739]

[0884] [Chemistry 740]

[0885] [Chemistry 741]

[0886] [Chemistry 742]

[0887] In formulas (2) and (3), Mq+ is a monium cation. Examples of the aforementioned monium cations include strontium cations, monium cations, and ammonium cations. Specific examples of the aforementioned strontium cations include those exemplified by the strontium cation represented by formula (1), those described in paragraphs

[0102] to

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

[0044] to

[0049] of International Patent Publication No. 2024 / 128017, those described in paragraphs

[0035] to

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

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

[0888] Specific examples of onium salts represented by formula (2) or (3) can be listed as any combination of the aforementioned anions and cations. Furthermore, these onium salts can be easily prepared by ion exchange reactions using known organic chemical methods. For example, Japanese Patent Application Publication No. 2007-145797 can be consulted regarding ion exchange reactions.

[0889] The onium salts represented by formula (2) or (3) function as quenchers in the chemical amplification inhibitor composition of the present invention. This is because the onium salts are conjugate bases of the aforementioned relative anionic weak acids. Here, "weak acid" means an acidity that cannot be protected by the acid unstable group of the unit containing the acid unstable group used in the base polymer. When the onium salts represented by formula (2) or (3) are used in combination with the conjugate base of a strong acid such as an α-fluorinated sulfonic acid as a relative anionic onium salt-type photoacid generator, they function as quenchers. That is, when an onium salt that produces a strong acid such as α-fluorinated sulfonic acid is mixed with an onium salt that produces a weak acid such as unfluorinated sulfonic acid or carboxylic acid, the strong acid produced by the photoacid generator irradiated by high-energy rays collides with the onium salt containing unreacted weak acid anions. This results in the release of the weak acid through salt exchange, producing an onium salt containing strong acid anions. In this process, the strong acid exchanges with the weak acid with lower catalytic energy, thus macroscopically the acid loses its activity and acid diffusion can be controlled.

[0890] Furthermore, (D) the quenching agent may also be an onium salt having strontium cation and benzene oxide anion sites in the same molecule as described in Japanese Patent No. 6848776, as well as an onium salt having strontium cation and carboxylate anion sites in the same molecule as described in Japanese Patent No. 6583136, Japanese Patent Application Publication No. 2020-200311, and an onium salt having monium cation and carboxylate anion sites in the same molecule as described in Japanese Patent No. 6274755.

[0891] Therefore, it is believed that when the photoacid generator producing strong acids is an onium salt, as mentioned above, the strong acid produced by high-energy ray irradiation can exchange with a weak acid. On the other hand, the weak acid produced by high-energy ray irradiation is difficult to collide with the onium salt that produces unreacted strong acid to achieve salt exchange. This is because onium cations readily form ion pairs with the anions of stronger acids.

[0892] When the chemical amplification inhibitor composition of the present invention contains an onium salt represented by formula (2) or (3) as a quencher (D), its content relative to 80 parts by mass of the base polymer (B) is preferably 0.1 to 20 parts by mass, and more preferably 0.1 to 10 parts by mass. If the content of the aforementioned onium salt quencher is within the aforementioned range, the resolution is good and the sensitivity does not decrease significantly, which is ideal. The onium salt represented by formula (2) or (3) can be used alone or in combination of two or more.

[0893] The chemical amplification inhibitor composition of the present invention may also include a nitrogen-containing compound as a (D) quencher. Specific examples of the aforementioned nitrogen-containing compounds include the first-, second-, or third-order amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Publication No. 2008-111103, particularly amine compounds having hydroxyl groups, ether bonds, ester bonds, lactone rings, cyano groups, or sulfonate bonds. Furthermore, compounds of first- or second-order amines protected with carbamate groups as described in Japanese Patent Publication No. 3790649 may also be cited.

[0894] Alternatively, strontium sulfonate salts with nitrogen-containing substituents, which are nitrogen-containing compounds, can also be used. Such compounds function as quenchers in the unexposed areas, while in the exposed areas, they lose their quenching ability due to neutralization with the acid they generate, and instead function as so-called photodegrading bases. By using photodegrading bases, the contrast between the exposed and unexposed areas can be further enhanced. For example, Japanese Patent Application Publication Nos. 2009-109595 and 2012-46501 can be referenced for photodegrading bases.

[0895] When the chemical amplification inhibitor composition of the present invention includes a nitrogen-containing compound as a (D) quencher, its content relative to 80 parts by mass of the (B) base polymer is preferably 0.001 to 12 parts by mass, 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.

[0896] [(E) Other photoacid generating agents] The chemical amplification inhibitor composition of the present invention may also include photoacid generators other than component (A) which is component (E) (hereinafter also referred to as other photoacid generators). The aforementioned other photoacid generators are not particularly limited as long as they are compounds that produce strong acids when irradiated by high-energy rays. Preferred other photoacid generators may be represented by the following formulas (4) or (5). [Chemistry 743]

[0897] In formula (4), R101 to R105 are each independently a halogen atom, or may contain a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms. Furthermore, any two of R101, R102, and R103 may bond to each other and form a ring together with the sulfur atoms of these bonds. Specific examples of the aforementioned hydrocarbon groups can be listed as those exemplified by the hydrocarbon groups represented by R1 and R2 in the explanation of formula (1).

[0898] Specific examples of strontium salt cations represented by formula (4) may be exemplified by examples of strontium salt cations represented by formula (1), those described in paragraphs

[0102] to

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

[0044] to

[0049] of International Patent Publication No. 2024 / 128017, those described in paragraphs

[0035] to

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

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

[0899] In equations (4) and (5), Xa- is an anion of a strong acid. Specific examples of the aforementioned strong acid anions can be listed as any of those represented in equations (c1-1) to (c1-5).

[0900] Furthermore, component (E), i.e., other photoacid generating agents, should preferably be represented by the following formula (6). [Chemistry 744]

[0901] In formula (6), R201 and R202 are each independently a hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. R203 is also a hydrocarbon group with 1 to 30 carbon atoms, which may contain heteroatoms. Furthermore, any two of R201, R202 and R203 may bond to each other and form a ring together with the sulfur atoms of these bonds.

[0902] R201 and R202 represent hydrocarbon groups with 1 to 30 carbon atoms, which can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, tripentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornel, oxanorbornel, tricyclic [5.2.1.02, 6] Decyl, adamantyl, and other cyclic saturated hydrocarbon groups having 3 to 30 carbon atoms; phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, dibutylphenyl, tributylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, dibutylnaphthyl, tributylnaphthyl, anthracene, and other aryl groups having 6 to 30 carbon atoms; and groups obtained by combining these. Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Similarly, one part of the -CH2- group in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it can 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.

[0903] R203 represents an extended hydrocarbon group with 1 to 30 carbon atoms, which 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, hexadecane-1,16-diyl, decadecane, and so on. Alkyl groups with 1 to 30 carbon atoms, such as heptadecane-1,17-diyl; cyclopentanediyl, cyclohexanediyl, norcamphenediyl, adamantanediyl, and other cyclic saturated alkyl groups with 3 to 30 carbon atoms; and aryl groups such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, dibutylphenylene, tributylphenylene, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, dibutylnaphthyl, and tributylnaphthyl. Furthermore, some or all of the hydrogen atoms in the aforementioned alkyl group can be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, the -CH2- portion of the aforementioned alkyl group can also be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This results in the possible inclusion of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), or haloalkyl groups. The aforementioned heteroatoms should preferably be oxygen atoms.

