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

Abstract

The present invention addresses the use of strontium salt monomers in chemical amplification inhibitor compositions that exhibit excellent solvent solubility, high sensitivity, high contrast, and superior lithography properties such as LWR, CDU, EL, and DOF in photolithography using high-energy rays; polymers containing repeating units derived from the strontium salt monomers; chemical amplification inhibitor compositions containing the polymers; and a patterning method using the chemical amplification inhibitor composition. The solution of the present invention is a strontium salt monomer represented by the following formula (A).

Description

Technical Field

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

[0002] With the increasing integration and speed of LSI, the miniaturization of patterning is progressing rapidly. In particular, the expansion of the flash memory market and the increase in memory capacity are driving miniaturization. As the most advanced miniaturization technology, mass production of 65nm node devices using ArF lithography has been implemented, and preparations for mass production of 45nm node devices using next-generation ArF immersion lithography are underway. For next-generation 32nm node devices, immersion lithography using an ultra-high NA lens composed of a liquid with a higher refractive index than water, a high refractive index lens, and a high refractive index resist film, extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm, and double exposure (double patterning lithography) of ArF lithography are among the candidates being explored.

[0003] As miniaturization progresses and the diffraction limit of light approaches, the contrast of light decreases. Due to this decrease in contrast, the resolution of the hole and groove patterns and the focusing limit in the positive resist film decrease.

[0004] As patterns become increasingly finer, the linewidth roughness (LWR) of line patterns and the dimensional uniformity (CDU) of hole patterns are considered problems. Some have pointed to uneven distribution of the base polymer and acid-generating agent, the effects of aggregation, and the influence of acid diffusion. Furthermore, the LWR tends to increase with the thinning of resist films, and the deterioration of LWR caused by thinning accompanying the miniaturization process becomes a serious problem.

[0005] In EUV lithography resist formulations, it is necessary to simultaneously achieve high sensitivity, high resolution, and low light-to-weight ratio (LWR). Shortening the acid diffusion distance reduces LWR but decreases sensitivity. For example, lowering the post-exposure baking (PEB) temperature reduces LWR but decreases sensitivity. Increasing the amount of quencher also reduces LWR but decreases sensitivity. Therefore, it is necessary to break down the trade-off between sensitivity and LWR.

[0006] To suppress acid diffusion, a resisting compound containing repeating units from onium salts of sulfonic acids with polymerizable unsaturated bonds has been proposed (Patent Document 1). Such a polymer-bonded acid generator, due to the generation of polymeric sulfonic acid upon exposure, exhibits a very short acid diffusion distance. Furthermore, sensitivity can be improved by increasing the ratio of the acid generator. Increasing the amount added to an additive-type acid generator also increases sensitivity, but in this case, the acid diffusion distance also increases. Due to the uneven diffusion of acid, increased acid diffusion degrades LWR and CDU. In terms of balancing sensitivity, LWR, and CDU, polymer-type acid generators can be considered to possess a high level of capability.

[0007] Regarding iodine atoms, due to their extremely high absorption at a wavelength of 13.5 nm in EUV, it has been confirmed that iodine atoms generate secondary electrons during exposure, thus attracting attention in EUV lithography. Patent Document 2 describes a photoacid generator formed by introducing iodine atoms into anions, and Patent Document 3 describes a photoacid generator containing polymeric groups formed by introducing iodine atoms into anions. While this confirms some improvement in lithography performance, there is a concern that iodine atoms have low solubility in organic solvents and may precipitate out in the solvent.

[0008] Patent documents 4 and 5 describe photoacid generators formed by introducing pentafluorosulfonyl (-SF5) and trifluoromethoxy (-OCF3) groups into cations. While these methods improve lithography performance to some extent, there is still room for improvement, and further development of resist materials that are effective in forming fine patterns is desired. [Previous Technical Documents] [Patent Literature]

[0009] [Patent Document 1] Japanese Patent No. 4425776 [Patent Document 2] Japanese Patent No. 6720926 [Patent Document 3] Japanese Patent No. 6973274 [Patent Document 4] International Publication No. 2023 / 223624 [Patent Document 5] Japanese Patent Application Publication No. 2022-59112 Summary of the Invention

[0010] [The problem that the invention aims to solve] The goal is to develop resist compositions with higher sensitivity and improved lithography properties such as LWR, CDU, exposure margin (EL), and depth of focus (DOF) in chemical amplification resist compositions that use acid as a catalyst.

[0011] In view of the foregoing, the present invention aims to provide a strontium salt monomer, a polymer containing repeating units from the strontium salt monomer, a chemical amplification inhibitor composition containing the polymer, and a patterning method using the chemical amplification inhibitor composition, which has excellent solvent solubility, high sensitivity, high contrast, and excellent lithography performance such as LWR, CDU, EL, and DOF, especially in photolithography using high-energy rays such as KrF excimer laser, ArF excimer laser, electron beam (EB), and EUV. [Methods for solving problems]

[0012] In order to achieve the aforementioned objectives, the inventors of this invention conducted repeated and in-depth research and discovered that, as a polymer-bonded acid generator, by using a polymer containing repeating units of strontium salt-type monomers composed of strontium cations having pentafluorosulfonyl and hydroxyl carbonyl groups and fluorosulfonic acid anions having polymerizable groups, it is possible to obtain a chemical amplification inhibitor composition with high sensitivity, improved lithography properties such as LWR, CDU, EL, and DOF, high contrast, and high resolution, thus completing this invention.

[0013] That is, the present invention provides the following strontium salt type monomer, polymer, chemical amplification inhibitor composition and pattern formation method. 1. A strontium salt type monomer, represented by the following formula (A); [Chemistry 1] In the formula, n1 is 0 or 1; n2 is 0, 1, or 2; n3 is 0, 1, or 2; n4 is 0, 1, or 2; however, when n1 is 0, then 0 ≤ n2 + n3 + n4 ≤ 5, and when n1 is 1, then 0 ≤ n2 + n3 + n4 ≤ 7; n5 is 0 or 1; n6 is 0, 1, or 2; n7 is 0, 1, or 2; n8 is 0, 1, or 2; however, when n5 is 0, then 0 ≤ n6 + n7 + n8 ≤ 5. When n5 is 1, then 0 ≦ n6 + n7 + n8 ≦ 7; n9 is 0 or 1; n10 is 0, 1, or 2; n11 is 0, 1, or 2; n12 is 0, 1, or 2; however, when n9 is 0, then 0 ≦ n10 + n11 + n12 ≦ 5, and when n9 is 1, then 0 ≦ n10 + n11 + n12 ≦ 7; also, 1 ≦ n2 + n6 + n10 ≦ 6, 1 ≦ n3 + n7 + n11 ≦ 6; R1, R2, and R3 are each independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms; when n3 is 2, each R1 may be the same or different; when n7 is 2, each R2 may be the same or different; when n11 is 2, each R3 may be the same or different. R4, R5, and R6 can each be a halogen atom, nitro group, hydroxyl group, carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxy group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms; when n4 is 2, each R4 can be the same or different, and two R4s can bond to each other and form a ring together with the carbon atoms of these bonds; when n8 is 2, each R5 can be the same or different, and two R5s can bond to each other and form a ring together with the carbon atoms of these bonds; when n12 is 2, each R6 can be the same or different, and two R6s can bond to each other and form a ring together with the carbon atoms of these bonds; Furthermore, two of the three aromatic rings bonded to S+ can also bond to each other and form a ring together with the sulfur atoms of these bonds; Z-series fluoroalkane sulfonic acid anions with polymerizable groups. 2. As in 1., strontium salt-type monomers are represented by the following formula (A1); [Chemistry 2] In the formula, n2~n4, n6~n8, n10~n12, R1~R6 and Z- are the same as those mentioned above. 3. Sulphur salt type monomers such as 1. or 2, wherein the Z-series anion is represented by the formula (Z1); [Chemistry 3] In the formula, m represents 0, 1, 2, or 3; Each of RA can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; Z1 can be a single bond, or it can have substituents such as phenyl, naphthyl, or *-C(=O)-O-Z11-; Z11 is an aliphatic alkyl group, phenyl, or naphthyl group with 1 to 10 carbon atoms, and the aliphatic alkyl group can also contain halogen atoms, hydroxyl groups, ether bonds, ester bonds, or lactone rings; Z2 series single bonds, ether bonds, ester bonds, amide bonds, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds; Each Z3 group can be a single bond, ***-Z31-C(=O)-O-, ***-C(=O)-NH-Z31-, or ***-O-Z31-; the Z31 series can also contain alkyl groups with 1 to 20 carbon atoms in the heteroatom; Each Z4 group can be independently a single bond, ****-Z41-C(=O)-O-, ****-C(=O)-NH-Z41-, or ****-O-Z41-; the Z41 series can also contain alkyl groups with 1 to 20 carbon atoms in the heteroatoms; * indicates an atomic bond with a carbon atom in the main chain; *** indicates an atomic bond with Z2; **** indicates an atomic bond with Z3. L1 series single bonds, ether bonds, ester bonds, carbonyl groups, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds; Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. 4. Sulphur salt type monomers such as 1. or 2, wherein the Z-series anion is represented by the formula (Z2); [Chemistry 4] In the formula, m1 is 0 or 1; m2 is 0, 1, 2, 3 or 4; m3 is 0, 1, 2 or 3; m4 is 0 or 1; m5 is 0, 1, 2, 3 or 4; m6 is 0, 1, 2 or 3; m7 is 0 or 1; m8 is 1, 2, 3 or 4; m9 is 0, 1, 2 or 3; m10 is 0, 1, 2, 3 or 4; m11 is 0 or 1; m12 is 0 or... 1; However, when m1 is 0, then 0 ≦ m2 + m3 + m1² ≦ 4; when m1 is 1, then 0 ≦ m2 + m3 + m1² ≦ 6; when m4 is 0, then 0 ≦ m5 + m6 ≦ 4; when m4 is 1, then 0 ≦ m5 + m6 ≦ 6; when m7 is 0, then 0 ≦ m8 + m9 ≦ 5; when m7 is 1, then 0 ≦ m8 + m9 ≦ 7; also, 1 ≦ m2 + m5 + m8 ≦ 4; RA series: hydrogen atom, fluorine atom, methyl or trifluoromethyl; R11, R12, and R13 are each independently a halogen atom other than an iodine atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, or may contain a hydrocarbon group with 1 to 20 carbon atoms of a heteroatom, a hydrocarbon oxy group with 1 to 20 carbon atoms of a heteroatom, a hydrocarbon thio group with 1 to 20 carbon atoms of a heteroatom, or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms of a heteroatom; when m3 is 2 or 3, each R11 can be the same or different, and two R11s can also be bonded to each other and form a ring together with the bonded carbon atoms; when m6 is 2 or 3, each R12 can be the same or different, and two R12s can also be bonded to each other and form a ring together with the bonded carbon atoms; when m9 is 2 or 3, each R13 can be the same or different, and two R13s can also be bonded to each other and form a ring together with the bonded carbon atoms; LA, LB, LC, LD, and LE are each independently a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond; XL1 and XL2 are each independently a single bond, or may contain a heteroatom of 1 to 40 carbon atoms in an alkyl group; Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; However, m11 and m12 are not both 0, and LA, LB, LC, LD, XL1 and XL2 are not both single bonds. 5. A monomeric photoacid generator, comprising a strontium salt type monomer as described in any one of 1 to 4. 6. A polymer comprising repeating units from a monomeric photoacid generator as described in 5. 7. The polymer as described in 6. further comprises at least one of the repeating units represented by formula (a1), formula (a2), and formula (a3); [Chemistry 5] In the formula, RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; X1 series consists of single bonds, pendiphenyl, pendinaphthyl, or *-C(=O)-O-X11-. The pendiphenyl or pendinaphthyl group may be substituted with hydroxyl, nitro, cyano, or a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, or a saturated hydrocarbon oxygen group containing fluorine atoms with 1 to 10 carbon atoms, or a halogen atom. X11 series consists of saturated pendialkyl groups with 1 to 10 carbon atoms, pendiphenyl, or pendinaphthyl groups. These saturated pendialkyl groups may also contain hydroxyl, ether bonds, ester bonds, or lactone rings. X2 series single bonds or *-C(=O)-O-; * indicates an atomic bond with a carbon atom in the main chain; R21 can be a halogen atom, cyano group, hydroxyl group, nitro group, or may contain a hydrocarbon group with 1-20 carbon atoms, a hydrocarbon oxygen group with 1-20 carbon atoms, a hydrocarbon carbonyl group with 2-20 carbon atoms, a hydrocarbon carbonyl oxygen group with 2-20 carbon atoms, or a hydrocarbon oxygen carbonyl group with 2-20 carbon atoms; when a1 is 2, 3, or 4, each R21 can be the same or different from the others; AL1 and AL2 are each independently acid-labile groups; a1 series: 0, 1, 2, 3, or 4; [Chemistry 6] In the formula, b1 is 0 or 1; b2 is 0, 1, 2 or 3 when b1 is 0, and 0, 1, 2, 3, 4 or 5 when b1 is 1; RA series: hydrogen atom, fluorine atom, methyl or trifluoromethyl; X3 series single bonds, *-C(=O)-O- or *-C(=O)-NH-; * indicates an atomic bond with a carbon atom in the main chain; X4 group consisting of single bonds, aliphatic hydrocarbon groups with 1 to 4 carbon atoms, carbonyl groups, sulfonyl groups, or combinations thereof; X5 and X6 are each independently oxygen or sulfur atoms; however, X4 and X6 are bonded to adjacent carbon atoms in an aromatic ring. R22 and R23 are each independently hydrogen atoms, or may contain heteroatoms and be hydrocarbon groups with 1 to 20 carbon atoms; furthermore, R22 and R23 may also bond to each other and form a ring together with the bonded carbon atoms; R24 can be a halogen atom, hydroxyl group, cyano group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms, or -N(R24A)(R24B); R24A and R24B are each independently a hydrogen atom or a hydrocarbon group with 1 to 6 carbon atoms; when b2 is 2 or more, each R24 can be the same or different from each other, and multiple R24s can also be bonded to each other and form a ring together with the carbon atoms of the aromatic rings of these bonds. 8. The polymer as described in 6 or 7 further comprises at least one of the repeating units represented by formula (b1) and formula (b2); [Chemistry 7] In the formula, RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; Y1 series single bonds or *-C(=O)-O-; * indicates an atomic bond with a carbon atom in the main chain; R31 refers to a hydrogen atom, or a group containing at least one of the following: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulcinolone ring, and carboxylic anhydride (-C(=O)-OC(=O)-). R32 can be a halogen atom, carboxyl group, nitro group, cyano group, or may contain a hydrocarbon group with 1-20 carbon atoms, a hydrocarbon oxygen group with 1-20 carbon atoms, a hydrocarbon carbonyl group with 2-20 carbon atoms, a hydrocarbon carbonyl oxygen group with 2-20 carbon atoms, or a hydrocarbon oxygen carbonyl group with 2-20 carbon atoms; when c2 is 2, 3, or 4, each R32 can be the same or different. c1 is 1, 2, 3 or 4; c2 is 0, 1, 2, 3 or 4; however, 1 ≦ c1 + c2 ≦ 5. 9. A chemical amplification inhibitor composition comprising (A) a base polymer containing a polymer of any one of 6 to 8. 10. As in 9, the chemical amplification inhibitor composition further includes (B) an organic solvent. 11. Chemical amplification inhibitor compositions such as 9 or 10, further include (C) quencher. 12. Any chemical amplification inhibitor composition such as in 9 to 11 further includes (D) a photoacid generator. 13. The chemical amplification inhibitor composition of any one of 9 to 12 further includes (E) a surfactant. 14. A method for forming a pattern, comprising the following steps: A resist film is formed on a substrate using any one of the chemical amplification resist compositions described in 9 to 13, the resist film is exposed to high-energy rays, and the exposed resist film is developed using a developer. 15. The pattern forming method as described in 14, wherein the high-energy ray is a KrF excimer laser, an ArF excimer laser, an electron beam, or extreme ultraviolet light with a wavelength of 3 to 15 nm. [Effects of the Invention]

[0014] When patterning is performed using a chemical amplification resist composition containing repeating units of a polymer that function as a photoacid generator and contains strontium salt monomers from the present invention, high contrast and good sensitivity can be achieved, and resist patterns with excellent photolithography properties such as LWR, CDU, EL, and DOF can be formed. Implementation

[0015] The present invention will now be described in detail. Furthermore, in the following description, depending on the structure represented by the chemical formula, there may be asymmetric carbon, and mirror-image isomers and non-mirror-image isomers may exist. In this case, each isomer is represented by a single formula. These isomers may be used individually or as a mixture of two or more.

[0016] [Sulphur salt type monomer] The strontium salt type single system of the present invention is represented by formula (A). [Chemistry 8]

[0017] In formula (A), n1 is 0 or 1. When n1 is 0, it is a benzene ring; when n1 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with n1 of 0 is preferred. n2 is 0, 1, or 2. n3 is 0, 1, or 2. n4 is 0, 1, or 2. Considering the availability of raw materials, n4 should preferably be 0 or 1. However, when n1 is 0, then 0 ≤ n2 + n3 + n4 ≤ 5; when n1 is 1, then 0 ≤ n2 + n3 + n4 ≤ 7.

[0018] In formula (A), n5 is 0 or 1. When n5 is 0, it is a benzene ring; when n5 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with n5 of 0 is preferable. n6 is 0, 1, or 2. n7 is 0, 1, or 2. n8 is 0, 1, or 2. Considering the availability of raw materials, n8 should ideally be 0 or 1. However, when n5 is 0, then 0 ≤ n6 + n7 + n8 ≤ 5; when n5 is 1, then 0 ≤ n6 + n7 + n8 ≤ 7.

