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

Abstract

The present invention addresses the need to provide a novel onium salt, a chemically amplified resist composition, and a patterning method for use in photolithography using high-energy rays. This composition provides high sensitivity, excellent resolution, improved photolithography performance of EL, LWR, CDU, DOF, etc., and suppresses resist pattern collapse. The solution to this problem is an onium salt composed of a cation represented by formula (1A) and an anion represented by formula (1B).

Description

[Technical Field]

[0001] This invention relates to onium salts, chemical amplification inhibitor compositions, and pattern formation methods. [Previous Technology]

[0002] With the increasing integration and speed of LSI, the miniaturization of pattern regularity is also progressing rapidly. This is due to the widespread adoption of high-speed 5G communication and artificial intelligence (AI), making high-performance devices necessary to handle them essential. Regarding the most advanced miniaturization technology, mass production of 5nm node devices using 13.5nm extreme ultraviolet (EUV) lithography is already underway. Furthermore, research is also being conducted on the use of EUV lithography in next-generation 3nm node devices and the next-next-generation 2nm node devices.

[0003] With the advancement of miniaturization, image blurring caused by acid diffusion becomes a problem. In order to ensure the resolution of fine patterns below 45 nm in size, in addition to the previously proposed improvement of dissolution contrast, it has been suggested that the control of acid diffusion is important (Non-Patent Document 1). However, chemical amplification inhibitor compositions utilize acid diffusion to improve sensitivity and contrast. Therefore, if the post-exposure baking (PEB) temperature is reduced or the time is shortened to suppress acid diffusion to the limit, the sensitivity and contrast will be significantly reduced.

[0004] This demonstrates a triangular trade-off between sensitivity, resolution, and edge roughness (LWR). To improve resolution, acid diffusion needs to be suppressed, but if the acid diffusion distance is shortened, sensitivity will decrease.

[0005] Adding an acid-generating agent that produces a bulky acid is effective in suppressing acid diffusion. Therefore, it has been proposed to include repeating units from onium salts with polymerizable unsaturated bonds in the polymer. In this case, the polymer also functions as an acid-generating agent (polymer-bonded acid-generating agent). Patent Document 1 proposes strontium salts and monazite salts with polymerizable unsaturated bonds that produce specific sulfonic acids. Patent Document 2 proposes strontium salts with sulfonic acids directly bonded to the main chain.

[0006] The acid-indestructible group in the (meth)acrylate polymer used in the ArF inhibitor composition undergoes a deprotection reaction by using an acid generator that produces sulfonic acid with α-position fluorine atom substitution. However, if the acid generator produces sulfonic acid or carboxylic acid with α-position unsubstituted fluorine atom substitution, the deprotection reaction will not occur. If a strontium salt or ferrophosphate salt that produces sulfonic acid with α-position fluorine atom substitution is mixed with a strontium salt or ferrophosphate salt that produces sulfonic acid with α-position unsubstituted fluorine atom substitution, the strontium salt or ferrophosphate salt that produces sulfonic acid with α-position unsubstituted fluorine atom substitution will undergo ion exchange with the sulfonic acid with α-position fluorine atom substitution. The sulfonic acid with α-position fluorine atom substitution generated by light will reverse back to the strontium salt or ferrophosphate salt through ion exchange. Therefore, the strontium salt or ferrophosphate salt of sulfonic acid or carboxylic acid with α-position unsubstituted fluorine atom substitution functions as a quencher. Some have proposed using strontium salts or ferric salts that produce carboxylic acids as quenching agent components (Patent Document 3).

[0007] Some researchers have proposed strontium salt-type quenchers that produce carboxylic acids. Examples include strontium salts of salicylic acid, β-hydroxycarboxylic acid (Patent Document 4), salicylic acid derivatives (Patent Documents 5 and 6), fluorosalicylic acid (Patent Document 7), hydroxynaphthoic acid (Patent Document 8), salicylic acid with iodine-containing aromatic substituents (Patent Document 9), and salicylic acid with a cyclic acetal structure (Patent Document 10). Salicylic acid, in particular, exhibits a high degree of acid diffusion inhibition due to the intramolecular hydrogen bonding between the carboxyl and hydroxyl groups.

[0008] It has been pointed out that the dimensional uniformity (CDU) of the resist pattern decreases due to the aggregation of the quencher. It is hoped that by preventing the aggregation of the quencher in the resist film and making its distribution uniform, the dimensional uniformity of the developed pattern can be improved.

[0009] For further miniaturization requirements, especially during alkaline development in positive resists, swelling caused by the developer and pattern collapse during the formation of fine patterns have become a problem. To address this miniaturization challenge, the development of novel materials for resist compositions is crucial, and it is desirable to develop onium salt-type quenchers with good sensitivity, well-controlled acid diffusion, excellent solvent solubility, and effective suppression of pattern collapse. [Prior Art Documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 2006-45311 [Patent Document 2] Japanese Patent Application Publication No. 2006-178317 [Patent Document 3] Japanese Patent Application Publication No. 2007-114431 [Patent Document 4] International Publication No. 2018 / 159560 [Patent Document 5] Japanese Patent Application Publication No. 2020-203984 [Patent Document 6] Japanese Patent Application Publication No. 2020-91404 [Patent Document 7] Japanese Patent Application Publication No. 2020-91312 [Patent Document 8] Japanese Patent Application Publication No. 2019-120760 [Patent Document 9] Japanese Patent Application Publication No. 2022-77505 [Patent Document 10] International Publication No. 2023 / 189502 [Non-Patent Documents]

[0011] [Non-Patent Literature 1] SPIE Vol. 6520 65203L-1 (2007) [Summary of the Invention]

[0012] [Problem to be Solved by the Invention] In response to the high-resolution requirements of resist patterns in recent years, resist compositions using conventional strontium salt-type acid generators and quenchers cannot adequately suppress acid diffusion, resulting in degradation of photolithography properties such as contrast, exposure latitude (EL), LWR, CDU, and depth of focus (DOF). Furthermore, there is a problem of pattern collapse due to swelling during the formation of fine patterns.

[0013] This invention is made in view of the foregoing circumstances, and its object is to provide a novel onium salt, a chemically amplified resist composition, and a patterning method for use in photolithography using high-energy rays such as far-ultraviolet light, electron beams (EB), and EUV, which provides high sensitivity, excellent resolution, improves the photolithography performance of EL, LWR, CDU, and DOF, and suppresses the collapse of resist patterns. [Means for Solving the Problem]

[0014] After repeated and in-depth explorations in order to achieve the aforementioned objectives, the inventors of this case obtained the following insights and thus completed the present invention: the onium salt composed of a strontium cation having a cyano group and an aromatic carboxylic acid anion containing at least one iodine atom on the aromatic ring has excellent solvent solubility. The chemical amplification inhibitor composition using it as a quenching agent has high sensitivity and high contrast, and excellent lithography properties such as EL, LWR, CDU, and DOF. It is extremely effective in suppressing pattern collapse during the formation of fine patterns.

[0015] That is, the present invention provides the following onium salt, chemical amplification inhibitor composition and pattern forming method. 1. An onium salt, which is composed of a cation represented by the following formula (1A) and an anion represented by the following formula (1B). [Chemical 1] In the formula, p is 1, 2 or 3. n1 is 0 or 1. n2 is 1 or 2. n3 is 0, 1, 2 or 3. However, when n1 is 0, it is 1≦n2+n3≦5, and when n1 is 1, it is 1≦n2+n3≦7. R1 is a halogen atom, nitro group, hydroxyl group, carboxyl group, or may contain a hydrocarbon group with 1 to 20 carbon atoms of heteroatoms, or may contain a hydrocarbon oxy group with 1 to 20 carbon atoms of heteroatoms, or may contain a hydrocarbon thio group with 1 to 20 carbon atoms of heteroatoms, or may contain a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms of heteroatoms. When n3 is 2 or 3, each R1 can be the same or different from the others. Two R1s can also bond to each other and form a ring together with the carbon atoms they are bonded to. R2 is a halogen atom, or it can also contain a hydrocarbon group with 1 to 30 carbon atoms containing heteroatoms. When p is 1, two R2s can be the same or different from each other. Also, two of the three substituents bonded to S+ can bond to each other and form a ring together with the sulfur atoms they are bonded to. [Chemistry 2] In the formula, n11 is 0 or 1. n12 is 1, 2, 3 or 4. n13 is 0, 1 or 2. n14 is 0, 1, 2, 3 or 4. However, when n11 is 0, it is 2≦n12+n13+n14≦5, and when n11 is 1, it is 2≦n12+n13+n14≦7. LA is a single bond, an oxygen atom, a sulfur atom, an ester bond or a carbonate bond. R3 is a hydrogen atom when LA is a single bond, or may contain a hydrocarbon group with 1 to 20 carbon atoms of heteroatoms. When LA is an oxygen atom, sulfur atom, ester bond, or carbonate bond, it is a hydrogen atom, or may contain a hydrocarbon group with 1 to 20 carbon atoms of heteroatoms (excluding acid-labile groups) or acid-labile groups. R4 is a halogen atom other than iodine, a nitro group, a cyano group, or may contain a hydrocarbon group with 1 to 20 carbon atoms of heteroatoms, or a hydrocarbon oxy group with 1 to 20 carbon atoms of heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms of heteroatoms. 2. Onium salts as in 1, wherein the aforementioned cation is represented by the following formula (1A-1). [Chemical 3] In the formula, p, n1 to n3, R1, and Z- are the same as above. n4 is 0 or 1. n5 is 0, 1, 2, 3, 4, or 5. R2a is a halogen atom, nitro, hydroxyl, carboxyl, alkoxy carbonyl, or may contain a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxy group with 1 to 20 carbon atoms, or a hydrocarbon thio group with 1 to 20 carbon atoms. When n5 is 2, 3, 4, or 5, each R2a can be the same or different, and two R2a can also bond to each other and form a ring together with the carbon atoms they are bonded to. 3. Onium salts such as 1. or 2. wherein the aforementioned anion is represented by the following formula (1B-1). [Chemical 4] In the formula, n12 to n14, LA, R3, and R4 are the same as those mentioned above. 4. Onium salts such as any one of 1. to 3. wherein LA is an oxygen atom or an ester bond.5. An onium salt of any one of 1. to 4., wherein LA is an oxygen atom, a sulfur atom, an ester bond, or a carbonate bond, and R3 is an acid-unstable group. 6. An onium salt of any one of 1. to 5., wherein the aforementioned acid-unstable group is represented by the following formula (AL-1) or (AL-2). [Chemical 5] In the formula, p1 and p2 are independently 0 or 1, respectively. q1 and q2 are independently 0, 1, 2, 3, or 4, respectively. RL1, RL2, and RL3 are independently hydrocarbon groups having 1 to 12 carbon atoms, and a portion of the -CH2- group may be substituted with -O- or -S-. When the hydrocarbon group contains an aromatic ring, a portion or all of the hydrogen atoms in the aromatic ring may be substituted with 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 may also bond to each other and form a ring with the carbon atoms to which they are bonded, and a portion of the -CH2- of the ring may be replaced by -O- or -S-. 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- of the hydrocarbon group may be replaced by -O- or -S-. Furthermore, RL5 and RL6 may also bond to each other and form a heterocyclic group having 3 to 20 carbon atoms with the carbon atoms to which they are bonded and LB, and a portion of the -CH2- of the heterocyclic group may be replaced by -O- or -S-. LB is -O- or -S-. RLa to RLd are each independently a hydrogen atom, or may contain a hydrocarbon group having 1 to 20 carbon atoms. * indicates an atomic bond with an adjacent oxygen or sulfur atom. 7. A quencher composed of an onium salt of any one of 1. to 6. 8. A chemical amplification inhibitor composition comprising a quencher as described in 7. 9. A chemical amplification inhibitor composition as described in 8, comprising: a base polymer comprising a repeating unit represented by formula (a1). [Chemical 6] In the formula, RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X1 is a single bond, a phenyl group, a naphthyl group, *-C(=O)-O-X11-, or *-C(=O)-NH-X11-, and the phenyl or naphthyl group may also be substituted by an alkoxy or halogen atom of 1 to 10 carbon atoms, which may also contain a fluorine atom. X11 is a saturated alkyl group of 1 to 10 carbon atoms, a phenyl group, or a naphthyl group, and the saturated alkyl 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 of the main chain. AL1 is an acid-indestructible group. 10. A chemical amplification inhibitor composition as described in 9, wherein the aforementioned base polymer comprises a repeating unit represented by formula (a2). [Chem. 7] In the formula, RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X2 is a single bond or *-C(=O)-O-. * indicates an atomic bond with a carbon atom in the main chain.R11 is a halogen atom, cyano, hydroxyl, nitro, or may contain a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxy group with 1 to 20 carbon atoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms, a hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms, or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms. When a1 is 2, 3, or 4, each R11 may be the same or different. AL2 is an acid-instable group. a is 0, 1, 2, 3, or 4. 11. A chemical amplification inhibitor composition as in 9 or 10, wherein the aforementioned base polymer contains a repeating unit represented by the following formula (a3). [Chemical 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 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)-NH-. * indicates an atomic bond with a carbon atom in the main chain. R12 and R13 are independently hydrogen atoms, or may contain heteroatoms of 1-20 carbon atoms in a hydrocarbon group. Furthermore, R12 and R13 may also bond to each other and form a ring with the carbon atoms they are bonded to. R14 is a halogen atom, hydroxyl, cyano, nitro, or may contain heteroatoms of 1-20 carbon atoms in a hydrocarbon group, or heteroatoms of 1-20 carbon atoms in a hydrocarbon oxy group, or heteroatoms of 2-20 carbon atoms in a hydrocarbon oxycarbonyl group, or heteroatoms of 1-20 carbon atoms in a hydrocarbon thio group, or -N(R14A)(R14B). R14A and R14B are independently hydrogen atoms or hydrocarbon groups of 1-6 carbon atoms. When b2 is 2 or more, multiple R14s can also bond to each other and form a ring together with the carbon atoms of the aromatic rings they are bonded to. X4 is a single bond, an aliphatic hydrocarbon group with 1 to 4 carbon atoms, a carbonyl group, a sulfonyl group, or a group obtained by combining them. X5 and X6 are independently oxygen atoms or sulfur atoms, respectively. However, X4 and X6 are bonded to adjacent carbon atoms of the aromatic ring. 12. A chemical amplification inhibitor composition as described in any of 9. to 11, wherein the aforementioned base polymer contains a repeating unit represented by the following formula (b1) or (b2). [Chemical 9] In the formula, RA is independently hydrogen atom, fluorine atom, methyl or trifluoromethyl, respectively. Y1 is a single bond or *-C(=O)-O-. * indicates an atomic bond with the carbon atom of the main chain. R21 is a hydrogen atom, or a group with 1 to 20 carbon atoms containing at least one of the following structures: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulcinolone ring, and carboxylic anhydride (-C(=O)-OC(=O)-).R22 can be a halogen atom, carboxyl, nitro, cyano, alkoxycarbonyl, or may contain a hydrocarbon group with 1-20 carbon atoms, a hydrocarbon oxy group with 1-20 carbon atoms, a hydrocarbon carbonyl group with 2-20 carbon atoms, or a hydrocarbon carbonyl oxy group with 2-20 carbon atoms. When c2 is 2, 3, or 4, each R22 can be the same or different. c1 can be 1, 2, 3, or 4. c2 can be 0, 1, 2, 3, or 4. However, 1 ≤ c1 + c2 ≤ 5. 13. A chemical amplification inhibitor composition as described in any one of 9. to 12, wherein the aforementioned base polymer contains 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). [Chemical 10] In the formula, d1 and d2 are independently 0, 1, 2, or 3, respectively. e1 is 0 or 1. e2 is 0, 1, 2, 3, or 4. e3 is 0, 1, 2, 3, or 4. However, when e1 is 0, 0 ≤ e2 + e3 ≤ 4, and when e1 is 1, 0 ≤ e2 + e3 ≤ 6. RA are independently hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups, respectively. Z1 is a single bond or may also have substituents, such as phenyl groups. Z2 is a single bond, **-C(=O)-O-Z21-, **-C(=O)-NH-Z21-, or **-O-Z21-. Z21 is an aliphatic alkyl group, phenyl group, or a divalent group obtained by combining them, having 1 to 6 carbon atoms, and may also contain a halogen atom, carbonyl group, ester bond, ether bond, or hydroxyl group. Z3 is a single bond, ether bond, ester bond, amide bond, sulfonate 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 them, having 1 to 6 carbon atoms, and may also contain a halogen atom, carbonyl group, ester bond, ether bond, or hydroxyl group. Z5 is independently a single bond, or may contain a substituent such as phenyl group, naphthyl group, or *-C(=O)-O-Z51-. Z51 is an aliphatic alkyl group, phenyl group, or naphthyl group with 1 to 10 carbon atoms, and this aliphatic alkyl group may also contain a halogen atom, hydroxyl group, ether bond, ester bond, or lactone ring. Z6 is a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Z7 is independently a single bond, ***-Z71-C(=O)-O-, ***-C(=O)-NH-Z71-, or ***-O-Z71-. Z71 is an alkyl group with 1 to 20 carbon atoms, which may also contain heteroatoms. Z8 is independently a single bond, ****-Z81-C(=O)-O-, ****-C(=O)-NH-Z81-, or ****-O-Z81-. Z81 is an alkyl group with 1 to 20 carbon atoms, which may also contain heteroatoms.Z9 can be a single bond, methylene, ethyl, phenyl, fluorinated phenyl, trifluoromethyl-substituted phenyl, *-C(=O)-O-Z91-, *-C(=O)-N(H)-Z91-, or *-O-Z91-. Z91 can be 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. * 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. L1 can be a single bond, ether bond, ester bond, carbonyl group, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Rf1 and Rf2 can be independently fluorine atoms or fluorinated saturated hydrocarbon groups with 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 simultaneously hydrogen atoms. 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, or a fluorinated alkyl thio group having 1 to 6 carbon atoms. R31 and R32 are each independently a hydrocarbon group having 1 to 20 carbon atoms, which may also contain heteroatoms. Furthermore, R31 and R32 may also bond to each other and form a ring with the sulfur atoms they are bonded to. R33 is a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms, which may also contain heteroatoms. When e3 is 2, 3, or 4, each R33 may be the same or different from the others, and multiple R33 may also bond to each other and form a ring with the carbon atoms they are bonded to. M- is a non-nucleophilic relative ion. A+ is an onium cation. 14. The chemical amplification inhibitor composition of any one of 8. to 13, further contains an organic solvent. 15. The chemical amplification inhibitor composition of any one of 8. to 14, further contains a photoacid generator that produces a strong acid. 16. The chemical amplification inhibitor composition of any one of 8. to 15, further contains a quencher other than the quencher of 7. 17. The chemical amplification inhibitor composition of any one of 8. to 16, further contains a surfactant. 18. A pattern forming method, comprising the following steps: forming a resist film on a substrate using a chemical amplification inhibitor composition of any one of 8. to 17, exposing the resist film to high-energy radiation, and developing the exposed resist film using a developer. 19. The pattern forming method of 18, wherein the aforementioned high-energy rays are KrF excimer laser light, ArF excimer laser light, EB, or EUV with a wavelength of 3-15 nm. [Effects of the invention].