[0904] In formula (6), L21 is a single bond, an ether bond, or may contain a heteroatom with 1 to 20 carbon atoms in an extended hydrocarbon group. The aforementioned extended hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the extended hydrocarbon group represented by R203.

[0905] In formula (6), Xa, Xb, Xc and Xd are each independently a hydrogen atom, a fluorine atom or a trifluoromethyl group. However, at least one of Xa, Xb, Xc and Xd is a fluorine atom or a trifluoromethyl group.

[0906] The photoacid generator represented by formula (6) should preferably be represented by the following formula (6'). [Chemistry 745]

[0907] In formula (6'), L21 is the same as described above. Xe is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R301, R302, and R303 are each independently a hydrogen atom, or may contain a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon group represented by Rfa1 in formula (c1-1-1). p and q are each independently 0, 1, 2, 3, 4, or 5, and r is 0, 1, 2, 3, or 4.

[0908] Specific examples of photoacid generators represented by formula (6) can be listed as those similar to those exemplified by the photoacid generators represented by formula (2) in Japanese Patent Application Publication No. 2017-26980.

[0909] 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, which is particularly desirable. Furthermore, those represented by formula (6') exhibit extremely low acid diffusion, which is also particularly desirable.

[0910] When the chemical amplification inhibitor composition of this invention includes (E) other photoacid generating agents, its content relative to 80 parts by weight of the (B) base polymer is preferably 0.1 to 40 parts by weight, and more preferably 0.5 to 20 parts by weight. If the amount of (E) component, i.e., the photoacid generating agent, is within the aforementioned range, the resolution is good, and there is no risk of foreign matter being generated after the inhibitor film is developed or during peeling, which is ideal. (E) Other photoacid generating agents can be used alone or in combination of two or more.

[0911] (F) Surfactants The chemical amplification inhibitor composition of the present invention may further include a surfactant as component (F). The surfactant (F) is preferably a surfactant that is insoluble or sparingly soluble in water but soluble in alkaline developing solution, or a surfactant that is insoluble or sparingly soluble in both water and alkaline developing solution. Such surfactants can be referred to in Japanese Patent Application Publication Nos. 2010-215608 and 2011-16746.

[0912] Regarding surfactants that are insoluble or poorly soluble in water and alkaline developing solutions, the surfactants described in the aforementioned announcement should preferably be 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). [Chemistry 746]

[0913] 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, ranging from 2 to 4 valences. Among the aforementioned aliphatic groups, examples of divalent groups include ethylenyl, 1,4-butylenyl, 1,2-propylenyl, 2,2-dimethyl-1,3-propylenyl, and 1,5-pentylenyl, while examples of trivalent or tetravalent groups include the following. [Chemistry 747] In the formula, the dashed lines represent atomic bonds, which are secondary structures derived from glycerol, trimethylolethane, trimethylolpropane, and neopentyl tertrol, respectively.

[0914] Among these, 1,4-endobutyl and 2,2-dimethyl-1,3-endopropyl are preferred.

[0915] 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 limited; they can be block-bonded or randomly bonded. For details on the manufacture of surfactants based on partially fluorinated oxyheterocyclic butane ring-opening polymers, please refer to the specification of US Patent No. 5650483, etc.

[0916] Surfactants that are insoluble or sparingly soluble in water but soluble in alkaline developing solutions can reduce water penetration and leaching caused by alignment with the surface of the resist film during ArF wet lithography without the use of a resist protective film. Therefore, they are useful for reducing damage to the exposure equipment by inhibiting the leaching of water-soluble components from the resist film. Furthermore, they are useful for soluble development in alkaline aqueous solutions after exposure or post-exposure baking (PEB), reducing the likelihood of foreign matter becoming a cause of defects. Such surfactants, which are insoluble or sparingly soluble in water but soluble in alkaline developing solutions, are polymer-type surfactants, also known as hydrophobic resins, and those with high water-repellent properties that enhance hydrophobicity are particularly desirable.

[0917] Specific examples of such polymeric surfactants include surfactants comprising at least one of the repeating units represented by formula (7A) (hereinafter also referred to as repeating unit 7A.), repeating units represented by formula (7B) (hereinafter also referred to as repeating unit 7B.), repeating units represented by formula (7C) (hereinafter also referred to as repeating unit 7C.), repeating units represented by formula (7D) (hereinafter also referred to as repeating unit 7D.), and repeating units represented by formula (7E) (hereinafter also referred to as repeating unit 7E.). [Chemistry 748]

[0918] In formulas (7A) to (7E), RB represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. W1 represents -CH2-, -CH2CH2-, -O-, or two separate -H groups. Rs1 is independently a hydrogen atom or a hydrocarbon group with 1 to 10 carbon atoms. Rs2 is a single bond or a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms. Rs3 is independently a hydrogen atom, a hydrocarbon group with 1 to 15 carbon atoms, a fluorinated hydrocarbon group, or an acid-unstable group. When Rs3 is a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond or a carbonyl group may be inserted between carbon-carbon bonds. Rs4 is a (u+1) valence hydrocarbon group or a fluorinated hydrocarbon group with 1 to 20 carbon atoms. u represents 1, 2, or 3. Rs5 is independently a hydrogen atom or a group represented by -C(=O)-O-Rsa. Rsa is a fluorinated hydrocarbon group with 1 to 20 carbon atoms. Rs6 series hydrocarbon groups or fluorinated hydrocarbon groups with 1 to 15 carbon atoms can also have ether bonds or carbonyl groups inserted between the carbon-carbon bonds.

[0919] Rs1 represents a hydrocarbon group with 1 to 10 carbon atoms, which should preferably be a saturated hydrocarbon group and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, 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.

[0920] The alkyl group represented by Rs2 should preferably be a saturated alkyl group, and can be straight-chain, branched, or cyclic. Specific examples include methylene, ethyl alkyl, propyl alkyl, butyl alkyl, and pentyl alkyl.

[0921] The hydrocarbon groups represented by Rs3 or Rs6 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, with saturated hydrocarbon groups being preferable. Besides those exemplified by hydrocarbon groups represented by Rs1, specific examples of saturated hydrocarbon groups include undecayl, dodecyl, tridecayl, tetradecayl, and decadecyl. Fluorinated hydrocarbon groups represented by Rs3 or Rs6 can be groups where one or all of the hydrogen atoms of the carbon atom bonded to the aforementioned hydrocarbon group are replaced by fluorine atoms. As mentioned earlier, ether bonds or carbonyl groups can also be inserted between these carbon-carbon bonds.

[0922] Specific examples of acid-instable groups represented by Rs3 include groups represented by the aforementioned formulas (AL-3) to (AL-5), trialkylsilyl groups with each alkyl group having 1 to 6 carbon atoms, and alkyl groups containing side oxygen atoms having 4 to 20 carbon atoms.

[0923] Rs4 represents a (u+1) valence hydrocarbon group or fluorinated hydrocarbon group, which can be straight-chain, branched, or cyclic. Specific examples can be listed as groups obtained by removing u hydrogen atoms from the aforementioned hydrocarbon group or fluorinated hydrocarbon group.

