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

Abstract

The present invention addresses the use of strontium salt monomers in photolithography employing high-energy rays. These compositions offer excellent solvent solubility, high sensitivity, high contrast, and superior photolithography properties such as EL, LWR, CDU, and DOF. The invention also includes 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. The solution provided by the present invention is a strontium salt monomer represented by 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 the decrease in light contrast, the resolution of hole patterns and groove patterns, as well as the focal limit, decrease in the positive resist film.

[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 aim is to develop resist compositions with higher sensitivity and improved lithography properties such as exposure margin (EL), LWR, CDU, 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, particularly in photolithography using high-energy rays such as KrF excimer laser, ArF excimer laser, electron beam (EB), and EUV, a strontium salt monomer used in a chemical amplification inhibitor composition that exhibits excellent solvent solubility, high sensitivity, high contrast, and excellent photolithography performance such as EL, LWR, CDU, and DOF; 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. [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, in terms of polymer-bonded acid generators, by using polymers containing repeating units of strontium salt-type monomers composed of strontium cations with nitro groups and aromatic sulfonic acid anions with aromatic vinyl structures and iodine atoms, a chemical amplification inhibitor composition with high sensitivity, improved EL, LWR, CDU, DOF and other imaging properties, high contrast and high resolution can be obtained, 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, p is 1, 2, or 3; n1 is 0 or 1; n2 is 1 or 2; and n3 is 0, 1, 2, or 3. However, when n1 is 0, then 1 ≤ n2 + n3 ≤ 5; and when n1 is 1, then 1 ≤ n2 + n3 ≤ 7. R1 can be a halogen atom, cyano group, hydroxyl group, carboxyl group, or may contain a hydrocarbon group with 1-20 carbon atoms, a hydrocarbon oxy group with 1-20 carbon atoms, a hydrocarbon thio group with 1-20 carbon atoms, or a hydrocarbon oxy carbonyl group with 2-20 carbon atoms. When n3 is 2 or 3, each R1 can be the same or different from the others. Two R1s can also be bonded to each other and form a ring together with the bonded carbon atoms. R2 is a halogen atom, or may contain heteroatoms and be a hydrocarbon group with 1 to 30 carbon atoms. When p is 1, two R2 atoms can be the same or different. Furthermore, two of the three substituents bonded to S+ can also bond to each other and form a ring together with the sulfur atoms of these bonds. Z-series aromatic sulfonic acid anions with aromatic vinyl structures. 2. As in 1., the strontium salt type monomer is represented by the following formula (A1), [Chemistry 2] In the formula, p, n1~n3, R1, and Z- are the same as those mentioned above. n4 series: 0 or 1; n5 series: 0, 1, 2, 3, 4, or 5. R3 can be a halogen atom, cyano group, hydroxyl group, carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms that is a heteroatom, or a hydrocarbon oxy group with 1 to 20 carbon atoms that is a heteroatom, or a hydrocarbon thio group with 1 to 20 carbon atoms that is a heteroatom, or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms that is a heteroatom. When n5 is 2, 3, 4 or 5, each R3 can be the same or different from the others. Two R3s can also be bonded to each other and form a ring together with the carbon atoms of these bonds. 3. Sulphur salt type monomers such as 1. or 2, wherein the Z- group represents the anion of the following formula (Z). [Chemistry 3] 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 or 1, m11 is 0, 1, 2, 3 or 4, m12 is 0, 1, 2 or 3, m13 is 0 or 1, m14 is 0 or 1, m15 is 0 or 1, only m When 1 is 0, then 0 ≤ m2 + m3 + m14 ≤ 4; when m1 is 1, then 0 ≤ m2 + m3 + m14 ≤ 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; when m10 is 0, then 0 ≤ m11 + m12 ≤ 4; when m10 is 1, then 0 ≤ m11 + m12 ≤ 6; and 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 1-20 carbon atoms (heteroatomic), a hydrocarbon oxy group with 1-20 carbon atoms (heteroatomic), a hydrocarbon thio group with 1-20 carbon atoms (heteroatomic), or a hydrocarbon oxy carbonyl group with 2-20 carbon atoms (heteroatomic). When m3 is 2 or 3, each R11 can be the same or different from each other. Two R11s can also bond to each other and form a ring with the bonded carbon atoms. When m6 is 2 or 3, each R12 can be the same or different from each other. Two R12s can also bond to each other and form a ring with the bonded carbon atoms. When m9 is 2 or 3, each R13 can be the same or different from each other. Two R13s can also bond to each other and form a ring with the bonded carbon atoms. R14 can be a halogen atom other than fluorine and iodine atoms, a nitro group, a hydroxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. When m12 is 2 or 3, each R14 can be the same or different from the others. Two R14s can also be bonded to each other and form a ring together with the carbon atoms of these bonds. RF consists of a fluorine atom, a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group with 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group with 1 to 6 carbon atoms. When m11 is 2, 3, or 4, the RFs can be the same or different from each other. 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 elongated hydrocarbon group. However, m13 and m14 cannot both be 0 at the same time, and LA, LB, LC, LD, XL1 and XL2 cannot both be single bonds at the same time. 4. As in 3. strontium salt type monomer, where m15 is 1. 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 repeating unit selected from the repeating units represented by formula (a1), formula (a2), and formula (a3). [Chemistry 4] In the formula, RA can be independently represented by a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X1 refers to single bonds, pendiphenyl, pendinaphthyl, *-C(=O)-O-X11-, or *-C(=O)-NH-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 refers to 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, *-C(=O)-O- or *-C(=O)-NH-, * 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. AL1 and AL2 are each independently acid-labile groups. a1 series 0, 1, 2, 3 or 4, [Chemistry 5] In the formula, b1 is 0 or 1, and b2 is 0, 1, 2 or 3 when b1 is 0, and 0, 1, 2, 3, 4 or 5 when b1 is 1. RA series: hydrogen atom, fluorine atom, methyl or trifluoromethyl, X3 series single bonds, *-C(=O)-O- or *-C(=O)-NH-, where * 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 the 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 can 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. 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 comprising at least one repeating unit selected from the repeating units represented by formula (b1) and formula (b2) below. [Chemistry 6] In the formula, RA can be independently represented by a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y1 series single bonds or *-C(=O)-O-, where * indicates an atomic bond with a carbon atom in the main chain. R31 refers to a group with 1 to 20 carbon atoms, or a structure containing at least one of the following: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulopentalide ring, and carboxylic anhydride (-C(=O)-OC(=O)-). R32 can be a halogen atom, carboxyl, nitro, cyano 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, but 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 a polymer of repeating units that function as photoacid generators and contain strontium salt-type monomers from the present invention, high contrast and good sensitivity can be achieved, and resist patterns with excellent photolithography properties such as EL, LWR, CDU, 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 monomer of the present invention is represented by the following formula (A). [Chemistry 7]