[0019] In formula (A), n9 is 0 or 1. When n9 is 0, it is a benzene ring; when n9 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with n9 of 0 is preferable. n10 is 0, 1, or 2. n11 is 0, 1, or 2. n12 is 0, 1, or 2. Considering the availability of raw materials, n12 should preferably be 0 or 1. However, when n9 is 0, then 0 ≤ n10 + n11 + n12 ≤ 5; when n9 is 1, then 0 ≤ n10 + n11 + n12 ≤ 7.

[0020] In formula (A), the number of pentafluorosulfon groups is 1≦n²+n⁶+n¹⁰≦6, preferably 1≦n²+n⁶+n¹⁰≦3, and even more preferably 1≦n²+n⁶+n¹⁰≦2. When the number of pentafluorosulfon groups is 2 or more, each pentafluorosulfon group can be bonded to the same aromatic ring or to different aromatic rings.

[0021] In formula (A), the number of alkyl oxy carbonyl groups is 1≦n3+n7+n11≦6, preferably 1≦n3+n7+n11≦3, and even more preferably 1≦n3+n7+n11≦2. When the number of alkyl oxy carbonyl groups is 2 or more, each alkyl oxy carbonyl group can be bonded to the same aromatic ring or to different aromatic rings.

[0022] In formula (A), R1, R2, and R3 are each independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecyl, octadecyl, nonadecanyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these, but not limited to these.

[0023] Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, halogen, or other heteroatoms. Similarly, one part of the -CH2- group in the aforementioned hydrocarbon group may be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, or other heteroatoms. This results in the possible inclusion of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), and haloalkyl groups. Specific examples of heteroatom-containing hydrocarbon groups include trifluoromethyl, 1,1,1-trifluoroethyl, 1,1,1,3,3,3-hexafluoroisopropyl, nonafluorobutyl, octafluoropentyl, and other fluoroalkyl groups; oxanorbenzyl, etc., but are not limited to these. The aforementioned fluoroalkyl groups are preferably those with 1 to 6 carbon atoms.

[0024] When n3 is 2, each R1 can be the same or different. When n7 is 2, each R2 can be the same or different. When n11 is 2, each R3 can be the same or different.

[0025] In formula (A), R4, R5, and R6 are each independently a halogen atom, a nitro group, a hydroxyl group, a carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. The hydrocarbon groups, hydroxyl 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, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecanyl, octadecyl, nonadecanyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclounsaturated cycloalkyl 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 these. Of these, aryl is preferable. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, halogen, etc., and the -CH2- portion of the aforementioned hydrocarbon group can also be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, etc. The result is that it can also contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When n4 is 2, each R4 can be the same or different. Furthermore, when n4 is 2, the two R4s can also bond to each other and form a ring together with the bonded carbon atoms. The aforementioned ring is preferably a 5- to 8-membered ring. When n8 is 2, each R5 can be the same or different. Furthermore, when n8 is 2, the two R5 atoms can also bond to each other and form a ring together with the carbon atoms of these bonds. The aforementioned rings are preferably 5-8 membered rings. When n12 is 2, the R6 atoms can be the same or different. Furthermore, when n12 is 2, the two R6 atoms can also bond to each other and form a ring together with the carbon atoms of these bonds. The aforementioned rings are preferably 5-8 membered rings.

[0026] Furthermore, two of the three aromatic rings bonded to S+ can also bond to each other and form a ring together with the sulfur atoms of these bonds. In this case, specific examples of the aforementioned ring structures can be given by formulas such as the following. [Chemistry 9] In the formula, the dashed lines represent atomic bonds.

[0027] The strontium salt type monomer represented by formula (A) should preferably be represented by the following formula (A1). [Chemistry 10] In the formula, n2~n4, n6~n8, n10~n12 and R1~R6 are the same as those mentioned above. Z will be discussed later.

[0028] Specific examples of strontium salt-type monomer cations represented by formula (A) are shown below, but are not limited to these. Furthermore, in the following formula, Me is a methyl group. [Chemistry 11]

[0029] [Chemistry 12]

[0030] [Chemistry 13]

[0031] [Chemistry 14]

[0032] [Chemistry 15]

[0033] [Chemistry 16]

[0034] [Chemistry 17]

[0035] [Chemistry 18]

[0036] [Chemistry 19]

[0037] [Chemistry 20]

[0038] [Chemistry 21]

[0039] [Chemistry 22]

[0040] [Chemistry 23]

[0041] [Chemistry 24]

[0042] [Chemistry 25]

[0043] [Chemistry 26]

[0044] [Chemistry 27]

[0045] [Chemistry 28]

[0046] [Chemistry 29]

[0047] [Chemistry 30]

[0048] [Chemistry 31]

[0049] [Chemistry 32]

[0050] [Chemistry 33]

[0051] [Chemistry 34]

[0052] [Chemistry 35]

[0053] [Chemistry 36]

[0054] [Chemistry 37]

[0055] [Chemistry 38]

[0056] [Chemistry 39]

[0057] [Chemistry 40]

[0058] [Chemistry 41]

[0059] [Chemistry 42]

[0060] [Chemistry 43]

[0061] [Chemistry 44]

[0062] [Chemistry 45]

[0063] [Chemistry 46]

[0064] [Chemistry 47]

[0065] [Chemistry 48]

[0066] [Chemistry 49]

[0067] [Transformation 50]

[0068] [Chemistry 51]

[0069] [Chemistry 52]

[0070] [Chemistry 53]

[0071] [Chemistry 54]

[0072] [Chemistry 55]

[0073] [Chemistry 56]

[0074] [Chemistry 57]

[0075] In formulas (A) and (A1), Z- is a fluoroalkyl sulfonic acid anion with a polymerizable group. The aforementioned fluoroalkyl sulfonic acid anion should preferably be represented by the following formula (Z1). [Chem.58]

[0076] In formula (Z1), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z1 is independently a single bond, and may also contain substituents such as phenyl, naphthyl, or *-C(=O)-O-Z11-. Z11 is an aliphatic alkyl group, phenyl, or naphthyl group with 1 to 10 carbon atoms, which may also contain halogen atoms, hydroxyl groups, ether bonds, ester bonds, or lactone rings. Z2 is a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Z3 is independently a single bond, ***-Z31-C(=O)-O-, ***-C(=O)-NH-Z31-, or ***-O-Z31-. Z31 may also contain heteroatoms and be an alkyl group with 1 to 20 carbon atoms. Each Z4 group can be independently a single bond, ****-Z41-C(=O)-O-, ****-C(=O)-NH-Z41-, or ****-O-Z41-. The Z41 series can also contain alkyl groups with 1 to 20 carbon atoms in the heteroatom. * indicates an atomic bond with a carbon atom in the main chain. *** indicates an atomic bond with Z2. **** indicates an atomic bond with Z3.

[0077] Z11 represents an aliphatic alkyl group, which can be straight-chain, branched, or cyclic. Specific examples include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, propane-2,2-diyl, butane-1,1-diyl, butane-1,2-diyl, butane-1,3-diyl, butane-2,3-diyl, butane-1,4-diyl, 1,1-dimethylethane-1,2-diyl, pentane-1,5-diyl, 2-methylbutane-1,2-diyl, hexane-1,6-diyl, and other alkane diyl groups; cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, cyclohexanediyl, and other cycloalkane diyl groups; and groups obtained by combining these.

[0078] Z31 and Z41 can also contain heteroatomic extended hydrocarbon groups, which can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples are shown below, but are not limited to these. [Chemistry 59] In the formula, the dashed lines represent atomic bonds.

[0079] In formula (Z1), m is 0, 1, 2 or 3, with 1 being preferred.

[0080] In formula (Z1), L1 represents single bonds, ether bonds, ester bonds, carbonyl groups, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Among these, from a synthetic point of view, ether bonds, ester bonds, and carbonyl groups are preferred, with ester bonds and carbonyl groups being even more preferred.

[0081] In formula (Z1), Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Among these, it is preferable that Rf1 and Rf2 are both fluorine atoms in order to improve the acid strength of the produced acid.

[0082] In formula (Z1), 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 these, for the purpose of improving solvent solubility, it is preferable that at least one of Rf3 and Rf4 is trifluoromethyl.

[0083] The Z- fluorinated alkyl sulfonic acid anion should preferably be represented by the formula (Z2). [Transformation 60]

[0084] In formula (Z2), m1 is 0 or 1. When m1 is 0, it represents a benzene ring; when m1 is 1, it represents a naphthalene ring. Considering solvent solubility, a benzene ring with m1 of 0 is preferred. m2 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, m2 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better, and 0 or 1 being the most desirable. m3 is 0, 1, 2, or 3.

[0085] In formula (Z2), m4 is 0 or 1. When m4 is 0, it represents a benzene ring; when m4 is 1, it represents a naphthalene ring. Considering solvent solubility, a benzene ring with m4 of 0 is preferred. m5 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, m5 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better. m6 is 0, 1, 2, or 3.

[0086] In formula (Z2), m7 is 0 or 1. When m7 is 0, it represents a benzene ring; when m7 is 1, it represents a naphthalene ring. Considering solvent solubility, a benzene ring with m7 of 0 is preferred. m8 is 1, 2, 3, or 4. Considering the availability of raw materials, m8 is preferably 1, 2, or 3, with 1 or 2 being even better. m9 is 0, 1, 2, or 3.

[0087] In formula (Z2), m10 is 0, 1, 2, 3 or 4, with 0, 1, 2 or 3 being preferred, 1, 2 or 3 being even better, and 1 being the best. m11 is 0 or 1. m12 is 0 or 1.

[0088] When m1 is 0, then 0 ≤ m2 + m3 + m1² ≤ 4; when m1 is 1, then 0 ≤ m2 + m3 + m1² ≤ 6. Also, when m4 is 0, then 0 ≤ m5 + m6 ≤ 4; when m4 is 1, then 0 ≤ m5 + m6 ≤ 6. Also, when m7 is 0, then 0 ≤ m8 + m9 ≤ 5; when m7 is 1, then 0 ≤ m8 + m9 ≤ 7. Furthermore, regarding the number of iodine atoms in the anion, a higher number of iodine atoms, especially for EUV absorption, increases the absorption, leading to reduced solvent solubility and potential precipitation in the inhibitor composition. Therefore, 1 ≤ m2 + m5 + m8 ≤ 4 is preferable.

[0089] In formula (Z2), 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 preferred.

[0090] In formula (Z2), R11 refers to a halogen atom other than iodine, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms (heteroatomic), a hydrocarbon oxy group with 1 to 20 carbon atoms (heteroatomic), a hydrocarbon thio group with 1 to 20 carbon atoms (heteroatomic), or a hydrocarbon oxycarbonyl group with 2 to 20 carbon atoms (heteroatomic). The aforementioned halogen atom other than iodine is preferably a fluorine, chlorine, or bromine atom, with fluorine being more preferred. The hydrocarbon portion of the aforementioned hydrocarbon group, hydrocarbon oxy group, hydrocarbon thio group, and hydrocarbon oxycarbonyl group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecanyl, octadecyl, nonadecanyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclounsaturated cycloalkyl 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 these. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, halogen, etc., and some of the -CH2- group in the aforementioned hydrocarbon group can also be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, etc. As a result, it can also contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When m3 is 2 or 3, each R11 can be the same or different.

[0091] Furthermore, when m3 is 2 or 3, the two R11 atoms can also bond to each other and form a ring together with the carbon atoms of these bonds. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Also, some or all of the hydrogen atoms in the aforementioned rings can be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and some of the -CH2- groups in the aforementioned rings can also be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, etc. The result is that the rings may also contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0092] In formula (Z2), R12 represents a halogen atom other than an iodine atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, an alkyloxy group with 1 to 20 carbon atoms containing heteroatoms, an alkylthio group with 1 to 20 carbon atoms containing heteroatoms, or an alkyloxycarbonyl group with 2 to 20 carbon atoms containing heteroatoms. Specific examples of the aforementioned halogen atoms other than iodine atoms include fluorine atoms, chlorine atoms, bromine atoms, etc. The hydrocarbon portion of the aforementioned hydrocarbon group, alkyloxy group, alkylthio group, and alkyloxycarbonyl group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be the same as those exemplified by the hydrocarbon group represented by R11, but are not limited to these. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, halogen, etc., and some of the -CH2- group in the aforementioned hydrocarbon group can also be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, etc. As a result, it can also contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When m6 is 2 or 3, each R12 can be the same or different.

[0093] Furthermore, when m6 is 2 or 3, the two R12 atoms can also bond to each other and form a ring together with the carbon atoms of these bonds. The aforementioned rings are preferably 5 to 8-membered rings.

[0094] In formula (Z2), R13 represents a halogen atom other than an iodine atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, an alkyloxy group with 1 to 20 carbon atoms containing heteroatoms, an alkylthio group with 1 to 20 carbon atoms containing heteroatoms, or an alkyloxycarbonyl group with 2 to 20 carbon atoms containing heteroatoms. Specific examples of the aforementioned halogen atoms other than iodine atoms include fluorine atoms, chlorine atoms, bromine atoms, etc. The hydrocarbon portion of the aforementioned hydrocarbon group, alkyloxy group, alkylthio group, and alkyloxycarbonyl group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be the same as those exemplified by the hydrocarbon group represented by R11, but are not limited to these. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, halogen, etc., and some of the -CH2- group in the aforementioned hydrocarbon group can also be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, etc. As a result, it can also contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonolactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When m9 is 2 or 3, each R13 can be the same or different.

[0095] Furthermore, when m9 is 2 or 3, the two R13 atoms can also bond to each other and form a ring together with the carbon atoms of these bonds. The aforementioned rings are preferably 5 to 8-membered rings.

[0096] In formula (Z2), LA, LB, LC, LD, and LE are each independently a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond. Of these, LA is preferably a single bond, ether bond, ester bond, or sulfonate bond, with ether, ester, or sulfonate bonds being more preferred. LB is preferably a single bond, ether bond, ester bond, amide bond, sulfonamide bond, or sulfonate bond, with ester or sulfonate bonds being more preferred. LC is preferably a single bond, ether bond, ester bond, amide bond, or sulfonate bond, with single bond, ether, or ester bond being more preferred. LD is preferably a single bond, ether bond, ester bond, amide bond, or sulfonate bond, with single bond, ether, or ester bond being more preferred. LE is preferably a single bond, ether bond, ester bond, or sulfonate bond, with single bond, ether, or ester bond being more preferred.

[0097] When m12 is 1, it is preferable for LA and LB to be bonded to adjacent carbon atoms of the aromatic ring. In this case, substituents containing the aforementioned fluorosulfonic acid anion structure and substituents containing aromatic rings substituted with iodine atoms are located in closer spatial positions, thus higher sensitivity can be expected.

[0098] In formula (Z2), XL1 and XL2 are each independently a single bond, or may contain a heteroatom with 1 to 40 carbon atoms in an extended hydrocarbon group. The aforementioned extended hydrocarbon group can be straight-chain, branched, or cyclic; specific examples include alkane dimethyl groups, cyclic saturated extended hydrocarbon groups, and extended aryl groups. Specific examples of the aforementioned heteroatoms include oxygen atoms, nitrogen atoms, and sulfur atoms.

[0099] XL1 and XL2 may also represent specific examples of extended hydrocarbon groups with 1 to 40 carbon atoms, as shown below, but are not limited to these. Furthermore, in the following formulas, * represents the atomic bonds with LA and LC, or LB and LD, respectively. [Chemistry 61]

[0100] [Chemistry 62]

[0101] [Chemistry 63]

[0102] [Chemistry 64]

[0103] Of these, XL-0~XL-22, XL-29~XL-34, and XL-47~XL-58 are preferred.

[0104] However, in equation (Z2), m11 and m12 are not both 0, and LA, LB, LC, LD, XL1 and XL2 are not both single bonds.

[0105] In formula (Z2), Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. A fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms is preferably trifluoromethyl. It is even more preferable that Rf1 and Rf2 are fluorine atoms.

[0106] In formula (Z2), Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. The fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms is preferably trifluoromethyl.

[0107] In formula (Z2), -[C(Rf3)(Rf4)]m10-C(Rf1)(Rf2)-SO3- represents a specific example of the substructure, which is preferred but not limited to those shown below. Furthermore, in the following formula, * represents an atomic bond with LE. [Chemistry 65]

[0108] Of these, Acid-1 to Acid-7 are preferred, and Acid-1 to Acid-3, Acid-6 and Acid-7 are even better.