[0924] The fluorinated hydrocarbon group represented by Rsa should preferably be saturated and can be linear, branched, or cyclic. Specific examples include those in which one or all of the hydrogen atoms of the aforementioned hydrocarbon group are replaced by fluorine atoms. Specific 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-dodecylfluoroheptyl, 2-(perfluorobutyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorooctyl)ethyl, 2-(perfluorodecyl)ethyl, etc.

[0925] Specific examples of repeating units 7A to 7E may be listed below, but are not limited to these. Furthermore, in the following formula, RB is the same as described above. [Chemistry 749]

[0926] [Chemical 750]

[0927] [Chemistry 751]

[0928] [Chemistry 752]

[0929] [Chemistry 753]

[0930] [Chem. 754]

[0931] The aforementioned polymeric surfactants may also include repeating units other than 7A-7E. Specific examples of other repeating units include repeating units derived from methacrylic acid, α-trifluoromethacrylic acid derivatives, etc. In polymeric surfactants, the content of repeating units 7A-7E is preferably 20 mol% or more, more preferably 60 mol% or more, and even more preferably 100 mol% among all repeating units.

[0932] The Mw of the aforementioned polymeric surfactant is preferably 1,000 to 500,000, and more preferably 3,000 to 100,000. The Mw / Mn ratio is preferably 1.0 to 2.0, and more preferably 1.0 to 1.6.

[0933] A method for synthesizing the aforementioned polymeric surfactants may include a method of polymerizing a monomer containing unsaturated bonds, selected from at least one repeating unit 7A-7E and other repeating units as needed, in an organic solvent by adding a free radical initiator and heating. Specific examples of organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, and dialkylene. Specific examples of polymerization initiators include AIBN, 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid), benzoyl peroxide, and lauryl peroxide. The reaction temperature is preferably 50-100°C. The reaction time is preferably 4-24 hours. Acid-labile groups may be directly introduced into the monomer, or they may be protected or partially protected after polymerization.

[0934] When synthesizing the aforementioned polymeric surfactants, known chain transfer agents such as dodecyl mercaptan and 2-mercaptoethanol can also be used to adjust the molecular weight. In this case, the amount of such chain transfer agent added is preferably 0.01 to 10 mol% relative to the total moles of the monomers to be polymerized.

[0935] When the chemical amplification inhibitor composition of this invention includes surfactant (F), its content relative to 80 parts by mass of the base polymer (B) is preferably 0.1 to 50 parts by mass, and more preferably 0.5 to 10 parts by mass. If the content of surfactant (F) is 0.1 parts by mass or more, the receding contact angle between the inhibitor film surface and water will be sufficiently increased; if it is less than 50 parts by mass, the dissolution rate of the inhibitor film surface to the developer will be low, and the height of the formed fine pattern will be sufficiently maintained. Surfactant (F) can be used alone or in combination of two or more.

[0936] [(G) Other ingredients] The chemical amplification inhibitor composition of this invention may also include, as other components (G), compounds that decompose due to acid to produce acid (acid-increasing compounds), organic acid derivatives, fluorinated alcohols, and compounds with a Mw of 3000 or less whose solubility in the developer changes due to the action of acid (solution inhibitors). The aforementioned acid-increasing compounds can be found in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608. When the aforementioned acid-increasing compounds are included, their content relative to 80 parts by mass of the base polymer (B) is preferably 0 to 5 parts by mass, and more preferably 0 to 3 parts by mass. If the content is too high, it will be difficult to control acid diffusion, resulting in degradation of resolution and pattern shape. The aforementioned organic acid derivatives, fluorinated alcohols, and solvent inhibitors can be found in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608.

[0937] [Pattern Formation Method] The pattern forming method of the present invention includes the following steps: forming a resist film on a substrate using the aforementioned chemical amplification resist composition, exposing the aforementioned resist film to high-energy radiation, and developing the aforementioned exposed resist film using a developing solution.

[0938] The aforementioned substrate, for example, can be 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 masking circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.).

[0939] The inhibitor film, for example, can be formed by coating the aforementioned chemically amplified inhibitor composition onto a substrate with a preferred film thickness of 0.05 to 2 μm using methods such as spin coating, and then pre-baking it on a heating plate, preferably at 60 to 150°C for 1 to 10 minutes, more preferably at 80 to 140°C for 1 to 5 minutes.

[0940] High-energy rays used in the exposure of resist films can include KrF excimer laser, ArF excimer laser, EB, and EUV with wavelengths of 3-15 nm. When using KrF excimer laser, ArF excimer laser, or EUV, a mask used to form the target pattern can be used for irradiation, preferably at an exposure dose of 1-200 mJ / cm², more preferably 10-100 mJ / cm². When using EB, a mask used to form the target pattern can be used or irradiation can be performed directly, preferably at an exposure dose of 1-300 μC / cm², more preferably 10-200 μC / cm².

[0941] Furthermore, in addition to the usual exposure method, an immersion method can be used, in which a liquid with a refractive index of 1.0 or higher is placed between the resist film and the projection lens. In this case, a water-insoluble protective film can also be used.

[0942] The aforementioned water-insoluble protective film is used to prevent leaching from the resist film and improve the hydrophobicity of the film surface. It is broadly classified into two types. One type is an organic solvent-stripping type, which requires peeling 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 developing solution and removes the protective film simultaneously with the soluble portion of the resist film. The latter is preferably a material based on a polymer containing 1,1,1,3,3,3-hexafluoro-2-propanol residues that are insoluble in water but soluble in alkaline developing solution, dissolved in alcohol solvents with 4 or more carbon atoms, ether solvents with 8 to 12 carbon atoms, or a mixture of these solvents. Alternatively, it can be a material made by dissolving the aforementioned water-insoluble but alkaline developing solution-soluble surfactant in alcohol solvents with 4 or more carbon atoms, ether solvents with 8 to 12 carbon atoms, or a mixture of these solvents.

[0943] After exposure, PEB can also be performed. PEB can be performed, for example, by heating on a hot plate at a temperature of 60-150°C for 1-5 minutes, or more preferably at 80-140°C for 1-3 minutes.

[0944] For example, a developing solution containing an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) of preferably 0.1-5% by mass, more preferably 2-3% by mass, can be used. The developing process is carried out using conventional methods such as dip, immersion, or spraying, preferably for 0.1-3 minutes, more preferably 0.5-2 minutes. In this way, the exposed part will dissolve, and the target pattern can be formed on the substrate.

[0945] Furthermore, after the resist film is formed, acid-generating agents and other particles from the film surface can be separated by rinsing with pure water, or washed off. It can also be used to remove water remaining on the film after exposure.

[0946] Furthermore, a double patterning method can also be used to form patterns. Examples of double patterning methods include: a groove method that uses a first exposure and etching to process a 1:3 groove pattern on a substrate, moves the substrate, and uses a second exposure to form a 1:3 groove pattern to create a 1:1 pattern; and a line method that uses a first exposure and etching to process a 1:3 isolated residual pattern on a first substrate, moves the substrate, and uses a second exposure to process a 1:3 isolated residual pattern on a second substrate below the first substrate to form a 1:1 pattern with a half-pitch.

[0947] In the pattern forming method of the present invention, a negative development method that uses an organic solvent to dissolve the unexposed areas can also be used instead of the aforementioned alkaline aqueous solution as the developer.