[0017] In equation (A), p refers to 1, 2, or 3.

[0018] 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 1 or 2. Considering the availability of raw materials, n2 of 1 is preferred. n3 is 0, 1, 2, or 3. Considering the availability of raw materials, n3 of 0, 1, or 2 is preferred. However, when n1 is 0, then 1 ≤ n2 + n3 ≤ 5; when n1 is 1, then 1 ≤ n2 + n3 ≤ 7.

[0019] In formula (A), R1 represents a halogen atom, a cyano group, a hydroxyl group, a carboxyl group, or may include a hydrocarbon group with 1 to 20 carbon atoms (heteroatomic), a hydrocarbon oxy group with 1 to 20 carbon atoms, a hydrocarbon thio group with 1 to 20 carbon atoms, or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. The hydrocarbon groups, hydrocarbon oxy groups, and hydrocarbon thio groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecanyl, octadecyl, nonadecanyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclohexenyl and other cyclounsaturated hydrocarbon groups with 3 to 20 carbon atoms; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these. Of these, aryl is preferable. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, halogen, etc., and the -CH2- portion of the aforementioned hydrocarbon group may also be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, etc. The result may 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 n3 is 2 or 3, each R1 may be the same or different. Furthermore, when n3 is 2 or 3, multiple R1s may also bond to each other and form a ring together with the bonded carbon atoms. The aforementioned ring is preferably a 5- to 8-membered ring.