[0016] When patterning is performed using a chemical amplification resist composition containing the onium salt of the present invention as a quencher, a resist pattern with high contrast and good sensitivity, and excellent lithography properties such as EL, LWR, CDU, and DOF can be formed.

Implementation Method

[0017] [Onium Salt] The onium salt of the present invention contains a cation represented by the following formula (1A). [Chemical 11]

[0018] In formula (1A), p is 1, 2 or 3.

[0019] In formula (1A), 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, it is preferable to have a benzene ring with n1 = 0. n2 is 1 or 2. Considering the availability of raw materials, n2 is preferably 1. n3 is 0, 1, 2, or 3. Considering the availability of raw materials, n3 is preferably 0, 1, or 2. However, when n1 is 0, it is 1 ≤ n2 + n3 ≤ 5; when n1 is 1, it is 1 ≤ n2 + n3 ≤ 7.

[0020] In formula (A), R1 can be a halogen atom, a nitro group, a hydroxyl group, a carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, a hydrocarbon oxy group with 1 to 20 carbon atoms containing heteroatoms, a hydrocarbon thio group with 1 to 20 carbon atoms, or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. The hydrocarbon groups, hydrocarbon oxy groups, and hydrocarbon thio groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining them. Among these, aryl groups are preferred. 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, and a portion of the -CH2- group in the aforementioned hydrocarbon group can also be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This can result in the presence of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), or haloalkyl groups. When n3 is 2 or 3, each R1 can be the same or different. Also, when n3 is 2 or 3, multiple R1s can bond to each other and form a ring together with the carbon atoms they are bonded to. The aforementioned ring is preferably a 5- to 8-membered ring.

[0021] In formula (1A), R2 is a halogen atom, or may contain a hydrocarbon group with 1 to 30 carbon atoms containing heteroatoms. When p is 1, the two R2s may be the same or different.

[0022] Specific examples of halogen atoms represented by R2 include: fluorine atom, chlorine atom, bromine atom, iodine atom, etc.

[0023] The hydrocarbon group represented by R2 can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, and tertiary butyl; cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 30 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclohexenyl; aryl groups with 6 to 30 carbon atoms such as phenyl, naphthyl, and thiophene; aralkyl groups with 7 to 30 carbon atoms such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these, which should preferably be aryl. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- in the aforementioned hydrocarbon group may also be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0024] Furthermore, two of the three substituents bonded to S+ can also bond to each other and form a ring together with the sulfur atoms they are bonded to. In this case, specific examples of the aforementioned ring structure can be shown in the following formula. [Chemical 12] In the formula, the dashed lines represent atomic bonds.

[0025] The cation represented by formula (1A) should preferably be represented by the following formula (1A-1). [Chemical 13] In the formula, p, n1~n3 and R1 are the same as those mentioned above.

[0026] In formula (1A-1), n4 is 0 or 1. When n4 is 0, it is a benzene ring; when n4 is 1, it is a naphthalene ring. Considering solvent solubility, it is preferable to have a benzene ring with n4 of 0. n5 is 0, 1, 2, 3, 4, or 5. Considering the availability of raw materials, n5 is preferable to be 0, 1, or 2.

[0027] In formula (1A-1), R2a can be a halogen atom, nitro group, hydroxyl group, carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, a hydrocarbon oxy group with 1 to 20 carbon atoms containing heteroatoms, a hydrocarbon thio group with 1 to 20 carbon atoms, or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms. The hydrocarbon group and the hydrocarbon oxy group and hydrocarbon thio group mentioned above can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated as examples of hydrocarbon groups represented by R1, but are not limited thereto. When n5 is 2, 3, 4, or 5, each R2a can be the same or different from each other, and two R2a can also be bonded to each other and form a ring together with the carbon atoms they are bonded to.

[0028] Specific examples of cations represented by formula (1A) are shown below, but are not limited thereto. [Chemistry 14]

[0029] [Chemical 15]

[0030] [Chemical 16]

[0031] [Chemical 17]

[0032] [Chemical 18]

[0033] [Chemical 19]

[0034] [Chemical 20]

[0035] [Chemical 21]

[0036] [Chemical 22]

[0037] [Chemical 23]

[0038] [Chemical 24]

[0039] [Chemical 25]

[0040] [Chemical 26]

[0041] [Chemical 27]

[0042] [Chemical 28]

[0043] [Chemical 29]

[0044] [Chemical 30]

[0045] [Chemical 31]

[0046] [Chemical 32]

[0047] [Chemical 33]

[0048] The onium salt of the present invention contains a carboxylic acid anion represented by formula (1B). [Chemical 34]

[0049] In formula (1B), n11 is 0 or 1. When n11 is 0, it is a benzene ring; when n11 is 1, it is a naphthalene ring. Considering solvent solubility, it is preferable to have a benzene ring with n11 of 0. n12 is 1, 2, 3, or 4. Considering the availability of raw materials, it is preferable to have 1, 2, or 3. Considering solvent solubility, 1 or 2 is more preferred. n13 is 0, 1, or 2. n14 is 0, 1, 2, 3, or 4. However, when n11 is 0, it is 2≦n12+n13+n14≦5; when n11 is 1, it is 2≦n12+n13+n14≦7. Considering the availability of raw materials, n14 is preferable to have 0, 1, 2, or 3, with 0, 1, or 2 being more preferred.

[0050] In formula (1B), LA is a single bond, an oxygen atom, a sulfur atom, an ester bond, or a carbonate bond. When R3 is a hydrogen atom as described later, LA is preferably an oxygen atom. Furthermore, when R3 is an unstable acid group as described later, R3 is preferably an oxygen atom, an ester bond, or a carbonate bond, with oxygen atom or ester bond being more preferred.

[0051] In formula (1B), R3 is a hydrogen atom when LA is a single bond, or it may contain a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms. The aforementioned hydrocarbon group with 1 to 20 carbon atoms may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, tertiary butyl, tertiary pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, etc., alkyl groups with 1 to 20 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, norcamphenylmethyl, adamantyl, adamantylmethyl, tricyclic [5.2.1.02,6]decyl, tetracyclic [6.2]decyl, tetracyclic [6.2]decyl, etc. [1.13,6.02,7] Cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as dodecyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, pentenyl, and hexenyl; alkynyl groups with 2 to 20 carbon atoms, such as ethynyl, propynyl, butynyl, pentynyl, and hexynyl; cyclic unsaturated aliphatic hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopentenyl and cyclohexenyl; aryl groups with 6 to 20 carbon atoms, such as phenyl, naphthyl, and dihydroindenyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these. Furthermore, the aforementioned hydrocarbon groups may also contain heteroatoms, specifically halogen atoms, oxygen atoms, sulfur atoms, etc.

[0052] When LA is an oxygen atom, sulfur atom, ester bond or carbonate bond, R3 is a hydrogen atom, or may contain a hydrocarbon group with 1 to 20 carbon atoms (excluding acid-labile groups) or an acid-labile group. The aforementioned hydrocarbon groups may include those other than the acid-labile groups mentioned above.

[0053] The aforementioned unstable acid group is preferably represented by the following formula (AL-1) or (AL-2). [Chemical 35] In the formula, * represents the atomic bond with the adjacent oxygen or sulfur atom.

[0054] In formulas (AL-1) and (AL-2), p1 and p2 are independently 0 or 1, respectively. q1 and q2 are independently 0, 1, 2, 3, or 4, respectively. When LA is an oxygen atom and forms a carbonate bond with it, p1 or p2 is 1; otherwise, p1 or p2 should preferably be 0. Furthermore, when p1 is 1, q1 should preferably be 1 or 2; when p1 is 0, q1 is 0. When p2 is 1, q2 should preferably be 1 or 2; when p2 is 0, q2 is 0.

[0055] In formula (AL-1), RL1, RL2 and RL3 are each independently a hydrocarbon group with 1 to 12 carbon atoms, and part of the -CH2- of the hydrocarbon group may 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 may 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.

[0056] The hydrocarbon groups represented by RL1, RL2, and RL3, having 1 to 12 carbon atoms, can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, tertiary butyl, tertiary pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, etc., alkyl groups having 1 to 12 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornel, norbornelmethyl, adamantyl, adamantylmethyl, tricyclic [5.2.1.02,6]decyl, tetracyclic [6.2]decyl, etc. [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, allyl, 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 dihydroindenyl; aralkyl groups with 7 to 12 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these.

[0057] Furthermore, RL1 and RL2 can also bond to each other and form a ring together with the carbon atoms they are bonded to, and a portion of the -CH2- of this ring can 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. Also, a portion of the -CH2- of the aforementioned rings can be replaced by -O- or -S-.

[0058] In formula (AL-2), RL4 and RL5 are independently hydrogen atoms or hydrocarbon groups with 1 to 10 carbon atoms, respectively. 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 and illustrated by examples of hydrocarbon groups with 1 to 10 carbon atoms represented by RL1, RL2, and RL3.

[0059] In formula (AL-2), 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-. 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, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, norcamphenylmethyl, adamantyl, adamantylmethyl, tricyclic [5.2.1.02,6]decyl, tetracyclic [6.2.1.13,6.02,7]dodecyl, etc. Hydrocarbon groups; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, propynyl, butenyl, pentenyl, and hexenyl; alkynyl groups with 2 to 20 carbon atoms, such as ethynyl, propynyl, butynyl, pentynyl, and hexynyl; cyclic unsaturated aliphatic hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopentenyl, cyclohexenyl, and norcamphenyl; aryl groups with 6 to 20 carbon atoms, such as phenyl, tolyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, secondary butynyl, tertiary butynyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butynyl, isobutynyl, secondary butynyl, and tertiary butynyl; 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 they bond to and LB, form heterocyclic groups with 3 to 20 carbon atoms, and part of the -CH2- of the heterocyclic group can also be replaced by -O- or -S-.

[0060] In formula (AL-2), LB is -O- or -S-.

[0061] In formulas (AL-1) and (AL-2), RLa~RLd are each independently a hydrogen atom, or may contain heteroatoms and are hydrocarbon groups with 1 to 20 carbon atoms. The aforementioned hydrocarbon groups with 1 to 20 carbon atoms may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be given and illustrated as hydrocarbon groups represented by R3, but are not limited thereto.

[0062] Specific examples of the unstable acid group represented by formula (AL-1) are shown below, but are not limited thereto. Additionally, in the following formula, * indicates an atomic bond with an adjacent oxygen or sulfur atom. [Chemistry 36]

[0063] [Chemical 37]

[0064] [Chemical 38]

[0065] [Chemical 39]

[0066] [Chemical 40]

[0067] [Chemical 41]

[0068] [Chemical 42]

[0069] [Chemical 43]

[0070] [Chemical 44]

[0071] [Chemical 45]

[0072] [Chemical 46]

[0073] Specific examples of the unstable acid group represented by formula (AL-2) are shown below, but are not limited thereto. Additionally, in the following formula, * indicates an atomic bond with an adjacent oxygen or sulfur atom. [Chemistry 47]

[0074] [Chemical 48]

[0075] In formula (1B), R4 can be a halogen atom other than an iodine atom, a nitro group, a cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms. Examples of halogen atoms other than an iodine atom include fluorine, chlorine, and bromine atoms, preferably fluorine. The aforementioned hydrocarbon group with 1 to 20 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given and illustrated using the same examples as those represented by R3. Furthermore, the aforementioned hydrocarbon group can also contain heteroatoms; specifically, it can contain halogen atoms, oxygen atoms, sulfur atoms, etc.

[0076] Furthermore, when n14 is 2, 3, or 4, multiple R4s can also bond to each other and form ring structures together with the carbon atoms on the bonded aromatic rings, and a portion of the -CH2- of the ring can 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, a portion of the -CH2- of the aforementioned rings can also be replaced by -O- or -S-.

[0077] The carboxylic acid anion represented by formula (1B) should preferably be represented by formula (1B-1). [Chemical 49] In the formula, n12~n14, LA, R3 and R4 are the same as those mentioned above.

[0078] Specific examples of the anions of onium salts represented by formula (1B) are shown below, but are not limited thereto. [Chem. 50]

[0079] [Chemical 51]

[0080] [Chemical 52]

[0081] [Chemical 53]

[0082] [Chemical 54]

[0083] [Chemical 55]

[0084] [Chemical 56]

[0085] [Chemical 57]

[0086] [Chemical 58]

[0087] [Chemical 59]

[0088] [Chemical 60]

[0089] [Chemical 61]

[0090] [Chemical 62]

[0091] [Chemical 63]

[0092] [Chemical 64]

[0093] [Chemical 65]

[0094] [Chemical 66]

[0095] [Chemical 67]

[0096] [Chemical 68]

[0097] [Chemical 69]

[0098] [Chemical 70]

[0099] [Chemistry 71]

[0100] [Chemistry 72]

[0101] [Chemistry 73]

[0102] [Chemistry 74]

[0103] [Chemistry 75]

[0104] [Chemistry 76]

[0105] [Chemistry 77]

[0106] [Chemistry 78]

[0107] [Chemistry 79]

[0108] [Chemical 80]

[0109] [Chemistry 81]

[0110] [Chemistry 82]

[0111] [Chemistry 83]

[0112] [Chemical 84]

[0113] [Chemical 85]

[0114] [Chemical 86]

[0115] [Chemical 87]

[0116] [Chemical 88]

[0117] [Chemistry 89]

[0118] [Chemical 90]

[0119] [Chemistry 91]

[0120] [Chemical 92]

[0121] [Chemistry 93]

[0122] [Chemical 94]

[0123] [Chemical 95]

[0124] [Chemical 96]

[0125] [Chemical 97]

[0126] [Chemical 98]

[0127] [Chemistry 99]

[0128] [Chemical 100]

[0129] [Chemistry 101]

[0130] [Chemical 102]

[0131] [Chemical 103]

[0132] [Chemical 104]

[0133] [Chemical 105]

[0134] [Chemical 106]

[0135] [Chemical 107]

[0136] [Chemical 108]

[0137] [Chemistry 109]

[0138] [Chemical 110]

[0139] [Chemistry 111]

[0140] [Chemical 112]

[0141] [Chemical 113]

[0142] [Chemical 114]

[0143] [Chemical 115]

[0144] [Chemical 116]

[0145] [Chemical 117]

[0146] [Chemical 118]

[0147] [Chemistry 119]

[0148] [Chemical 120]

[0149] [Chemistry 121]

[0150] [Chemistry 122]

[0151] [Chemistry 123]

[0152] [Chemistry 124]

[0153] [Chemical 125]

[0154] [Chemistry 126]

[0155] [Chemistry 127]

[0156] [Chemistry 128]

[0157] [Chemistry 129]

[0158] [Chemistry 130]

[0159] [Chemistry 131]

[0160] [Chemistry 132]

[0161] [Chemistry 133]

[0162] [Chemistry 134]

[0163] [Chemistry 135]

[0164] [Chemistry 136]

[0165] [Chemistry 137]

[0166] [Chemistry 138]

[0167] [Chemistry 139]

[0168] [Chemical 140]

[0169] [Chemistry 141]

[0170] [Chemistry 142]

[0171] [Chemistry 143]

[0172] [Chemistry 144]

[0173] [Chemistry 145]

[0174] [Chemistry 146]

[0175] [Chemistry 147]

[0176] [Chemistry 148]

[0177] [Chemistry 149]

[0178] Specific examples of the onium salts of the present invention can be listed as any combination of the aforementioned anions and cations.