[0948] For the aforementioned organic solvent development, the following can be used as developing solutions: 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methyl acetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, methyl valerate, methyl valerate, methyl crotonate, croton... Ethyl propionate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenyl acetate, ethyl phenyl acetate, benzyl formate, phenyl ethyl formate, methyl 3-phenylpropionate, benzyl propionate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in mixtures of two or more. [Example]

[0949] The present invention is illustrated below with examples of synthesis, embodiments, and comparative examples. However, the present invention is not limited to the embodiments described below. Furthermore, the apparatus used is as follows. MALDI TOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[0950] [1] Synthesis of strontium salts [Example 1-1] Synthesis of strontium salt PAG-1 [Chemistry 755]

[0951] (1) Synthesis of intermediate In-1 Compounds SM-1 (25.0 g), SM-2 (43.5 g), DMAP (1.2 g), and dichloromethane (150 g) were added to a reaction vessel under nitrogen atmosphere and cooled in an ice bath. The temperature inside the reaction vessel was maintained below 20°C, and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (24.9 g) in powder form was added simultaneously. After addition, the temperature was raised to room temperature and allowed to mature for 12 hours. After maturation, water was added to stop the reaction, and a standard aqueous work-up was performed. After distilling off the solvent, diisopropyl ether was added to wash away the residue, thereby obtaining 57.7 g of intermediate In-1 in oily form (92% yield).

[0952] (2) Synthesis of PAG-1 Under nitrogen atmosphere, intermediate In-1 (12.6 g), compound SM-3 (12.7 g), dichloromethane (50 g), and water (30 g) were added. After stirring for 15 minutes, the organic layer was separated, washed with water, and then concentrated under reduced pressure. Methyl isobutyl ketone (50 g) was added to the concentrate and azeotropically dehydrated. Diisopropyl ether was then added to wash away the residue, thereby obtaining 20.1 g of PAG-1 in oily form as the target compound (yield 93%).

[0953] MALDI TOF-MS: POSITIVE M+601 (equivalent to C26H22F4IO2S+) NEGATIVE M-477 (equivalent to C23H13F4O5S-)

[0954] [Examples 1-2~1-9] Synthesis of strontium salts PAG-2~PAG-9 Using the corresponding raw materials and known organic synthesis reactions, strontium salts PAG-2 to PAG-9 represented by the following formulas were synthesized. [Chemistry 756]

[0955] [Chemistry 757]

[0956] [Chem.758]

[0957] [2] Synthesis of basic polymers [Synthetic Example] Synthesis of basic polymers (P-1~P-5) The monomers were 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 basic polymers (P-1~P-5) with the compositions shown below. The composition of the obtained basic polymers was confirmed by 1H-NMR, and Mw and Mw / Mn were confirmed by GPC (solvent: THF, standard: polystyrene). [Chemistry 759]

[0958] [3] Preparation of chemical amplification inhibitor composition [Examples 2-1 to 2-30, Comparative Examples 1-1 to 1-20] A solution was prepared by dissolving the photoacid generators (PAG-1 to PAG-9) composed of strontium salts of the present invention, comparative photoacid generators (PAG-A to PAG-E), other photoacid generators (PAG-X), base polymers (P-1 to P-5), and quenchers (Q-1 to Q-4) in a solvent containing 0.01% by mass of surfactant A (OMNOVA). The solution was then filtered using a 0.2 μm Teflon (registered trademark) filter to prepare chemical amplification inhibitor compositions (R-1 to R-30 and CR-1 to CR-20).

[0959] [Table 1] inhibitor Composition Base polymer (parts by weight) Photoacid generator (parts by weight) other Photoacid generator (parts by weight) Quenching agent (parts by weight) Solvent 1 (parts by weight) Solvent 2 (parts by weight) Solvent 3 (parts by weight) Example 2-1 R-1 P-1(80) PAG-1(28) - Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-2 R-2 P-1(80) PAG-2(28) - Q-1(7.8) PGMEA(2250) EL(2800) DAA(550) Example 2-3 R-3 P-1(80) PAG-3(20) PAG-X(10) Q-1(7.4) PGMEA(2250) EL(2800) DAA(550) Examples 2-4 R-4 P-1(80) PAG-4(27) - Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Examples 2-5 R-5 P-1(80) PAG-5(15) PAG-X(10) Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Examples 2-6 R-6 P-1(80) PAG-6(28) - Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Examples 2-7 R-7 P-1(80) PAG-7(28) - Q-1(7.8) PGMEA(2250) EL(2800) DAA(550) Examples 2-8 R-8 P-1(80) PAG-8(29) - Q-1(7.4) PGMEA(2250) EL(2800) DAA(550) Examples 2-9 R-9 P-1(80) PAG-9(15) PAG-X(8) Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-10 R-10 P-2(80) PAG-1(29) - Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-11 R-11 P-2(80) PAG-2(30) - Q-3(7.8) PGMEA(2250) EL(2800) DAA(550) Example 2-12 R-12 P-2(80) PAG-4(28) - Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-13 R-13 P-2(80) PAG-5(18) PAG-X(7) Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-14 R-14 P-2(80) PAG-7(28) - Q-2(4.0) Q-4(4.0) PGMEA(2250) EL(2800) DAA(550) Example 2-15 R-15 P-3(80) PAG-1(10) - Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-16 R-16 P-3(80) PAG-2(9) - Q-3(7.6) PGMEA(2250) EL(2800) DAA(550) Example 2-17 R-17 P-3(80) PAG-5(8) PAG-X(4) Q-1(7.8) PGMEA(2250) EL(2800) DAA(550) Example 2-18 R-18 P-3(80) PAG-7(9) - Q-3 (8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-19 R-19 P-3(80) PAG-9(8) PAG-X(4) Q-2(8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-20 R-20 P-4(80) PAG-1(10) - Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-21 R-21 P-4(80) PAG-3(7) PAG-X(3) Q-1(7.6) PGMEA(2250) EL(2800) DAA(550) Example 2-22 R-22 P-4(80) PAG-4(8) PAG-X(4) Q-3 (8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-23 R-23 P-4(80) PAG-6(10) - Q-2(8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-24 R-24 P-4(80) PAG-8(8) - Q-3(4.0) Q-4(4.0) PGMEA(2250) EL(2800) DAA(550) Example 2-25 R-25 P-5(80) PAG-1(10) - Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-26 R-26 P-5(80) PAG-2(8) - Q-2(8.0) PGMEA(2250) EL(2800) DAA(550) Example 2-27 R-27 P-5(80) PAG-4(8) - Q-3(7.8) PGMEA(2250) EL(2800) DAA(550) Example 2-28 R-28 P-5(80) PAG-6(10) - Q-1(4.0) Q-4(4.0) PGMEA(2250) EL(2800) DAA(550) Example 2-29 R-29 P-5(80) PAG-7(10) - Q-3 (8.0) PGMEA(2250) EL(2800) DAA(550) Examples 2-30 R-30 P-5(80) PAG-9(8) PAG-X(4) Q-2(7.6) PGMEA(2250) EL(2800) DAA(550)