[0109] Specific examples of anions represented by Z- can be listed below, but are not limited to these. Furthermore, in the following formula, RA and Rf4 are the same as described above, and Me is a methyl group. Also, the bonding positions of the various substituents on the aromatic ring can be interchanged. [Chemistry 66]

[0110] [Chemistry 67]

[0111] [Chemistry 68]

[0112] [Chemistry 69]

[0113] [Chemistry 70]

[0114] [Chemistry 71]

[0115] [Chemistry 72]

[0116] [Chemistry 73]

[0117] [Chemistry 74]

[0118] [Chemistry 75]

[0119] [Chemistry 76]

[0120] [Chemistry 77]

[0121] [Chemistry 78]

[0122] [Chemistry 79]

[0123] [Chemistry 80]

[0124] [Chemistry 81]

[0125] [Chemistry 82]

[0126] [Chemistry 83]

[0127] [Chemistry 84]

[0128] [Chemistry 85]

[0129] [Chemistry 86]

[0130] [Chemistry 87]

[0131] [Chemistry 88]

[0132] [Chemistry 89]

[0133] [Chemistry 90]

[0134] [Chemistry 91]

[0135] [Chemistry 92]

[0136] [Chemistry 93]

[0137] [Chemistry 94]

[0138] [Chem. 95]

[0139] [Chemistry 96]

[0140] [Chemistry 97]

[0141] [Chem. 98]

[0142] [Chemistry 99]

[0143] [Chemistry 100]

[0144] [Chemistry 101]

[0145] [Chemistry 102]

[0146] [Chemistry 103]

[0147] [Chemistry 104]

[0148] [Chemistry 105]

[0149] [Chemistry 106]

[0150] [Chemistry 107]

[0151] [Chemistry 108]

[0152] [Chemistry 109]

[0153] [Chemical 110]

[0154] [Chemistry 111]

[0155] [Chemistry 112]

[0156] [Chemistry 113]

[0157] [Chemistry 114]

[0158] [Chemistry 115]

[0159] [Chemistry 116]

[0160] [Chemistry 117]

[0161] [Chemistry 118]

[0162] [Chemistry 119]

[0163] [Chemistry 120]

[0164] [Chemistry 121]

[0165] [Chemistry 122]

[0166] [Chemistry 123]

[0167] [Chemistry 124]

[0168] [Chemistry 125]

[0169] [Chemistry 126]

[0170] [Chemistry 127]

[0171] [Chemistry 128]

[0172] [Chemistry 129]

[0173] [Chemistry 130]

[0174] [Chemistry 131]

[0175] [Chemistry 132]

[0176] [Chemistry 133]

[0177] [Chemistry 134]

[0178] [Chemistry 135]

[0179] [Chemistry 136]

[0180] [Chemistry 137]

[0181] [Chemistry 138]

[0182] [Chemistry 139]

[0183] [Chemistry 140]

[0184] [Chemistry 141]

[0185] [Chemistry 142]

[0186] [Chemistry 143]

[0187] [Chemistry 144]

[0188] [Chemistry 145]

[0189] [Chemistry 146]

[0190] [Chemistry 147]

[0191] [Chemistry 148]

[0192] [Chemistry 149]

[0193] [Chemistry 150]

[0194] [Chemistry 151]

[0195] [Chemistry 152]

[0196] [Chemistry 153]

[0197] [Chemistry 154]

[0198] [Chemistry 155]

[0199] [Chemistry 156]

[0200] [Chemistry 157]

[0201] [Chemistry 158]

[0202] [Chemistry 159]

[0203] [Chemistry 160]

[0204] [Chemistry 161]

[0205] [Chemistry 162]

[0206] [Chemistry 163]

[0207] [Chemistry 164]

[0208] [Chemistry 165]

[0209] [Chemistry 166]

[0210] [Chemistry 167]

[0211] [Chemistry 168]

[0212] [Chemistry 169]

[0213] [Chemistry 170]

[0214] [Chemistry 171]

[0215] [Chemistry 172]

[0216] [Chemistry 173]

[0217] [Chemistry 174]

[0218] [Chemistry 175]

[0219] [Chemistry 176]

[0220] [Chemistry 177]

[0221] [Chemistry 178]

[0222] [Chemistry 179]

[0223] [Chemistry 180]

[0224] [Chemistry 181]

[0225] [Chemistry 182]

[0226] [Chemistry 183]

[0227] [Chemistry 184]

[0228] [Chemistry 185]

[0229] [Chemistry 186]

[0230] [Chemistry 187]

[0231] [Chem.188]

[0232] [Chemistry 189]

[0233] [Chemistry 190]

[0234] [Chemistry 191]

[0235] [Chemistry 192]

[0236] [Chemistry 193]

[0237] [Chemistry 194]

[0238] [Chemistry 195]

[0239] [Chemistry 196]

[0240] [Chemistry 197]

[0241] [Chemistry 198]

[0242] [Chemistry 199]

[0243] [Chem.200]

[0244] [Chemical Engineering 201]

[0245] [Chemical Engineering 202]

[0246] [Chemical Engineering 203]

[0247] [Chemical 204]

[0248] [Chemical Engineering 205]

[0249] [Chemical Engineering 206]

[0250] Specific examples of the strontium salt type monomers of this invention can be listed as any combination of the aforementioned anions and cations.

[0251] The strontium salt monomer of this invention can be synthesized using known methods. For example, it can be converted into the target strontium salt by performing a salt exchange reaction between a salt having the aforementioned strontium cation synthesized by a known method and a salt having the aforementioned anion. The salt exchange with the corresponding anion can be easily carried out using known methods, for example, see Japanese Patent Application Publication No. 2007-145797. Furthermore, the aforementioned manufacturing method is only one example, and the manufacturing method of the strontium salt of this invention is not limited thereto.

[0252] Regarding the structural characteristics of the strontium salt type monomers of the present invention, examples include the anionic structure of fluorosulfonic acid with polymerizable groups, and the aromatic ring of the strontium cation bonded with pentafluorothio groups and hydroxyl groups. In the strontium salt type monomers of the present invention, the anion has a polymerizable group; therefore, the polymers of the present invention obtained using it become anionic bonded acid generators with the anionic side bonded to the polymer backbone. That is, since an acid bonded to the polymer backbone is generated, the diffusion of the generated acid can be suppressed. Furthermore, polymerizable groups composed of styrene and vinylnaphthalene structures are particularly rigid than polymerizable groups such as methacrylates, and the glass transition temperature (Tg) of the polymer is increased, which is ideal. It is believed that the aromatic rings within or between polymers interact (π-π stacking effect), and the polymers are arranged regularly and correctly, exhibiting resistance to pattern collapse in the developer during the formation of fine patterns. Furthermore, the etching step following the formation of the fine pattern exhibits excellent etching resistance due to the aromatic rings directly bonded to the main chain. Additionally, the presence of iodine atoms in the anion is preferable. For iodine atoms, especially in EUV lithography at a wavelength of 13.5 nm, the absorption of EUV by iodine atoms is extremely high, thus generating secondary electrons during exposure. On the other hand, the pentafluorothio group bonded to the aromatic ring of the strontium cation is known to be a strong electron-withdrawing group. Therefore, it is believed that the LUMO energy level in the leading-edge orbital theory will decrease. Consequently, it becomes easier to accept secondary electrons generated from iodine atoms in the anion, promoting the decomposition of the cation and efficiently generating acid. The alkyloxycarbonyl group substituted on the aromatic ring of the strontium cation possesses lone pairs of electrons from the ester bond, and therefore can also be expected to interact with the protons of the generated acid, functioning as an acid diffusion inhibitor. Furthermore, while not to the extent of pentafluorothioyl groups, hydroxyl carbonyl groups still exhibit electron-withdrawing properties, thus a decrease in the LUMO energy level in leading-edge orbital theory can be expected. Moreover, hydroxyl carbonyl groups are hydrolyzable by alkaline developers, therefore the cationic decomposition products in the exposure section will show an affinity for alkaline developers, thereby suppressing development residues. Due to these addition effects, sensitivity is increased, preventing resolution loss caused by acid diffusion blurring, and improving the performance of lithography equipment such as LWR and CDU. Therefore, the polymer of this invention is particularly suitable as a material for chemically amplified positive resist components.

[0253] [polymer] The polymer of the present invention comprises repeating units derived from strontium salt type monomers represented by formula (A) (hereinafter also referred to as repeating unit A).

[0254] The aforementioned polymer may also contain repeating units represented by formula (a1) (hereinafter also referred to as repeating unit a1.) or repeating units represented by formula (a2) (hereinafter also referred to as repeating unit a2.). [Chemical 207]

[0255] In formulas (a1) and (a2), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0256] In formula (a1), X1 is a single bond, an phenyl group, a naphthyl group, or *-C(=O)-O-X11-. This phenyl or naphthyl group may be substituted with a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, a saturated hydrocarbon oxygen group containing fluorine atoms with 1 to 10 carbon atoms, or a halogen atom. X11 is a saturated hydrocarbon group with 1 to 10 carbon atoms, an phenyl group, or a naphthyl group. This saturated hydrocarbon group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * indicates an atomic bond with a carbon atom in the main chain.

[0257] In formula (a2), X2 is a single bond or *-C(=O)-O-. * indicates an atomic bond with a carbon atom in the main chain. R21 is a halogen atom, cyano group, hydroxyl group, nitro group, or may contain a hydrocarbon group with 1-20 carbon atoms of a heteroatom, a hydrocarbon oxygen group with 1-20 carbon atoms of a heteroatom, a hydrocarbon carbonyl group with 2-20 carbon atoms of a heteroatom, a hydrocarbon carbonyl oxygen group with 2-20 carbon atoms of a heteroatom, or a hydrocarbon oxygen carbonyl group with 2-20 carbon atoms of a heteroatom. a1 is 0, 1, 2, 3, or 4, preferably 0 or 1. When a1 is 2, 3, or 4, each R21 can be the same or different.

[0258] In formulas (a1) and (a2), AL1 and AL2 are each independently acid-indestructible groups. Specific examples of the aforementioned acid-indestructible groups can be cited, for example, those described in Japanese Patent Application Publication Nos. 2013-80033 and 2013-83821.

[0259] Generally speaking, specific examples of the aforementioned unstable acid groups can be represented by the following formulas (AL-1) to (AL-3). [Chemical Engineering 208] In the formula, * represents an atomic bond.

[0260] In formulas (AL-1) and (AL-2), RL1 and RL2 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.

[0261] In formula (AL-1), a2 is an integer from 0 to 10, and should preferably be 1, 2, 3, 4 or 5.

[0262] In formula (AL-2), RL3 and RL4 are each independently a hydrogen atom or a hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Furthermore, two of RL2, RL3, and RL4 can also bond to each other and form a ring with 3 to 20 carbon atoms together with the bonded carbon atoms or carbon and oxygen atoms. The aforementioned rings are preferably rings with 4 to 16 carbon atoms, and especially alicyclic rings.

[0263] In formula (AL-3), RL5, RL6, and RL7 are each independently a hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Furthermore, two of RL5, RL6, and RL7 can also bond to each other and form a ring with 3 to 20 carbon atoms together with the bonded carbon atoms. The aforementioned ring is preferably a ring with 4 to 16 carbon atoms, and especially preferably an alicyclic ring.

[0264] Other specific examples of the aforementioned acid-indestabilized groups can be cited in paragraphs

[0064] to

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

[0013] to

[0014] of Japanese Patent Publication No. 7492842. These examples use the formation of conjugated olefins or acrylate derivatives after acid desorption reactions as the driving force for the reaction.

[0265] Specific examples of repeating unit a1 may be listed below, but are not limited to these. Furthermore, in the following formula, RA and AL1 are the same as those described above. [Chemical Engineering 209]

[0266] [Chemical 210]

[0267] [Chemistry 211]

[0268] [Chemistry 212]

[0269] Specific examples of repeating unit a2 may be listed below, but are not limited to these. Furthermore, in the following formula, RA and AL2 are the same as those described above. [Chemistry 213]

[0270] [Chemistry 214]

[0271] [Chemical 215]

[0272] The aforementioned polymer may also contain repeating units represented by the following formula (a3) ​​(hereinafter also referred to as repeating unit a3). [Chemistry 216]

[0273] In formula (a3), b1 is 0 or 1. When b1 is 0, it represents a benzene ring; when b1 is 1, it represents a naphthalene ring. Considering solvent solubility, a benzene ring with b1 of 0 is preferred. b2 represents 0, 1, 2, or 3 when b1 is 0, and 0, 1, 2, 3, 4, or 5 when b1 is 1. Considering the availability of raw materials, b2 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0274] In formula (a3), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. It is preferable for RA to be a hydrogen atom or a methyl group, with hydrogen being even more preferred.

[0275] In formula (a3), X3 represents a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * indicates an atomic bond with a carbon atom in the main chain. Among these, single bonds are preferred, and *-C(=O)-O- is even more preferred.

[0276] In formula (a3), X4 is a single bond, an aliphatic hydrocarbon group with 1 to 4 carbon atoms, a carbonyl group, a sulfonyl group, or a combination thereof. Among these, considering the availability of raw materials, a single bond, a carbonyl group, or a sulfonyl group is preferred; considering the polar group generated after the reaction, a single bond or a carbonyl group is even better.

[0277] In formula (a3), X5 and X6 are each independently an oxygen atom or a sulfur atom. However, X4 and X6 are bonded to adjacent carbon atoms of the aromatic ring. X5 and X6 can be the same or different. From the perspective of reactivity, it is better if X5 and X6 are both oxygen atoms.

[0278] In formula (a3), R22 and R23 are each independently hydrogen atoms, or may contain hydrocarbon groups with 1 to 20 carbon atoms containing heteroatoms. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecanyl, octadecyl, nonadecanyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclounsaturated cycloalkyl 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 these. Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and one part of the -CH2- group in the aforementioned hydrocarbon group can also be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, etc. As a result, it can also include 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.

[0279] Furthermore, R22 and R23 can also bond to each other and form rings together with the carbon atoms of these bonds. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Also, some or all of the hydrogen atoms in the aforementioned rings can be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and some of the -CH2- groups in the aforementioned rings can also be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, etc. The result is that the rings may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0280] In formula (a3), R24 represents a halogen atom, hydroxyl group, cyano group, nitro group, or may include a hydrocarbon group with 1 to 20 carbon atoms (heteroatomic), a hydrocarbon oxygen group with 1 to 20 carbon atoms (heteroatomic), a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms (heteroatomic), or a hydrocarbon thio group with 1 to 20 carbon atoms (heteroatomic), or -N(R24A)(R24B). R24A and R24B are each independently a hydrogen atom or a hydrocarbon group with 1 to 6 carbon atoms. The aforementioned halogen atom is preferably a fluorine atom, chlorine atom, bromine atom, or iodine atom, with fluorine or iodine atom being more preferred. The hydrocarbon part of the aforementioned hydrocarbon group, hydrocarbon oxygen group, hydrocarbon oxygen carbonyl group, and hydrocarbon thio group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon groups represented by R22 and R23. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, halogen, etc., and some of the -CH2- group in the aforementioned hydrocarbon group can also be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, etc. As a result, it can also include 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 R24 can be the same or different.

[0281] Furthermore, when b2 is 2 or more, multiple R24 atoms can bond to each other and form a ring together with the carbon atoms of the aromatic rings formed by these bonds. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Also, some or all of the hydrogen atoms in the aforementioned rings can be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and some of the -CH2- groups in the aforementioned rings can also be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, etc. The result is that the rings may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0282] Specific examples of repeating unit a3 may be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above, and Me is a methyl group. Also, the bonding positions of the various substituents on the aromatic ring can be interchanged. [Chemistry 217]

[0283] [Chemistry 218]

[0284] [Chemistry 219]

[0285] [Chem.220]

[0286] [Chemistry 221]

[0287] [Chemistry 222]

[0288] [Chemistry 223]

[0289] [Chemistry 224]

[0290] [Chemistry 225]

[0291] [Chemistry 226]

[0292] [Chemistry 227]

[0293] [Chemistry 228]

[0294] [Chemistry 229]

[0295] [Chemistry 230]

[0296] [Chemistry 231]

[0297] [Chemistry 232]

[0298] [Chemistry 233]

[0299] [Chemistry 234]

[0300] [Chemistry 235]

[0301] [Chemistry 236]

[0302] [Chemistry 237]

[0303] [Chemistry 238]

[0304] [Chemistry 239]

[0305] [Chemistry 240]

[0306] [Chemistry 241]

[0307] [Chemistry 242]

[0308] [Chemistry 243]

[0309] [Chemistry 244]

[0310] [Chemistry 245]

[0311] [Chemistry 246]

[0312] [Chemistry 247]

[0313] [Chemistry 248]

[0314] [Chemistry 249]

[0315] [Chemistry 250]

[0316] [Chemistry 251]

[0317] [Chemistry 252]

[0318] [Chemistry 253]

[0319] [Chemistry 254]

[0320] [Chemistry 255]

[0321] [Chemistry 256]

[0322] [Chemistry 257]

[0323] [Chemistry 258]

[0324] [Chemistry 259]

[0325] [Chemistry 260]

[0326] [Chemistry 261]

[0327] [Chemistry 262]

[0328] [Chemistry 263]

[0329] [Chemistry 264]

[0330] [Chemistry 265]

[0331] [Chemistry 266]

[0332] The aforementioned polymer may also contain repeating units represented by formula (b1) (hereinafter also referred to as repeating unit b1.) or repeating units represented by formula (b2) (hereinafter also referred to as repeating unit b2.). [Chemistry 267]

[0333] In formulas (b1) and (b2), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y1 is a single bond or *-C(=O)-O-. * indicates an atomic bond with a carbon atom in the main chain. R31 is a hydrogen atom, or a group containing at least one of the following: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulfonyl lactone ring, and carboxylic anhydride (-C(=O)-OC(=O)-). R32 is a halogen atom, carboxyl group, nitro group, cyano group, or a hydrocarbon group containing a heteroatom with 1 to 20 carbon atoms, or a hydrocarbon oxygen group containing a heteroatom with 1 to 20 carbon atoms, or a hydrocarbon carbonyl group containing a heteroatom with 2 to 20 carbon atoms, or a hydrocarbon carbonyl oxygen group containing a heteroatom with 2 to 20 carbon atoms, or a hydrocarbon oxygen carbonyl group containing a heteroatom with 2 to 20 carbon atoms. When c2 is 2, 3, or 4, each R32 can be the same or different. c1 is 1, 2, 3, or 4. c2 is 0, 1, 2, 3, or 4. However, 1 ≤ c1 + c2 ≤ 5.

[0334] Specific examples of repeating unit b1 may be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 268]

[0335] [Chemistry 269]

[0336] [Chemistry 270]

[0337] [Chemistry 271]

[0338] [Chemistry 272]

[0339] [Chemistry 273]

[0340] [Chemistry 274]

[0341] [Chemistry 275]

[0342] [Chemistry 276]

[0343] [Chemistry 277]

[0344] [Chemistry 278]

[0345] [Chemistry 279]

[0346] [Chemistry 280]

[0347] [Chemistry 281]

[0348] [Chemistry 282]

[0349] [Chemistry 283]

[0350] Examples of repeated units b2 may be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 284]

[0351] [Chemistry 285]

[0352] [Chemistry 286]

[0353] [Chemistry 287]

[0354] [Chemistry 288]

[0355] For repeating units b1 or b2, the presence of a lactone ring as a polar group is preferred in ArF lithography, while the presence of a phenolic site is preferred in KrF lithography, EB lithography, and EUV lithography.