[0020] In formula (A), R2 is a halogen atom, or may contain a hydrocarbon group with 1 to 30 carbon atoms of heteroatoms. When p is 1, the two R2s may be the same or different.

[0021] Specific examples of halogen atoms represented by R2 include fluorine, chlorine, bromine, and iodine atoms.

[0022] R2 represents a hydrocarbon group that can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, and tributyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 30 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclohexenyl and other cyclic unsaturated hydrocarbon groups with 3 to 30 carbon atoms; aryl groups with 6 to 30 carbon atoms such as phenyl, naphthyl, and thiophene; and aralkyl groups with 7 to 30 carbon atoms such as benzyl, 1-phenylethyl, and 2-phenylethyl. Groups formed by combining these should preferably be aryl groups. 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 contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0023] Furthermore, two of the three substituents 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 structure can be given by formulas such as the following. [Chemistry 8] In the formula, the dashed lines represent atomic bonds.

[0024] The strontium salt type monomer represented by formula (A) should preferably be represented by the following formula (A1). [Chemistry 9] In the formula, p, n1~n3 and R1 are the same as described above. Z will be described later.

[0025] In formula (A1), n4 is 0 or 1. When n4 is 0, it is a benzene ring; when n4 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with n4 of 0 is preferred. n5 is 0, 1, 2, 3, 4, or 5. Considering the availability of raw materials, n5 is preferably 0, 1, or 2.

[0026] In formula (A1), R3 can be a halogen atom, cyano group, hydroxyl group, 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. The hydrocarbon portion of the aforementioned hydrocarbon group and the aforementioned alkyloxy and alkylthio groups 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 R1, but are not limited to these. When n5 is 2, 3, 4, or 5, each R3 can be the same or different from each other, and two R3s can also be bonded to each other and form a ring together with the bonded carbon atoms.

[0027] Specific examples of strontium salt type monomer cations represented by formula (A) are shown below, but are not limited to these. [Chemistry 10]

[0028] [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] In formula (A), Z- is an aromatic sulfonic acid anion having an aromatic vinyl structure. The aforementioned aromatic sulfonic acid anion should preferably be represented by the following formula (Z). [Chemistry 30]

[0048] In formula (Z), 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 should preferably be 0, 1, 2, or 3, with 0, 1, or 2 being better, and 0 or 1 being even better. m3 is 0, 1, 2, or 3.

[0049] In formula (Z), 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 should preferably be 0, 1, 2, or 3, with 0, 1, or 2 being more desirable. m6 is 0, 1, 2, or 3.

[0050] In formula (Z), 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 should preferably be 1, 2, or 3, with 1 or 2 being more desirable. m9 is 0, 1, 2, or 3.

[0051] In formula (Z), m10 is 0 or 1. When m10 is 0, it is a benzene ring; when m10 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m10 of 0 is preferred. m11 is 0, 1, 2, 3, or 4. m12 is 0, 1, 2, or 3.

[0052] In formula (Z), m13 is either 0 or 1. m14 is either 0 or 1.

[0053] In equation (Z), m15 is either 0 or 1. Considering the structural changes, m15 being 1 is preferable.

[0054] However, when m1 is 0, then 0 ≤ m2 + m3 + m14 ≤ 4; when m1 is 1, then 0 ≤ m2 + m3 + m14 ≤ 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. When m10 is 0, then 0 ≤ m11 + m12 ≤ 4; when m10 is 1, then 0 ≤ m11 + m12 ≤ 6. Furthermore, regarding the number of iodine atoms in the anion, a higher number of iodine atoms, especially for EUV absorption, will increase absorption, but it will also reduce solvent solubility, raising concerns about precipitation in the inhibitor composition. Therefore, 1 ≤ m2 + m5 + m8 ≤ 4 is preferable.