[0179] The onium salt of the present invention can be synthesized, for example, using the same method as that described in Japanese Patent Application Publication No. 2020-91312, but is not limited thereto.

[0180] The structural features of the onium salt of the present invention can be exemplified by being composed of a strontium cation having a cyano group and an aromatic carboxylic acid anion having an iodine atom. The aromatic carboxylic acid anion containing the iodine atom exhibits very high EUV absorption, especially at a wavelength of 13.5 nm, thus generating secondary electrons from the iodine atom during exposure. Furthermore, the strontium cation having the cyano group utilizes the electron-withdrawing effect of the cyano group to lower the energy level of the lowest unoccupied molecular orbital (LOMO) in Frontier orbital theory, making it more receptive to the generated secondary electrons. This promotes cation decomposition and, due to these synergistic effects, increases sensitivity. In addition, the nitrogen atom of the cyano group has an isolated electron pair, thus it can be expected to interact with the protons of the generated acid, functioning as an acid diffusion inhibitor. Moreover, the iodine atom has appropriate solubility inhibition capabilities, particularly for suppressing pattern collapse in unexposed areas in alkaline developing solutions. Furthermore, when the anion has an acid-instable group, the deprotection reaction of the acid-instable group will occur, and the change in solubility can be expected to improve contrast and increase sensitivity. In the exposure section of a positive resist, the higher the affinity for alkaline developer, the lower the risk of development defects. In addition, the ononium salt of the present invention has an aromatic carboxylic acid anion, so it is more basic and can effectively capture the strong acid generated by photoacid generators. Through these synergistic effects, when using the ononium salt of the present invention, patterns with high dissolution contrast, excellent line pattern LWR, excellent hole pattern CDU, and strong pattern collapse resistance can be formed, making it suitable as a material for use as a positive resist component.

[0181] The onium salt of the present invention can be ideally used as a quencher. Furthermore, in the present invention, the quencher is a material used to form a desired pattern by capturing the strong acid generated from the photoacid generator to prevent its diffusion to the unexposed area. The photoacid generator is a compound that generates a strong acid due to high-energy radiation, and the strong acid is a compound with sufficient acidity to cause a deprotection reaction of the acid-instable group. The aforementioned aromatic carboxylic acids, when the acid-instable group is a tertiary ester or tertiary ether, do not have sufficient acidity to cause a deprotection reaction. Therefore, as described later, it is effective to add a photoacid generator that generates a strong acid, i.e., an α-fluorinated sulfonic acid, amide, or methylated acid, to induce a deprotection reaction of the acid-instable group. Furthermore, the photoacid generator that generates an α-fluorinated sulfonic acid, amide, or methylated acid can be additive or polymerically bonded to a base polymer.

[0182] When a photoacid generator that produces the aforementioned onium salt of aromatic carboxylic acids and a perfluoroalkyl sulfonic acid that produces a superacid are irradiated in a mixed state, aromatic carboxylic acids and perfluoroalkyl sulfonic acids will be produced. Since the photoacid generator will not completely decompose, undecomposed photoacid generator will remain nearby. Here, if the onium salt of aromatic carboxylic acids and perfluoroalkyl sulfonic acids coexist, initially the perfluoroalkyl sulfonic acid will undergo ion exchange with the onium salt of aromatic carboxylic acids, producing a perfluoroalkyl sulfonate onium salt and releasing the aromatic carboxylic acid. This is because perfluoroalkyl sulfonates, which have high acid strength, are more stable. On the other hand, even if the perfluoroalkyl sulfonate onium salt and aromatic carboxylic acids coexist, ion exchange will not occur. Not only perfluoroalkyl sulfonic acids will cause ion exchange, but aromatic sulfonic acids, alkyl sulfonic acids, amide acids, methyl acids, etc., which have higher acid strength than the aromatic carboxylic acids produced from the onium salt of the present invention, will also cause the same ion exchange.

[0183] [Chemical Amplification Inhibitor Composition] [(A) Quencher] The chemical amplification inhibitor composition of the present invention contains (A) a quencher composed of an onium salt represented by formula (1) as an essential component.

[0184] In the chemical amplification inhibitor composition of the present invention, the content of (A) quencher relative to 80 parts by mass of the base polymer described below is preferably 0.1 to 40 parts by mass, and more preferably 0.5 to 30 parts by mass. If the content of (A) quencher is within the aforementioned range, the sensitivity and resolution are good, and there is no concern about the generation of foreign matter after the inhibitor film is developed or peeled off, which is ideal. (A) Quencher can be used alone or in combination of two or more.

[0185] [(B) Base Polymer] The chemical amplification inhibitor composition of the present invention may also contain a base polymer as component (B). The (B) base polymer preferably contains a repeating unit represented by the following formula (a1) (hereinafter also referred to as repeating unit a1). [Chemical 150]

[0186] In formula (a1), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0187] In formula (a1), X1 is a single bond, phenyl, naphthyl, *-C(=O)-O-X11- or *-C(=O)-NH-X11-, and the phenyl or naphthyl may be substituted by an alkoxy or halogen atom with 1 to 10 carbon atoms, which may also contain a fluorine atom. X11 is a saturated alkyl group, phenyl or naphthyl with 1 to 10 carbon atoms, and the saturated alkyl group may also contain a hydroxyl group, an ether bond, an ester bond or an lactone ring. * indicates an atomic bond with a carbon atom of the main chain.

[0188] In formula (a1), AL1 is an acid-instable group. Specific examples of the aforementioned acid-instable groups can be cited, for example, those described in Japanese Patent Application Publication No. 2013-80033 and Japanese Patent Application Publication No. 2013-83821.

[0189] For representativeness, specific examples of the aforementioned unstable acid groups can be listed as those represented by the following formulas (AL-3) to (AL-5). [Chemistry 151] In the formulas, the dashed lines represent atomic bonds.

[0190] 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. The aforementioned hydrocarbon groups are preferably those with 1 to 20 carbon atoms.

[0191] In formula (AL-3), k is an integer from 0 to 10, preferably 1, 2, 3, 4 or 5.

[0192] In formula (AL-4), RL13 and RL14 are independently hydrogen atoms or hydrocarbon groups with 1 to 20 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. The aforementioned hydrocarbon groups are preferably with 1 to 20 carbon atoms. Furthermore, 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 carbon atoms they are bonded to, or with carbon atoms and oxygen atoms. The aforementioned ring is preferably a ring with 4 to 16 carbon atoms, and an alicyclic ring is particularly preferred.

[0193] 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 may be saturated or unsaturated, and may be linear, branched, or cyclic. The aforementioned hydrocarbon groups are preferably those with 1 to 20 carbon atoms. Furthermore, any two of RL15, RL16, and RL17 may also bond to each other and together with the carbon atoms they are bonded to form a ring with 3 to 20 carbon atoms. The aforementioned ring is preferably a ring with 4 to 16 carbon atoms, and an alicyclic ring is particularly preferred.

[0194] Specific examples of repeated unit a1 can be listed below, but are not limited to these. Furthermore, in the following formula, RA and AL1 are the same as described above. [Chemistry 152]

[0195] [Chemistry 153]

[0196] [Chemistry 154]

[0197] [Chemistry 155]

[0198] [Chemistry 156]

[0199] [Chemistry 157]

[0200] [Chemistry 158]

[0201] The aforementioned basic polymer may also contain repeating units represented by the following formula (a2) (hereinafter also referred to as repeating unit a2). [Chemistry 159]

[0202] In formula (a2), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X2 is a single bond or *-C(=O)-O-. * indicates an atomic bond with a carbon atom in the main chain. R11 is a halogen atom, a cyano group, a hydroxyl group, a nitro group, or may contain a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxy group with 1 to 20 carbon atoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms, a hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms, or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms. AL2 is an acid-instable group. Specific examples of the aforementioned acid-instable groups can be listed and illustrated as similar examples of acid-instable groups represented by AL1. a is 0, 1, 2, 3, or 4, preferably 0 or 1.

[0203] Specific examples of repeated unit a2 can be listed below, but are not limited to these. Furthermore, in the following formula, RA and AL2 are the same as described above. [Chemistry 160]

[0204] [Chemical 161]

[0205] [Chemical 162]

[0206] The aforementioned basic polymer may also contain repeating units represented by the following formula (a3) ​​(hereinafter also referred to as repeating unit a3). [Chemistry 163]

[0207] In formula (a3), b1 is 0 or 1. When b1 is 0, it is a benzene ring; when b1 is 1, it is a naphthalene ring. Considering solvent solubility, it is preferable to have a benzene ring with b1 being 0. b2 is 0, 1, 2, or 3 when b1 is 0, and 0, 1, 2, 3, 4, or 5 when b1 is 1. Considering the availability of raw materials, b2 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being more preferred.

[0208] In formula (a3), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. RA is preferably a hydrogen atom or a methyl group, with hydrogen being even more preferable.

[0209] In formula (a3), X3 is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * indicates an atomic bond with a carbon atom in the main chain. Among these, a single bond or *-C(=O)-O- is preferred, with a single bond being even better.

[0210] In formula (a3), R12 and R13 are each independently hydrogen atoms, or may contain heteroatoms and hydrocarbon groups with 1 to 20 carbon atoms. 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, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining them. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- group in the aforementioned hydrocarbon group may also be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0211] Furthermore, R12 and R13 can also bond to each other and form a ring together with the carbon atoms they are bonded to. Specific examples of the rings formed in this case include: cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, norbornene ring, adamantane ring, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and some of the -CH2- in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, etc. As a result, 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.

[0212] In formula (a3), R14 can be a halogen atom, hydroxyl group, cyano group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, a hydrocarbon oxy group with 1 to 20 carbon atoms containing heteroatoms, 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(R14A)(R14B). R14A and R14B 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 group, hydrocarbon oxy 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 and illustrated as similar examples of hydrocarbon groups represented by R12 and R13. 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, and a portion of the -CH2- group in the aforementioned hydrocarbon group can also be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This can result in the presence of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When b2 is 2 or more, each R14 can be the same or different.

[0213] Furthermore, when b2 is 2 or more, multiple R14 atoms can also bond to each other and form a ring together with the carbon atoms of the aromatic rings they are bonded to. Specific examples of the rings formed in this case include: cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, 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.

[0214] 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 group obtained by combining them. Among these, considering the availability of raw materials, it is preferable to be a single bond, a carbonyl group, or a sulfonyl group. Considering the polar group generated after the reaction, it is more preferable to be a single bond or a carbonyl group.

[0215] In formula (a3), X5 and X6 are independently oxygen atoms or sulfur atoms, respectively. However, X4 and X6 are bonded to adjacent carbon atoms of the aromatic ring. X5 and X6 can be the same or different. Considering reactivity, X5 and X6 should both be oxygen atoms.

[0216] Specific examples of the repeating unit a3 can be listed below, but are not limited thereto. Furthermore, in the following formula, RA is the same as described above, and Me is methyl. Also, the bonding positions of various substituents on the aromatic ring can be interchanged. [Chemistry 164]

[0217] [Chemistry 165]

[0218] [Chemistry 166]

[0219] [Chemistry 167]

[0220] [Chemistry 168]

[0221] [Chemistry 169]

[0222] [Chemistry 170]

[0223] [Chemistry 171]

[0224] [Chemistry 172]

[0225] [Chemistry 173]

[0226] [Chemistry 174]

[0227] [Chemistry 175]

[0228] [Chemistry 176]

[0229] [Chemistry 177]

[0230] [Chemistry 178]

[0231] [Chemistry 179]

[0232] [Chemical 180]

[0233] [Chemistry 181]

[0234] [Chemical 182]

[0235] [Chemistry 183]

[0236] [Chemical 184]

[0237] [Chemical 185]

[0238] [Chemistry 186]

[0239] [Chemistry 187]

[0240] [Chemistry 188]

[0241] [Chemistry 189]

[0242] [Chemistry 190]

[0243] [Chemistry 191]

[0244] [Chemistry 192]

[0245] [Chemistry 193]

[0246] [Chemistry 194]

[0247] [Chemical 195]

[0248] [Chemistry 196]

[0249] [Chemistry 197]

[0250] [Chemistry 198]

[0251] [Chemical 199]

[0252] [Chemical 200]

[0253] [Chemical 201]

[0254] [Chemical 202]

[0255] [Chemical 203]

[0256] [Chemical 204]

[0257] [Chemical 205]

[0258] [Chemical 206]

[0259] [Chemical 207]

[0260] [Chemical 208]

[0261] [Chemical 209]

[0262] [Chemical 210]

[0263] [Chemical 211]

[0264] [Chemical 212]

[0265] [Chemical 213]

[0266] The aforementioned basic polymer preferably contains a repeating unit represented by formula (b1) (hereinafter also referred to as repeating unit b1) or a repeating unit represented by formula (b2) (hereinafter also referred to as repeating unit b2). [Chemical 214]

[0267] 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. R21 is a hydrogen atom, or a group containing at least one of the following structures with 1 to 20 carbon atoms: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulfonyl lactone ring, and carboxylic anhydride (-C(=O)-OC(=O)-). R22 is a halogen atom, carboxyl group, nitro group, cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, a hydrocarbon oxy group with 1 to 20 carbon atoms containing heteroatoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, a hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms containing heteroatoms. When c2 is 2, 3, or 4, each R22 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.

[0268] Specific examples of repeating unit b1 can be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 215]

[0269] [Chemical 216]

[0270] [Chemical 217]

[0271] [Chemical 218]

[0272] [Chemical 219]

[0273] [Chemical 220]

[0274] [Chemical 221]

[0275] [Chemical 222]

[0276] [Chemical 223]

[0277] [Chemical 224]

[0278] [Chemical 225]

[0279] [Chemical 226]

[0280] [Chemical 227]

[0281] [Chemical 228]

[0282] [Chemical 229]

[0283] [Chemical 230]

[0284] Specific examples of repeating unit b2 can be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 231]

[0285] [Chemical 232]

[0286] [Chemistry 233]

[0287] [Chemical 234]

[0288] [Chemical 235]

[0289] In ArF lithography, repeating units b1 or b2 are preferably those with lactone rings as polar groups, and in KrF lithography, EB lithography and EUV lithography, those with phenolic sites are preferred.

[0290] The aforementioned basic polymer may also contain at least one of the repeating units selected from the following formula (c1) (hereinafter also referred to as repeating unit c1), the following formula (c2) (hereinafter also referred to as repeating unit c2), the following formula (c3) (hereinafter also referred to as repeating unit c3), the following formula (c4) (hereinafter also referred to as repeating unit c4), and the following formula (c5) (hereinafter also referred to as repeating unit c5). [Chemical 236]

[0291] 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)-NH-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 them, 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, an amide bond, a sulfonate bond, a sulfonylurea 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 them, 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, or may contain substituents such as phenyl, naphthyl, or *-C(=O)-O-Z51-. Z51 is an aliphatic alkyl group, phenyl, or naphthyl with 1 to 10 carbon atoms, and this aliphatic alkyl group may also contain a halogen atom, hydroxyl group, ether bond, ester bond, or lactone ring. Z6 is a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Z7 is independently a single bond, ***-Z71-C(=O)-O-, ***-C(=O)-NH-Z71-, or ***-O-Z71-. Z71 is an alkyl group with 1 to 20 carbon atoms, and may also contain heteroatoms. Z8 is independently a single bond, ****-Z81-C(=O)-O-, ****-C(=O)-NH-Z81-, or ****-O-Z81-. Z81 is an alkyl group with 1 to 20 carbon atoms, which may also contain heteroatoms. Z9 is a single bond, methylene, ethyl, phenyl, fluorinated phenyl, phenyl substituted with trifluoromethyl, *-C(=O)-O-Z91-, *-C(=O)-N(H)-Z91-, or *-O-Z91-. Z91 is an aliphatic alkyl group with 1 to 6 carbon atoms, phenyl, fluorinated phenyl, or phenyl substituted with trifluoromethyl, and may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group. * indicates an atomic bond with a carbon atom in the main chain. ** indicates an atomic bond with Z1. *** indicates an atomic bond with Z6. **** indicates an atomic bond with Z7.

[0292] The aliphatic hydrocarbon groups represented by Z21, Z51, and Z91 can be any of the following: 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, 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 alkyldiyl groups; cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, cyclohexanediyl, and other cycloalkyldiyl groups; and groups obtained by combining them.

[0293] Z71 and Z81 can also contain heteroatoms. The extended hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples are shown below, but are not limited to these. [Chem. 237] In the formula, the dashed line represents the atomic bond.

[0294] In formula (c1), R31 and R32 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, secondary butyl, and tertiary butyl; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as 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; cyclic unsaturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups with 6 to 20 carbon atoms, such as phenyl, naphthyl, and thiophene; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining them, which are preferably aryl groups. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- in the aforementioned hydrocarbon group may also be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it 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, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0295] Furthermore, R31 and R32 can also bond to each other and form a ring together with the sulfur atoms they are bonded to. In this case, specific examples of the aforementioned rings can be shown in the following formula. [Chemistry 238] In the formula, the dashed lines represent the atomic bonds with Z4.