[0960] [Table 2] inhibitor Composition Base polymer (parts by weight) Photoacid generator (parts by weight) other Photoacid generator (parts by weight) Quenching agent (parts by weight) Solvent 1 (parts by weight) Solvent 2 (parts by weight) Solvent 3 (parts by weight) Comparative Example 1-1 CR-1 P-1(80) PAG-A(28) - Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-2 CR-2 P-1(80) PAG-B(28) - Q-1(7.8) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-3 CR-3 P-1(80) PAG-C(20) PAG-X(10) Q-1(7.8) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-4 CR-4 P-1(80) PAG-D(27) - Q-1(8.2) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-5 CR-5 P-1(80) PAG-E(15) PAG-X(10) Q-1(8.2) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-6 CR-6 P-2(80) PAG-A(27) - Q-2(8.0) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-7 CR-7 P-2(80) PAG-B(25) - Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-8 CR-8 P-2(80) PAG-E(18) PAG-X(7) Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-9 CR-9 P-3(80) PAG-A(10) - Q-1(7.8) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-10 CR-10 P-3(80) PAG-B(9) - Q-3 (8.0) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-11 CR-11 P-3(80) PAG-C(7) PAG-X(3) Q-1(4.0) Q-4(4.0) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-12 CR-12 P-3(80) PAG-D(8) - Q-2(7.6) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-13 CR-13 P-4(80) PAG-A(10) - Q-1(7.8) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-14 CR-14 P-4(80) PAG-B(10) - Q-2(8.0) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-15 CR-15 P-4(80) PAG-C(10) - Q-3(4.0) Q-4(4.0) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-16 CR-16 P-4(80) PAG-E(8) PAG-X(4) Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-17 CR-17 P-5(80) PAG-A(10) - Q-1(8.0) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-18 CR-18 P-5(80) PAG-B(10) - Q-3(7.6) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-19 CR-19 P-5(80) PAG-C(8) - Q-1(4.0) Q-4(4.0) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-20 CR-20 P-5(80) PAG-E(8) PAG-X(4) Q-2(8.0) PGMEA(2250) EL(2800) DAA(550)

[0961] Tables 1 and 2 list the solvent, other photoacid generators PAG-X and PAG-Y, comparative photoacid generators PAG-A to PAG-E, quenchers Q-1 to Q-4, and surfactant A as follows. Solvent: PGMEA (Propylene Glycol Monomethyl Ether Acetate) EL (ethyl lactate) DAA (diacetone alcohol)

[0962] Other photoacid generators: PAG-X [Chemistry 760]

[0963] • Comparison of photoacid generating agents: PAG-A~PAG-E [Chemistry 761]

[0964] Quenching agents: Q-1~Q-4 [Chemistry 762]

[0965] Surfactant A: 3-Methyl-3-(2,2,2-trifluoroethoxymethyl)oxetane / tetrahydrofuran / 2,2-dimethyl-1,3-propanediol copolymer (manufactured by OMNOVA). [Chemistry 763] a:(b+b'):(c+c')=1:4~7:0.01~1 (Morbies) Mw=1500

[0966] [4] Evaluation of EUV lithography (1) [Examples 3-1 to 3-30, Comparative Examples 2-1 to 2-20] The chemical amplification resist compositions (R-1~R-30, CR-1~CR-20) shown in Tables 1-3 were spin-coated onto a Si substrate containing a silicon spin-coated hard mask SHB-A940 (silicon content of 43% by mass) manufactured by Shin-Etsu Chemical Industry Co., Ltd., with a film thickness of 20 nm. A resist film with a thickness of 50 nm was pre-baked at 100°C for 60 seconds using a hot plate. For the aforementioned resist film, an LS pattern with a wafer size of 18 nm and a pitch of 36 nm was exposed using an EUV scanning exposure machine manufactured by ASML NXE3400 (NA 0.33, σ 0.9 / 0.6, dipole illumination). The exposure amount and focal length were varied (exposure amount pitch: 1 mJ / cm2, focal length pitch: 0.020 μm). After exposure, PEB was performed for 60 seconds at the temperatures shown in Tables 4 and 5. Subsequently, the model was immersed in a 2.38% TMAH aqueous solution for 30 seconds for development, rinsed with a washing material containing surfactant, and then rotated to dry, thus obtaining a positive pattern. The obtained LS patterns were observed using a Hitachi Advanced Semiconductor Critical Dimension SEM (CG6300), and the sensitivity, EL, LWR, depth of focus (DOF), and collapse limit were evaluated according to the methods described below. Furthermore, the development defects of the obtained LS patterns were evaluated. The results are shown in Tables 3 and 4.

[0967] [Sensitivity Evaluation] The optimal exposure value Eop (mJ / cm2) for obtaining an LS pattern with a linewidth of 18nm and a pitch of 36nm was determined and defined as the sensitivity. The smaller this value, the higher the sensitivity.

[0968] [EL Review] The exposure amount formed within ±10% (16.2~19.8nm) of the 18nm spacing in the aforementioned LS pattern is used to calculate the EL (unit: %) using the following formula. The larger this value, the better the performance. EL(%) = (|E1-E2| / Eop) × 100 E1: Provides optimal exposure for LS patterns with a linewidth of 16.2nm and a pitch of 36nm. E2: Provides optimal exposure for LS patterns with a linewidth of 19.8nm and a pitch of 36nm. Eop: Provides optimal exposure for LS patterns with a linewidth of 18nm and a pitch of 36nm.

[0969] [LWR Evaluation] For the LS pattern obtained by Eop irradiation, the dimensions at 10 points along the length of the line are measured, and the standard deviation (σ) of the results is calculated as 3σ as the LWR. The smaller this value, the more uniform the line width and roughness of the pattern will be.

[0970] [DOF Rating] In terms of depth of focus evaluation, the focal length range is determined by the range of ±10% (16.2~19.8nm) of the 18nm dimension in the aforementioned LS pattern. The larger this value, the wider the depth of focus.

[0971] [Collapse Limit Assessment of Line Patterns] The line dimensions of each exposure at the optimal focal length of the aforementioned LS pattern were measured along the length direction at 10 points. The finest line dimension obtained in the undamaged state was defined as the collapse limit dimension. The smaller this value, the better the collapse limit.

[0972] [Evaluation of Development Defects] For an LS pattern with a linewidth of 18nm and a pitch of 36nm formed using the aforementioned optimal exposure, a defect detection device KLA2360 (trade name) manufactured by KLA Tencor was used. The pixel size of the defect detection device was set to 0.16μm, and the threshold was set to 20. Defects (number / cm²) identified by comparing the overlap between the image and pixel units were detected, and the number of defects per unit area (defects / cm²) was calculated. Subsequently, through defect evaluation, development defects were classified and identified from all defects, and the number of development defects per unit area (defects / cm²) was calculated. Values ​​below 0.5 were rated A, values ​​between 0.5 and 1.0 were rated B, values ​​between 1.0 and 5.0 were rated C, and values ​​above 5.0 were rated D. The smaller the value, the better the performance.