[0055] In formula (Z), 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 more preferred.

[0056] In formula (Z), 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 atom, a chlorine atom, or a bromine atom, with fluorine being more preferred. The hydrocarbon portion of the aforementioned hydrocarbon group, hydrocarbon oxy group, and hydrocarbon thio group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecanyl, octadecyl, nonadecanyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclohexenyl and other cyclounsaturated hydrocarbon groups with 3 to 20 carbon atoms; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by 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.

[0057] 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.

[0058] In formula (Z), R12 can be 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 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 part of the aforementioned hydrocarbon group, alkyloxy group, and alkylthio 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. When m6 is 2 or 3, each R12 can be the same or different from each other.

[0059] 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.

[0060] In formula (Z), R13 can be 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 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, and alkylthio 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. When m9 is 2 or 3, each R13 can be the same or different from each other.

[0061] 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.

[0062] In formula (Z), R14 represents a halogen atom other than fluorine and iodine atoms, a nitro group, a hydroxyl 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. Specific examples of halogen atoms other than fluorine and iodine atoms include chlorine atoms, bromine atoms, etc. The hydrocarbon portion of the aforementioned hydrocarbon group, hydrocarbon thio group, and hydrocarbon thio group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be the same as those exemplified by the hydrocarbon group represented by R11, but are not limited to these. When m12 is 2 or 3, each R14 can be the same or different from the others.

[0063] Furthermore, when m12 is 2 or 3, the two R14 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.

[0064] In formula (Z), RF refers to a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms. Among these, it is preferable to have a fluorine atom, trifluoromethyl, trifluoromethoxy, or trifluoromethylthio group, with fluorine atom being more preferred. When m11 is 2, 3, or 4, each RF may be the same or different from the others.

[0065] In formula (Z), 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 bond being more preferred. LB is preferably a single bond, ether bond, ester bond, amide bond, sulfonamide bond, or sulfonate bond, with ester or sulfonate bond 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.

[0066] When m14 is 1, LA and LB should preferably be carbon atoms bonded to adjacent carbon atoms of the aromatic ring. In this case, the substituents containing the fluorosulfonic acid anion structure and the substituents containing the aromatic ring substituted with an iodine atom can be expected to have higher sensitivity because they are located in closer spatial positions.

[0067] In formula (Z), 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.

[0068] 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 31]

[0069] [Chemistry 32]

[0070] [Chemistry 33]

[0071] [Chemistry 34]

[0072] Of these, XL-0~XL-22, XL-29~XL-34, and XL-47~XL-58 are preferred.

[0073] However, in equation (Z), m13 and m14 are not both 0, and LA, LB, LC, LD, XL1 and XL2 are not both single bonds.

[0074] Specific examples of anions represented by Z- can 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 35]

[0075] [Chemistry 36]

[0076] [Chemistry 37]

[0077] [Chemistry 38]

[0078] [Chemistry 39]

[0079] [Chemistry 40]

[0080] [Chemistry 41]

[0081] [Chemistry 42]

[0082] [Chemistry 43]

[0083] [Chemistry 44]

[0084] [Chemistry 45]

[0085] [Chemistry 46]

[0086] [Chemistry 47]

[0087] [Chemistry 48]

[0088] [Chemistry 49]

[0089] [Transformation 50]

[0090] [Chemistry 51]

[0091] [Chemistry 52]

[0092] [Chemistry 53]

[0093] [Chemistry 54]

[0094] [Chemistry 55]

[0095] [Chemistry 56]

[0096] [Chemistry 57]

[0097] [Chem.58]

[0098] [Chemistry 59]

[0099] [Transformation 60]

[0100] [Chemistry 61]

[0101] [Chemistry 62]

[0102] [Chemistry 63]

[0103] [Chemistry 64]

[0104] [Chemistry 65]

[0105] [Chemistry 66]

[0106] [Chemistry 67]

[0107] [Chemistry 68]