[0356] The aforementioned polymer may also contain repeating units (hereinafter also referred to as repeating unit c) that protect hydroxyl groups with acid-independent groups. Repeating unit c is not particularly limited as long as it has a structure with one or more hydroxyl groups protected, and the protecting group decomposes to generate hydroxyl groups by the action of acid, but is preferably represented by the following formula (c1). [Chemistry 289]

[0357] In formula (c1), RA refers to hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups. R41 may also contain heteroatoms with a carbon number of 1 to 30 and a (d+1) valence hydrocarbon group. R42 refers to acid-labile groups. d refers to 1, 2, 3, or 4.

[0358] In formula (c1), R42 represents an acid-insecure group, which can be protected by the action of an acid to generate a hydroxyl group. The structure of R42 is not particularly limited, but it is preferable to have an acetal structure, a ketal structure, a hydroxyl group, or a hydroxyl group represented by formula (c2), especially a hydroxyl group represented by formula (c2). [Chemistry 290] In the formula, * represents an atomic bond. R43 refers to hydrocarbon groups with 1 to 15 carbon atoms.

[0359] Specific examples of the acid-labile group represented by R42, the hydroxymethyl group represented by formula (c2), and the repeating unit c include the same ones as those exemplified in the description of the repeating unit c described in JP-A-2020-111564.

[0360] The aforementioned polymer may also include a repeating unit d derived from indene, benzofuran, benzothiophene, acenaphthylene, chromone, coumarin, norbornadiene, or derivatives thereof. Specific examples of the monomer providing the repeating unit d include those shown below, but are not limited thereto. [Chemical formula 291]

[0361] The aforementioned polymer may also include a repeating unit e derived from indan, vinylpyridine, or vinylcarbazole.

[0362] In the polymer of the present invention, the content ratios of the repeating units A, a1, a2, a3, b1, b2, c, d, and e are preferably 0 < A ≤ 0.4, 0 ≤ a1 ≤ 0.8, 0 ≤ a2 ≤ 0.8, 0 ≤ a3 ≤ 0.6, 0 < a1 + a2 + a3 ≤ 0.8, 0 ≤ b1 ≤ 0.6, 0 ≤ b2 ≤ 0.6, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.3, and 0 ≤ e ≤ 0.3, more preferably 0 < A ≤ 0.3, 0 ≤ a1 ≤ 0.7, 0 ≤ a2 ≤ 0.7, 0 ≤ a3 ≤ 0.5, 0 < a1 + a2 + a3 ≤ 0.7, 0 ≤ b1 ≤ 0.5, 0 ≤ b2 ≤ 0.5, 0 ≤ c ≤ 0.3, 0 ≤ d ≤ 0.3, and 0 ≤ e ≤ 0.3. However, A + a1 + a2 + a3 + b1 + b2 + c + d + e ≤ 1.0.

[0363] The weight average molecular weight (Mw) of the aforementioned polymer is preferably 1000 to 500000, more preferably 3000 to 100000. If Mw is within this range, sufficient etching resistance can be obtained, and there is no concern about a decrease in resolution due to an inability to ensure a difference in dissolution rate before and after exposure. In the present invention, Mw is a polystyrene equivalent measurement value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or N,N-dimethylformamide (DMF) as a solvent. <000178​The molecular weight distribution (Mw / Mn) of the aforementioned polymers tends to increase with the refinement of the pattern. Therefore, to obtain a resist composition suitable for fine pattern sizes, a narrow dispersion of Mw / Mn of 1.0 to 2.0 is preferable. Within this range, there are fewer low- and high-molecular-weight polymers, eliminating concerns about foreign matter being observed on the pattern after exposure or deterioration of the pattern shape.

[0365] For example, a method for synthesizing the aforementioned polymer can be described as a method in which a monomer providing the aforementioned repeating unit is added to an organic solvent, a free radical polymerization initiator is added, and the mixture is heated to carry out polymerization.

[0366] Specific examples of organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, dialkylene, cyclohexane, cyclopentane, methyl ethyl ketone (MEK), propylene glycol monomethyl ether acetate (PGMEA), and γ-butyrolactone (GBL). Specific examples of polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl-2,2-azobis(2-methylpropionate), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, and lauryl peroxide. The amount of these initiators added relative to the total monomers to be polymerized is preferably 0.01~25 moles. The reaction temperature is preferably 50~150℃, and more preferably 60~100℃. A reaction time of 2 to 24 hours is preferable, but from the perspective of production efficiency, 2 to 12 hours is even better.

[0367] The aforementioned polymerization initiator can be added to the monomer solution and supplied to the reactor, or the initiator solution can be prepared separately from the monomer solution and supplied to the reactor independently. Since there is a possibility that the polymerization reaction may proceed due to free radicals generated by the initiator during the standby time, resulting in the formation of ultra-high molecular weight polymers, from a quality management perspective, it is preferable that the monomer solution and initiator solution be prepared and added dropwise independently. 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 such chain transfer agents added relative to the total amount of monomers to be polymerized should preferably be 0.01~20 mol%.

[0368] In the case of monomers containing hydroxyl groups, the hydroxyl groups can be replaced in advance during polymerization with acetal groups such as ethoxy-ethoxy, which are easily deprotected by acids. After polymerization, the protection can be removed using weak acids and water. Alternatively, they can be replaced in advance with acetyl, methyl, neopentyl, etc., and then subjected to alkaline hydrolysis after polymerization.

[0369] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, hydroxystyrene or hydroxyvinylnaphthalene can be copolymerized with other monomers in an organic solvent, with the addition of a free radical polymerization initiator and heating. Alternatively, acetoxystyrene or acetoxyvinylnaphthalene can be used, and after polymerization, the acetoxy group can be deprotected by alkaline hydrolysis to become polyhydroxystyrene or hydroxyvinylnaphthalene.

[0370] Specific examples of alkali used in alkaline hydrolysis include ammonia and triethylamine. Furthermore, the reaction temperature should preferably be -20 to 100°C, more preferably 0 to 60°C. The reaction time should preferably be 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0371] Furthermore, the amount of each monomer in the aforementioned monomer solution can be appropriately set, for example, in a manner that makes it a preferred content ratio for the aforementioned repeating unit.

[0372] The polymer obtained by the aforementioned manufacturing method can be used as the final product by the reaction solution obtained through polymerization reaction, or it can be used as the final product by the powder obtained through refining steps such as adding the polymer liquid to a solvent-poor solution to obtain the powder. Considering the perspective of work efficiency and quality stability, it is better to use the polymer solution obtained by dissolving the powder obtained through the refining step in the solvent as the final product.

[0373] Specific examples of solvents used at this time can be cited from paragraphs

[0144] to

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

[0374] In the aforementioned polymer solution, the polymer concentration is preferably 0.01~30% by mass, and more preferably 0.1~20% by mass.

[0375] The aforementioned reaction solutions and polymer solutions are best filtered. Filtering removes foreign matter and colloids that could cause defects, thus effectively stabilizing the quality.

[0376] The materials used in the aforementioned filters include fluorocarbon-based, cellulose-based, nylon-based, polyester-based, and hydrocarbon-based materials. In the filtration step involving the inhibitor composition, filters made of fluorocarbon-based materials such as Teflon (registered trademark), polyethylene, polypropylene, or nylon are preferred. The pore size of the filter should be appropriately selected according to the target cleanliness level, preferably below 100 nm, and more preferably below 20 nm. Furthermore, these filters can be used individually or in combination. The filtration method can preferably involve passing the solution through only once, followed by multiple filtrations through solution circulation. The filtration steps can be performed in any order and number of times during the polymer manufacturing process, preferably filtering the reaction solution, polymer solution, or both after the polymerization reaction.

[0377] [Chemical Amplification Inhibitor Composition] [(A) Basic Polymer] The chemical amplification inhibitor composition of the present invention contains a base polymer containing the aforementioned polymer as component (A).

[0378] The aforementioned polymers may be used alone or in combination with two or more polymers having different composition ratios, Mw and / or Mw / Mn. Furthermore, (A) the base polymer, in addition to the aforementioned polymers, may also include hydrides of ring-opening shift polymers, for which the polymers described in Japanese Patent Application Publication No. 2003-66612 may be used.

[0379] [(B) Organic solvents] The chemical amplification inhibitor composition of the present invention may also include an organic solvent as component (B). The organic solvent (B) is not particularly limited as long as it can dissolve the aforementioned components and the components described below. Specific examples of such organic solvents include ketones such as cyclopentanone, cyclohexanone, and methyl-2-n-pentanone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ketols such as DAA; ethers such as PGME, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tributyl acetate, tributyl propionate, and propylene glycol monotert-butyl ether acetate; lactones such as GBL; and mixed solvents of these.

[0380] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, cyclohexanone, GBL, ethyl lactate, DAA, and mixed solvents thereof are preferred as they have particularly good solubility for component (A), i.e., the base polymer.

[0381] In the chemical amplification inhibitor composition of the present invention, the content of (B) organic solvent relative to 80 parts by mass of (A) base polymer is preferably 200-7000 parts by mass, and more preferably 400-5000 parts by mass. (B) Organic solvent can be used alone or in combination with two or more.

[0382] [(C) Quenching agent] The chemical amplification inhibitor composition of the present invention may also include a quencher as component (C). Furthermore, the quencher in the present invention is a material used to prevent diffusion toward the unexposed area by capturing the acid generated by the photoacid generator in the chemical amplification inhibitor composition, thereby forming a desired pattern.

[0383] (C) Specific examples of quenching agents can be listed as onion salts represented by formula (1) or (2). [Chemistry 292]

[0384] In formula (1), Rq1 is a hydrogen atom, or may also contain a hydrocarbon group with 1 to 40 carbon atoms of heteroatoms, except that the hydrogen atom at the α-position of the sulfonic acid group is replaced by a fluorine atom or a fluoroalkyl group. In formula (2), Rq2 is a hydrogen atom, or may also contain a hydrocarbon group with 1 to 40 carbon atoms of heteroatoms.

[0385] Rq1 represents hydrocarbon groups with 1 to 40 carbon atoms. Specifically, examples include alkyl groups with 1 to 40 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, tripentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclo[5.2.1.02,6]decyl, and adamantylalkyl; and aryl groups with 6 to 40 carbon atoms such as phenyl, naphthyl, and anthracene. Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and one part of the aforementioned hydrocarbon group -CH2- can also be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, etc. As a result, it can also contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0386] Specifically, the hydrocarbon group represented by Rq2, in addition to the substituents exemplified in the specific examples of Rq1, can also include fluorinated saturated hydrocarbon groups such as trifluoromethyl and trifluoroethyl, and fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

[0387] Specific examples of the anions of the onium salts represented by formula (1) are shown below, but are not limited to these. [Chemistry 293]

[0388] [Chemistry 294]

[0389] [Chemistry 295]

[0390] [Chemistry 296]

[0391] [Chemistry 297]

[0392] Specific examples of the anions of the onium salts represented by equation (2) are shown below, but are not limited to these. [Chemistry 298]

[0393] [Chemistry 299]

[0394] [Chemical 300]

[0395] [Chemical Engineering 301]

[0396] [Chemical 302]

[0397] In formulas (1) and (2), Mq+ is a ium cation. Examples of the aforementioned ium cations include strontium cations, monium cations, and ammonium cations. Specific examples of the aforementioned strontium cations include those exemplified by the strontium salt type monomer cations represented by 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 Patent Publication No. 2024 / 128017, and those described in paragraphs

[0035] to

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

[0398] Furthermore, among the aforementioned strontium cations, the strontium cation represented by the formula (sulfo-1) is also preferred. [Chemical 303]

[0399] In formula (sulfo-1), e1 is either 0 or 1. When e1 is 0, it is a benzene ring; when e1 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with e1 of 0 is preferred. e2 is either 0 or 1. When e2 is 0, it is a benzene ring; when e2 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with e1 of 0 is preferred. e3 is either 0 or 1. When e3 is 0, it is a benzene ring; when e3 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with e3 of 0 is preferred.

[0400] In formula (sulfo-1), e4 is 0, 1, 2, 3, or 4. The more iodine atoms in the cation structure, the higher the absorption of EUV, but the less solvent-soluble it becomes, raising concerns about precipitation in the inhibitor composition. Therefore, e4 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0401] In formula (sulfo-1), e5 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, e5 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better. e6 is 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, e6 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better. e7 is 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, e7 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0402] In formula (sulfo-1), e8 is 0, 1, or 2. Considering the availability of raw materials, e8 is preferably 0 or 1. e9 is 0, 1, or 2. Considering the availability of raw materials, e9 is preferably 0 or 1. e10 is 0, 1, or 2. Considering the availability of raw materials, e10 is preferably 0 or 1.

[0403] In formula (sulfo-1), e11 is either 0 or 1. When e11 is 0, it is a benzene ring; when e11 is 1, it is a naphthalene ring. Considering the solubility of the solvent, it is better for e11 to be 0, which is a benzene ring.

[0404] In formula (sulfo-1), e12 is 0, 1, 2, 3, or 4. The more iodine atoms in the cation structure, the higher the absorption of EUV, which can lead to poor solvent solubility and potential precipitation in the inhibitor composition. Therefore, e12 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0405] In formula (sulfo-1), e13 is 0, 1, or 2. From the perspective of raw material availability, e13 is preferably 0 or 1. e14 is 0, 1, or 2. From a synthetic perspective, e14 is preferably 0 or 1.

[0406] However, when e1 is 0, then 0 ≦ e6 + e9 ≦ 4; when e1 is 1, then 0 ≦ e6 + e9 ≦ 6. When e2 is 0, then 0 ≦ e7 + e10 ≦ 4; when e2 is 1, then 0 ≦ e7 + e10 ≦ 6. When e3 is 0, then 1 ≦ e4 + e5 + e8 + e14 ≦ 4; when e3 is 1, then 1 ≦ e4 + e5 + e8 + e14 ≦ 6. When e11 is 0, then 0 ≦ e12 + e13 ≦ 4; when e11 is 1, then 0 ≦ e12 + e13 ≦ 6. Also, e4 + e12 ≧ 1.

[0407] In formula (sulfo-1), RF1 to RF3 are each independently a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms. Among these, trifluoromethyl, trifluoromethoxy, and trifluorothiomethoxy are preferred. When e5 is 2, 3, or 4, each RF1 may be the same or different from the others. When e6 is 2, 3, 4, 5, or 6, each RF2 may be the same or different from the others. When e7 is 2, 3, 4, 5, or 6, each RF3 may be the same or different from the others.

[0408] In formula (sulfo-1), Rq11 to Rq14 are halogen atoms other than iodine and fluorine atoms, nitro groups, cyano groups, and may also include hydrocarbon groups with 1 to 20 carbon atoms (heteroatomic), hydroxyl groups with 1 to 20 carbon atoms (heteroatomic), or thioalkyl groups with 1 to 20 carbon atoms (heteroatomic). The hydrocarbon portion of the aforementioned hydrocarbon groups, hydroxyl groups, and thioalkyl groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon groups represented by R1 to R3 in the description of formula (A). Furthermore, one or all of the hydrogen atoms in the hydrocarbon group, hydroxyl group, and thiol group can be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc. The -CH2- part of the aforementioned hydrocarbon group can also be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, etc. As a result, it can also include 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.

[0409] Furthermore, when e8 is 2, the two Rq11 atoms can be the same or different, and they can also bond to each other and form a ring together with the carbon atoms of these bonds. When e9 is 2, the two Rq12 atoms can be the same or different, and they can also bond to each other and form a ring together with the carbon atoms of these bonds. When e10 is 2, the two Rq13 atoms can be the same or different, and they can also bond to each other and form a ring together with the carbon atoms of these bonds. When e13 is 2, the two Rq14 atoms can be the same or different, and they can also bond to each other and form a ring together with the carbon atoms of these bonds. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norcamphene rings, adamantane rings, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned ring can be replaced by heteroatom groups such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Similarly, some of the -CH2- in the aforementioned ring can be replaced by heteroatom groups such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it can also contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0410] Furthermore, aromatic rings of S+ in the sulfonium cation represented by formula (sulfo-1) can also bond to each other and form rings together with S+. In this case, specific examples of the aforementioned ring structures can be listed as those represented by the following formulas. [Chemical 304] In the formula, the dashed lines represent atomic bonds.

[0411] In formula (sulfo-1), LF and LG are each independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Of these, LF is preferably a single bond, ether bond, ester bond, or sulfonate bond, with ester or sulfonate bond being more preferred. LG is preferably a single bond, ether bond, or ester bond, with single bond being more preferred.

[0412] In formula (sulfo-1), XL3 is a single bond, or may contain a heteroatom and be an extended hydrocarbon group with 1 to 40 carbon atoms. The aforementioned extended hydrocarbon group can be straight-chain, branched, or cyclic; specific examples include alkane dimethyl, cyclic saturated extended hydrocarbon group, and extended aryl. Specific examples of the aforementioned heteroatom include oxygen, nitrogen, and sulfur atoms. Specific examples of extended hydrocarbon groups with 1 to 40 carbon atoms represented by XL3 can be exemplified by XL-0 to XL-58, as shown in the description of formula (Z2) where XL1 and XL2 represent extended hydrocarbon groups with 1 to 40 carbon atoms. Among these, XL3 is preferably XL-0 to XL-22, XL-29 to XL-34, and XL-47 to XL-58.

[0413] The strontium cation represented by formula (sulfo-1) should preferably be represented by the following formula (sulfo-1-1). [Chemical 305] In the formula, e4~e10, e12~e14, RF1~RF3, Rq11~Rq14, LF, LG and XL3 are the same as those mentioned above.