[0973] [Table 3] inhibitor Composition PEB temperature (°C) Optimal exposure (mJ / cm2) EL (%) LWR (nm) DOF (nm) Collapse Limit (nm) Development defects Example 3-1 R-1 100 31 19 2.2 110 10.9 A Example 3-2 R-2 100 32 19 2.3 120 11.2 A Example 3-3 R-3 100 33 18 2.2 110 10.8 A Examples 3-4 R-4 105 32 17 2.3 100 11.0 A Examples 3-5 R-5 105 31 17 2.4 120 10.9 A Examples 3-6 R-6 95 32 17 2.2 100 11.1 A Examples 3-7 R-7 105 32 18 2.3 110 11.0 A Examples 3-8 R-8 100 33 18 2.2 120 11.3 A Examples 3-9 R-9 100 33 19 2.3 110 10.9 A Examples 3-10 R-10 105 33 17 2.4 120 10.8 A Example 3-11 R-11 100 33 17 2.3 120 10.9 A Example 3-12 R-12 105 32 18 2.4 100 11.3 A Example 3-13 R-13 105 34 17 2.2 120 11.2 A Example 3-14 R-14 100 33 19 2.1 100 11.2 A Example 3-15 R-15 100 31 19 2.3 110 10.9 A Example 3-16 R-16 100 32 16 2.2 110 11.0 A Example 3-17 R-17 105 33 17 2.3 120 11.1 A Example 3-18 R-18 95 32 18 2.4 110 10.7 A Example 3-19 R-19 100 32 19 2.2 100 10.9 A Example 3-20 R-20 105 32 17 2.3 120 11.3 A Example 3-21 R-21 100 31 18 2.2 110 11.2 A Example 3-22 R-22 100 32 18 2.4 100 10.7 A Example 3-23 R-23 105 34 17 2.3 100 11.3 A Example 3-24 R-24 100 33 18 2.5 110 11.3 A Example 3-25 R-25 100 32 17 2.4 120 10.8 A Example 3-26 R-26 100 32 18 2.3 120 10.8 A Example 3-27 R-27 100 33 19 2.2 110 10.8 A Example 3-28 R-28 105 32 17 2.4 100 11.1 A Example 3-29 R-29 100 31 18 2.3 120 11.2 A Examples 3-30 R-30 100 32 18 2.2 110 11.0 A

[0974] [Table 4] inhibitor Composition PEB temperature (°C) Optimal exposure (mJ / cm2) EL (%) LWR (nm) DOF (nm) Collapse Limit (nm) Development defects Comparative Example 2-1 CR-1 100 38 14 3.0 90 11.9 B Comparative Example 2-2 CR-2 100 38 14 2.8 90 12.0 C Comparative Examples 2-3 CR-3 105 40 15 3.1 100 12.1 B Comparative Examples 2-4 CR-4 100 42 15 3.1 90 12.2 B Comparative Examples 2-5 CR-5 100 40 14 2.8 90 12.3 C Comparative Examples 2-6 CR-6 100 37 13 3.2 80 12.3 C Comparative Examples 2-7 CR-7 100 37 15 2.9 90 12.1 B Comparative Examples 2-8 CR-8 105 38 14 3.2 70 12.1 C Comparative Examples 2-9 CR-9 100 40 13 2.8 100 12.5 C Comparative Example 2-10 CR-10 100 40 13 3.0 90 12.2 C Comparative Example 2-11 CR-11 95 41 14 3.6 70 12.1 C Comparative Example 2-12 CR-12 100 37 15 2.8 90 12.1 B Comparative Example 2-13 CR-13 100 38 16 3.0 80 12.1 C Comparative Example 2-14 CR-14 100 39 15 2.6 90 11.7 B Comparative Example 2-15 CR-15 100 42 14 2.7 90 12.4 C Comparative Example 2-16 CR-16 95 39 15 3.0 80 11.9 B Comparative Example 2-17 CR-17 100 37 13 3.0 80 12.1 C Comparative Example 2-18 CR-18 105 38 15 2.9 90 11.8 B Comparative Example 2-19 CR-19 100 38 14 3.1 90 11.7 B Comparative Example 2-20 CR-20 100 39 15 2.7 80 12.1 C

[0975] As shown in Tables 3 and 4, the chemical amplification inhibitor composition containing the photoacid generator composed of the strontium salt of the present invention exhibits good sensitivity and excellent EL, LWR, and DOF. Furthermore, it was confirmed that the collapse limit value is small, resisting pattern collapse even during the formation of fine patterns. Moreover, it was confirmed that it also suppresses development defects. Therefore, the chemical amplification inhibitor composition of the present invention is suitable as a material for EUV lithography.

[0976] [5] Evaluation of EUV lithography (2) [Examples 4-1 to 4-30, Comparative Examples 3-1 to 3-20] 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 containing a silicon spin-coated hard mask SHB-A940 (silicon content 43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd., with a film thickness of 20 nm. A resist film with a thickness of 50 nm was formed by pre-baking at 105°C for 60 seconds using a hot plate. The aforementioned resist film was exposed using an ASML NXE3400 EUV scanning exposure machine (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, mask with a pitch of 46 nm on the wafer, and a hole pattern with a deviation of +20%). A hole pattern with a size of 23 nm was formed by PEB treatment for 60 seconds at the temperatures recorded in Tables 5 and 6 using a hot plate and development for 30 seconds with a 2.38% by mass TMAH aqueous solution. Using a Hitachi Advanced Semiconductor Critical Dimension SEM (CG6300), the exposure required to form a hole size of 23 nm was measured and defined as the sensitivity. Furthermore, the size of 50 holes at this point was measured, and the standard deviation (σ) calculated from these results, multiplied by three (3σ), was defined as the CDU. The results are shown in Tables 5 and 6.

[0977] [Table 5] inhibitor composition PEB temperature (°C) Optimal exposure (mJ / cm2) CDU (nm) Example 4-1 R-1 95 twenty two 2.1 Example 4-2 R-2 95 twenty one 2.3 Example 4-3 R-3 95 twenty two 2.2 Example 4-4 R-4 90 twenty three 2.1 Examples 4-5 R-5 90 twenty three 2.2 Examples 4-6 R-6 95 twenty four 2.3 Examples 4-7 R-7 90 twenty two 2.2 Examples 4-8 R-8 95 twenty four 2.2 Examples 4-9 R-9 90 twenty four 2.3 Examples 4-10 R-10 95 twenty three 2.1 Example 4-11 R-11 90 twenty two 2.2 Example 4-12 R-12 90 twenty three 2.3 Example 4-13 R-13 95 twenty four 2.2 Example 4-14 R-14 95 twenty two 2.3 Examples 4-15 R-15 95 twenty three 2.2 Example 4-16 R-16 95 twenty four 2.3 Example 4-17 R-17 90 twenty one 2.4 Example 4-18 R-18 90 twenty two 2.2 Example 4-19 R-19 95 twenty three 2.2 Example 4-20 R-20 90 twenty two 2.3 Example 4-21 R-21 95 twenty one 2.5 Example 4-22 R-22 90 twenty three 2.3 Example 4-23 R-23 95 twenty two 2.4 Example 4-24 R-24 90 twenty two 2.4 Example 4-25 R-25 95 twenty three 2.3 Example 4-26 R-26 90 twenty four 2.2 Example 4-27 R-27 95 twenty two 2.2 Example 4-28 R-28 90 twenty one 2.3 Example 4-29 R-29 90 twenty three 2.4 Example 4-30 R-30 95 twenty two 2.3

[0978] [Table 6] inhibitor composition PEB temperature (°C) Optimal exposure (mJ / cm2) CDU (nm) Comparative Example 3-1 CR-1 90 26 2.9 Comparative Example 3-2 CR-2 90 27 2.9 Comparative Example 3-3 CR-3 90 26 2.7 Comparative Examples 3-4 CR-4 90 27 2.7 Comparative Examples 3-5 CR-5 95 29 3.0 Comparative Examples 3-6 CR-6 90 27 3.1 Comparative Examples 3-7 CR-7 85 27 2.8 Comparative Examples 3-8 CR-8 90 27 3.1 Comparative Examples 3-9 CR-9 90 27 2.9 Comparative Example 3-10 CR-10 90 28 2.8 Comparative Example 3-11 CR-11 90 31 2.9 Comparative Example 3-12 CR-12 90 28 3.1 Comparative Example 3-13 CR-13 90 30 3.0 Comparative Example 3-14 CR-14 90 30 3.1 Comparative Example 3-15 CR-15 90 28 2.9 Comparative Example 3-16 CR-16 90 29 2.8 Comparative Example 3-17 CR-17 90 27 2.7 Comparative Example 3-18 CR-18 90 27 2.9 Comparative Example 3-19 CR-19 90 29 2.7 Comparative Example 3-20 CR-20 90 28 2.9

[0979] The results shown in Tables 5 and 6 confirm that the chemical amplification inhibitor composition containing the photoacid generator composed of the strontium salt of the present invention has good sensitivity and excellent CDU.