[0108] [Chemistry 69]

[0109] [Chemistry 70]

[0110] [Chemistry 71]

[0111] [Chemistry 72]

[0112] [Chemistry 73]

[0113] [Chemistry 74]

[0114] [Chemistry 75]

[0115] [Chemistry 76]

[0116] [Chemistry 77]

[0117] [Chemistry 78]

[0118] [Chemistry 79]

[0119] [Chemistry 80]

[0120] [Chemistry 81]

[0121] [Chemistry 82]

[0122] [Chemistry 83]

[0123] [Chemistry 84]

[0124] [Chemistry 85]

[0125] [Chemistry 86]

[0126] [Chemistry 87]

[0127] [Chemistry 88]

[0128] [Chemistry 89]

[0129] [Chemistry 90]

[0130] [Chemistry 91]

[0131] [Chemistry 92]

[0132] [Chemistry 93]

[0133] [Chemistry 94]

[0134] [Chem. 95]

[0135] [Chemistry 96]

[0136] [Chemistry 97]

[0137] [Chem. 98]

[0138] [Chemistry 99]

[0139] [Chemistry 100]

[0140] [Chemistry 101]

[0141] [Chemistry 102]

[0142] [Chemistry 103]

[0143] [Chemistry 104]

[0144] [Chemistry 105]

[0145] [Chemistry 106]

[0146] [Chemistry 107]

[0147] [Chemistry 108]

[0148] [Chemistry 109]

[0149] [Chemical 110]

[0150] [Chemistry 111]

[0151] [Chemistry 112]

[0152] [Chemistry 113]

[0153] [Chemistry 114]

[0154] [Chemistry 115]

[0155] [Chemistry 116]

[0156] [Chemistry 117]

[0157] [Chemistry 118]

[0158] [Chemistry 119]

[0159] [Chemistry 120]

[0160] [Chemistry 121]

[0161] [Chemistry 122]

[0162] [Chemistry 123]

[0163] [Chemistry 124]

[0164] [Chemistry 125]

[0165] [Chemistry 126]

[0166] [Chemistry 127]

[0167] [Chemistry 128]

[0168] [Chemistry 129]

[0169] [Chemistry 130]

[0170] [Chemistry 131]

[0171] [Chemistry 132]

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[0174] [Chemistry 135]

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[0176] [Chemistry 137]

[0177] [Chemistry 138]

[0178] [Chemistry 139]

[0179] [Chemistry 140]

[0180] [Chemistry 141]

[0181] [Chemistry 142]

[0182] [Chemistry 143]

[0183] [Chemistry 144]

[0184] [Chemistry 145]

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[0189] [Chemistry 150]

[0190] [Chemistry 151]

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[0194] [Chemistry 155]

[0195] [Chemistry 156]

[0196] [Chemistry 157]

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[0200] [Chemistry 161]

[0201] [Chemistry 162]

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[0240] [Chemical Engineering 201]

[0241] [Chemical Engineering 202]

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[0243] [Chemical 204]

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[0312] [Chemistry 273]

[0313] [Chemistry 274]

[0314] [Chemistry 275]

[0315] [Chemistry 276]

[0316] [Chemistry 277]

[0317] [Chemistry 278]

[0318] [Chemistry 279]

[0319] The specific structure of the strontium salt type monomer of this invention can be described by any combination of the aforementioned anions and cations.

[0320] The strontium salt monomer of this invention can be synthesized using known methods. For example, firstly, a strontium salt containing the aforementioned strontium cation can be synthesized using the synthesis method described in ARKIVOC (Gainesville, FL, United States) (2022), (7), 7-18. Then, by performing a salt exchange reaction with the anion corresponding to the synthesized strontium salt, it can be converted into the target strontium salt. 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.

[0321] Furthermore, the aforementioned manufacturing method is merely one example, and the manufacturing method of strontium salt of the present invention is not limited to this.