[0414] The strontium cation represented by formula (sulfo-1-1) should preferably be represented by formula (sulfo-1-2). [Chemical 306] In the formula, e4~e10, RF1~RF3 and Rq11~Rq13 are the same as those mentioned above.

[0415] Specific examples of strontium cations represented by formula (sulfo-1) are shown below, but are not limited to these. Furthermore, in the following formula, Me is a methyl group. [Chemical 307]

[0416] [Chemical 308]

[0417] [Chemical 309]

[0418] [Chemical 310]

[0419] [Chemistry 311]

[0420] [Chemistry 312]

[0421] [Chemistry 313]

[0422] [Chemical 314]

[0423] [Chemical 315]

[0424] [Chemistry 316]

[0425] [Chemistry 317]

[0426] [Chemistry 318]

[0427] [Chemistry 319]

[0428] [Chem.320]

[0429] [Chemistry 321]

[0430] [Chemistry 322]

[0431] [Chemistry 323]

[0432] [Chemistry 324]

[0433] [Chemistry 325]

[0434] [Chemistry 326]

[0435] [Chemistry 327]

[0436] [Chemistry 328]

[0437] [Chemistry 329]

[0438] [Chemistry 330]

[0439] [Chemistry 331]

[0440] [Chemistry 332]

[0441] [Chemistry 333]

[0442] [Chemistry 334]

[0443] Specific examples of the aforementioned cations can be cited in paragraph

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

[0444] Specific examples of the aforementioned ammonium cations can be represented by the following formula (am-1). [Chemistry 335] In formula (am-1), Rq21 to Rq24 are each independently a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. Furthermore, Rq21 and Rq22 may also bond to each other and form a ring together with the nitrogen atoms of these bonds. Specific examples of the aforementioned hydrocarbon groups can be listed as those exemplified by the hydrocarbon groups represented by R1 to R3 in the description of formula (A).

[0445] Specific examples of ammonium cations represented by formula (am-1) are shown below, but are not limited to these. [Chemistry 336]

[0446] Specific examples of onium salts represented by formula (1) or (2) can be listed as any combination of the aforementioned anions and cations. Furthermore, these onium salts can be easily prepared by ion exchange reactions using known organic chemical methods. For example, Japanese Patent Application Publication No. 2007-145797 can be consulted regarding ion exchange reactions.

[0447] The onium salts represented by formula (1) or (2) function as quenchers in the chemical amplification inhibitor composition of the present invention. This is because the onium salts are conjugate bases of the aforementioned relative anionic weak acids. Here, a weak acid is defined as an acidity that exhibits an acidity that cannot be protected by the acid-instable groups of the units containing acid-instable groups used in the base polymer. When the onium salts represented by formula (1) or (2) are used in combination with a conjugate base having a strong acid such as a sulfonic acid with fluorinated α-position as a relative anionic onium salt-type photoacid generator, they function as quenchers. That is, when an onium salt that produces a strong acid like sulfonic acid with α-fluorination is mixed with an onium salt that produces a weak acid like unfluorinated sulfonic acid or carboxylic acid, the strong acid produced by the photoacid generator irradiated by high-energy rays collides with the onium salt containing unreacted weak acid anions. This results in the release of the weak acid through salt exchange, producing an onium salt containing strong acid anions. In this process, the strong acid exchanges with the weak acid with lower catalytic energy, thus macroscopically the acid loses its activity and acid diffusion can be controlled.

[0448] Furthermore, (C) the quenching agent may also be an onium salt having strontium cation and benzene oxide anion sites in the same molecule as described in Japanese Patent No. 6848776, as well as an onium salt having strontium cation and carboxylate anion sites in the same molecule as described in Japanese Patent No. 6583136, Japanese Patent Application Publication No. 2020-200311, and an onium salt having monium cation and carboxylate anion sites in the same molecule as described in Japanese Patent No. 6274755.

[0449] Therefore, it is believed that when the photoacid generator producing strong acids is an onium salt, as mentioned above, the strong acid produced by high-energy ray irradiation can exchange with a weak acid. On the other hand, the weak acid produced by high-energy ray irradiation is difficult to collide with the onium salt that produces unreacted strong acid to achieve salt exchange. This is because onium cations readily form ion pairs with the anions of stronger acids.

[0450] When the chemical amplification inhibitor composition of the present invention contains an onium salt represented by formula (1) or (2) as a quencher in (C), its content relative to 80 parts by mass of the base polymer in (A) is preferably 0.1 to 20 parts by mass, and more preferably 0.1 to 10 parts by mass. If the content of the onium salt-type quencher in component (C) is within the aforementioned range, the resolution is good and the sensitivity does not decrease significantly, which is ideal. The onium salt represented by formula (1) or (2) can be used alone or in combination of two or more.

[0451] The chemical amplification inhibitor composition of the present invention may also include a nitrogen-containing compound as a quencher (C). Specific examples of nitrogen-containing compounds as component (C) include the first-, second-, or third-order amine compounds described in paragraphs

[0146] to

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

[0452] Alternatively, strontium sulfonate salts with nitrogen-containing substituents, which are nitrogen-containing compounds, can also be used. Such compounds function as quenchers in the unexposed areas, while in the exposed areas, they lose their quenching ability due to neutralization with the acid they generate, and instead function as so-called photodegrading bases. By using photodegrading bases, the contrast between the exposed and unexposed areas can be further enhanced. For example, Japanese Patent Application Publication Nos. 2009-109595 and 2012-46501 can be referenced for photodegrading bases.

[0453] When the chemical amplification inhibitor composition of the present invention includes a nitrogen-containing compound as a quencher (C), its content relative to 80 parts by mass of the base polymer (A) 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.

[0454] [(D) Photoacid generator] The chemical amplification inhibitor composition of the present invention may also include a photoacid generator as component (D). The aforementioned photoacid generator is not particularly limited as long as it is a compound that produces acid upon irradiation by high-energy rays. Preferred photoacid generators may be represented by formulas (3) or (4) below. [Chemistry 337]

[0455] In formula (3), R101 to R105 are each independently a halogen atom, or may contain a hydrocarbon group with 1 to 20 carbon atoms of heteroatoms. Furthermore, any two of R101, R102 and R103 may also bond to each other and form a ring together with the sulfur atoms of such bonds.

[0456] Specific examples of strontium salt cations represented by formula (3) may be exemplified by specific examples of strontium salt type monomer cations represented by 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 Patent Publication No. 2024 / 128017, those described in paragraphs

[0035] to

[0046] of Japanese Patent Publication No. 7491173, and specific examples of strontium cations represented by formula (sulfo-1), but are not limited to these. Specific examples of ferrous salt cations represented by formula (4) may be exemplified by paragraph

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

[0457] In equations (3) and (4), Xa- is the anion of a strong acid. The anions of the aforementioned strong acids can be represented by any of the following equations (Xa-1) to (Xa-4). [Chemistry 338]

[0458] In formula (Xa-1), Rfa 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 as those exemplified by the hydrocarbon group represented by Rfa1 in formula (Xa-1-1) described later.

[0459] The anion represented by formula (Xa-1) should preferably be represented by the following formula (Xa-1-1). [Chemistry 339]

[0460] In formula (Xa-1-1), Q1 and Q2 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms. For improved solvent solubility, at least one of them is preferably trifluoromethyl. m is 0, 1, 2, 3, or 4, with 1 being particularly preferred. The Rfa1 system may also include a hydrocarbon group with 1 to 35 carbon atoms and heteroatoms. The aforementioned heteroatoms are preferably oxygen, nitrogen, sulfur, or halogen atoms, with oxygen atoms being even more preferred. Considering the need to obtain high resolution when forming fine patterns, the aforementioned hydrocarbon groups are preferably with 6 to 30 carbon atoms.

[0461] In formula (Xa-1-1), Rfa1 represents a hydrocarbon group with 1 to 35 carbon atoms, which can be saturated or unsaturated, and can be 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, tributyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and icosyl; cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norcamphenyl, norcamphenylmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups with 2 to 35 carbon atoms, such as 2-propenyl and 3-cyclohexenyl; aryl groups with 6 to 35 carbon atoms, such as phenyl, 1-naphthyl, 2-naphthyl, and 9-enyl; aralkyl groups with 7 to 35 carbon atoms, such as benzyl and diphenylmethyl; and groups obtained by combining these.

[0462] Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, halogen, etc., and the -CH2- portion of the aforementioned hydrocarbon group can also be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, etc. As a result, it can also contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulopentalide ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. Specific examples of hydrocarbon groups containing heteroatoms include tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetaminomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-sideoxypropyl, 4-sideoxy-1-adamantyl, 3-sideoxycyclohexyl, etc.

[0463] In formula (Xa-1-1), the La1 group consists of single bonds, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, or carbamate bonds. From a synthetic point of view, ether bonds or ester bonds are preferred, with ester bonds being even better.

[0464] Specific examples of anions represented by formula (Xa-1) are shown below, but are not limited to these. Furthermore, in the following formula, Q1 is the same as described above, and Ac is an acetyl group. [Transformation 340]

[0465] [Chemistry 341]

[0466] [Chemistry 342]

[0467] [Chemistry 343]

[0468] [Chemistry 344]

[0469] [Chemistry 345]

[0470] [Chemistry 346]

[0471] [Chemistry 347]

[0472] [Chemistry 348]

[0473] [Chemistry 349]

[0474] [Chemical 350]

[0475] [Chemistry 351]

[0476] In formula (Xa-2), Rfb1 and Rfb2 are each independently a fluorine atom, or may contain heteroatoms and be a hydrocarbon group with 1 to 40 carbon atoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon group represented by Rfa1 in formula (Xa-1-1). Rfb1 and Rfb2 are preferably fluorine atoms or linear fluorinated alkyl groups with 1 to 4 carbon atoms. Furthermore, Rfb1 and Rfb2 may also be bonded to each other and form a ring together with the bonded group (-CF2-SO2-N--SO2-CF2-). In this case, the group obtained by the bonded Rfb1 and Rfb2 is preferably a fluorinated ethyl or fluorinated propyl group.

[0477] In formula (Xa-3), Rfc1, Rfc2, and Rfc3 are each independently a fluorine atom, or may contain heteroatoms and be a hydrocarbon group with 1 to 40 carbon atoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon group represented by Rfa1 in formula (Xa-1-1). Rfc1, Rfc2, and Rfc3 are preferably fluorine atoms or linear fluorinated alkyl groups with 1 to 4 carbon atoms. Furthermore, Rfc1 and Rfc2 can also be bonded to each other and form a ring together with the bonded group (-CF2-SO2-C--SO2-CF2-). In this case, the group obtained by the bonded Rfc1 and Rfc2 is preferably a fluorinated ethyl or fluorinated propyl group.

[0478] In formula (Xa-4), the Rfd system may also include hydrocarbon groups with 1 to 40 carbon atoms. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon group represented by Rfa1 in formula (Xa-1-1).

[0479] Specific examples of anions represented by formula (Xa-4) are shown below, but are not limited to these. [Chemistry 352]

[0480] [Chemistry 353]

[0481] The aforementioned examples of non-nucleophilic relative ions can be further illustrated by anions having aromatic rings substituted with iodine or bromine atoms. Specific examples of such anions can be represented by the following formula (Xa-5). [Chemistry 354]

[0482] In equation (Xa-5), x is 1, 2, or 3. y is 1, 2, 3, 4, or 5. z can be 0, 1, 2, or 3. However, 1 ≤ y + z ≤ 5. y is better if it is 1, 2, or 3, with 2 or 3 being even better. z should be 0, 1, or 2.

[0483] In formula (Xa-5), XBI represents an iodine atom or a bromine atom. When x and / or y are 2 or more, each XBI may be the same or different.

[0484] In formula (Xa-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 an ether bond or ester bond. The aforementioned saturated alkyl group may be straight-chain, branched, or cyclic.

[0485] In formula (Xa-5), L12 is a single bond or a divalent linker with 1 to 20 carbon atoms when x is 1, and a (x+1) valent linker with 1 to 20 carbon atoms when x is 2 or 3. The linker may also contain oxygen, sulfur or nitrogen atoms.

[0486] In formula (Xa-5), Rfe is a hydroxyl, carboxyl, fluorine, chlorine, bromine, 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 refers to a hydrogen atom or a saturated hydrocarbon group with 1 to 6 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group with 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group with 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group with 2 to 6 carbon atoms. RfeD refers to an aliphatic hydrocarbon group with 1 to 16 carbon atoms, an aryl group with 6 to 12 carbon atoms, or an aralkyl group with 7 to 15 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group with 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group with 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group with 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. The aforementioned hydrocarbon groups, hydrocarbon oxy groups, hydrocarbon carbonyl groups, hydrocarbon oxycarbonyl groups, hydrocarbon carbonyloxy groups, and hydrocarbon sulfonyloxy groups may be linear, branched, or cyclic. When x and / or z are 2 or more, each Rfe may be the same or different from the others.

[0487] Among these, Rfe should preferably be a hydroxyl group, -N(RfeC)-C(=O)-RfeD, -N(RfeC)-C(=O)-O-RfeD, a fluorine atom, a chlorine atom, a bromine atom, a methyl group, a methoxy group, etc.

[0488] In formula (Xa-5), Rf11 to Rf14 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, at least one of which is a fluorine atom or a trifluoromethyl group. Furthermore, Rf11 and Rf12 can also form a carbonyl group together. In particular, it is preferable that both Rf13 and Rf14 are fluorine atoms.

[0489] Specific examples of anions represented by formula (Xa-5) are shown below, but are not limited to these. Furthermore, in the following formula, XBI is the same as described above. [Chemistry 355]

[0490] [Chemistry 356]

[0491] [Chemistry 357]

[0492] [Chemistry 358]

[0493] [Chemistry 359]

[0494] [Hua360]

[0495] [Chemistry 361]

[0496] [Chemistry 362]

[0497] [Chem.363]

[0498] [Chem.364]

[0499] [Chemical formula 365]

[0500] [Chemical formula 366]

[0501] [Chemical formula 367]

[0502] [Chemical formula 368]

[0503] [Chemical formula 369]

[0504] [Chemical formula 370]

[0505] [Chemical formula 371]

[0506] [Chemical formula 372]

[0507] [Chemical formula 373]

[0508] [Chemical formula 374]

[0509] [Chemical formula 375]

[0510] [Chemical formula 376]

[0511] [Chemical formula 377]

[0512] [Chemistry 378]

[0513] The aforementioned non-nucleophilic relative ions may also include the fluorobenzenesulfonic acid anion bonded to an aromatic group containing an iodine atom as described in Japanese Patent No. 6648726, the anion with a mechanism that decomposes 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 described in Japanese Patent Application Publication No. 2018-92159.

[0514] The aforementioned non-nucleophilic relative ions may also include the anions of benzenesulfonic acid derivatives without fluorine atoms as 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 benzenesulfonic acid anions without fluorine atoms bonded to an aromatic group containing iodine atoms, and the alkylsulfonic acid anions as described in Japanese Patent No. 6645464.

[0515] The aforementioned non-nucleophilic relative ions may also include the anions of disulfonic acid described in Japanese Patent Application Publication No. 2015-206932, the anions of sulfonamide and sulfenamide that are different from sulfonic acid on one side as described in International Patent Application Publication No. 2020 / 158366, and the anions of sulfonamide and carboxylic acid that are different from sulfonic acid on the other side as described in Japanese Patent Application Publication No. 2015-24989.

[0516] Furthermore, component (D), i.e., photoacid generator, is better represented by the following formula (5). [Chemistry 379]

[0517] In formula (5), R201 and R202 are each independently a hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. R203 is also a hydrocarbon group with 1 to 30 carbon atoms, which may contain heteroatoms. Furthermore, any two of R201, R202 and R203 may bond to each other and form a ring together with the sulfur atoms of these bonds.

[0518] R201 and R202 represent hydrocarbon groups with 1 to 30 carbon atoms, which can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, tripentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornel, oxanorbornel, tricyclic [5.2.1.02, 6] Decyl, adamantyl, and other cyclic saturated hydrocarbon groups having 3 to 30 carbon atoms; phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, dibutylphenyl, tributylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, dibutylnaphthyl, tributylnaphthyl, anthracene, and other aryl groups having 6 to 30 carbon atoms; and groups obtained by combining these. Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Similarly, one part of the -CH2- group in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it can also contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0519] R203 represents an extended hydrocarbon group with 1 to 30 carbon atoms, which can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, decadecane, and so on. Alkyl groups with 1 to 30 carbon atoms, such as heptadecane-1,17-diyl; cyclopentanediyl, cyclohexanediyl, norcamphenediyl, adamantanediyl, and other cyclic saturated alkyl groups with 3 to 30 carbon atoms; and aryl groups such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, dibutylphenylene, tributylphenylene, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, dibutylnaphthyl, and tributylnaphthyl. Furthermore, some or all of the hydrogen atoms in the aforementioned alkyl group can be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, the -CH2- portion of the aforementioned alkyl group can also be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This results in the possible inclusion of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), or haloalkyl groups. The aforementioned heteroatoms should preferably be oxygen atoms.

[0520] In formula (5), L21 is a single bond, an ether bond, or may contain a heteroatom with 1 to 20 carbon atoms in an extended hydrocarbon group. The aforementioned extended hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the extended hydrocarbon group represented by R203.

[0521] In formula (5), Xa, Xb, Xc and Xd are each independently a hydrogen atom, a fluorine atom or a trifluoromethyl group. However, at least one of Xa, Xb, Xc and Xd is a fluorine atom or a trifluoromethyl group.

[0522] The photoacid generator represented by formula (5) should preferably be represented by the following formula (5'). [Chemistry 380]

[0523] In formula (5'), L21 is the same as described above. Xe is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R301, R302, and R303 are each independently a hydrogen atom, or may contain a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon group represented by Rfa1 in formula (Xa-1-1). s and t are each independently 0, 1, 2, 3, 4, or 5, and u is 0, 1, 2, 3, or 4.