[0296] Specific examples of the cation of repeating unit c1 can be listed below, but are not limited thereto. Furthermore, in the following formula, RA is the same as described above. [Chemistry 239]

[0297] [Chemical 240]

[0298] [Chemical 241]

[0299] [Chemical 242]

[0300] [Chemistry 243]

[0301] [Chemical 244]

[0302] [Chemical 245]

[0303] [Chemical 246]

[0304] [Chemical 247]

[0305] [Chemical 248]

[0306] In formula (c1), M- is a non-nucleophilic relative ion. The aforementioned non-nucleophilic relative ion is preferably a halide ion, sulfonate anion, aceimide anion, or methylated acid anion. Specific examples of the aforementioned halide ions include chloride ions, bromide ions, etc. Specific examples of the aforementioned sulfonate 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 amide anions (amide ions) include: bis(trifluoromethylsulfonyl)amide ions, bis(perfluoroethylsulfonyl)amide ions, bis(perfluorobutylsulfonyl)amide ions, etc. Specific examples of the aforementioned methylated anions (methylated ions) include: trifluoromethylsulfonyl methylated ions, trifluoroethylsulfonyl methylated ions, etc.

[0307] 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). [Chemistry 249]

[0308] In formula (c1-1), Rfa is a fluorine atom or a hydrocarbon group with 1 to 40 carbon atoms that may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed and illustrated as examples of hydrocarbon groups represented by Rfa1 in the following formula (c1-1-1).

[0309] The anion represented by formula (c1-1) should preferably be represented by the following formula (c1-1-1). [Chemistry 250]

[0310] In formula (c1-1-1), Q1 and Q2 are independently hydrogen atoms, fluorine atoms, or fluorinated saturated hydrocarbon groups with 1 to 6 carbon atoms, respectively. To improve solvent solubility, at least one of them is preferably trifluoromethyl. m can be 0, 1, 2, 3, or 4, with 1 being particularly preferred. Rfa1 can also be a hydrocarbon group with 1 to 35 carbon atoms containing heteroatoms. The aforementioned heteroatoms are preferably oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms, etc., with oxygen atoms being more preferred. Considering the viewpoint that high resolution can be obtained in the formation of fine patterns, the aforementioned hydrocarbon groups with 6 to 30 carbon atoms are particularly preferred.

[0311] In formula (c1-1-1), the hydrocarbon group represented by Rfa1 with 1 to 35 carbon atoms can be saturated or unsaturated, and can be any of the following: straight chain, branched, or cyclic. Specific examples include: alkyl groups with 1 to 35 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and eicosyl; cyclic saturated hydrocarbon groups with 3 to 35 carbon atoms, such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norcamphenyl, norcamphenylmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups with 2 to 35 carbon atoms, such as 2-propenyl and 3-cyclohexenyl; aryl groups with 6 to 35 carbon atoms, such as phenyl, 1-naphthyl, 2-naphthyl, and 9-enyl; aralkyl groups with 7 to 35 carbon atoms, such as benzyl and diphenylmethyl; and groups obtained by combining them.

[0312] Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, or halogen atoms, and a portion of the -CH2- group in the aforementioned hydrocarbon group may also be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, or nitrogen atoms. As a result, it may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, 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.

[0313] In formula (c1-1-1), La1 is a single bond, ether bond, ester bond, sulfonate bond, carbonate bond or carbamate bond. From a synthetic point of view, it is preferable to be an ether bond or an ester bond, and an ester bond is even better.

[0314] Specific examples of anions represented by formula (c1-1) are shown below, but are not limited thereto. Additionally, in the following formula, Q1 is the same as described above, and Ac is acetyl. [Chem. 251]

[0315] [Chemical 252]

[0316] [Chemical 253]

[0317] [Chemical 254]

[0318] [Chemistry 255]

[0319] [Chemistry 256]

[0320] [Chemistry 257]

[0321] [Chemistry 258]

[0322] [Chemistry 259]

[0323] [Chemical 260]

[0324] In formula (c1-2), Rfb1 and Rfb2 are each independently a fluorine atom or a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be given and illustrated by the same example as 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 group they are bonded to (-CF2-SO2-N--SO2-CF2-). In this case, the group obtained by the mutual bonding of Rfb1 and Rfb2 is preferably fluorinated ethyl or fluorinated propyl.

[0325] In formula (c1-3), Rfc1, Rfc2, and Rfc3 are each independently a fluorine atom or a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be given and illustrated by the same example as 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 may also be bonded to each other and form a ring together with the group they are bonded to (-CF2-SO2-C--SO2-CF2-). In this case, the group obtained by the mutual bonding of Rfc1 and Rfc2 is preferably fluorinated ethyl or fluorinated propyl.

[0326] In formula (c1-4), Rfd is a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed and illustrated as hydrocarbon groups represented by Rfa1 in formula (c1-1-1).

[0327] Specific examples of anions represented by formula (c1-4) are shown below, but are not limited to these. [Chemistry 261]

[0328] [Chemistry 262]

[0329] Further examples of the aforementioned non-nucleophilic relative ions can be exemplified 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). [Chem. 263]

[0330] In formula (c1-5), x1 is 1, 2, or 3. y1 is 1, 2, 3, 4, or 5. z1 is 0, 1, 2, or 3. However, 1≦y1+z1≦5. y1 should preferably be 1, 2, or 3, with 2 or 3 being better. z1 should preferably be 0, 1, or 2.

[0331] In formula (c1-5), XBI is an iodine atom or a bromine atom, and when x1 and / or y1 are 2 or more, they can be the same or different.

[0332] In formula (c1-5), L11 is a single bond, ether bond, or ester bond, or may contain a saturated alkyl group with 1 to 6 carbon atoms of ether or ester bond. The aforementioned saturated alkyl group may be straight-chain, branched, or cyclic.

[0333] In formula (c1-5), L12 is a single bond or a divalent linker with 1 to 20 carbon atoms when x1 is 1, and a (x1+1) valent linker with 1 to 20 carbon atoms when x1 is 2 or 3, and the linker may also contain oxygen, sulfur or nitrogen atoms.

[0334] In formula (c1-5), Rfe is a hydroxyl group, carboxyl group, fluorine atom, chlorine atom, bromine atom, or amino group, or may contain a 1-20 carbon-1 hydrocarbon group, a 1-20 carbon-1 hydrocarbon oxygen group, a 2-20 carbon-2 hydrocarbon carbonyl group, a 2-20 carbon-2 hydrocarbon oxygen carbonyl group, a 2-20 carbon-2 hydrocarbon carbonyl oxygen group, or a 1-20 carbon-1 hydrocarbon sulfonyl oxygen group, or -N(RfeA)(RfeB), -N(RfeC)-C(=O)-RfeD or -N(RfeC)-C(=O)-O-RfeD. RfeA and RfeB are each independently a hydrogen atom or a 1-6 carbon-1 saturated hydrocarbon group. 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 carbonyl oxy 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 carbonyl oxy group having 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. The aforementioned hydrocarbon group, hydrocarbon oxy group, hydrocarbon carbonyl group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyl oxy group, and hydrocarbon sulfonyl oxy group may be linear, branched, or cyclic. When x1 and / or z1 are 2 or more, each Rfe can be the same or different.

[0335] Among them, Rfe should preferably be hydroxyl, -N(RfeC)-C(=O)-RfeD, -N(RfeC)-C(=O)-O-RfeD, fluorine atom, chlorine atom, bromine atom, methyl, methoxy, etc.

[0336] In formula (c1-5), Rf11 to Rf14 are independently hydrogen atoms, fluorine atoms, or trifluoromethyl groups, respectively, and at least one of them is a fluorine atom or a trifluoromethyl group. Furthermore, Rf11 and Rf12 can also combine to form a carbonyl group. It is particularly preferred that both Rf13 and Rf14 are fluorine atoms.

[0337] Specific examples of anions represented by formula (c1-5) are shown below, but are not limited thereto. Furthermore, in the following formula, XBI is the same as described above. [Chemistry 264]

[0338] [Chemical 265]

[0339] [Chemistry 266]

[0340] [Chemistry 267]

[0341] [Chemistry 268]

[0342] [Chemistry 269]

[0343] [Chemical 270]

[0344] [Chemical 271]

[0345] [Chemistry 272]

[0346] [Chemical 273]

[0347] [Chemical 274]

[0348] [Chemical 275]

[0349] [Chemistry 276]

[0350] [Chemistry 277]

[0351] [Chemical 278]

[0352] [Chemical 279]

[0353] [Chemical 280]

[0354] [Chemical 281]

[0355] [Chemical 282]

[0356] [Chemical 283]

[0357] [Chemical 284]

[0358] [Chemical 285]

[0359] [Chemical 286]

[0360] The aforementioned non-nucleophilic relative ions may also include the fluorobenzenesulfonate anion bonded to an aromatic group containing an iodine atom as described in Japanese Patent No. 6648726, the anion with a mechanism of decomposition due to 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 as described in Japanese Patent Application Publication No. 2018-92159.

[0361] The aforementioned non-nucleophilic relative ions may also be the bulky benzenesulfonic acid derivative anions without fluorine atoms described in Japanese Patent Application Publication No. 2006-276759, Japanese Patent Application Publication No. 2015-117200, Japanese Patent Application Publication No. 2016-65016 and Japanese Patent Application Publication No. 2019-202974, the benzenesulfonate anion without fluorine atoms bonded to an aromatic group containing iodine atoms, and the alkylsulfonate anion described in Japanese Patent No. 6645464.

[0362] The aforementioned non-nucleophilic relative ions may also be the anions of disulfonic acid as described in Japanese Patent Application Publication No. 2015-206932, the anions of sulfonic acid on one side and sulfenamide or sulfenimide 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.

[0363] In formulas (c2) and (c3), d1 and d2 are 0, 1, 2 or 3 independently, and it is preferable to be 1.

[0364] In formula (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, it is 0≦e2+e3≦4, and when e1 is 1, it is 0≦e2+e3≦6.

[0365] In formulas (c2), (c3), and (c4), L1 can be a single bond, ether bond, ester bond, carbonyl group, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Among these, from a synthetic point of view, ether bond, ester bond, and carbonyl group are preferred, with ester bond and carbonyl group being even more preferred.

[0366] In formula (c2), Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Among them, Rf1 and Rf2 are preferably both fluorine atoms to improve the acid strength of the resulting 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. Among them, to improve solvent solubility, at least one of Rf3 and Rf4 is preferably trifluoromethyl.

[0367] 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 of Rf5 and Rf6 are simultaneously hydrogen atoms. Among them, to improve solvent solubility, at least one of Rf5 and Rf6 should preferably be trifluoromethyl.

[0368] 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, or a fluorinated alkyl thiogroup having 1 to 6 carbon atoms. Rf7 is preferably a fluorine atom, trifluoromethyl, difluoromethyl, trifluoromethoxy, difluoromethoxy, trifluoromethyl thiogroup, or difluoromethyl thiogroup, with fluorine atom, trifluoromethyl, or trifluoromethoxy being more preferred. When e2 is 2, 3, or 4, each Rf7 can be the same or different.

[0369] In formula (c4), R33 is a halogen atom other than fluorine, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given as those illustrated in the explanation of formula (1) where the hydrocarbon group is represented by R1, but are not limited thereto. Furthermore, when e3 is 2, 3, or 4, each R33 can be the same or different from the others.

[0370] Furthermore, when e3 is 2, 3, or 4, multiple R33 atoms can also bond to each other and form a ring together with the carbon atoms they are bonded to. Specific examples of the rings formed in this case include: cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, 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.

[0371] Specific examples of the anion of the repeating unit c2 can be listed below, but are not limited thereto. Additionally, in the following formula, RA is the same as described above, and Me is a methyl group. [Chemistry 287]

[0372] [Chemical 288]

[0373] [Chemistry 289]

[0374] [Chemical 290]

[0375] [Chemistry 291]

[0376] [Chemistry 292]

[0377] [Chemical 293]

[0378] [Chemical 294]

[0379] [Chemical 295]

[0380] [Chemistry 296]

[0381] [Chemistry 297]

[0382] [Chemical 298]

[0383] [Chemistry 299]

[0384] Specific examples of anions in the repeating unit c3 can be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 300]

[0385] [Chemical 301]

[0386] [Chemical 302]

[0387] [Chemical 303]

[0388] [Chemical 304]

[0389] [Chemical 305]

[0390] [Chemical 306]

[0391] [Chemical 307]

[0392] [Chemical 308]

[0393] [Chemical 309]

[0394] [Chemical 310]

[0395] Specific examples of anions in the repeating unit c4 can be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 311]

[0396] [Chemical 312]

[0397] [Chemical 313]

[0398] [Chemical 314]

[0399] [Chemical 315]

[0400] [Chemical 316]

[0401] [Chemical 317]

[0402] [Chemical 318]

[0403] [Chemical 319]

[0404] [Chemical 320]

[0405] [Chemical 321]

[0406] [Chemical 322]

[0407] [Chemical 323]

[0408] [Chemical 324]

[0409] [Chemical 325]

[0410] [Chemistry 326]

[0411] [Chemistry 327]

[0412] Specific examples of anions in the repeating unit c5 can be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 328]

[0413] In formulas (c2) to (c5), A+ is a monium cation. The aforementioned monium cations can be listed as: strontium cations, monium cations, ammonium cations, etc., and strontium cations and monium cations are preferred. Specific examples of the aforementioned strontium cation ions may be listed, such as those exemplified as strontium cation ions in formula (A), 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 No. 7491173, but are not limited thereto.

[0414] Furthermore, the aforementioned strontium cation should also be represented by the following formula (sulfo-1). [Chemical Engineering 329]

[0415] In formula (sulfo-1), f1 is 0 or 1. When f1 is 0, it is a benzene ring; when f1 is 1, it is a naphthalene ring. Considering solvent solubility, it is preferable to have a benzene ring with f1 = 0. f2 is 0 or 1. When f2 is 0, it is a benzene ring; when f2 is 1, it is a naphthalene ring. Considering solvent solubility, it is preferable to have a benzene ring with f2 = 0. f3 is 0 or 1. When f3 is 0, it is a benzene ring; when f3 is 1, it is a naphthalene ring. Considering solvent solubility, it is preferable to have a benzene ring with f3 = 0.

[0416] 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 there is a concern that it will become less solvent-soluble and precipitate in the inhibitor composition. Therefore, f4 should preferably be 0, 1, 2 or 3, with 0, 1 or 2 being more preferred.

[0417] In formula (sulfo-1), f5 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, f5 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being more preferred. f6 is 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, f6 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being more preferred. f7 is 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, f7 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being more preferred.

[0418] In formula (sulfo-1), f8 is 0, 1, or 2. From the perspective of raw material availability, f8 should preferably be 0 or 1. f9 is 0, 1, or 2. From the perspective of raw material availability, f9 should preferably be 0 or 1. f10 is 0, 1, or 2. From the perspective of raw material availability, f10 should preferably be 0 or 1.

[0419] In formula (sulfo-1), f11 is 0 or 1. When f11 is 0, it is a benzene ring; when f11 is 1, it is a naphthalene ring. Considering the solubility of the solvent, it is preferable to have a benzene ring with f11 of 0.

[0420] 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 there is a concern that it will become less solvent-soluble and precipitate in the inhibitor composition. Therefore, f12 is preferably 0, 1, 2 or 3, with 0, 1 or 2 being more preferred.

[0421] In formula (sulfo-1), f13 is 0, 1, or 2. From the perspective of obtaining raw materials, f13 should preferably be 0 or 1. f14 is 0, 1, or 2. From the perspective of synthesis, f14 should preferably be 0 or 1.

[0422] However, when f1 is 0, 0 ≦ f6 + f9 ≦ 4; when f1 is 1, 0 ≦ f6 + f9 ≦ 6. When f2 is 0, 0 ≦ f7 + f10 ≦ 4; when f2 is 1, 0 ≦ f7 + f10 ≦ 6. When f3 is 0, 1 ≦ f4 + f5 + f8 + f14 ≦ 4; when f3 is 1, 1 ≦ f4 + f5 + f8 + f14 ≦ 6. When f11 is 0, 0 ≦ f12 + f13 ≦ 4; when f11 is 1, 0 ≦ f12 + f13 ≦ 6. Also, f4 + f12 ≧ 1.

[0423] In formula (sulfo-1), RF1 to RF3 are independently fluorine atoms, fluorinated saturated hydrocarbon groups with 1 to 6 carbon atoms, fluorinated saturated hydrocarbon group oxy groups with 1 to 6 carbon atoms, or fluorinated saturated hydrocarbon group thio groups with 1 to 6 carbon atoms. Among them, trifluoromethyl, trifluoromethoxy, and trifluorothiomethoxy are preferred. When f5 is 2, 3, or 4, each RF1 can be the same or different from each other; when f6 is 2, 3, 4, 5, or 6, each RF2 can be the same or different from each other; when f7 is 2, 3, 4, 5, or 6, each RF3 can be the same or different from each other.