[0322] Regarding the structural characteristics of the strontium salt type monomer of the present invention, examples include an aromatic vinyl structure serving as a polymerizable group, an aromatic sulfonic acid anion structure of iodine atoms, and a nitro group bonded to the aromatic ring of the strontium cation. The aromatic sulfonic acid anion structure is more rigid than the alkane sulfonic acid anion structure, exhibiting low acid diffusion. For iodine atoms, especially in EUV lithography at a wavelength of 13.5 nm, due to the extremely high EUV absorption of iodine atoms, secondary electrons from iodine atoms are generated during exposure. Because the anionic portion of the strontium salt type monomer of the present invention has a polymerizable group, the polymer obtained using it becomes an anionic bonded acid generator formed by the anionic side being 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, the polymerizable group, especially composed of styrene and vinylnaphthalene structures, is more rigid than polymerizable groups such as methacrylates, increasing the glass transition temperature (Tg) of the polymer. It is believed that the aromatic rings within or between polymers interact (π-π stacking effect), resulting in a regular and correct arrangement of the polymer, and exhibiting resistance to pattern collapse during micropattern formation. Furthermore, in the etching step following micropattern formation, the aromatic rings directly bonded to the main chain also exhibit excellent etching resistance. On the other hand, the nitro groups substituted on the aromatic rings of the strontium cation are known to be strong electron-withdrawing groups. Therefore, it is believed that the LUMO energy level in the front-edge molecular orbital theory decreases. This makes it easier to accept secondary electrons generated from the iodine atom in the anion, promoting the decomposition of the cation and efficiently generating acid. Moreover, the nitro group has a resonance structure with a positive charge on its nitrogen atom and a negative charge on one oxygen atom; therefore, it is expected that the negative charge on the oxygen atom will interact with the protons of the generated acid, functioning as an acid diffusion inhibitor. Due to its charged nature, it exhibits high affinity for alkaline developers, and the residue from cationic decomposition is efficiently removed by the alkaline developer, thus reducing the risk of development defects in the exposed section. This additive effect also enhances sensitivity, preventing resolution degradation caused by acid diffusion blurring and improving LWR and CDU. Therefore, the polymer of this invention is particularly suitable as a material for chemically amplified positive resist components.

[0323] [polymer] The polymer system of the present invention comprises repeating units (hereinafter also referred to as repeating unit A) derived from strontium salt type monomers represented by formula (A).

[0324] 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.). [Chemistry 280]

[0325] In formulas (a1) and (a2), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0326] 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 also 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.

[0327] 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.

[0328] 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.

[0329] Generally speaking, specific examples of the aforementioned unstable acid groups can be represented by the following formulas (AL-1) to (AL-3). [Chemistry 281] In the formula, * represents an atomic bond.

[0330] 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 group may be saturated or unsaturated, and may be linear, branched, or cyclic. The aforementioned hydrocarbon group is preferably one with 1 to 20 carbon atoms.

[0331] In formula (AL-1), a2 is an integer from 0 to 10, and should preferably be 1, 2, 3, 4 or 5.

[0332] 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 may be saturated or unsaturated, and may be linear, branched, or cyclic. The aforementioned hydrocarbon groups are preferably those with 1 to 20 carbon atoms. Furthermore, any two of RL2, RL3, and RL4 may 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 alicyclic rings are particularly preferred.

[0333] 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 may be saturated or unsaturated, and may be linear, branched, or cyclic. The aforementioned hydrocarbon groups are preferably those with 1 to 20 carbon atoms. Furthermore, any two of RL5, RL6, and RL7 may bond to each other and together with the bonded carbon atoms to form a ring with 3 to 20 carbon atoms. The aforementioned ring is preferably a ring with 4 to 16 carbon atoms, and is especially preferably an alicyclic ring.

[0334] 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. [Chemistry 282]

[0335] [Chemistry 283]

[0336] [Chemistry 284]

[0337] [Chemistry 285]

[0338] 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 286]

[0339] [Chemistry 287]

[0340] [Chemistry 288]

[0341] The aforementioned polymer may also contain repeating units represented by the following formula (a3) ​​(hereinafter also referred to as repeating unit a3). [Chemistry 289]

[0342] 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.