[0524] Specific examples of photoacid generators represented by formula (5) can be listed as those exemplified by the photoacid generators represented by formula (2) in Japanese Patent Application Publication No. 2017-26980.

[0525] Among the aforementioned photoacid generators, those containing anions represented by formula (Xa-1-1) or (Xa-4) exhibit low acid diffusion and excellent solvent solubility, which is particularly desirable. Furthermore, those represented by formula (5') exhibit extremely low acid diffusion, which is also particularly desirable.

[0526] When the chemical amplification inhibitor composition of the present invention includes (D) a photoacid generating agent, its content relative to 80 parts by weight of (A) the base polymer is preferably 0.1 to 40 parts by weight, and more preferably 0.5 to 20 parts by weight. If the amount of (D) photoacid generating agent added is within the aforementioned range, the resolution is good, and there is no risk of foreign matter being generated after the inhibitor film is developed or peeled off, which is ideal. (D) The photoacid generating agent can be used alone or in combination of two or more.

[0527] (E) Surfactants The chemical amplification inhibitor composition of the present invention may further include a surfactant as component (E). The surfactant (E) 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.

[0528] Regarding surfactants that are insoluble or poorly soluble in water and alkaline developing solutions, the surfactants described in the aforementioned announcement should preferably be FC-4430 (manufactured by 3M), Surflon (registered trademark) S-381 (manufactured by AGC Seimichemical), Olfine (registered trademark) E1004 (manufactured by Nissin Chemical Industry), KH-20, KH-30 (manufactured by AGC Seimichemical), and oxobutane ring-opening polymers represented by the following formula (surf-1). [Chemistry 381]

[0529] Here, R, Rf, A, B, C, m, and n are not limited to the foregoing description, but only apply to formula (surf-1). R is an aliphatic group with 2 to 5 carbon atoms, ranging from 2 to 4 valences. Among the aforementioned aliphatic groups, examples of divalent groups include ethylenyl, 1,4-butylenyl, 1,2-propylenyl, 2,2-dimethyl-1,3-propylenyl, and 1,5-pentylenyl, while examples of trivalent or tetravalent groups include the following. [Chemistry 382] In the formula, the dashed lines represent atomic bonds, which are secondary structures derived from glycerol, trimethylolethane, trimethylolpropane, and neopentyl tertrol, respectively.

[0530] Among these, 1,4-endobutyl and 2,2-dimethyl-1,3-endopropyl are preferred.

[0531] Rf is trifluoromethyl or pentafluoroethyl, preferably trifluoromethyl. m is an integer from 0 to 3, n is an integer from 1 to 4, and the sum of n and m is the valence of R, which is an integer from 2 to 4. A is 1. B is an integer from 2 to 25, preferably an integer from 4 to 20. C is an integer from 0 to 10, preferably 0 or 1. Furthermore, the arrangement of the constituent units in formula (surf-1) is not limited; they can be block-bonded or randomly bonded. For details on the manufacture of surfactants based on partially fluorinated oxyheterocyclic butane ring-opening polymers, please refer to the specification of US Patent No. 5650483, etc.

[0532] Surfactants that are insoluble or sparingly soluble in water but soluble in alkaline developing solutions can reduce water penetration and leaching caused by alignment with the surface of the resist film during ArF wet lithography without the use of a resist protective film. Therefore, they are useful for reducing damage to the exposure equipment by inhibiting the leaching of water-soluble components from the resist film. Furthermore, they are useful for soluble development in alkaline aqueous solutions after exposure or post-exposure baking (PEB), reducing the likelihood of foreign matter becoming a cause of defects. Such surfactants, which are insoluble or sparingly soluble in water but soluble in alkaline developing solutions, are polymer-type surfactants, also known as hydrophobic resins, and those with high water-repellent properties that enhance hydrophobicity are particularly desirable.

[0533] Specific examples of such polymeric surfactants include those containing at least one repeating unit selected from any of the following formulas (6A) to (6E). [Chemistry 383]

[0534] In formulas (6A) to (6E), RB represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. W1 represents -CH2-, -CH2CH2-, -O-, or two separate -H groups. Rs1 is independently a hydrogen atom or a hydrocarbon group with 1 to 10 carbon atoms. Rs2 is a single bond or a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms. Rs3 is independently a hydrogen atom, a hydrocarbon group with 1 to 15 carbon atoms, a fluorinated hydrocarbon group, or an acid-unstable group. When Rs3 is a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond or a carbonyl group may be inserted between carbon-carbon bonds. Rs4 is a (w+1) valence hydrocarbon group or a fluorinated hydrocarbon group with 1 to 20 carbon atoms. w represents 1, 2, or 3. Rs5 is independently a hydrogen atom or a group represented by -C(=O)-O-Rsa. Rsa is a fluorinated hydrocarbon group with 1 to 20 carbon atoms. Rs6 series hydrocarbon groups or fluorinated hydrocarbon groups with 1 to 15 carbon atoms can also have ether bonds or carbonyl groups inserted between the carbon-carbon bonds.

[0535] Rs1 represents a hydrocarbon group with 1 to 10 carbon atoms, which should preferably be a saturated hydrocarbon group and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and cyclic saturated hydrocarbon groups with 3 to 10 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornel. Among these, those with 1 to 6 carbon atoms are preferred.

[0536] 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, and pentyl alkyl.

[0537] The hydrocarbon groups represented by Rs3 or Rs6 can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include saturated hydrocarbon groups, alkenyl groups, alkynyl groups, and other aliphatic unsaturated hydrocarbon groups, with saturated hydrocarbon groups being preferable. Besides those exemplified by hydrocarbon groups represented by Rs1, specific examples of saturated hydrocarbon groups include undecayl, dodecyl, tridecayl, tetradecayl, and decadecyl. Fluorinated hydrocarbon groups represented by Rs3 or Rs6 can be groups where one or all of the hydrogen atoms of the carbon atom bonded to the aforementioned hydrocarbon group are replaced by fluorine atoms. As mentioned earlier, ether bonds or carbonyl groups can also be inserted between these carbon-carbon bonds.

[0538] Specific examples of acid-instable groups represented by Rs3 include groups represented by the aforementioned formulas (AL-3) to (AL-5), trialkylsilyl groups with each alkyl group having 1 to 6 carbon atoms, and alkyl groups containing side oxygen atoms having 4 to 20 carbon atoms.

[0539] Rs4 represents a (w+1) valence hydrocarbon group or fluorinated hydrocarbon group, which can be straight-chain, branched, or cyclic. Specific examples can be listed as groups obtained by removing w hydrogen atoms from the aforementioned hydrocarbon group or fluorinated hydrocarbon group.

[0540] The fluorinated hydrocarbon group represented by Rsa should preferably be saturated and can be linear, branched, or cyclic. Specific examples include those in which one or all of the hydrogen atoms of the aforementioned hydrocarbon group are replaced by fluorine atoms. Specific examples include trifluoromethyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoro-1-propyl, 3,3,3-trifluoro-2-propyl, 2,2,3,3-tetrafluoropropyl, 1,1,1,3,3,3-hexafluoroisopropyl, 2,2,3,3,4,4,4-heptafluorobutyl, 2,2,3,3,4,4,5,5-octafluoropentyl, 2,2,3,3,4,4,5,5,6,6,7,7-dodecylfluoroheptyl, 2-(perfluorobutyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorooctyl)ethyl, 2-(perfluorodecyl)ethyl, etc.

[0541] Specific examples of repeating units represented by any of equations (6A) to (6E) may be listed below, but are not limited to these. Furthermore, in the following equations, RB is the same as described above. [Chem. 384]

[0542] [Chem.385]

[0543] [Chemistry 386]

[0544] [Chemistry 387]

[0545] [Chem.388]

[0546] [Chemistry 389]

[0547] The aforementioned polymeric surfactants may also include repeating units other than 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% in all repeating units.

[0548] 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.

[0549] A method for synthesizing the aforementioned polymeric surfactants includes polymerizing monomers containing unsaturated bonds, representing repeating units of formulas (6A) to (6E) and providing other repeating units as needed, in an organic solvent by adding a free radical initiator and heating. Specific examples of organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, and dialkylene. Specific examples of polymerization initiators include AIBN, 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid), benzoyl peroxide, and lauryl peroxide. The reaction temperature is preferably 50–100°C. The reaction time is preferably 4–24 hours. Acid-unstable groups can be directly introduced into the monomer, or they can be protected or partially protected after polymerization.

[0550] When synthesizing the aforementioned polymeric surfactants, known chain transfer agents such as dodecyl mercaptan and 2-mercaptoethanol can also be used to adjust the molecular weight. In this case, the amount of such chain transfer agent added is preferably 0.01 to 10 mol% relative to the total moles of the monomers to be polymerized.

[0551] When the chemical amplification inhibitor composition of the present invention includes surfactant (E), its content relative to 80 parts by mass of the base polymer (A) is preferably 0.1 to 50 parts by mass, and more preferably 0.5 to 10 parts by mass. If the content of surfactant (E) is 0.1 parts by mass or more, the receding contact angle between the inhibitor film surface and water will be sufficiently increased; if it is less than 50 parts by mass, the dissolution rate of the inhibitor film surface to the developer is low, and the height of the formed fine pattern will be sufficiently maintained. Surfactant (E) can be used alone or in combination of two or more.

[0552] [(F) Other ingredients] The chemical amplification inhibitor composition of this invention may also include, as other components in (F), compounds that decompose due to acid to produce acid (acid-increasing compounds), organic acid derivatives, fluorinated alcohols, and compounds with a Mw of 3000 or less whose solubility in the developer changes due to the action of acid (solution inhibitors). The aforementioned acid-increasing compounds can be referred to in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608. When the aforementioned acid-increasing compounds are included, their content relative to 80 parts by mass of the base polymer in (A) is preferably 0 to 5 parts by mass, and more preferably 0 to 3 parts by mass. If the content is too high, it will be difficult to control acid diffusion, resulting in degradation of resolution and pattern shape. The aforementioned organic acid derivatives, fluorinated alcohols, and solvent inhibitors can be referred to in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608.

[0553] [Pattern Formation Method] The pattern forming method of the present invention includes the following steps: forming a resist film on a substrate using the aforementioned chemical amplification resist composition, exposing the aforementioned resist film to high-energy radiation, and developing the aforementioned exposed resist film using a developing solution.

[0554] The aforementioned substrate, for example, can be a substrate used for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective film, etc.) or a substrate used for masking circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.).

[0555] The inhibitor film, for example, can be formed by coating the aforementioned chemically amplified inhibitor composition onto a substrate with a preferred film thickness of 0.05 to 2 μm using methods such as spin coating, and then pre-baking it on a heating plate, preferably at 60 to 150°C for 1 to 10 minutes, more preferably at 80 to 140°C for 1 to 5 minutes.

[0556] High-energy rays used in the exposure of resist films can include KrF excimer laser, ArF excimer laser, EB, and EUV with wavelengths of 3-15 nm. When using KrF excimer laser, ArF excimer laser, or EUV, a mask used to form the target pattern can be used for irradiation, preferably at an exposure dose of 1-200 mJ / cm², more preferably 10-100 mJ / cm². When using EB, a mask used to form the target pattern can be used or irradiation can be performed directly, preferably at an exposure dose of 1-300 μC / cm², more preferably 10-200 μC / cm².

[0557] Furthermore, in addition to the usual exposure method, an immersion method can be used, in which a liquid with a refractive index of 1.0 or higher is placed between the resist film and the projection lens. In this case, a water-insoluble protective film can also be used.

[0558] The aforementioned water-insoluble protective film is used to prevent leaching from the resist film and improve the hydrophobicity of the film surface. It is broadly classified into two types. One type is an organic solvent-stripping type, requiring peeling with an organic solvent that does not dissolve the resist film before alkaline aqueous solution development. The other type is an alkaline aqueous solution-soluble type, soluble in alkaline developing solution, which removes the soluble portion of the resist film and simultaneously removes the protective film. The latter is preferably based on a polymer containing 1,1,1,3,3,3-hexafluoro-2-propanol residues that are insoluble in water but soluble in alkaline developing solution, dissolved in alcohol solvents with 4 or more carbon atoms, ether solvents with 8 to 12 carbon atoms, or mixed solvents thereof. Alternatively, it can be a material made by dissolving the aforementioned water-insoluble but alkaline developing solution-soluble surfactant in alcohol solvents with 4 or more carbon atoms, ether solvents with 8 to 12 carbon atoms, or mixed solvents thereof.

[0559] After exposure, PEB can also be performed. PEB can be performed, for example, by heating on a hot plate at a temperature of 60-150°C for 1-5 minutes, or more preferably at 80-140°C for 1-3 minutes.

[0560] For example, a developing solution containing an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) of preferably 0.1-5% by mass, more preferably 2-3% by mass, can be used. The developing process is carried out using conventional methods such as dip, immersion, or spraying, preferably for 0.1-3 minutes, more preferably 0.5-2 minutes. In this way, the exposed part will dissolve, and the target pattern can be formed on the substrate.

[0561] Furthermore, after the resist film is formed, acid-generating agents and other particles from the film surface can be separated by rinsing with pure water, or washed off. It can also be used to remove water remaining on the film after exposure.

[0562] Furthermore, a double patterning method can also be used to form patterns. Examples of double patterning methods include: a groove method that uses a first exposure and etching to process a 1:3 groove pattern on a substrate, moves the substrate, and uses a second exposure to form a 1:3 groove pattern to create a 1:1 pattern; and a line method that uses a first exposure and etching to process a 1:3 isolated residual pattern on a first substrate, moves the substrate, and uses a second exposure to process a 1:3 isolated residual pattern on a second substrate below the first substrate to form a 1:1 pattern with a half-pitch.

[0563] In the pattern forming method of the present invention, a negative development method that uses an organic solvent to dissolve the unexposed areas can also be used instead of the aforementioned alkaline aqueous solution as the developer.

[0564] For the aforementioned organic solvent development, the following can be used as developing solutions: 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methyl acetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, methyl valerate, methyl valerate, methyl crotonate, croton... Ethyl propionate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenyl acetate, ethyl phenyl acetate, benzyl formate, phenyl ethyl formate, methyl 3-phenylpropionate, benzyl propionate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in mixtures of two or more. [Example]

[0565] The present invention is illustrated below with examples of synthesis, embodiments, and comparative examples. However, the present invention is not limited to the embodiments described below. Furthermore, the apparatus used is as follows. MALDI TOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[0566] [1] Synthesis of strontium salt type monomers [Example 1-1] Synthesis of monomer PAG-1 (1) Synthesis of intermediate In-1 [Chemistry 390]

[0567] Under nitrogen atmosphere, SM-1 (37.0 g), SM-2 (47.3 g), and copper acetate (0.9 g) were dissolved in dichloroethane (300 g). The reaction mixture was then heated to 100 °C and matured for 15 hours. After maturation, the reaction mixture was cooled, and water (150 g) was added to stop the reaction. The organic layer was then separated and washed with water, followed by concentration under reduced pressure to remove the solvent. The residue was purified by silicone column chromatography to obtain 48.9 g of a yellow, viscous, oily intermediate, In-1 (yield 82%).

[0568] (2) Synthesis of monomer PAG-1 [Chemistry 391]

[0569] Under nitrogen atmosphere, intermediates In-1 (48.9 g), In-2 (77.0 g), dichloromethane (300 g), and water (150 g) were added and stirred at room temperature for 30 minutes. The organic layer was separated and washed with water, followed by concentration under reduced pressure. The residue was washed with diisopropyl ether and concentrated to obtain 97.3 g of monomer PAG-1 in oily form (96% yield).

[0570] The TOF-MS results of PAG-1 are shown below. MALDI TOF-MS: POSITIVE M+447 (equivalent to C20H16F5O2S2+) NEGATIVE M-789 (equivalent to C18H10F2I3O7S-)

[0571] [Examples 1-2~1-9] Synthesis of monomers PAG-2~PAG-9 Using corresponding raw materials and various organic synthesis reactions, the strontium salt type monomers PAG-2 to PAG-9 shown below were synthesized. [Chemistry 392]

[0572] [Chemistry 393]

[0573] [Comparative Examples 1-1 to 1-6] Comparison of the synthesis of monomers PAG-A to PAG-F Using corresponding raw materials and various organic synthesis reactions, the comparative strontium salt monomers PAG-A to PAG-F shown below were synthesized. [Chem. 394]

[0574] [2] Synthesis of basic polymers The monomers used in the synthesis of basic polymers, other than PAG-1 to PAG-9 and PAG-A to PAG-F, are as follows. [Chemistry 395]

[0575] [Chemistry 396]

[0576] [Chemistry 397]

[0577] [Example 2-1] Synthesis of Polymer P-1 Under nitrogen atmosphere, monomer-polymerization initiator solution was prepared by taking 35.7 g of monomer a1-1, 10.5 g of monomer b1-1, 54.0 g of monomer PAG-1, 3.35 g of V-601 (manufactured by Wako Pure Chemical Industries, Ltd.), and 140 g of MEK in a flask. In another flask under nitrogen atmosphere, 46 g of MEK was taken, and the mixture was heated to 80°C with stirring. The aforementioned monomer-polymerization initiator solution was then added dropwise over 4 hours. After the addition was complete, the polymerization solution was maintained at 80°C and stirred for another 2 hours, then cooled to room temperature. The obtained polymerization solution was added dropwise to 3000 g of hexane after vigorous stirring, and the precipitated polymer was filtered. The obtained polymer was then washed twice with 600 g of hexane and vacuum dried at 50°C for 20 hours to obtain a white powder polymer P-1 (yield 98.1 g, 98% yield). The Mw ratio of polymer P-1 is 9200, and the Mw / Mn ratio is 1.61. Furthermore, the Mw ratio is the polystyrene equivalent value obtained by GPC using DMF as a solvent. [Chemistry 398]

[0578] [Examples 2-2~2-26, Comparative Examples 2-1~2-18] Synthesis of polymers P-2~P-26, CP-1~CP-18 Except for changing the type and blending ratio of each monomer, the polymers shown in Tables 1 and 2 were manufactured using the same method as in Example 2-1.