Claims

1. A strontium salt, represented by the following formula (1); wherein, n1 is 0 or 1; n2 is 1, 2, 3 or 4; n3 is 1; n4 is 0; n5 is 0; n6 is 1, 2, 3 or 4; n7 is 0; n8 is 1 or 2; RF is a fluorine atom, a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon sulfide group with 1 to 6 carbon atoms, or a pentafluorosulfide group; when n6 is 2, 3 or 4, each RF may be the same as or different from the others; R1 and R2 are each independently a halogen atom other than fluorine, nitro, cyano, hydroxyl, carboxyl, 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 R1 can be the same or different from each other, and the two R1s can also bond to each other and form a ring together with the bonded carbon atoms; when n7 is 2, each R2 can be the same or different from each other, and the two R2s can also bond to each other and form a ring together with the bonded carbon atoms; LA refers to ether bonds, ester bonds, or carbonate bonds; RAL refers to the acid unstable group represented by the following formula (AL-1) or (AL-2); the iodine atom in formula (1) and -LA-RAL are bonded to adjacent carbon atoms; also, two of the three aromatic rings bonded to S+ can also bond to each other and form a ring together with the bonded sulfur atoms; Z-series aromatic sulfonic acid anions having at least one cyclic structure, represented by the formula (Z); In the formula, RL1 and RL2 are each independently a hydrocarbon group having 1 to 12 carbon atoms; RL3 is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; the -CH2- portion of the hydrocarbon group represented by RL1, RL2, and RL3 can also be replaced by -O- or -S-; when the hydrocarbon group contains an aromatic ring, part or all of the hydrogen atoms of the aromatic ring can also be replaced by a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 4 carbon atoms containing a halogen atom, or an alkoxy group having 1 to 4 carbon atoms containing a halogen atom; furthermore, RL1 and RL2 can also be bonded to each other and form a ring together with the bonded carbon atoms, and the -CH2- portion of the ring can also be replaced by -O- or -S-; however, when RL3 is a hydrogen atom, RL1 and RL2 are bonded to each other and form an alicyclic ring containing multiple bonds together with the bonded carbon atoms; furthermore, a portion of the hydrogen atoms of the alicyclic ring can also be replaced by a halogen atom. RL4 and RL5 are each independently a hydrogen atom or a hydrocarbon group with 1 to 10 carbon atoms; RL6 is a hydrocarbon group with 1 to 20 carbon atoms, and part of the -CH2- of this hydrocarbon group may be replaced by -O- or -S-; LB is -O- or -S-; * indicates an atomic bond with LA; In the formula, m1 is 0 or 1; m2 is 0, 1, 2, 3, 4 or 5; m3 is 0, 1, 2, 3, 4 or 5; m4 is 0, 1, 2, 3, 4 or 5; however, when m1 is 0, then 0≦m2+m3+m4≦5, and when m1 is 1, then 0≦m2+m3+m4≦7; W is a hydrocarbon group with 6 to 40 carbon atoms containing at least one alicyclic or aromatic ring, and this hydrocarbon group may also contain heteroatoms;RF1 consists of a fluorine atom, a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon thio group with 1 to 6 carbon atoms, or a pentafluorothio group; when m2 is 2, 3, or 4, each RF1 may be the same or different from the others; R11 consists of a halogen atom other than fluorine, a hydroxyl group, 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; when m3 is 2, 3, or 4, each R11 may be the same or different from the others, and multiple R11 may also be bonded to each other and form a ring together with the carbon atoms of these bonds; LC and LD are each independently a single bond, an ether bond, an ester bond, a sulfonate bond, a amide bond, a sulfonamide bond, a carbonate bond, or a carbamate bond; XL1 is a single bond, or may also contain a hydrocarbon group with 1 to 40 carbon atoms containing heteroatoms. ; 2. The strontium salt of request item 1 is represented by the following formula (1A); where n2~n4, n6~n8, RF, R1, R2, LA, RAL and Z- are the same as above.

3. As in request item 1, strontium salt, wherein, The W series is represented by formulas (W-1) or (W-2); where m5 represents 0 or 1; m6 represents 0, 1, 2, 3 or 4; m7 represents 1, 2, 3 or 4; m8 represents 0 or 1; m9 represents 0 or 1; m10 represents 0, 1, 2, 3 or 4; m11 represents 0, 1, 2, 3 or 4; R12 is independently a halogen atom other than hydrogen or iodine, or may contain a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; R13 and R14 are independently hydrogen atoms, halogen atoms, or may contain a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; R15 to R19 are independently hydrogen atoms, halogen atoms, or may contain a hydrocarbon group with 1 to 40 carbon atoms containing heteroatoms; the dashed lines represent atomic bonds with LC.

4. As in request item 1, strontium salt, wherein, The anion system is represented by the following formula (Z1); where m1~m4, W, RF1, R11 and LC are the same as those mentioned above.