[0343] In formula (a3), RA refers to a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Among these, hydrogen atoms and methyl groups are preferred, with hydrogen atoms being even more preferred.

[0344] 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.

[0345] 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.

[0346] 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 in the aromatic ring. X5 and X6 can be the same or different; from a reactivity perspective, it is better if X5 and X6 are both oxygen atoms.

[0347] In formula (a3), R22 and R23 are each independently hydrogen atoms, or may contain hydrocarbon groups with 1 to 20 carbon atoms containing heteroatoms. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecanyl, octadecyl, nonadecanyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclohexenyl and other cyclounsaturated hydrocarbon groups with 3 to 20 carbon atoms; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these. Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by 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.

[0348] 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.

[0349] 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.

[0350] 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.

[0351] 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 290]

[0352] [Chemistry 291]

[0353] [Chemistry 292]

[0354] [Chemistry 293]

[0355] [Chemistry 294]

[0356] [Chemistry 295]

[0357] [Chemistry 296]

[0358] [Chemistry 297]

[0359] [Chemistry 298]

[0360] [Chemistry 299]

[0361] [Chemical 300]

[0362] [Chemical Engineering 301]

[0363] [Chemical 302]

[0364] [Chemical 303]

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[0368] [Chemical 307]

[0369] [Chemical 308]

[0370] [Chemical 309]

[0371] [Chemical 310]

[0372] [Chemistry 311]

[0373] [Chemistry 312]

[0374] [Chemistry 313]

[0375] [Chemical 314]

[0376] [Chemical 315]

[0377] [Chemistry 316]

[0378] [Chemistry 317]

[0379] [Chemistry 318]

[0380] [Chemistry 319]

[0381] [Chemistry 320]

[0382] [Chemistry 321]

[0383] [Chemistry 322]

[0384] [Chemistry 323]

[0385] [Chemistry 324]

[0386] [Chemistry 325]

[0387] [Chemistry 326]

[0388] [Chemistry 327]

[0389] [Chemistry 328]

[0390] [Chemistry 329]

[0391] [Chemistry 330]

[0392] [Chemistry 331]

[0393] [Chemistry 332]

[0394] [Chemistry 333]

[0395] [Chemistry 334]

[0396] [Chemistry 335]

[0397] [Chemistry 336]

[0398] [Chemistry 337]

[0399] [Chemistry 338]

[0400] [Chemistry 339]

[0401] The aforementioned base 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.). [Transformation 340]

[0402] 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.

[0403] 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 341]

[0404] [Chemistry 342]

[0405] [Chemistry 343]

[0406] [Chemistry 344]

[0407] [Chemistry 345]

[0408] [Chemistry 346]

[0409] [Chemistry 347]

[0410] [Chemistry 348]

[0411] [Chemistry 349]

[0412] [Chemical 350]

[0413] [Chemistry 351]

[0414] [Chemistry 352]

[0415] [Chemistry 353]

[0416] [Chemistry 354]

[0417] [Chemistry 355]

[0418] [Chemistry 356]

[0419] 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 357]

[0420] [Chemistry 358]

[0421] [Chemistry 359]

[0422] [Hua360]

[0423] [Chemistry 361]

[0424] In ArF lithography, repeating units b1 or b2 are preferred, especially those with a lactone ring as a polar group; in KrF lithography, EB lithography, and EUV lithography, those with a phenolic site are preferred.

[0425] The aforementioned basic polymer may also contain repeating units (hereinafter also referred to as repeating units c) having a structure in which hydroxyl groups are protected by acid-insecure groups. Repeating units c are not particularly limited as long as they have a structure in which one or more hydroxyl groups are protected, and the protecting groups decompose to generate hydroxyl groups due to the action of acid. The following formula (c1) is preferred. [Chemistry 362]

[0426] 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.