[0424] In formula (sulfo-1), Rct1 to Rct4 are halogen atoms other than iodine and fluorine atoms, nitro, cyano, or hydrocarbon groups with 1 to 20 carbon atoms containing heteroatoms, hydrocarbon oxygen groups with 1 to 20 carbon atoms containing heteroatoms, or hydrocarbon thio groups with 1 to 20 carbon atoms containing heteroatoms. The hydrocarbon groups, hydrocarbon oxygen groups, and hydrocarbon thio groups mentioned above can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given as the same examples as those exemplified in the description of formula (1) where the hydrocarbon group is represented by R1. Furthermore, some or all of the hydrogen atoms in the hydrocarbon group, hydrocarbon oxygen group, and hydrocarbon sulfur group can be replaced by a group containing heteroatoms such as oxygen atom, sulfur atom, nitrogen atom, and halogen atom. Also, some of the -CH2- group in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atom, sulfur atom, and nitrogen atom. As a result, it can also contain hydroxyl group, cyano group, fluorine atom, chlorine atom, bromine atom, iodine atom, carbonyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulfonolactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl group, etc.

[0425] Furthermore, when f8 is 2, the two Rct1s can be identical or dissimilar, and the two Rct1s can also bond to each other and form a ring together with the carbon atoms they are bonded to. When f9 is 2, the two Rct2s can be identical or dissimilar, and the two Rct2s can also bond to each other and form a ring together with the carbon atoms they are bonded to. When f10 is 2, the two Rct3s can be identical or dissimilar, and the two Rct3s can also bond to each other and form a ring together with the carbon atoms they are bonded to. When f13 is 2, the two Rct4s can be identical or dissimilar, and the two Rct4s can also bond to each other and form a ring together with the carbon atoms they are bonded to. 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 groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- in the aforementioned ring can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, 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.

[0426] Furthermore, the aromatic rings of S+ directly bonded to the strontium 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 structure can be listed in the following formulas, etc. [Chemical 330] In the formula, the dashed lines represent atomic bonds.

[0427] In formula (sulfo-1), LC and LD are independently single bonds, ether bonds, ester bonds, amide bonds, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Among them, LC is preferably a single bond, ether bond, ester bond, or sulfonate bond, with ester bonds or sulfonate bonds being more preferred. LD is preferably a single bond, ether bond, or ester bond, with single bonds being more preferred.

[0428] In formula (sulfo-1), XL is a single bond, or may contain a heteroatom with 1 to 40 carbon atoms in an alkyl group. The aforementioned alkyl group can be straight-chain, branched, or cyclic, and specific examples include: alkyl diel, cyclic saturated alkyl group, alkyl aryl, etc. Specific examples of the aforementioned heteroatom include: oxygen atom, nitrogen atom, sulfur atom, etc.

[0429] XL can also contain alkyl groups with 1 to 40 carbon atoms, and specific examples are shown below, but are not limited to these. Additionally, in the following formula, * represents atomic bonds with LC and LD, respectively. [Chemistry 331]

[0430] [Chemistry 332]

[0431] [Chemistry 333]

[0432] [Chemistry 334]

[0433] Among them, the most suitable are XL-0~XL-22, XL-29~XL-34, and XL-47~XL-58.

[0434] The strontium cation represented by formula (sulfo-1) should preferably be represented by the following formula (sulfo-1-1). [Chemical 335] In the formula, f4~f10, f12~f14, RF1~RF3, Rct1~Rct4, LC, LD and XL are the same as those mentioned above.

[0435] The strontium cation represented by formula (sulfo-1-1) is preferably represented by formula (sulfo-1-2). [Chemical 336] In the formula, f4~f10, RF1~RF3 and Rct1~Rct3 are the same as those mentioned above.

[0436] Specific examples of strontium cations represented by formula (sulfo-1) are shown below, but are not limited thereto. Additionally, in the following formula, Me is a methyl group. [Chemical 337]

[0437] [Chemistry 338]

[0438] [Chemistry 339]

[0439] [Chemistry 340]

[0440] [Chemistry 341]

[0441] [Chemistry 342]

[0442] [Chemistry 343]

[0443] [Chemistry 344]

[0444] [Chemistry 345]

[0445] [Chemistry 346]

[0446] [Chemistry 347]

[0447] [Chemistry 348]

[0448] [Chemistry 349]

[0449] [Chemical 350]

[0450] [Chemistry 351]

[0451] [Chemistry 352]

[0452] [Chemistry 353]

[0453] [Chemistry 354]

[0454] [Chemistry 355]

[0455] [Chemistry 356]

[0456] [Chemistry 357]

[0457] [Chemistry 358]

[0458] [Chemistry 359]

[0459] [Chemistry 360]

[0460] [Chemistry 361]

[0461] [Chemistry 362]

[0462] [Chemistry 363]

[0463] [Chemistry 364]

[0464] Specific examples of the aforementioned cations can be cited in paragraph

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

[0465] Specific examples of the aforementioned ammonium cation can be exemplified by the following formula (am-1). [Chemical 365] 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 also bond to each other and form a ring together with the nitrogen atom to which they are bonded. Specific examples of the aforementioned hydrocarbons can be exemplified by the same type as the hydrocarbon represented by R1 in the explanation of formula (1A).

[0466] Specific examples of ammonium cations represented by formula (am-1) can be listed below, but are not limited to these. [Chemistry 366]

[0467] The specific structures of the repeating units c1~c5 can be listed as any combination of the aforementioned anions and cations.

[0468] 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 generated acid, repeating units c2, c4 and c5 are even better. Considering the solvent solubility, repeating unit c2 is even better.

[0469] The aforementioned basic polymer may also contain repeating units (hereinafter also referred to as repeating units d) with a structure in which hydroxyl groups are protected by acid-indestructible groups. If repeating unit d has one or more hydroxyl groups protected, and the protecting group decomposes and generates hydroxyl groups due to acid action, there are no particular restrictions, and it is preferable to be represented by the following formula (d1). [Chemistry 367] In formula (d1)

[0470] , RA is the same as described above. R41 is a (g+1) valence hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. R42 is an acid-labile group. g is 1, 2, 3, or 4.

[0471] In formula (d1), R42 represents an acid-indestructible group that is deprotected by the acid and produces a hydroxyl group. The structure of R42 is not particularly limited; it is preferably an acetal, ketal, alkoxycarbonyl, or an alkoxymethyl group represented by formula (d2), with an alkoxymethyl group represented by formula (d2) being particularly preferred. [Chemical 368] In the formula, * represents an atomic bond. R43 is a hydrocarbon group with 1 to 15 carbon atoms.

[0472] Specific examples of the acid unstable group represented by R42, the alkoxymethyl group represented by formula (d2), and the repeating unit d can be listed as examples similar to those illustrated in the description of the repeating unit d described in Japanese Patent Application Publication No. 2020-111564.

[0473] The aforementioned basic polymer may also contain repeating unit e derived from indene, benzofuran, benzothiophene, acenaphthene, crromone, coumarin, norcamphorne, or derivatives thereof. Specific examples of monomers providing repeating unit e are listed below, but are not limited thereto. [Chem. 369]

[0474] The aforementioned base polymer may also contain repeating units f derived from dihydroindene, vinylpyridine, or vinylcarbazole.

[0475] In the polymer of the present invention, the content ratio of repeating units a1, a2, a3, b1, b2, c1, c2, c3, c4, d, e and f is preferably 0≦a1≦0.8, 0≦a2≦0.8, 0≦a3≦0.6, 0≦b1≦0.8, 0≦b2≦0.5, 0≦c1≦0.4, 0≦c2≦0.4, 0≦c3≦0.4, 0≦c4≦ 0.4, 0≦d≦0.3, 0≦e≦0.3, and 0≦f≦0.3 are better than 0≦a1≦0.7, 0≦a2≦0.7, 0≦a3≦0.5, 0≦b1≦0.7, 0≦b2≦0.4, 0≦c1≦0.3, 0≦c2≦0.3, 0≦c3≦0.3, 0≦c4≦0.3, 0≦d≦0.2, 0≦e≦0.2, and 0≦f≦0.2. However, a1+a2+a3+b1+b2+c1+c2+c3+c4+d+e+f≦1.0.

[0476] The weight-average molecular weight (Mw) of the aforementioned polymer is preferably 1,000 to 500,000, and more preferably 3,000 to 100,000. If Mw is within this range, sufficient etch resistance can be obtained, and there is no concern that the difference in dissolution rate before and after exposure may lead to a decrease in resolution. In addition, in this invention, Mw is a polystyrene conversion value determined by gel permeation chromatography (GPC) using THF or N,N-dimethylformamide (DMF) as a solvent.

[0477] Furthermore, regarding the aforementioned molecular weight distribution (Mw / Mn) of the polymer, the influence of Mw / Mn tends to increase as the pattern becomes more regular and refined. Therefore, in order to obtain a resist composition that can be ideally used for fine pattern sizes, Mw / Mn should preferably be a narrow dispersion of 1.0 to 2.0. If it is within the above range, there will be fewer low-molecular-weight and high-molecular-weight polymers, and there will be no concern about foreign matter being observed on the pattern after exposure or the shape of the pattern deteriorating.

[0478] When synthesizing the aforementioned polymer, for example, the monomer that provides the aforementioned repeating unit can be polymerized by adding a free radical polymerization initiator to an organic solvent and heating it.

[0479] 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), γ-butyrolactone (GBL), etc. Specific examples of polymerization initiators include: 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl-2,2-azobis(2-methylpropionate), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, lauryl peroxide, etc. The amount of these initiators added relative to the total amount of monomers used in polymerization should preferably be 0.01~25 moles. The reaction temperature should preferably be 50~150℃, preferably 60~100℃. The reaction time should be 2 to 24 hours, but considering production efficiency, 2 to 12 hours is even better.

[0480] The aforementioned polymerization initiator can be added to the aforementioned monomer solution to supply to the reactor, or a different initiator solution can be prepared and supplied to the reactor separately. Since there is a possibility that free radicals generated from the initiator may cause the polymerization reaction to proceed and generate ultra-high molecular weight polymers during the standby time, from a quality management perspective, the monomer solution and initiator solution should preferably be prepared separately and added 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 in combination. In this case, the amount of these chain transfer agents added relative to the total amount of monomers used to polymerize should preferably be 0.01 to 20 mol%.

[0481] In the case of monomers containing hydroxyl groups, the hydroxyl groups can be replaced with acetal groups such as ethoxyethoxy that are easily deprotected by acid during polymerization, and deprotection can be carried out using weak acid and water after polymerization. Alternatively, acetyl, methyl, trimethylacetyl, etc. can be used for replacement first, and alkaline hydrolysis can be carried out after polymerization.

[0482] When copolymerizing hydroxystyrene or hydroxyvinyl naphthalene, hydroxystyrene or hydroxyvinyl naphthalene can be copolymerized with other monomers in an organic solvent by adding a free radical polymerization initiator and heating. Alternatively, acetostyrene or acetovinyl naphthalene can be used, and after polymerization, the acetosyl group can be deprotected by alkaline hydrolysis to obtain polyhydroxystyrene or hydroxyvinyl naphthalene.

[0483] The alkali used in alkaline hydrolysis can be ammonia, triethylamine, etc. Furthermore, the reaction temperature should preferably be -20~100℃, with 0~60℃ being more preferable. The reaction time should preferably be 0.2~100 hours, with 0.5~20 hours being more preferable.

[0484] In addition, the amount of each monomer in the aforementioned monomer solution can be appropriately set, for example, in a manner that makes it an ideal content ratio for the aforementioned repeating unit.

[0485] Regarding the polymer obtained by the aforementioned manufacturing method, the reaction solution obtained by the polymerization reaction can be used as the final product, or the powder obtained by purification steps such as adding the polymer solution to a poor solvent to obtain the powder can be used as the final product. Considering the viewpoints of work efficiency and quality stability, it is advisable to use the polymer solution obtained by dissolving the powder obtained by the purification step into a solvent as the final product.

[0486] Specific examples of the solvents used at this time can be cited from paragraphs

[0144] to

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

[0487] In the aforementioned polymer solution, the concentration of the polymer is preferably 0.01 to 30% by mass, and more preferably 0.1 to 20% by mass.

[0488] The aforementioned reaction solutions and polymer solutions should be filtered. By filtering, foreign matter and gel that could be the cause of defects can be removed, which is effective in stabilizing quality.

[0489] The materials used in the aforementioned filters can be listed as follows: fluorocarbon, cellulose, nylon, polyester, hydrocarbon, etc. For filtration steps involving inhibitor components, filters made of fluorocarbon (such as Teflon, a registered trademark), polyethylene, polypropylene, or nylon are preferable. The pore size of the filter can be appropriately selected according to the target cleanliness level, preferably below 100 nm, and even better if below 20 nm. Furthermore, these filters can be used individually or in combination. The filtration method can be to pass the solution only once, but it is better to circulate the solution and perform multiple filtrations. The filtration steps can be performed in any order and number of times during the polymer manufacturing process, preferably filtering the reaction solution after the polymerization reaction, the polymer solution, or both.

[0490] (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) in addition to the aforementioned polymers, the base polymer may also contain hydrides of ring-opening metathesis polymers, in which case the polymers described in Japanese Patent Application Publication No. 2003-66612 may be used.

[0491] [(C) Organic Solvent] The chemical amplification inhibitor composition of the present invention may also contain an organic solvent as component (C). There are no particular limitations on whether the organic solvent (C) is capable of dissolving the aforementioned components and the components described below. Specific examples of such organic solvents include: ketones such as cyclopentanone, cyclohexanone, and methyl-2-n-pentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ketols such as DAA; ethers such as PGME, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tributyl acetate, tributyl propionate, and propylene glycol monotert-butyl ether acetate; lactones such as GBL; and their mixed solvents.

[0492] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, cyclohexanone, GBL, DAA and their mixtures are particularly good at dissolving the base polymer of component (B).

[0493] 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 to 5000 parts by mass, and more preferably 400 to 3500 parts by mass. (C) Organic solvent can be used alone or in combination with two or more types.

[0494] [(D) Photoacid Generator] The chemical amplification inhibitor composition of the present invention may also contain a photoacid generator as component (D). There are no particular limitations if the aforementioned photoacid generator is a compound that produces an acid with a stronger acid strength than the sulfonic acid produced by the quencher of component (A) when irradiated by high-energy rays.

[0495] Ideal photoacid generators can be represented by formulas (2) or (3). [Chemistry 370]

[0496] In formula (2), R101 to R105 are each independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. Furthermore, any two of R101, R102, and R103 may bond to each other and form a ring together with the sulfur atoms they are bonded to. Specific examples of the aforementioned hydrocarbon groups can be given as examples of hydrocarbon groups represented by R1 in the explanation of formula (1A).

[0497] Specific examples of strontium salt cations represented by formula (2) can be listed; examples of strontium cations in formula (1A) include 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, those described in paragraphs

[0035] to

[0046] of Japanese Patent Application Publication No. 7491173, and examples of strontium cations in formula (d3), but are not limited thereto. Specific examples of monazite salt cations represented by formula (3) can be listed in paragraph

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

[0498] In formulas (2) and (3), Xa- is the anion of a strong acid. Specific examples of the anions of the aforementioned strong acids can be listed as any of the examples represented by formulas (c1-1) to (c1-5).

[0499] Also, the photoacid generator of component (D) should preferably be represented by the following formula (4). [Chemistry 371]

[0500] In formula (4), R201 and R202 are each independently a hydrocarbon group with 1 to 30 carbon atoms that may also contain heteroatoms. R203 is an extended hydrocarbon group with 1 to 30 carbon atoms that may also contain heteroatoms. Furthermore, any two of R201, R202 and R203 may bond to each other and form a ring together with the sulfur atoms they are bonded to.

[0501] The hydrocarbon groups represented by R201 and R202 with 1 to 30 carbon atoms can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, tertiary butyl, tertiary pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, etc., alkyl groups with 1 to 30 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornel, oxanorbornel, tricyclic [5]. 2.1.02,6] Decyl, adamantyl, and other cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms; phenyl, tolyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, secondary butylphenyl, tertiary butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, secondary butylnaphthyl, tertiary butylnaphthyl, anthracene, and other aryl groups with 6 to 30 carbon atoms; and groups obtained by combining them. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- group in the aforementioned hydrocarbon group may also be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0502] R203 indicates that the hydrocarbon group with 1 to 30 carbon atoms 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. Alkyl groups with 1 to 30 carbon atoms, such as heptadecanyl-1,17-diyl; cyclic saturated alkyl groups with 3 to 30 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norcamphenediyl, and adamantanediyl; and aryl groups, such as methyl aryl, ethyl aryl, n-propyl aryl, isopropyl aryl, n-butyl aryl, isobutyl aryl, dibutyl aryl, tertiary aryl, naphthyl, methyl aryl, ethyl aryl, n-propyl aryl, isopropyl aryl, n-butyl aryl, isobutyl aryl, dibutyl aryl, and tertiary aryl. 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, and a portion of the -CH2- group in the aforementioned alkyl group can also be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This can result in the presence of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride (-C(=O)-OC(=O)-), or haloalkyl groups. The aforementioned heteroatoms should preferably be oxygen atoms.

[0503] In formula (4), L21 is a single bond, an ether bond, or may contain a heteroatom of 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 and illustrated by examples of extended hydrocarbon groups represented by R203.