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

6. A chemical amplification inhibitor composition comprising a photoacid generator as claimed in claim 5 and a base polymer, the base polymer comprising a polymer containing at least one repeating unit selected from the repeating units represented by formula (a1), formula (a2), and formula (a3); the content of the photoacid generator is 0.1 to 40 parts by mass relative to 80 parts by mass of the base polymer; wherein RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; X1 is a single bond, a phenyl group, a naphthyl group, or *-C(=O)-O-X11-, the phenyl group or naphthyl group may also be substituted by a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbon group containing 1 to 10 carbon atoms containing a fluorine atom, a saturated hydrocarbon oxygen group containing 1 to 10 carbon atoms, or a halogen atom; X11 is a saturated hydrocarbon group containing 1 to 10 carbon atoms, a phenyl group, or a naphthyl group, the saturated hydrocarbon group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring; X2 represents a single bond or *-C(=O)-O-; * indicates an atomic bond with a carbon atom in the main chain; R21 represents a halogen atom, cyano, hydroxyl, nitro, pentafluorothio, or may contain a hydrocarbon group with 1-20 carbon atoms, a hydrocarbon oxygen group with 1-20 carbon atoms, a hydrocarbon carbonyl group with 2-20 carbon atoms, a hydrocarbon carbonyl oxygen group with 2-20 carbon atoms, or a hydrocarbon oxygen carbonyl group with 2-20 carbon atoms; when a1 is 2, 3, or 4, each R21 may be the same or different; AL1 and AL2 are each independently an acid-unstable group represented by any of the following formulas (AL-3) to (AL-5); a1 is 0, 1, 2, 3, or 4; where * represents an atomic bond, and a2 is an integer from 0 to 10; RL11 and RL12 are each independently a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms; RL13 and RL14 are each independently a hydrogen atom or a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms; any two of RL12, RL13, and RL14 may also bond to each other and form a ring with 3 to 20 carbon atoms together with the bonded carbon atoms or carbon atoms and oxygen atoms; RL15, RL16, and RL17 are each independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms; any two of RL15, RL16, and RL17 may also bond to each other and form a ring with 3 to 20 carbon atoms together with the bonded carbon atoms; in the formula, b1 is 0 or 1; b2 is 0, 1, 2, or 3 when b1 is 0, and 0, 1, 2, 3, 4, or 5 when b1 is 1; RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; X3 is a single bond, *-C(=O)-O- or *-C(=O)-N(H)-; * indicates an atomic bond with a carbon atom in the main chain; X4 is a single bond, an aliphatic hydrocarbon group with 1 to 4 carbon atoms, a carbonyl group, a sulfonyl group, or a combination thereof; X5 and X6 are each independently an oxygen atom or a sulfur atom; however, X4 and X6 are bonded to adjacent carbon atoms in an aromatic ring;R22 and R23 are each independently hydrogen atoms, or may contain heteroatoms of 1 to 20 carbon atoms in a hydrocarbon group; furthermore, R22 and R23 may also bond to each other and form a ring together with the carbon atoms of these bonds; R24 is a halogen atom, hydroxyl group, cyano group, nitro group, pentafluorothio group, or may contain heteroatoms of 1 to 20 carbon atoms in a hydrocarbon group, or may contain heteroatoms of 1 to 20 carbon atoms in a hydrocarbon oxy group, or may contain heteroatoms of 2 to 20 carbon atoms in a hydrocarbon oxycarbonyl group, or may contain heteroatoms of 1 to 20 carbon atoms in a hydrocarbon thio group or -N(R24A)(R24B); R24A and R24B are each independently hydrogen atoms or hydrocarbon groups of 1 to 6 carbon atoms; when b2 is 2 or more, each R24 may be the same or different from each other, and multiple R24s may also bond to each other and form a ring together with the carbon atoms of these bonded aromatic rings.

7. The chemical amplification inhibitor composition as claimed in claim 6, wherein, The polymer contains repeating units represented by formula (b1) or (b2); wherein RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; Y1 is a single bond or *-C(=O)-O-; * represents an atomic bond with a carbon atom of the main chain; R31 is a hydrogen atom, or a group containing at least one of the following: hydroxyl group other than a 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)-); R32 can be a halogen atom, carboxyl group, nitro group, cyano group, pentafluorothio group, or may contain 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 oxygen group with 2 to 20 carbon atoms, or a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms; when c2 is 2, 3, or 4, each R32 can be the same or different; c1 is 1, 2, 3, or 4; c2 is 0, 1, 2, 3, or 4; however, 1≦c1+c2≦5.

8. The chemical amplification inhibitor composition as claimed in claim 6, wherein, The polymer comprises at least one repeating unit selected from the following formula (c1), the following formula (c2), the following formula (c3), the following formula (c4), and the following formula (c5); wherein d1 and d2 are each independently 0, 1, 2, or 3; 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, then 0 ≦ e2 + e3 ≦ 4, and when e1 is 1, then 0 ≦ e2 + e3 ≦ 6; RA are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; Z1 is a single bond or may also have substituents, such as an phenyl group; Z2 is a single bond, **-C(=O)-O-Z21-, **-C(=O)-N(H)-Z21-, or **-O-Z21-; Z21 is an aliphatic alkyl group, phenyl group, or a divalent group obtained by combining the above with 1 to 6 carbon atoms, and may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups; Z3 is a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond; Z4 is a single bond, or an aliphatic alkyl group, phenyl group, or a divalent group obtained by combining the above with 1 to 6 carbon atoms, and may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups; Z5 can be a single bond, or it can be a substituent phenyl group, a substituent naphthyl group, *-C(=O)-O-Z51-, or *-C(=O)-N(R)-Z51-; Z51 is an aliphatic alkyl group, phenyl group, or naphthyl group with 1 to 10 carbon atoms, which may also contain a halogen atom, hydroxyl group, ether bond, ester bond, or lactone ring; R is a hydrogen atom, or it may also contain a hydrocarbon group with 1 to 10 carbon atoms containing heteroatoms; Z6 is a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond; Z7 is independently a single bond, ***-Z71-C(=O)-O-, ***-C(=O)-N(R)-Z71-, or ***-O-Z71-; the Z71 series may also contain a heteroatom with 1 to 20 carbon atoms and an extended hydrocarbon group; R is the same as described above; Z8 is independently a single bond, ****-Z81-C(=O)-O-, ****-C(=O)-N(R)-Z81-, or ****-O-Z81-; the Z81 series may also contain a heteroatom with 1 to 20 carbon atoms and an extended hydrocarbon group; R is the same as described above; Z9 series includes single bonds, methylene, ethyl, phenyl, fluorinated phenyl, trifluoromethyl-substituted phenyl, *-C(=O)-O-Z91-, *-C(=O)-N(R)-Z91-, or *-O-Z91-; Z91 is an aliphatic phenyl group with 1 to 6 carbon atoms, phenyl, fluorinated phenyl, or trifluoromethyl-substituted phenyl, and may also contain carbonyl, ester, ether, or hydroxyl groups; R is the same as above; * indicates an atomic bond with a carbon atom in the main chain; ** indicates an atomic bond with Z1; *** indicates an atomic bond with Z6; **** indicates an atomic bond with Z7;L11 consists of single bonds, ether bonds, ester bonds, carbonyl groups, sulfonate bonds, sulfonamide bonds, carbonate bonds, or aminocarbamate bonds; Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; Rf5 and Rf6 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; however, not all Rf5 and Rf6 are hydrogen atoms simultaneously; Rf7 consists of fluorine atoms, fluorinated alkyl groups having 1 to 6 carbon atoms, fluorinated alkoxy groups having 1 to 6 carbon atoms, fluorinated alkylthio groups having 1 to 6 carbon atoms, or pentafluorothio groups; when e2 is 2, 3, or 4, each Rf7 can be the same or different; R41 and R42 are each independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms; furthermore, R41 and R42 may bond with each other and form a ring with the sulfur atoms of these bonds; R43 is a halogen atom other than fluorine, or a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms; when e3 is 2, 3, or 4, each R43 may be the same or different, and multiple R43s may bond with each other and form a ring with the carbon atoms of these bonds; M- is a non-nucleophilic relative ion; this non-nucleophilic relative ion is a halide ion, sulfonic acid anion, amide anion, or methyl acid anion; A+ is an onium cation; this onium cation is a strontium cation, monium cation, or ammonium cation.

9. The chemical amplification inhibitor composition as described in claim 6 further includes an organic solvent.

10. The chemical amplification inhibitor composition of claim 6 further includes a quencher.

11. The chemical amplification inhibitor composition of claim 6 further includes photoacid generating agents other than the photoacid generating agent of claim 5.

12. The chemical amplification inhibitor composition of claim 6 further includes a surfactant.

13. A pattern forming method comprising the following steps: forming a resist film on a substrate using a chemical amplifying resist composition as claimed in claim 6, exposing the resist film to high-energy radiation, and developing the exposed resist film using a developing solution.

14. The pattern forming method as described in claim 13, wherein, This high-energy ray system includes KrF excimer laser light, ArF excimer laser light, electron beam, or extreme ultraviolet light with wavelengths of 3–15 nm.

Images