[0579] [Table 1] polymer Unit 1 Import ratio (mol%) Unit 2 Import ratio (mol%) Unit 3 Import ratio (mol%) Unit 4 Import ratio (mol%) Unit 5 Import ratio (mol%) Mw Mw / Mn P-1 PAG-1 15 a1-1 55 b1-1 30 - - - - 9200 1.61 P-2 2 15 a1-1 55 b1-1 30 - - - - 9200 1.62 P-3 3 15 a1-1 55 b1-1 30 - - - - 9500 1.63 P-4 PAG-4 15 a1-1 55 b1-1 30 - - - - 9400 1.63 P-5 5 15 a1-1 55 b1-1 30 - - - - 9100 1.61 P-6 PAG-6 15 a1-1 55 b1-1 30 - - - - 9300 1.62 P-7 PAG-7 15 a1-1 55 b1-1 30 - - - - 9200 1.65 P-8 PAG-8 15 a1-1 55 b1-1 30 - - - - 9100 1.61 P-9 PAG-9 15 a1-1 55 b1-1 30 - - - - 9700 1.62 P-10 PAG-1 15 a1-2 55 b1-1 30 - - - - 9400 1.60 P-11 PAG-1 15 a1-3 55 b1-1 30 - - - - 9100 1.61 P-12 PAG-1 15 a2-1 55 b1-1 30 - - - - 9800 1.62 P-13 PAG-1 15 a3-1 45 b1-1 40 - - - - 8900 1.63 P-14 2 15 a1-1 55 b1-2 30 - - - - 9300 1.61 P-15 2 15 a1-1 55 b1-3 30 - - - - 9000 1.62 P-16 PAG-2 15 a1-1 55 b1-4 30 - - - - 9300 1.64 P-17 PAG-1 15 a1-1 30 a2-1 20 b1-1 35 - - 9200 1.62 P-18 PAG-3 15 a1-1 35 a3-1 15 b1-2 35 - - 9900 1.61 P-19 PAG-4 15 a1-2 30 a2-1 15 b1-3 40 - - 9500 1.62 P-20 PAG-6 10 a1-1 35 a2-1 15 b1-1 30 b2-1 10 9400 1.63 P-21 PAG-7 15 a1-2 35 a3-1 15 b1-2 25 b2-2 10 9200 1.64 P-22 PAG-9 15 a1-1 50 b1-1 30 b2-3 5 - - 8900 1.61 P-23 PAG-1 5 a1-1 55 b1-2 40 - - - - 9700 1.62 P-24 PAG-2 5 a1-1 30 a1-3 25 b1-2 40 - - 9400 1.63 P-25 PAG-3 5 a1-2 30 a2-1 20 b1-4 35 b2-1 10 9200 1.61 P-26 PAG-7 5 a1-1 35 a3-1 15 b1-1 30 b2-2 15 9400 1.62

[0580] [Table 2] polymer Unit 1 Infusion ratio (mol%) Unit 2 Infusion ratio (mol%) Unit 3 Infusion ratio (mol%) Unit 4 Infusion ratio (mol%) Unit 5 Infusion ratio (mol%) Mw Mw / Mn CP-1 PAG-A 15 a1-1 55 b1-1 30 - - - - 9500 1.62 CP-2 PAG-B 15 a1-1 55 b1-1 30 - - - - 9100 1.61 CP-3 PAG-C 15 a1-1 55 b1-1 30 - - - - 9300 1.63 CP-4 PAG-D 15 a1-1 55 b1-1 30 - - - - 9100 1.62 CP-5 PAG-E 15 a1-1 55 b1-1 30 - - - - 9000 1.65 CP-6 F-F 15 a1-1 55 b1-1 30 - - - - 9500 1.62 CP-7 b 15 a1-2 55 b1-1 30 - - - - 9600 1.61 CP-8 c 15 a3-1 45 b1-1 40 - - - - 9700 1.63 CP-9 PAG-D 15 a1-1 55 b1-3 30 - - - - 9500 1.63 CP-10 e 15 a1-1 55 b1-4 30 - - - - 9400 1.62 CP-11 PAG-B 15 a1-1 35 a3-1 15 b1-2 35 - - 9700 1.64 CP-12 PAG-D 10 a1-1 35 a2-1 15 b1-1 30 b2-1 10 9500 1.62 CP-13 PAG-C 15 a1-2 35 a3-1 15 b1-2 25 b2-2 10 9300 1.61 CP-14 PAG-F 15 a1-1 50 b1-1 30 b2-3 5 - - 9100 1.60 CP-15 PAG-A 5 a1-1 55 b1-2 40 - - - - 9300 1.62 CP-16 PAG-D 5 a1-2 30 a2-1 20 b1-4 35 b2-1 10 9400 1.63 CP-17 a1-1 60 b1-1 40 - - - - - - 5700 1.55 CP-18 a1-1 50 b1-2 30 b2-1 20 - - - - 6100 1.54

[0581] [3] Preparation of chemical amplification inhibitor composition [Implementation Examples 3-1 to 3-26, Comparative Examples 3-1 to 3-18] A solution was prepared by dissolving the base polymers (P-1 to P-26) containing the strontium salt monomers (PAG-1 to PAG-9) of the present invention, the base polymers (CP-1 to CP-18) containing the comparative strontium salt monomers (PAG-A to PAG-F), the photoacid generators (PAG-X, PAG-Y), and the quenchers (Q-1 to Q-4) as shown in Tables 3 and 4 below in a solvent containing 0.01% by mass of surfactant A (OMNOVA). The solution was then filtered using a 0.2 μm Teflon (registered trademark) filter to prepare the chemical amplification inhibitor composition (R-1 to R-26, CR-1 to CR-18).

[0582] [Table 3] inhibitor Composition Basic polymers (parts by weight) Quenching agent (parts by weight) Photoacid generator (parts by weight) Solvent 1 (parts by weight) Solvent 2 (parts by weight) Solvent 3 (parts by weight) Example 3-1 R-1 P-1(80) Q-1(8.0) - PGMEA(2250) EL(2800) DAA(550) Example 3-2 R-2 P-2(80) Q-1(8.2) - PGMEA(2250) EL(2800) DAA(550) Example 3-3 R-3 P-3(80) Q-1(8.0) - PGMEA(2250) EL(2800) DAA(550) Examples 3-4 R-4 P-4(80) Q-1(7.8) - PGMEA(2250) EL(2800) DAA(550) Examples 3-5 R-5 P-5(80) Q-1(8.0) - PGMEA(2250) EL(2800) DAA(550) Examples 3-6 R-6 P-6(80) Q-1(8.0) - PGMEA(2250) EL(2800) DAA(550) Examples 3-7 R-7 P-7(80) Q-1(8.2) - PGMEA(2250) EL(2800) DAA(550) Examples 3-8 R-8 P-8(80) Q-1(8.0) - PGMEA(2250) EL(2800) DAA(550) Examples 3-9 R-9 P-9(80) Q-1(7.6) - PGMEA(2250) EL(2800) DAA(550) Examples 3-10 R-10 P-10(80) Q-2(8.2) - PGMEA(2250) EL(2800) DAA(550) Example 3-11 R-11 P-11(80) Q-3 (8.0) - PGMEA(2250) EL(2800) DAA(550) Example 3-12 R-12 P-12(80) Q-1(8.0) - PGMEA(2250) EL(2800) DAA(550) Example 3-13 R-13 P-13(80) Q-1(8.2) - PGMEA(2250) EL(2800) DAA(550) Example 3-14 R-14 P-14(80) Q-1(8.0) - PGMEA(2250) EL(2800) DAA(550) Example 3-15 R-15 P-15(80) Q-3(7.8) - PGMEA(2250) EL(2800) DAA(550) Example 3-16 R-16 P-16(80) Q-2(8.0) - PGMEA(2250) EL(2800) DAA(550) Example 3-17 R-17 P-17(80) Q-1(8.0) - PGMEA(2250) EL(2800) DAA(550) Example 3-18 R-18 P-18(80) Q-1(7.8) - PGMEA(2250) EL(2800) DAA(550) Example 3-19 R-19 P-19(80) Q-2(8.0) - PGMEA(2250) EL(2800) DAA(550) Example 3-20 R-20 P-20(80) Q-3(7.8) PAG-Y(15) PGMEA(2250) EL(2800) DAA(550) Example 3-21 R-21 P-21(80) Q-1(4.0) Q-4(3.8) - PGMEA(2250) EL(2800) DAA(550) Example 3-22 R-22 P-22(80) Q-1(8.2) - PGMEA(2250) EL(2800) DAA(550) Example 3-23 R-23 P-23(80) Q-3(7.6) - PGMEA(2250) EL(2800) DAA(550) Example 3-24 R-24 P-24(80) Q-1(8.0) PAG-X(10) PGMEA(2250) EL(2800) DAA(550) Example 3-25 R-25 P-25(80) Q-2(8.2) PAG-X(10) PGMEA(2250) EL(2800) DAA(550) Example 3-26 R-26 P-26(80) Q-3 (8.0) PAG-Y(15) PGMEA(2250) EL(2800) DAA(550)

[0583] [Table 4] inhibitor Composition Basic polymers (parts by weight) Quenching agent (parts by weight) Photoacid generator (parts by weight) Solvent 1 (parts by weight) Solvent 2 (parts by weight) Solvent 3 (parts by weight) Comparative Example 3-1 CR-1 CP-1(80) Q-1(8.0) - PGMEA(2250) EL(2800) DAA(550) Comparative Example 3-2 CR-2 CP-2(80) Q-1(8.2) - PGMEA(2250) EL(2800) DAA(550) Comparative Example 3-3 CR-3 CP-3(80) Q-1(8.0) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 3-4 CR-4 CP-4(80) Q-1(7.8) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 3-5 CR-5 CP-5(80) Q-1(8.0) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 3-6 CR-6 CP-6(80) Q-1(8.2) PGMEA(2250) EL(2800) DAA(550) Comparative Examples 3-7 CR-7 CP-7(80) Q-2(8.2) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 3-8 CR-8 CP-8(80) Q-1(8.2) - PGMEA(2250) EL(2800) DAA(550) Comparative Examples 3-9 CR-9 CP-9(80) Q-3(7.8) - PGMEA(2250) EL(2800) DAA(550) Comparative Example 3-10 CR-10 CP-10(80) Q-2(8.0) - PGMEA(2250) EL(2800) DAA(550) Comparative Example 3-11 CR-11 CP-11(80) Q-1(8.0) - PGMEA(2250) EL(2800) DAA(550) Comparative Example 3-12 CR-12 CP-12(80) Q-3(7.8) PAG-Y(15) PGMEA(2250) EL(2800) DAA(550) Comparative Example 3-13 CR-13 CP-13(80) Q-1(4.0) Q-4(3.8) - PGMEA(2250) EL(2800) DAA(550) Comparative Example 3-14 CR-14 CP-14(80) Q-1(8.2) - PGMEA(2250) EL(2800) DAA(550) Comparative Example 3-15 CR-15 CP-15(80) Q-3(7.6) - PGMEA(2250) EL(2800) DAA(550) Comparative Example 3-16 CR-16 CP-16(80) Q-2(8.2) PAG-X(10) PGMEA(2250) EL(2800) DAA(550) Comparative Example 3-17 CR-17 CP-17(80) Q-1(8.0) PAG-X(24) PGMEA(2250) EL(2800) DAA(550) Comparative Example 3-18 CR-18 CP-18(80) Q-1(8.0) PAG-Y(24) PGMEA(2250) EL(2800) DAA(550)

[0584] Tables 3 and 4 list the solvent, photoacid generators PAG-X and PAG-Y, quenchers Q-1 to Q-4, and surfactant A as follows. Solvent: PGMEA (Propylene Glycol Monomethyl Ether Acetate) EL (ethyl lactate) DAA (diacetone alcohol)

[0585] Photoacid generators: PAG-X, PAG-Y [Chemistry 399]

[0586] Quenching agents: Q-1~Q-4 [Chemical 400]

[0587] Surfactant A: 3-Methyl-3-(2,2,2-trifluoroethoxymethyl)oxetane / tetrahydrofuran / 2,2-dimethyl-1,3-propanediol copolymer (manufactured by OMNOVA). [Chemical Engineering 401] a:(b+b'):(c+c')=1:4~7:0.01~1 (Morbies) Mw=1500

[0588] [4] Evaluation of EUV lithography (1) [Examples 4-1 to 4-26, Comparative Examples 4-1 to 4-18] The chemical amplification resist compositions (R-1~R-26, CR-1~CR-18) shown in Tables 3 and 4 were spin-coated onto a Si substrate containing a silicon spin-coated hard mask SHB-A940 (silicon content of 43% by mass) manufactured by Shin-Etsu Chemical Industry Co., Ltd., with a film thickness of 20 nm. A resist film with a thickness of 50 nm was pre-baked at 100°C for 60 seconds using a hot plate. For the aforementioned resist film, an LS pattern with a wafer size of 18 nm and a pitch of 36 nm was exposed using an EUV scanning exposure machine manufactured by ASML NXE3400 (NA 0.33, σ 0.9 / 0.6, dipole illumination). The exposure amount and focal length were changed while exposing the pattern (exposure amount pitch: 1 mJ / cm2, focal length pitch: 0.020 μm). After exposure, a PEB treatment was performed for 60 seconds at the temperatures shown in Tables 5 and 6. Subsequently, the model was immersed in a 2.38% TMAH aqueous solution for 30 seconds for development, rinsed with a washing material containing surfactant, and then rotated to dry, thus obtaining a positive pattern. The obtained LS patterns were observed using a Hitachi Advanced Semiconductor Critical Dimension SEM (CG6300), and the sensitivity, EL, LWR, DOF, and collapse limit were evaluated according to the methods described below. Furthermore, the development defects of the obtained LS patterns were evaluated. The results are shown in Tables 5 and 6.

[0589] [Sensitivity Evaluation] The optimal exposure value Eop (mJ / cm2) for obtaining an LS pattern with a linewidth of 18nm and a pitch of 36nm was determined and defined as the sensitivity. The smaller this value, the higher the sensitivity.

[0590] [EL Review] The exposure amount formed within ±10% (16.2~19.8nm) of the 18nm spacing in the aforementioned LS pattern is used to calculate the EL (unit: %) using the following formula. The larger this value, the better the performance. EL(%) = (|E1-E2| / Eop) × 100 E1: Provides optimal exposure for LS patterns with a linewidth of 16.2nm and a pitch of 36nm. E2: Provides optimal exposure for LS patterns with a linewidth of 19.8nm and a pitch of 36nm. Eop: Provides optimal exposure for LS patterns with a linewidth of 18nm and a pitch of 36nm.

[0591] [LWR Evaluation] For the LS pattern obtained by Eop irradiation, the dimensions at 10 points along the length of the line are measured, and the standard deviation (σ) of the results is calculated as 3σ as the LWR. The smaller this value, the more uniform the line width and roughness of the pattern will be.

[0592] [DOF Rating] In terms of DOF evaluation, the focal length range is determined by ±10% (16.2~19.8nm) of the 18nm dimension in the aforementioned LS pattern. The larger this value, the wider the depth of focus.

[0593] [Collapse Limit Assessment of Line Patterns] The line dimensions of each exposure at the optimal focal length of the aforementioned LS pattern were measured along the length direction at 10 points. The finest line dimension obtained in the undamaged state was defined as the collapse limit dimension. The smaller this value, the better the collapse limit.

[0594] [Evaluation of Development Defects] For an LS pattern with a linewidth of 18nm and a pitch of 36nm formed using the aforementioned optimal exposure, a defect detection device KLA2360 (trade name) manufactured by KLA Tencor was used. The pixel size of the defect detection device was set to 0.16μm, and the threshold was set to 20. Defects (number / cm²) identified by comparing the overlap between the image and pixel units were detected, and the number of defects per unit area (defects / cm²) was calculated. Subsequently, through defect evaluation, development defects were classified and identified from all defects, and the number of development defects per unit area (defects / cm²) was calculated. Values ​​below 0.5 were rated A, values ​​between 0.5 and 1.0 were rated B, values ​​between 1.0 and 5.0 were rated C, and values ​​above 5.0 were rated D. The smaller the value, the better the performance.