[0504] In formula (4), Xa, Xb, Xc and Xd are each independently a hydrogen atom, a fluorine atom or a trifluoromethyl atom. However, at least one of Xa, Xb, Xc and Xd is a fluorine atom or a trifluoromethyl atom.

[0505] The photoacid generator represented by formula (4) should preferably be represented by the following formula (4'). [Chemistry 372]

[0506] In formula (4'), 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 hydrogen atoms, or may contain a hydrocarbon group 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 can be listed and illustrated as hydrocarbon groups represented by Rfa1 in formula (c1-1-1). x2 and y2 are each independently 0, 1, 2, 3, 4, or 5, and z2 is 0, 1, 2, 3, or 4.

[0507] Specific examples of photoacid generating agents represented by formula (4) can be cited as examples of photoacid generating agents represented by formula (2) in Japanese Patent Application Publication No. 2017-26980.

[0508] Among the aforementioned photoacid generators, those containing anions represented by formula (c1-1-1) or (c1-4) exhibit low acid diffusion and excellent solubility in solvents, making them particularly ideal. Furthermore, those represented by formula (4') exhibit extremely low acid diffusion, making them particularly ideal.

[0509] When the chemical amplification inhibitor composition of the present invention contains (D) a photoacid generating agent, its content relative to 80 parts by mass of (B) the base polymer is preferably 0.1 to 40 parts by mass, and more preferably 0.5 to 20 parts by mass. If the amount of (D) photoacid generating agent added is within the aforementioned range, the resolution is good, and there is no concern about the generation of foreign matter after the inhibitor film is developed or during peeling, which is ideal. (D) A photoacid generating agent can be used alone or in combination of two or more.

[0510] [(E) Other quenching agents] The chemical amplification inhibitor composition of the present invention may also contain quenching agents other than component (A) (hereinafter also referred to as other quenching agents) as component (E).

[0511] Specific examples of other quenching agents for component (E) can be listed as onion salts represented by formula (5) or (6). [Chemistry 373]

[0512] In formula (5), Rq1 is a hydrogen atom, or may contain a hydrocarbon group with 1 to 40 carbon atoms containing heteroatoms, except that the hydrogen atom of the carbon atom bonded to the α position of the sulfonyl group is replaced by a fluorine atom or a fluoroalkyl group. In formula (6), Rq2 is a hydrogen atom, or may contain a hydrocarbon group with 1 to 40 carbon atoms containing heteroatoms.

[0513] Rq1 represents hydrocarbon groups with 1 to 40 carbon atoms, specifically including: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, tertiary butyl, n-pentyl, tertiary pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, etc., alkyl groups with 1 to 40 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclo[5.2.1.02,6]decyl, adamantyl, etc., cyclic saturated hydrocarbon groups with 3 to 40 carbon atoms; phenyl, naphthyl, anthracene, etc., aryl groups with 6 to 40 carbon atoms, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- in the aforementioned hydrocarbon group may also be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it 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, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0514] Specific examples of the hydrocarbon group represented by Rq2 can be listed as substituents that are specific examples of Rq1. In addition, examples can also be listed as: fluorinated saturated hydrocarbon groups such as trifluoromethyl and trifluoroethyl, or fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

[0515] Specific examples of the anions of the onium salts represented by formula (5) are shown below, but are not limited thereto. [Chemistry 374]

[0516] [Chemistry 375]

[0517] [Chemistry 376]

[0518] [Chemistry 377]

[0519] Specific examples of the anions of onium salts represented by formula (6) are shown below, but are not limited thereto. [Chemistry 378]

[0520] [Chemistry 379]

[0521] [Chemical 380]

[0522] In formulas (5) and (6), Mq+ is an onium cation. Examples of the aforementioned onium cations include: strontium cation, monium cation, ammonium cation, etc. Specific examples of the aforementioned strontium cations include: examples of strontium cations in formula (A), paragraphs

[0102] to

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

[0044] to

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

[0035] to

[0046] of Japanese Patent Application Publication No. 7491173, examples of strontium cations in formula (d3), etc., but are not limited to these. Specific examples of monium cations include: 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 listed, such as examples of ammonium cations represented by formula (am-1).

[0523] Specific examples of onium salts represented by formulas (5) and (6) can be listed as any combination of the aforementioned anions and cations. Furthermore, these onium salts are easily prepared by ion exchange reactions using conventional organic chemical methods. For example, Japanese Patent Application Publication No. 2007-145797 can be consulted regarding ion exchange reactions.

[0524] The onium salts represented by formulas (5) and (6) function as quenchers in the chemical amplification inhibitor composition of the present invention. This is because the relative anions of the aforementioned onium salts are conjugate bases of weak acids. Here, "weak acid" means an acidity that cannot deprotect the acid unstable group of the unit containing the acid unstable group used in the base polymer. When the onium salts represented by formulas (5) and (6) are used in combination with onium salt-type photoacid generators that have a conjugate base of a strong acid such as sulfonic acid as a relative anion, they function as quenchers. That is, when onium salts that produce strong acids such as sulfonic acid are mixed with onium salts that produce weak acids such as carboxylic acids, if the strong acid generated from the photoacid generator due to high-energy radiation irradiation collides with the unreacted onium salt with a weak acid anion, the weak acid will be released through salt exchange, and an onium salt with a strong acid anion will be generated. During this process, the strong acid is exchanged for a weak acid with low catalytic ability, so it appears as if the acid is deactivated, thus allowing for the control of acid diffusion.

[0525] Furthermore, other quenching agents for component (E) may also be onium salts having strontium cations and benzene oxide anions within the same molecule as described in Japanese Patent No. 6848776. In addition, onium salts having strontium cations and carboxylate anions within the same molecule as described in Japanese Patent No. 6583136, Japanese Patent Application Publication No. 2020-200311, and onium salts having monium cations and carboxylate anions within the same molecule as described in Japanese Patent No. 6274755 may also be used.

[0526] Here, it is believed that when the photoacid generator that produces strong acids is an onium salt, the strong acid produced by high-energy ray irradiation, as mentioned above, can be exchanged into a weak acid. On the other hand, the weak acid produced by high-energy ray irradiation is not easily exchanged with the unreacted onium salt that produces strong acids. This is because onium cations are more likely to form ion pairs with the anions of strong acids.

[0527] When the chemical amplification inhibitor composition of the present invention contains an onium salt represented by formula (5) or (6) as another quencher of component (E), 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 type quencher is within the aforementioned range, the resolution is good and the sensitivity will not be significantly reduced, which is ideal. The onium salt represented by formula (5) or (6) can be used alone or in combination of two or more.

[0528] The chemical amplification inhibitor composition of the present invention may also contain other quenching agents as nitrogen-containing compounds as component (E). Specific examples of the aforementioned nitrogen-containing compounds include: first-, second-, or third-order amine compounds described in paragraphs

[0146] to

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

[0529] Alternatively, strontium sulfonate salts with nitrogen-containing substituents can be used as nitrogen-containing compounds. Such compounds function as quenchers in unexposed areas, but lose their quenching ability in exposed areas due to neutralization with the acid they generate, thus functioning as so-called photodegrading bases. By using photodegrading bases, the contrast between exposed and unexposed areas can be enhanced. For example, Japanese Patent Application Publication No. 2009-109595 and Japanese Patent Application Publication No. 2012-46501 can be referenced for photodegrading bases.

[0530] When the chemical amplification inhibitor composition of the present invention contains a nitrogen-containing compound as another quencher in component (E), its content relative to 80 parts by mass of the base polymer (B) 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.

[0531] [(F) Surfactant] The chemical amplification inhibitor composition of the present invention may further contain a surfactant as component (F). The surfactant of component (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.

[0532] Surfactants that are insoluble or sparingly soluble in water and alkaline developing solutions, among the surfactants described in the aforementioned announcement, are preferably FC-4430 (manufactured by 3M Corporation), SURFLON (registered trademark) S-381 (manufactured by AGC SEIMI CHEMICAL), OLFINE (registered trademark) E1004 (manufactured by Nissin Chemical Industry Co., Ltd.), KH-20, KH-30 (manufactured by AGC SEIMI CHEMICAL), and oxane ring-opening polymers represented by the following formula (surf-1), etc. [Chemical 381]

[0533] Here, R, Rf, A, B, C, m, and n are not related to the foregoing description, but are only applicable to formula (surf-1). R is an aliphatic group with 2 to 5 carbon atoms in a 2 to 4 valence. Among the aforementioned aliphatic groups, those with a 2 valence can be listed as: ethylenyl, 1,4-butylenyl, 1,2-propylenyl, 2,2-dimethyl-1,3-propylenyl, 1,5-pentylenyl, etc.; those with a 3 or 4 valence can be listed as follows. [Chemical 382] In the formula, the dashed lines represent atomic bonds, which are substructures derived from glycerol, trimethylolethane, trimethylolpropane, and neopentyl tetrol, respectively.

[0534] Among them, 1,4-endobutyl, 2,2-dimethyl-1,3-endopropyl, etc. are preferred.

[0535] Rf is trifluoromethyl or pentafluoroethyl, preferably trifluoromethyl. m is an integer from 0 to 3, n is an integer from 1 to 4, the sum of n and m is the valence of R, and is an integer from 2 to 4. A is 1. B is an integer from 2 to 25, preferably an integer from 4 to 20. C is an integer from 0 to 10, preferably 0 or 1. Furthermore, the arrangement of the constituent units in formula (surf-1) is not specified; they can be block-bonded or random-bonded. For details on the manufacture of surfactants in partially fluorinated oxyheterocyclic butane ring-opening polymer systems, please refer to the specification of US Patent No. 5650483, etc.

[0536] A surfactant that is insoluble or sparingly soluble in water but soluble in alkaline developing solutions can reduce water penetration and leaching in ArF immersion lithography when no resist protective film is used, by aligning it on the surface of the resist film. Therefore, it is useful for inhibiting the leaching of water-soluble components from the resist film and reducing damage to the exposure equipment. Furthermore, it is useful because it is soluble in alkaline aqueous solutions after exposure or post-exposure baking (PEB) and is unlikely to become a foreign substance causing 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 are particularly suitable for those with high water-repellent properties and improved hydrophobicity.

[0537] Specific examples of such polymeric surfactants may be listed as those containing at least one repeating unit selected from any of the following formulas (6A) to (6E). [Chemistry 383]

[0538] In formulas (6A) to (6E), RB is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. W1 is -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 or a fluorinated hydrocarbon group with 1 to 15 carbon atoms, 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 hydrocarbon group or a fluorinated hydrocarbon group with a (u+1) valence of 1 to 20 carbon atoms. u is 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 is a hydrocarbon group or fluorinated hydrocarbon group with 1 to 15 carbon atoms, and an ether bond or carbonyl group may also be inserted between the carbon-carbon bonds.

[0539] The hydrocarbon group represented by Rs1 with 1 to 10 carbon atoms should preferably be a saturated hydrocarbon group, and can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, tertiary butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and cyclic saturated hydrocarbon groups with 3 to 10 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornel. Among these, those with 1 to 6 carbon atoms are preferred.

[0540] The alkyl group represented by Rs2 should preferably be a saturated alkyl group, and can be linear, branched, or cyclic. Specific examples include: methylene, ethyl alkyl, propyl alkyl, butyl alkyl, pentyl alkyl, etc.

[0541] The hydrocarbon group represented by Rs3 or Rs6 can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: saturated hydrocarbon groups; aliphatic unsaturated hydrocarbon groups such as alkenyl and alkynyl groups, which are preferably saturated hydrocarbon groups. In addition to examples of hydrocarbon groups represented by Rs1, specific examples of the aforementioned saturated hydrocarbon groups include: undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, etc. Fluorinated hydrocarbon groups represented by Rs3 or Rs6 can be groups in which one or all of the hydrogen atoms of the carbon atom bonded to the aforementioned hydrocarbon group are replaced by fluorine atoms. As mentioned above, ether bonds or carbonyl groups can also be inserted between their carbon-carbon bonds.

[0542] Specific examples of acid-instable groups represented by Rs3 can be listed as follows: groups represented by the aforementioned formulas (AL-3) to (AL-5), trialkylsilyl groups in which each alkyl group has 1 to 6 carbon atoms, and alkyl groups containing side oxygen atoms in which each alkyl group has 4 to 20 carbon atoms.

[0543] The (u+1) valence hydrocarbon group or fluorinated hydrocarbon group represented by Rs4 can be any of the following: straight chain, branched, or cyclic. Specific examples can be listed as groups obtained by further removing u hydrogen atoms from the aforementioned hydrocarbon group or fluorinated hydrocarbon group.

[0544] The fluorinated hydrocarbon group represented by Rsa should preferably be saturated and can be any of the following: straight-chain, branched, or cyclic. Specific examples include those in which one or all of the hydrogen atoms in the aforementioned hydrocarbon groups are replaced by fluorine atoms, such as: trifluoromethyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoro-1-propyl, 3,3,3-trifluoro-2-propyl, 2,2,3,3-tetrafluoropropyl, 1,1,1,3,3,3-hexafluoroisopropyl, 2,2,3,3,4,4,4-heptafluorobutyl, 2,2,3,3,4,4,5,5-octafluoropentyl, 2,2,3,3,4,4,5,5,6,6,7,7-dodecylheptyl, 2-(perfluorobutyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorooctyl)ethyl, 2-(perfluorodecyl)ethyl, etc.

[0545] Specific examples of repeating units represented by any of equations (6A) to (6E) can be listed below, but are not limited thereto. Furthermore, in the following equation, RB is the same as described above. [Chemistry 384]

[0546] [Chemical 385]

[0547] [Chemical 386]

[0548] [Chemical 387]

[0549] [Chemical 388]

[0550] [Chemical 389]

[0551] The aforementioned polymeric surfactant may also contain other repeating units besides those represented by formulas (6A) to (6E). 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 represented by formulas (6A) to (6E) is preferably 20 mol% or more, more preferably 60 mol% or more, and even more preferably 100 mol% among all repeating units.

[0552] 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.

[0553] A method for synthesizing the aforementioned polymeric surfactants can be listed as follows: A monomer containing unsaturated bonds, representing repeating units of formulas (6A) to (6E) and other repeating units as needed, is polymerized 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, dialkylene, etc. Specific examples of polymerization initiators include: AIBN, 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid), benzoyl peroxide, lauryl peroxide, etc. The reaction temperature should preferably be 50~100℃. The reaction time should preferably be 4~24 hours. Acid-unstable groups can be directly introduced into the monomer, or they can be protected or partially protected after polymerization.

[0554] When synthesizing the aforementioned polymeric surfactant, known chain transfer agents such as dodecyl mercaptan and 2-mercaptoethanol may be used to adjust the molecular weight. In this case, the amount of these chain transfer agents added relative to the total number of moles of the monomers that polymerizes them should be 0.01 to 10 moles.

[0555] When the chemical amplification inhibitor composition of the present invention contains 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, it will sufficiently improve the receding contact angle between the inhibitor film surface and water; if it is 50 parts by mass or less, the dissolution rate of the inhibitor film surface to the developer is low, and the height of the formed fine pattern is sufficiently maintained. Surfactant (F) can be used alone or in combination of two or more.

[0556] [(G) Other Components] The chemical amplification inhibitor composition of the present invention may also contain compounds that decompose due to acid and produce acid (acid amplification compounds), organic acid derivatives, fluorinated alcohols, and compounds with a Mw of 3,000 or less whose solubility in the developer changes due to the action of acid (dissolution inhibitors), as other components in (G). The aforementioned acid amplification compounds can be referred to in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608. When containing the aforementioned acid amplification compounds, their content relative to 80 parts by mass of the (B) base polymer is preferably 0 to 5 parts by mass, and more preferably 0 to 3 parts by mass. Excessive content may sometimes make acid diffusion control difficult, leading to degradation of resolution and pattern shape. The aforementioned organic acid derivatives, fluorinated alcohols, and dissolution inhibitors can be referred to the compounds described in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608.

[0557] [Pattern Forming 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 rays, and developing the aforementioned exposed resist film using a developing solution.

[0558] The aforementioned substrate may be, for example, a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective film, etc.) or a substrate for masking circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.).

[0559] The inhibitor film can be formed by, for example, by spin coating or other methods, coating the aforementioned chemical amplification inhibitor composition onto a substrate with a film thickness preferably of 0.05 to 2 μm, and pre-baking it on a heating plate for preferably 60 to 150°C for 1 to 10 minutes, more preferably 80 to 140°C for 1 to 5 minutes.

[0560] Examples of high-energy rays used for exposure of resist films include: KrF excimer laser, ArF excimer laser, EB, EUV, etc. When using KrF excimer laser, ArF excimer laser, or EUV for exposure, it can be carried out by using a mask to form the desired pattern and irradiating with an exposure dose preferably of 1~200 mJ / cm2, and more preferably 10~100 mJ / cm2. When using EB, irradiation is carried out by using a mask to form the desired pattern or directly with an exposure dose preferably of 1~300 μC / cm2, and more preferably 10~200 μC / cm2.

[0561] In addition to the usual exposure method, the exposure can also be performed by an immersion method, in which a liquid with a refractive index of 1.0 or higher is inserted between the resist film and the projection lens. In this case, a protective film that is insoluble in water can also be used.

[0562] The aforementioned water-insoluble protective film is used to prevent leaching from the resist film and to improve the hydrophobicity of the film surface. It is generally divided into two types. One type is an organic solvent-stripping type, which must be stripped using an organic solvent that does not dissolve the resist film before alkaline aqueous solution development. The other type is an alkaline aqueous solution-soluble type, which is soluble in alkaline developing solution and removes the protective film while removing the soluble portion of the resist film. The latter is particularly preferred because it is based on a polymer containing 1,1,1,3,3,3-hexafluoro-2-propanol residues that is insoluble in water but soluble in alkaline developing solution, and is dissolved in alcohol solvents with 4 or more carbon atoms, ether solvents with 8 to 12 carbon atoms, or mixtures thereof. It is also possible to prepare a material by dissolving the aforementioned water-insoluble but alkaline developing solution surfactant in alcohol solvents with 4 or more carbon atoms, ether solvents with 8 to 12 carbon atoms, or mixtures thereof.

[0563] PEB can also be performed after exposure. PEB can be performed, for example, by heating on a hot plate at a temperature of 60-150°C for 1-5 minutes, preferably at 80-140°C for 1-3 minutes.

[0564] Developing is performed using an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) at a concentration of 0.1-5% by mass, preferably 2-3% by mass, and common methods such as dip, immersion, and spray are used. The development time is preferably 0.1-3 minutes, preferably 0.5-2 minutes, so that the exposed part will dissolve and form the desired pattern on the substrate.

[0565] Furthermore, after the resist film is formed, pure water rinsing can be used to extract acid-generating agents from the film surface or to rinse particles. It can also be used to remove water remaining on the film after exposure.

[0566] In addition, a double patterning method can also be used to form patterns. Examples of double patterning methods include: a trench method that uses a first exposure and etching to process a 1:3 trench pattern substrate, then offsets the position and uses a second exposure to form a 1:3 trench pattern, thus forming a 1:1 pattern; and a line method that uses a first exposure and etching to process a 1:3 isolated residual pattern first substrate, then offsets the position and uses a second exposure to form a 1:3 isolated residual pattern under the first substrate, and processes this second substrate to form a 1:1 pattern with a pitch of half.

[0567] In the pattern forming method of the present invention, a negative tone development method can also be used, in which the aforementioned alkaline aqueous solution is replaced with an organic solvent as the developer to dissolve the unexposed area.

[0568] In the aforementioned organic solvent development, the developing solution may include: 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methyl acetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl valerate, crotonic acid. Methyl ester, ethyl crotonate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, ethyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in combination of two or more. [Example]

[0569] Hereinafter, the present invention will be specifically described by way of example synthesis, examples, and comparative examples, but the present invention is not limited to the following examples. Furthermore, the apparatus used is as follows: • MALDI TOF-MS: Nippon Electronics Co., Ltd. S3000

[0570] [1] Synthesis of Onium Salts [Example 1-1] Synthesis of Onium Salt PDQ-1 [Chemical 390]

[0571] (1) Synthesis of onium salt PDQ-1: Under nitrogen atmosphere, SM-1 (4.0 g), sodium bicarbonate (1.0 g), and water (20 g) were mixed in a reaction vessel and stirred at an internal temperature of 45°C for 1 hour. Subsequently, the reaction solution was cooled to room temperature, and SM-2 (15.0 g, equivalent to 0.012 mol) and methyl isobutyl ketone (30 g) were added, and the mixture was stirred at room temperature for 30 minutes. After stirring, the organic layer was separated and washed with water, and then concentrated under reduced pressure. The concentrate was purified by silica gel chromatography, thereby obtaining 5.9 g of the target product, onium salt PDQ-1 (yield 86%), in the form of an oil.

[0572] The TOF-MS results of PDQ-1 are shown below. MALDI TOF-MS: POSITIVE M+288 (equivalent to C19H14NS+) NEGATIVE M-403 (equivalent to C8H5I2O3-)

[0573] [Examples 1-2~1-7] Synthesis of Onium Salts PDQ-2~PDQ-7: Onium salts PDQ-2~PDQ-7 were synthesized using corresponding raw materials and known organic chemical reactions. [Chemical 391]

[0574] [Synthesis Example] The monomers of the basic polymers (polymers P-1 to P-5) were combined and copolymerized in MEK as a solvent. The mixture was then placed in hexane, and the precipitated solids were washed with hexane, separated, and dried to obtain the basic polymers (polymers P-1 to 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: DMF, standard: polystyrene). [Chem. 392]

[0575] [3] Preparation of chemical amplification inhibitor composition [Examples 2-1~2-30, Comparative Examples 1-1~1-20] The quenchers of the present invention (PDQ-1~PDQ-7), comparative quenchers (PDQ-A~PDQ-D), photoacid generators (PAG-X, PAG-Y), base polymers (P-1~P-5) and other quenchers (AQ-1, AQ-2) were dissolved in a solvent containing 0.01% by mass of surfactant A (OMNOVA) according to the compositions shown in Tables 1 and 2 below to prepare a solution. The solution was filtered through a 0.2 μm Teflon (registered trademark) type filter to obtain chemical amplification inhibitor compositions (R-1~R-30 and CR-1~CR-20).

[0576] [Table 1] inhibitor Composition Base polymer (parts by weight) Quenching agent (parts by weight) Photoacid generator (parts by weight) other 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) PDQ-1(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Example 2-2 R-2 P-1(80) PDQ-2(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Example 2-3 R-3 P-1(80) PDQ-3(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Examples 2-4 R-4 P-1(80) PDQ-4(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Examples 2-5 R-5 P-1(80) PDQ-5(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Examples 2-6 R-6 P-1(80) PDQ-6(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Examples 2-7 R-7 P-1(80) PDQ-7(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Examples 2-8 R-8 P-1(80) PDQ-1(5) PAG-Y(15) - PGMEA(2250) EL(2800) DAA(550) Examples 2-9 R-9 P-1(80) PDQ-1(2.5) PAG-X(15) AQ-1(2.5) PGMEA(2250) EL(2800) DAA(550) Example 2-10 R-10 P-1(80) PDQ-2(3) PAG-Y(15) AQ-2(2) PGMEA(2250) EL(2800) DAA(550) Example 2-11 R-11 P-2(80) PDQ-1(5) PAG-X(14) - PGMEA(2250) EL(2800) DAA(550) Example 2-12 R-12 P-2(80) PDQ-2(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Example 2-13 R-13 P-2(80) PDQ-4(5) PAG-Y(14) - PGMEA(2250) EL(2800) DAA(550) Example 2-14 R-14 P-2(80) PDQ-6(5) PAG-Y(15) - PGMEA(2250) EL(2800) DAA(550) Example 2-15 R-15 P-2(80) PDQ-1(4) PAG-X(15) AQ-1(2) PGMEA(2250) EL(2800) DAA(550) Example 2-16 R-16 P-3(80) PDQ-1(5) - - PGMEA(2250) EL(2800) DAA(550) Example 2-17 R-17 P-3(80) PDQ-2(5) - - PGMEA(2250) EL(2800) DAA(550) Example 2-18 R-18 P-3(80) PDQ-3(5) - - PGMEA(2250) EL(2800) DAA(550) Example 2-19 R-19 P-3(80) PDQ-4(5) PAG-X(5) - PGMEA(2250) EL(2800) DAA(550) Example 2-20 R-20 P-3(80) PDQ-2(3) - AQ-1(2) PGMEA(2250) EL(2800) DAA(550) Example 2-21 R-21 P-4(80) PDQ-1(5) - - PGMEA(2250) EL(2800) DAA(550) Example 2-22 R-22 P-4(80) PDQ-2(5) - - PGMEA(2250) EL(2800) DAA(550) Example 2-23 R-23 P-4(80) PDQ-5(5) - - PGMEA(2250) EL(2800) DAA(550) Example 2-24 R-24 P-4(80) PDQ-6(6) PAG-Y(5) - PGMEA(2250) EL(2800) DAA(550) Example 2-25 R-25 P-4(80) PDQ-2(5) - - PGMEA(2250) EL(2800) DAA(550) Example 2-26 R-26 P-5(80) PDQ-1(5) - - PGMEA(2250) EL(2800) DAA(550) Example 2-27 R-27 P-5(80) PDQ-2(5) - - PGMEA(2250) EL(2800) DAA(550) Example 2-28 R-28 P-5(80) PDQ-7(3) PAG-Y(5) AQ-2(2) PGMEA(2250) EL(2800) DAA(550) Example 2-29 R-29 P-5(80) PDQ-3(5) - - PGMEA(2250) EL(2800) DAA(550) Examples 2-30 R-30 P-5(80) PDQ-2(2.5) - AQ-1(2.5) PGMEA(2250) EL(2800) DAA(550)

[0577] [Table 2] inhibitor Composition Base polymer (parts by weight) Comparison Quenching agent (parts by weight) Photoacid generator (parts by weight) other 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) PDQ-A(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-2 CR-2 P-1(80) PDQ-B(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-3 CR-3 P-1(80) PDQ-C(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-4 CR-4 P-1(80) PDQ-D(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-5 CR-5 P-1(80) PDQ-A(5) PAG-Y(15) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-6 CR-6 P-1(80) PDQ-B(5) PAG-Y(15) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-7 CR-7 P-1(80) PDQ-C(2.5) PAG-X(15) AQ-1(2.5) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-8 CR-8 P-1(80) PDQ-D(3) PAG-Y(15) AQ-2(2) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-9 CR-9 P-2(80) PDQ-A(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-10 CR-10 P-2(80) PDQ-B(5) PAG-X(15) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-11 CR-11 P-2(80) PDQ-C(4) PAG-X(15) AQ-1(2) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-12 CR-12 P-3(80) PDQ-A(5) - - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-13 CR-13 P-3(80) PDQ-C(5) - - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-14 CR-14 P-3(80) PDQ-D(3) - AQ-1(2) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-15 CR-15 P-4(80) PDQ-A(5) - - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-16 CR-16 P-4(80) PDQ-D(5) - - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-17 CR-17 P-4(80) PDQ-C(6) PAG-Y(5) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-18 CR-18 P-5(80) PDQ-A(5) - - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-19 CR-19 P-5(80) PDQ-B(3) PAG-Y(5) AQ-2(2) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 1-20 CR-20 P-5(80) PDQ-C(5) - - PGMEA(2250) EL(2800) DAA(550)

[0578] In Tables 1 and 2, the solvents, photoacid generators PAG-X and PAG-Y, comparative quenchers PDQ-A to PDQ-D, other quenchers AQ-1 and AQ-2, and surfactant A are as follows: • Solvents: PGMEA (propylene glycol monomethyl ether acetate), EL (ethyl lactate), DAA (diacetone alcohol)

[0579] ･Photoacid generators: PAG-X, PAG-Y [Chemical 393]

[0580] ･Comparative Quenching Agents: PDQ-A~PDQ-D [Chem. 394]

[0581] ･Other quenching agents: AQ-1, AQ-2 [Chemical 395]

[0582] ･Surfactant A: 3-methyl-3-(2,2,2-trifluoroethoxymethyl)oxetane-tetrahydrofuran-2,2-dimethyl-1,3-propanediol copolymer (manufactured by OMNOVA) [Chemical 396] a:(b+b'):(c+c')=1:4~7:0.01~1 (Morby) Mw=1500

[0583] [4]EUV lithography evaluation (1) [Examples 3-1~3-30, Comparative Examples 2-1~2-20] Each chemical amplification resist composition (R-1~R-30, CR-1~CR-20) was spin-coated onto a Si substrate with a silicon-containing 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. The substrate was pre-baked at 100°C for 60 seconds using a heating plate to obtain a resist film with a film thickness of 50 nm. For the aforementioned resist film, an LS pattern with a size of 18 nm and a pitch of 36 nm was exposed on the wafer using an ASML EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9 / 0.6, dipole illumination) while varying the exposure amount and focus (exposure interval: 1 mJ / cm2, focus interval: 0.020 μm). After exposure, PEB was performed for 60 seconds at the temperatures shown in Tables 4 and 5. Subsequently, immersion development was performed for 30 seconds with a 2.38% (w / w) TMAH aqueous solution, followed by rinsing with a surfactant-containing rinsing material and spin drying to obtain a positive pattern. The obtained LS pattern was observed using a Hitachi Advanced Technology Co., Ltd. length measuring SEM (CG6300), and the sensitivity, EL, LWR, depth of focus (DOF), and collapse limit were evaluated according to the following methods. Furthermore, the development defects of the obtained LS pattern were evaluated. The results are shown in Tables 3 and 4.

[0584] [Sensitivity Evaluation] Calculate the optimal exposure value Eop (mJ / cm2) for obtaining an LS pattern with a linewidth of 18nm and a pitch of 36nm, and set it as the sensitivity. The smaller this value, the higher the sensitivity.

[0585] [EL Evaluation] The EL (unit: %) is calculated using the following formula, based on the exposure within ±10% (16.2~19.8nm) of the 18nm pitch range in the aforementioned LS pattern. A larger value indicates better performance. EL(%) = (|E1-E2| / Eop)×100 E1: Optimal exposure for an LS pattern with a linewidth of 16.2nm and a pitch of 36nm. E2: Optimal exposure for an LS pattern with a linewidth of 19.8nm and a pitch of 36nm. Eop: Optimal exposure for an LS pattern with a linewidth of 18nm and a pitch of 36nm.

[0586] [LWR Evaluation] Measure the dimensions at 10 points of the LS pattern obtained by Eop irradiation along the length of the line, and calculate 3 times the standard deviation (σ) (3σ) as the LWR. The smaller this value, the more uniform the line width and roughness of the pattern can be obtained.

[0587] [DOF Evaluation] The focal depth is evaluated by determining the focal range within ±10% (16.2~19.8nm) of the 18nm dimension in the aforementioned LS pattern. The larger this value, the wider the focal depth.

[0588] [Collapse Limit Evaluation of Line Pattern] The line size was measured at 10 points along the length direction at various exposures for the optimal focal point of the aforementioned LS pattern. The finest line size that could be obtained without collapse was taken as the collapse limit size. The smaller this value, the better the collapse limit.

[0589] [Development Defect Evaluation] Using an LS pattern with a linewidth of 18nm and a pitch of 36nm formed at the aforementioned optimal exposure, a defect inspection device KLA2360 (trade name) manufactured by KLA-Tencor was used. The pixel size of the defect inspection device was set to 0.16μm, and the threshold was set to 20. Defects (number / cm2) extracted by comparing the difference between the image and the pixel unit were detected, and the number of defects per unit area (defects / cm2) was calculated. Subsequently, by performing defect inspection, development defects were extracted from all defects and the number of development defects per unit area (defects / cm2) was calculated. Values ​​below 0.5 were rated A, values ​​above 0.5 but below 1.0 were rated B, values ​​above 1.0 but below 5.0 were rated C, and values ​​above 5.0 were rated D. The smaller the value, the better the performance.