[0595] [Table 5] inhibitor Composition PEB temperature (°C) Optimal exposure (mJ / cm2) EL (%) LWR (nm) DOF (nm) Collapse Limit (nm) Development defects Example 4-1 R-1 100 31 17 2.2 120 10.7 A Example 4-2 R-2 95 32 18 2.3 110 10.8 A Example 4-3 R-3 100 32 19 2.2 120 10.6 A Example 4-4 R-4 95 32 17 2.3 110 11.2 A Examples 4-5 R-5 105 31 18 2.4 100 11.2 A Examples 4-6 R-6 100 33 18 2.3 120 11.3 A Examples 4-7 R-7 95 32 18 2.4 110 11.1 A Examples 4-8 R-8 95 32 17 2.2 100 11.2 A Examples 4-9 R-9 100 33 19 2.4 110 11.1 A Examples 4-10 R-10 100 33 17 2.2 120 11.2 A Example 4-11 R-11 100 33 18 2.3 120 11.3 A Example 4-12 R-12 95 33 18 2.2 110 10.7 A Example 4-13 R-13 105 31 18 2.4 120 10.7 A Example 4-14 R-14 100 32 18 2.2 100 10.9 A Examples 4-15 R-15 95 33 19 2.3 110 10.7 A Example 4-16 R-16 95 32 17 2.2 120 11.2 A Example 4-17 R-17 100 32 18 2.2 110 11.1 A Example 4-18 R-18 95 32 17 2.3 110 11.1 A Example 4-19 R-19 95 32 17 2.3 120 11.2 A Example 4-20 R-20 100 32 18 2.4 110 11.1 A Example 4-21 R-21 100 33 18 2.2 110 10.7 A Example 4-22 R-22 100 33 17 2.3 110 11.2 A Example 4-23 R-23 95 32 19 2.3 110 11.1 A Example 4-24 R-24 95 31 17 2.3 120 11.1 A Example 4-25 R-25 100 33 17 2.2 110 11.2 A Example 4-26 R-26 100 32 18 2.3 110 10.9 A

[0596] [Table 6] inhibitor Composition PEB temperature (°C) Optimal exposure (mJ / cm2) EL (%) LWR (nm) DOF (nm) Collapse Limit (nm) Development defects Comparative Example 4-1 CR-1 95 40 13 3.0 90 12.9 B Comparative Example 4-2 CR-2 100 37 12 2.8 80 12.6 C Comparative Example 4-3 CR-3 100 36 13 2.9 80 13.3 C Comparative Example 4-4 CR-4 100 36 14 2.7 90 13.3 B Comparative Examples 4-5 CR-5 95 37 14 2.8 80 12.7 C Comparative Examples 4-6 CR-6 100 37 12 3.1 60 12.3 B Comparative Examples 4-7 CR-7 100 36 13 2.9 90 12.9 C Comparative Examples 4-8 CR-8 100 37 14 2.8 80 12.3 C Comparative Examples 4-9 CR-9 95 36 15 2.8 90 13.4 B Comparative Example 4-10 CR-10 100 36 14 2.7 80 12.6 B Comparative Example 4-11 CR-11 100 37 13 2.8 80 12.5 B Comparative Example 4-12 CR-12 100 37 13 2.9 80 13.1 B Comparative Example 4-13 CR-13 95 38 15 2.8 90 12.4 B Comparative Example 4-14 CR-14 105 36 13 3.2 50 12.4 C Comparative Example 4-15 CR-15 100 39 13 3.1 70 12.1 C Comparative Example 4-16 CR-16 95 39 14 2.9 80 13.4 B Comparative Example 4-17 CR-17 95 41 12 3.5 60 12.7 B Comparative Example 4-18 CR-18 100 40 12 3.3 60 12.3 B

[0597] As shown in Tables 5 and 6, the chemical amplification inhibitor composition containing polymers composed of strontium salt monomers of the present invention exhibits good sensitivity, excellent EL, LWR, and DOF. Furthermore, it was confirmed that the collapse limit value is small, resisting pattern collapse even during the formation of fine patterns. Moreover, it was confirmed that it also suppresses development defects. Therefore, the chemical amplification inhibitor composition of the present invention is suitable as a material for EUV lithography.

[0598] [5] Evaluation of EUV lithography (2) [Examples 5-1 to 5-26, Comparative Examples 5-1 to 5-18] The chemically amplified resist compositions (R-1~R-26, CR-1~CR-18) shown in Tables 3 and 4 were spin-coated onto a Si substrate containing a silicon spin-coating hard mask SHB-A940 (silicon content 43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd., with a film thickness of 20 nm. A resist film with a thickness of 50 nm was formed by pre-baking at 105°C for 60 seconds using a hot plate. The aforementioned resist film was exposed using an ASML NXE3400 EUV scanning exposure machine (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, mask with a pitch of 46 nm on the wafer, and a hole pattern with a deviation of +20%). A hole pattern with a size of 23 nm was formed by PEB for 60 seconds using a hot plate at the temperature recorded in Tables 7 and 8, followed by development with a 2.38% by mass TMAH aqueous solution for 30 seconds. Using a Hitachi Advanced Semiconductor Critical Dimension SEM (CG6300), the exposure required to form a hole size of 23 nm was measured and defined as the sensitivity. Furthermore, the size of 50 holes at this point was measured, and three times the standard deviation (σ) calculated from the results (3σ) was defined as the CDU. The results are shown in Tables 7 and 8.

[0599] [Table 7] inhibitor Composition PEB temperature (°C) Optimal exposure (mJ / cm2) CDU (nm) Example 5-1 R-1 95 twenty one 2.2 Example 5-2 R-2 95 twenty two 2.2 Example 5-3 R-3 90 twenty one 2.3 Example 5-4 R-4 90 twenty two 2.2 Example 5-5 R-5 90 twenty two 2.2 Examples 5-6 R-6 95 twenty two 2.4 Examples 5-7 R-7 95 twenty two 2.3 Examples 5-8 R-8 90 twenty one 2.3 Examples 5-9 R-9 95 twenty three 2.4 Examples 5-10 R-10 95 twenty two 2.3 Examples 5-11 R-11 95 twenty three 2.3 Examples 5-12 R-12 90 twenty two 2.1 Examples 5-13 R-13 90 twenty three 2.4 Examples 5-14 R-14 90 twenty two 2.2 Examples 5-15 R-15 90 twenty three 2.3 Examples 5-16 R-16 85 twenty three 2.3 Examples 5-17 R-17 95 twenty two 2.2 Example 5-18 R-18 95 twenty three 2.3 Example 5-19 R-19 90 twenty one 2.4 Example 5-20 R-20 95 twenty three 2.3 Example 5-21 R-21 95 twenty one 2.4 Example 5-22 R-22 95 twenty four 2.3 Example 5-23 R-23 95 twenty two 2.3 Example 5-24 R-24 90 twenty three 2.4 Example 5-25 R-25 95 twenty two 2.3 Example 5-26 R-26 95 twenty two 2.2

[0600] [Table 8] inhibitor Composition PEB temperature (°C) Optimal exposure (mJ / cm2) CDU (nm) Comparative Example 5-1 CR-1 95 31 3.1 Comparative Example 5-2 CR-2 95 28 2.8 Comparative Example 5-3 CR-3 95 27 2.7 Comparative Example 5-4 CR-4 90 27 2.8 Comparative Example 5-5 CR-5 90 28 2.8 Comparative Examples 5-6 CR-6 95 25 3.4 Comparative Examples 5-7 CR-7 90 28 2.8 Comparative Examples 5-8 CR-8 90 27 2.7 Comparative Examples 5-9 CR-9 90 26 2.8 Comparative Examples 5-10 CR-10 95 28 2.8 Comparative Example 5-11 CR-11 95 28 2.7 Comparative Example 5-12 CR-12 95 29 2.9 Comparative Example 5-13 CR-13 85 27 2.8 Comparative Example 5-14 CR-14 95 25 3.4 Comparative Example 5-15 CR-15 95 31 3.2 Comparative Example 5-16 CR-16 90 29 2.9 Comparative Example 5-17 CR-17 95 32 3.3 Comparative Example 5-18 CR-18 95 32 3.2

[0601] The results shown in Tables 7 and 8 confirm that the chemical amplification inhibitor composition containing repeating units of strontium salt type monomers from the present invention has good sensitivity and excellent CDU.

Claims

1. A strontium salt type monomer, represented by the following formula (A); where n1 is 0 or 1; n2 is 0, 1, or 2; n3 is 0, 1, or 2; n4 is 0, 1, or 2; however, when n1 is 0, then 0 ≦ n2 + n3 + n4 ≦ 5, and when n1 is 1, then 0 ≦ n2 + n3 + n4 ≦ 7; n5 is 0 or 1; n6 is 0, 1, or 2; n7 is 0, 1, or 2; n8 is 0, 1, or 2; however, when n5 is 0, then 0 ≦ n6 + n7 + n8 ≦ 5. When n5 is 1, then 0 ≦ n6 + n7 + n8 ≦ 7; n9 is 0 or 1; n10 is 0, 1, or 2; n11 is 0, 1, or 2; n12 is 0, 1, or 2; however, when n9 is 0, then 0 ≦ n10 + n11 + n12 ≦ 5, and when n9 is 1, then 0 ≦ n10 + n11 + n12 ≦ 7; also, 1 ≦ n2 + n6 + n10 ≦ 6, 1 ≦ n3 + n7 + n11 ≦ 6; R1, R2, and R3 are each independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms; when n3 is 2, each R1 may be the same or different; when n7 is 2, each R2 may be the same or different; when n11 is 2, each R3 may be the same or different; R4, R5, and R6 are each independently a halogen atom, nitro group, hydroxyl group, carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxy group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms; when n4 is 2, each R4 can be the same or different from each other, and two R4s can also bond to each other and form a ring together with the carbon atoms of these bonds; when n8 is 2, each R5 can be the same or different from each other, and two R5s can also bond to each other and form a ring together with the carbon atoms of these bonds; when n12 is 2, each R6 can be the same or different from each other, and two R6s can also bond to each other and form a ring together with the carbon atoms of these bonds; furthermore, two of the three aromatic rings bonded to S+ can also bond to each other and form a ring together with the sulfur atoms of these bonds; Z- represents the fluoroalkane sulfonic acid anion with a polymerizable group represented by the following formula (Z1); In the formula, m refers to 0, 1, 2, or 3; RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; Z1 is independently a phenyl group, naphthyl group, or *-C(=O)-O-Z11- group, which may also have substituents; Z11 is an aliphatic alkyl group, phenyl group, or naphthyl group with 1 to 10 carbon atoms, which may also contain halogen atoms, hydroxyl groups, ether bonds, ester bonds, or lactone rings; Z2 is a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond; Z3 is independently a single bond, ***-Z31-C(=O)-O-, ***-C(=O)-NH-Z31-, or ***-O-Z31-; Z31 may also contain a heteroatom and be an alkyl group with 1 to 20 carbon atoms. Z4 can be a single bond, ****-Z41-C(=O)-O-, ****-C(=O)-NH-Z41-, or ****-O-Z41-.The Z41 series may also contain heteroatoms with 1 to 20 carbon atoms in a alkyl group; * indicates an atomic bond with a carbon atom in the main chain; *** indicates an atomic bond with Z2; **** indicates an atomic bond with Z3; the L1 series includes single bonds, ether bonds, ester bonds, carbonyl groups, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds; Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated alkyl group with 1 to 6 carbon atoms; Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated alkyl group with 1 to 6 carbon atoms.

2. A strontium salt type monomer, represented by the following formula (A); where n1 is 0 or 1; n2 is 0, 1, or 2; n3 is 0, 1, or 2; n4 is 0, 1, or 2; however, when n1 is 0, then 0 ≦ n2 + n3 + n4 ≦ 5, and when n1 is 1, then 0 ≦ n2 + n3 + n4 ≦ 7; n5 is 0 or 1; n6 is 0, 1, or 2; n7 is 0, 1, or 2; n8 is 0, 1, or 2; however, when n5 is 0, then 0 ≦ n6 + n7 + n8 ≦ 5. When n5 is 1, then 0 ≦ n6 + n7 + n8 ≦ 7; n9 is 0 or 1; n10 is 0, 1, or 2; n11 is 0, 1, or 2; n12 is 0, 1, or 2; however, when n9 is 0, then 0 ≦ n10 + n11 + n12 ≦ 5, and when n9 is 1, then 0 ≦ n10 + n11 + n12 ≦ 7; also, 1 ≦ n2 + n6 + n10 ≦ 6, 1 ≦ n3 + n7 + n11 ≦ 6; R1, R2, and R3 are each independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms; when n3 is 2, each R1 may be the same or different; when n7 is 2, each R2 may be the same or different; when n11 is 2, each R3 may be the same or different; R4, R5, and R6 are each independently a halogen atom, nitro group, hydroxyl group, carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxy group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms; when n4 is 2, each R4 can be the same or different from each other, and two R4s can also bond to each other and form a ring together with the carbon atoms of these bonds; when n8 is 2, each R5 can be the same or different from each other, and two R5s can also bond to each other and form a ring together with the carbon atoms of these bonds; when n12 is 2, each R6 can be the same or different from each other, and two R6s can also bond to each other and form a ring together with the carbon atoms of these bonds; furthermore, two of the three aromatic rings bonded to S+ can also bond to each other and form a ring together with the sulfur atoms of these bonds; Z- represents the fluoroalkane sulfonic acid anion with a polymerizable group represented by the following formula (Z2); In the formula, m1 is 0 or 1; m2 is 0, 1, 2, 3 or 4; m3 is 0, 1, 2 or 3; m4 is 0 or 1; m5 is 0, 1, 2, 3 or 4; m6 is 0, 1, 2 or 3; m7 is 0 or 1; m8 is 1, 2, 3 or 4; m9 is 0, 1, 2 or 3; m10 is 0, 1, 2, 3 or 4; m11 is 0 or 1; m12 is 0 or... 1; However, when m1 is 0, then 0≦m2+m3+m1²≦4, and when m1 is 1, then 0≦m2+m3+m1²≦6; when m4 is 0, then 0≦m5+m6≦4, and when m4 is 1, then 0≦m5+m6≦6; when m7 is 0, then 0≦m8+m9≦5, and when m7 is 1, then 0≦m8+m9≦7; also, 1≦m2+m5+m8≦4; RA is a hydrogen atom, fluorine atom, methyl or trifluoromethyl;R11, R12, and R13 are each independently a halogen atom other than an iodine atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, or may contain a hydrocarbon group with 1 to 20 carbon atoms of a heteroatom, a hydrocarbon oxy group with 1 to 20 carbon atoms of a heteroatom, a hydrocarbon thio group with 1 to 20 carbon atoms of a heteroatom, or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms of a heteroatom; when m3 is 2 or 3, each R11 can be the same or different from each other, and two R11s can also be bonded to each other and form a ring together with the bonded carbon atoms; when m6 is 2 or 3, each R12 can be the same or different from each other, and two R12s can also be bonded to each other and form a ring together with the bonded carbon atoms; when m9 is 2 or 3, each R13 can be the same or different from each other, and two R13s can also be bonded to each other and form a ring together with the bonded carbon atoms; LA, LB, LC, LD, and LE are each independently a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond; XL1 and XL2 are each independently a single bond, or may contain a heteroatom of a 1-40 carbon atom alkyl group; Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated alkyl group of 1-6 carbons; Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated alkyl group of 1-6 carbons; however, m11 and m12 are not simultaneously 0, and LA, LB, LC, LD, XL1, and XL2 are not simultaneously single bonds.

3. The strontium salt type monomers of request item 1 or 2 are represented by the following formula (A1); where n2~n4, n6~n8, n10~n12, R1~R6 and Z- are the same as above.

4. A monomeric photoacid generator, comprising a strontium salt type monomer as claimed in any one of claims 1 to 3.

5. A polymer comprising repeating units from a monomeric photoacid generator as claimed in claim 4.

6. The polymer of claim 5 further comprises at least one repeating unit selected from the repeating units represented by formula (a1), formula (a2), and formula (a3); wherein RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; X1 is a single bond, a phenyl group, a naphthyl group, or *-C(=O)-O-X11-, which may also be substituted by a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, or a halogen atom; X11 is a saturated hydrocarbon group with 1 to 10 carbon atoms, a phenyl group, or a naphthyl group, which may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring; X2 is a single bond or *-C(=O)-O-; * indicates an atomic bond with a carbon atom of the main chain; R21 can be 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 R21 can be the same or different; AL1 and AL2 are each independently an acid-labile group; a1 can be 0, 1, 2, 3, or 4; where b1 is 0 or 1; b2 can be 0, 1, 2, or 3 when b1 is 0, and 0, 1, 2, 3, 4, or 5 when b1 is 1; RA can be 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; X4 is a single bond, an aliphatic hydrocarbon group with 1 to 4 carbon atoms, a carbonyl group, a sulfonyl group, or a combination thereof; X5 and X6 are each independently an oxygen atom or a sulfur atom; however, X4 and X6 are bonded to adjacent carbon atoms in an aromatic ring; R22 and R23 are each independently a hydrogen atom, or may also contain a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; furthermore, R22 and R23 may also bond to each other and form a ring together with the bonded carbon atoms; R24 can be a halogen atom, hydroxyl group, cyano group, nitro group, or may contain a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms, a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms, or a hydrocarbon thio group with 1 to 20 carbon atoms, or -N(R24A)(R24B); R24A and R24B are each independently a hydrogen atom or a hydrocarbon group with 1 to 6 carbon atoms; when b2 is 2 or more, each R24 can be the same or different from each other, and multiple R24s can also be bonded to each other and form a ring together with the carbon atoms of the aromatic rings of these bonds.

7. The polymer of claim 5 further comprises at least one repeating unit selected from the repeating units represented by formula (b1) and formula (b2); wherein RA is independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; Y1 is a single bond or *-C(=O)-O-; * represents an atomic bond with a carbon atom of the main chain; R31 is a hydrogen atom, or a group containing at least one of the following structures: hydroxyl group other than phenolic hydroxyl group, cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulopentalide ring and carboxylic anhydride (-C(=O)-OC(=O)-); R32 can be a halogen atom, carboxyl group, nitro group, cyano group, or may contain a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms, a hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms, or a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms; when c2 is 2, 3, or 4, each R32 can be the same or different; c1 is 1, 2, 3, or 4; c2 is 0, 1, 2, 3, or 4; however, 1≦c1+c2≦5.

8. A chemical amplification inhibitor composition comprising (A) a base polymer containing the polymer of claim 5.

9. The chemical amplification inhibitor composition of claim 8 further includes (B) an organic solvent.

10. The chemical amplification inhibitor composition of claim 8 further includes (C) a quencher.

11. The chemical amplification inhibitor composition of claim 8 further includes (D) a photoacid generator.

12. The chemical amplification inhibitor composition of claim 8 further includes (E) a surfactant.

13. A pattern forming method comprising the following steps: forming a resist film on a substrate using a chemical amplifying resist composition as claimed in claim 8, exposing the resist film to high-energy radiation, and developing the exposed resist film using a developing solution.

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