[0590] [Table 3] inhibitor Composition PEB temperature (°C) Optimal exposure (mJ / cm 2 ) EL (%) LWR (nm) DOF (nm) Collapse Limit (nm) Development defects Example 3-1 R-1 100 32 18 2.3 110 11.2 A Example 3-2 R-2 100 34 18 2.3 120 11.1 A Example 3-3 R-3 100 32 17 2.4 110 10.9 A Examples 3-4 R-4 95 33 17 2.4 110 11.3 A Examples 3-5 R-5 100 34 18 2.5 120 11.2 A Examples 3-6 R-6 100 33 18 2.6 100 11.3 A Examples 3-7 R-7 105 32 17 2.3 120 11.4 A Examples 3-8 R-8 100 35 16 2.4 110 10.8 A Examples 3-9 R-9 100 33 17 2.3 100 11.4 A Examples 3-10 R-10 100 32 18 2.4 120 11.0 A Example 3-11 R-11 105 33 17 2.6 100 10.9 A Example 3-12 R-12 100 34 17 2.5 110 11.1 A Example 3-13 R-13 95 32 16 2.5 120 10.9 A Example 3-14 R-14 100 33 18 2.5 110 10.8 A Example 3-15 R-15 100 35 16 2.3 100 11.2 A Example 3-16 R-16 100 34 17 2.4 110 11.1 A Example 3-17 R-17 100 32 16 2.3 120 11.2 A Example 3-18 R-18 100 34 18 2.5 110 11.0 A Example 3-19 R-19 100 33 16 2.5 120 11.5 A Example 3-20 R-20 100 35 17 2.4 100 11.3 A Example 3-21 R-21 100 33 16 2.3 120 11.2 A Example 3-22 R-22 105 33 17 2.4 100 11.4 A Example 3-23 R-23 100 34 18 2.4 110 11.1 A Example 3-24 R-24 100 33 16 2.5 120 11.2 A Example 3-25 R-25 105 34 17 2.4 120 11.4 A Example 3-26 R-26 100 35 16 2.5 110 10.9 A Example 3-27 R-27 95 33 18 2.4 100 10.8 A Example 3-28 R-28 105 33 17 2.5 120 11.2 A Example 3-29 R-29 100 34 18 2.4 100 11.1 A Examples 3-30 R-30 95 34 18 2.6 110 11.3 A

[0591] [Table 4] inhibitor Composition PEB temperature (°C) Optimal exposure (mJ / cm 2 ) EL (%) LWR (nm) DOF (nm) Collapse Limit (nm) Development defects Comparative Example 2-1 CR-1 100 39 12 3.2 60 14.3 B Comparative Example 2-2 CR-2 100 37 13 3.1 80 12.8 B Comparative Examples 2-3 CR-3 105 38 14 3.1 70 12.8 C Comparative Examples 2-4 CR-4 100 39 14 3.3 80 12.9 B Comparative Examples 2-5 CR-5 100 39 12 3.2 80 13.1 B Comparative Examples 2-6 CR-6 100 40 14 3.2 80 13.2 C Comparative Examples 2-7 CR-7 100 41 14 3.2 90 12.8 B Comparative Examples 2-8 CR-8 100 39 13 3.4 70 12.6 C Comparative Examples 2-9 CR-9 105 38 14 3.2 70 13.1 B Comparative Example 2-10 CR-10 100 38 12 3.3 80 13.1 C Comparative Example 2-11 CR-11 100 38 14 3.2 90 13 B Comparative Example 2-12 CR-12 100 39 14 3.0 80 13.1 B Comparative Example 2-13 CR-13 100 38 13 3.2 90 12.8 C Comparative Example 2-14 CR-14 95 41 13 3.2 70 12.7 B Comparative Example 2-15 CR-15 105 39 14 3.1 100 13.3 C Comparative Example 2-16 CR-16 95 40 13 3.2 70 13.1 B Comparative Example 2-17 CR-17 100 38 14 3.2 90 12.8 C Comparative Example 2-18 CR-18 100 39 14 3.3 70 12.5 B Comparative Example 2-19 CR-19 100 41 13 3.1 70 12.6 C Comparative Example 2-20 CR-20 100 39 14 3.2 80 13.1 B

[0592] As shown in Tables 3 and 4, the chemical amplification inhibitor composition containing the quencher of the present invention exhibits good sensitivity, and excellent EL, LWR, and DOF. Furthermore, it is confirmed that the collapse limit value is small, and the pattern collapse resistance remains strong even during the formation of fine patterns. In addition, it is confirmed that development defects are also suppressed. Therefore, it is indicated that the chemical amplification inhibitor composition of the present invention is suitable as a material for EUV lithography.

[0593] [5]EUV lithography evaluation (2) [Examples 4-1~4-30, Comparative Examples 3-1~3-20] Each chemical amplification resist composition (R-1~R-30, CR-1~CR-20) was spin-coated onto a Si substrate with a silicon-containing 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. The substrate was pre-baked at 105°C for 60 seconds using a heating plate to obtain a resist film with a film thickness of 50 nm. The resist film was exposed using an ASML NXE3400 EUV scanning exposure machine (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, mask for a 46nm pitch hole pattern on the wafer, +20% deviation). Then, a PEB exposure was performed for 60 seconds at the temperatures described in Tables 5 and 6 using a heated plate, followed by 30 seconds of development with a 2.38% (w / w) TMAH aqueous solution to form a 23nm hole pattern. The exposure amount for forming the 23nm hole size was measured using a Hitachi Advanced Technology Co., Ltd. CG6300 length measuring SEM was used, and this was set as the sensitivity. The dimensions of 50 holes were measured at this time, and the dimensional variation (CDU) was calculated as three times the standard deviation (σ) obtained from the results. The results are shown in Tables 5 and 6.

[0594] [Table 5] inhibitor composition PEB temperature (°C) Optimal exposure (mJ / cm 2 ) CDU (nm) Example 4-1 R-1 90 twenty three 2.3 Example 4-2 R-2 90 twenty four 2.4 Example 4-3 R-3 95 twenty three 2.4 Example 4-4 R-4 90 twenty four 2.6 Examples 4-5 R-5 90 25 2.4 Examples 4-6 R-6 90 twenty four 2.6 Examples 4-7 R-7 95 twenty three 2.5 Examples 4-8 R-8 95 twenty four 2.3 Examples 4-9 R-9 90 twenty three 2.3 Examples 4-10 R-10 95 twenty four 2.3 Example 4-11 R-11 95 25 2.3 Example 4-12 R-12 90 twenty four 2.5 Example 4-13 R-13 90 25 2.4 Example 4-14 R-14 95 twenty three 2.4 Examples 4-15 R-15 95 twenty four 2.6 Example 4-16 R-16 85 twenty three 2.3 Example 4-17 R-17 95 twenty four 2.4 Example 4-18 R-18 90 twenty four 2.5 Example 4-19 R-19 95 25 2.4 Example 4-20 R-20 90 25 2.5 Example 4-21 R-21 90 twenty four 2.4 Example 4-22 R-22 90 25 2.4 Example 4-23 R-23 95 twenty three 2.3 Example 4-24 R-24 90 twenty three 2.4 Example 4-25 R-25 90 25 2.5 Example 4-26 R-26 85 25 2.4 Example 4-27 R-27 95 twenty three 2.4 Example 4-28 R-28 90 twenty four 2.5 Example 4-29 R-29 90 twenty three 2.3 Example 4-30 R-30 95 25 2.3

[0595] [Table 6] inhibitor composition PEB temperature (°C) Optimal exposure (mJ / cm 2 ) CDU (nm) Comparative Example 3-1 CR-1 90 30 3.2 Comparative Example 3-2 CR-2 90 29 2.9 Comparative Example 3-3 CR-3 95 27 2.9 Comparative Examples 3-4 CR-4 90 27 2.7 Comparative Examples 3-5 CR-5 95 31 3.0 Comparative Examples 3-6 CR-6 85 28 3.1 Comparative Examples 3-7 CR-7 90 29 2.9 Comparative Examples 3-8 CR-8 90 29 2.8 Comparative Examples 3-9 CR-9 90 30 2.8 Comparative Example 3-10 CR-10 95 29 2.8 Comparative Example 3-11 CR-11 90 29 3.0 Comparative Example 3-12 CR-12 90 28 2.7 Comparative Example 3-13 CR-13 95 30 2.9 Comparative Example 3-14 CR-14 90 28 3.1 Comparative Example 3-15 CR-15 90 29 2.9 Comparative Example 3-16 CR-16 90 28 3.2 Comparative Example 3-17 CR-17 95 28 3.0 Comparative Example 3-18 CR-18 90 28 2.9 Comparative Example 3-19 CR-19 85 30 2.8 Comparative Example 3-20 CR-20 90 29 2.9

[0596] The results shown in Tables 5 and 6 confirm that the chemical amplification inhibitor composition of the present invention has good sensitivity and excellent CDU.

Claims

1. An onium salt, comprising a cation represented by formula (1A-1) and an anion represented by formula (1B); wherein p is 1 or 2; n1 is 0; n2 is 1 or 2; n3 is 0, 1, 2 or 3; n4 is 0; n5 is 0, 1, 2, 3, 4 or 5; however, 1 ≤ n2 + n3 ≤ 5; R1 is a halogen atom, nitro group, hydroxyl group, carboxyl group, or may contain a hydrocarbon group with 1 to 20 carbon atoms of heteroatoms, a hydrocarbon oxy group with 1 to 20 carbon atoms of heteroatoms, a hydrocarbon thio group with 1 to 20 carbon atoms of heteroatoms, or a hydrocarbon oxycarbonyl group with 2 to 20 carbon atoms of heteroatoms; when n3 is 2 or 3, each R1 may be the same or different from the others, and two R1s may also bond to each other and form a ring together with the carbon atoms they are bonded to; R2a can be a halogen atom, nitro group, hydroxyl group, carboxyl group, alkoxy carbonyl 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 n5 is 2, 3, 4 or 5, each R2a can be the same or different from the others, and two R2a can also bond to each other and form a ring together with the carbon atoms they are bonded to; furthermore, two of the three substituents bonded to S+ can also bond to each other and form a ring together with the sulfur atoms they are bonded to. In the formula, n11 is 0 or 1; n12 is 1, 2, 3 or 4; n13 is 0, 1 or 2; n14 is 0, 1, 2, 3 or 4; however, when n11 is 0, it is 2≦n12+n13+n14≦5, and when n11 is 1, it is 2≦n12+n13+n14≦7; LA is a single bond, oxygen atom, sulfur atom, ester bond or carbonate bond; R3 is a hydrogen atom when LA is a single bond, or may contain a hydrocarbon group with 1 to 20 carbon atoms of heteroatoms, and a hydrogen atom when LA is an oxygen atom, sulfur atom, ester bond or carbonate bond, or may contain a hydrocarbon group with 1 to 20 carbon atoms of heteroatoms (excluding acid unstable groups) or acid unstable groups; R4 can be a halogen atom other than an iodine atom, a nitro group, a cyano group, or a hydrocarbon group with 1 to 20 carbon atoms that is a heteroatom, or a hydrocarbon group with 1 to 20 carbon atoms that is a heteroatom, or a hydrocarbon group with 1 to 20 carbon atoms that is a heteroatom.

2. As in request item 1, the onium salt, where, The anion system is represented by the following formula (1B-1); where n12~n14, LA, R3 and R4 are the same as those described in claim 1.

3. As in request item 1, the onium salt, where, LA represents an oxygen atom or an ester bond.

4. As in request item 1, the onium salt, where, LA represents an oxygen atom, a sulfur atom, an ester bond, or a carbonate bond, while R3 represents an acid-labile group.

5. As in request item 1, the onium salt, wherein, The unstable acid group is represented by the following formula (AL-1) or (AL-2); in which p1 and p2 are independently 0 or 1 respectively; q1 and q2 are independently 0, 1, 2, 3 or 4 respectively; RL1, RL2 and RL3 are independently hydrocarbon groups with 1 to 12 carbon atoms, and a portion of the -CH2- of the hydrocarbon group may be replaced by -O- or -S-. When the hydrocarbon group contains an aromatic ring, a portion or all of the hydrogen atoms of the aromatic ring may 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 may also bond to each other and form a ring together with the carbon atoms they bond to, and a portion of the -CH2- of the ring may be replaced by -O- or -S-. 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-; RL5 and RL6 may also bond to each other and together with the carbon atoms they are bonded to and LB to form a heterocyclic group with 3 to 20 carbon atoms, and part of the -CH2- of this heterocyclic group may be replaced by -O- or -S-; LB is -O- or -S-; RLa to RLd are each independently a hydrogen atom or a hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms; * indicates an atomic bond with an adjacent oxygen or sulfur atom.

6. A quenching agent comprising an onium salt of any one of claims 1 to 5.

7. A chemical amplification inhibitor composition comprising the quencher as claimed in claim 6.

8. The chemical amplification inhibitor composition of claim 7 comprises: a base polymer containing a repeating unit represented by the following formula (a1); wherein RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; X1 is a single bond, a phenyl group, a naphthyl group, *-C(=O)-O-X11-, or *-C(=O)-NH-X11-, and the phenyl group or naphthyl group may also be substituted by an alkoxy or halogen atom with 1 to 10 carbon atoms, which may also contain a fluorine atom; X11 is a saturated alkyl group, a phenyl group, or a naphthyl group with 1 to 10 carbon atoms, and the saturated alkyl group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring; * represents an atomic bond with a carbon atom of the main chain; AL1 is an acid-instable group.

9. The chemical amplification inhibitor composition as claimed in claim 8, wherein, The basic polymer contains repeating units represented by the following formula (a2); where RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; X2 is a single bond or *-C(=O)-O-; * represents an atomic bond with a carbon atom in the main chain; R11 is a halogen atom, a cyano group, a hydroxyl group, a nitro group, or may contain a hydrocarbon group with 1 to 20 carbon atoms of heteroatoms, a hydrocarbon oxy group with 1 to 20 carbon atoms of heteroatoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms of heteroatoms, a hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms of heteroatoms, or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms of heteroatoms; when a1 is 2, 3, or 4, each R11 can be the same or different; AL2 is an acid-unstable group; a is 0, 1, 2, 3, or 4.

10. The chemical amplification inhibitor composition as claimed in claim 8, wherein, The basic polymer contains repeating units represented by the following formula (a3); where 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)-NH-; * represents an atomic bond with a carbon atom in the main chain; R12 and R13 are each independently hydrogen atoms, or may contain hydrocarbon groups with 1 to 20 carbon atoms containing heteroatoms; furthermore, R12 and R13 may also bond to each other and form a ring together with the carbon atoms they are bonded to; R14 can be a halogen atom, hydroxyl, cyano, nitro, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, a hydrocarbon oxy group with 1 to 20 carbon atoms containing heteroatoms, a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group or -N(R14A)(R14B) containing heteroatoms; R14A and R14B are independently hydrogen atoms or hydrocarbon groups with 1 to 6 carbon atoms; when b2 is 2 or more, multiple R14s can also bond to each other and form a ring together with the carbon atoms of the aromatic ring they are bonded to; X4 is a single bond, an aliphatic hydrocarbon group with 1 to 4 carbon atoms, a carbonyl group, a sulfonyl group, or a group obtained by combining them; X5 and X6 are independently oxygen atoms or sulfur atoms; however, X4 and X6 are bonded to adjacent carbon atoms of the aromatic ring.

11. The chemical amplification inhibitor composition as claimed in claim 8, wherein, The basic polymer contains repeating units represented by formula (b1) or (b2); where 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 in the main chain; R21 is a hydrogen atom, or a group containing at least one of the following structures with 1 to 20 carbon atoms: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulopentalide ring, and carboxylic anhydride (-C(=O)-OC(=O)-); R22 can be a halogen atom, carboxyl group, nitro group, cyano group, alkoxy carbonyl group, or may contain a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxy group with 1 to 20 carbon atoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms, a hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms, or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms; when c2 is 2, 3, or 4, each R22 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.

12. The chemical amplification inhibitor composition as claimed in claim 8, wherein, The basic polymer contains at least one repeating unit selected from the following formulas (c1), (c2), (c3), (c4), and (c5); wherein d1 and d2 are 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, 0 ≤ e2 + e3 ≤ 4, and when e1 is 1, 0 ≤ e2 + e3 ≤ 6; RA are independently hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups; Z1 is a single bond or may also have substituents, such as phenyl groups; Z2 is a single bond, **-C(=O)-O-Z21-, **-C(=O)-NH-Z21-, or **-O-Z21-; Z21 is an aliphatic alkyl group with 1 to 6 carbon atoms, an alkyl phenyl group, or a divalent group obtained by combining them, 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, an amide bond, a sulfonate 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, an alkyl phenyl group, or a divalent group obtained by combining them, 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, or may contain substituents such as phenyl, naphthyl, or *-C(=O)-O-Z51-; Z51 is an aliphatic alkyl group, phenyl, or naphthyl with 1 to 10 carbon atoms, and the aliphatic alkyl group may also contain halogen atoms, hydroxyl groups, ether bonds, ester bonds, or lactone rings; Z6 is a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond; Z7 is independently a single bond, ***-Z71-C(=O)-O-, ***-C(=O)-NH-Z71-, or ***-O-Z71-; Z71 may also contain heteroatoms and is an alkyl group with 1 to 20 carbon atoms; Z8 can be a single bond, ****-Z81-C(=O)-O-, ****-C(=O)-NH-Z81-, or ****-O-Z81-; Z81 can be a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms; Z9 can be a single bond, methylene, ethyl, phenyl, fluorinated phenyl, phenyl substituted with trifluoromethyl, *-C(=O)-O-Z91-, *-C(=O)-N(H)-Z91-, or *-O-Z91-; Z91 can be an aliphatic hydrocarbon group with 1 to 6 carbon atoms, phenyl, fluorinated phenyl, or phenyl substituted with trifluoromethyl, and may also contain carbonyl, ester, ether, or hydroxyl groups; * 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; L1 can be a single bond, ether bond, ester bond, carbonyl group, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond; Rf1 and Rf2 can be independently fluorine atoms or fluorinated saturated hydrocarbon groups with 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 simultaneously hydrogen atoms; 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, or a fluorinated alkyl thio group having 1 to 6 carbon atoms; R31 and R32 are each independently a hydrocarbon group having 1 to 20 carbon atoms, which may also contain heteroatoms; furthermore, R31 and R32 may also bond to each other and form a ring together with the sulfur atoms they are bonded to; R33 is a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms, which may also contain heteroatoms; when e3 is 2, 3, or 4, each R33 may be the same or different from the others, and multiple R33 may also bond to each other and form a ring together with the carbon atoms they are bonded to; M- is a non-nucleophilic relative ion; A+ is an onium cation.

13. The chemical amplification inhibitor composition of claim 7 further contains organic solvents.

14. The chemical amplification inhibitor composition of claim 7 further contains a photoacid generator that produces strong acid.

15. The chemical amplification inhibitor composition of claim 7 further contains a quencher other than the quencher of claim 6.

16. The chemical amplification inhibitor composition of claim 7 further contains a surfactant.

17. 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 7, exposing the resist film to high-energy radiation, and developing the exposed resist film using a developing solution.

18. The pattern forming method as described in claim 17, wherein, The high-energy rays are KrF excimer laser light, ArF excimer laser light, electron beam, or extreme ultraviolet light with a wavelength of 3~15nm.