[0427] In formula (c1), R42 represents an acid-indestructible group that can be protected by the acid and generate a hydroxyl group. The structure of R42 is not particularly limited, but it is preferable to have an acetal structure, a ketal structure, an alkoxy carbonyl group, or an alkoxy methyl group represented by formula (c2), and is especially preferred to have an alkoxy methyl group represented by formula (c2). [Chem.363] In the formula, * represents an atomic bond. R43 refers to hydrocarbon groups with 1 to 15 carbon atoms.

[0428] Specific examples of the acid unstable group represented by R42, the alkoxymethyl group represented by formula (c2), and the repeating unit c can be cited as those illustrated in the description of the repeating unit c disclosed in Japanese Patent Application Publication No. 2020-111564.

[0429] The aforementioned base polymer may also contain repeating units d derived from indene, benzofuran, benzothiophene, acenaphthene, chromone, coumarin, northodiene, or derivatives thereof. Specific examples of monomers providing repeating units d may be listed below, but are not limited to these. [Chem.364]

[0430] The aforementioned base polymer may further include repeating units e derived from indene, vinylpyridine, or vinylcarbazole.

[0431] In the polymer of the present invention, the content ratios of 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.

[0432] The weight average molecular weight (Mw) of the aforementioned polymer is preferably 1,000 to 500,000, more preferably 3,000 to 100,000. If Mw is within this range, sufficient etching resistance can be obtained, and there is no concern about a decrease in resolution caused by an inability to ensure the difference in dissolution rate before and after exposure. Moreover, in the present invention, Mw is a polystyrene equivalent measurement value obtained by gel permeation chromatography (GPC) using THF or N,N-dimethylformamide (DMF) as a solvent.

[0433] Furthermore, as the pattern rule becomes finer, the influence of the molecular weight distribution (Mw / Mn) of the aforementioned polymer tends to become larger. Therefore, in order to obtain a resist composition suitable for fine pattern sizes, a narrow dispersion with Mw / Mn of 1.0 to 2.0 is preferred. If it is within the above range, there are fewer low molecular weight and high molecular weight polymers, and there is no concern about foreign substances observed on the pattern after exposure or deterioration of the pattern shape.

[0434] To synthesize the aforementioned polymer, for example, monomers providing the aforementioned repeating units can be added with a radical polymerization initiator and heated in an organic solvent to perform polymerization.

[0435] 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.

[0436] 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%.

[0437] 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.

[0438] 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.

[0439] The alkali used in alkaline hydrolysis can be ammonia, triethylamine, etc. 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.

[0440] 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.

[0441] 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.

[0442] 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.

[0443] In the aforementioned polymer solution, the polymer concentration is preferably 0.01~30% by mass, and more preferably 0.1~20% by mass.

[0444] 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.

[0445] 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.

[0446] [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).

[0447] 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.

[0448] [(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.

[0449] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, cyclohexanone, GBL, ethyl lactate, DAA, and mixed solvents thereof are preferred as they have particularly good solubility in component (A), i.e., the base polymer.

[0450] 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.

[0451] [(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.

[0452] (C) Specific examples of quenching agents can be listed as onion salts represented by formula (1) or (2). [Chem365]

[0453] 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.

[0454] The hydrocarbon group represented by Rq1 and having 1 to 40 carbon atoms specifically includes, for example, alkyl groups having 1 to 40 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl; cycloalkyl saturated hydrocarbon groups having 3 to 40 carbon atoms such as cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.02,6]decyl, adamantyl; aryl groups having 6 to 40 carbon atoms such as phenyl, naphthyl, anthryl, etc. Further, one or more of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted with a group containing heteroatoms such as oxygen atom, sulfur atom, nitrogen atom, halogen atom, etc., and a part of -CH2- of the aforementioned hydrocarbon group may also be substituted with a group containing heteroatoms such as oxygen atom, sulfur atom, nitrogen atom, etc., and as a result, it may also include hydroxyl group, fluorine atom, chlorine atom, bromine atom, iodine atom, cyano group, carbonyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sultone ring, carboxylic anhydride (-C(=O)-O-C(=O)-), haloalkyl, etc.

[0455] The hydrocarbon group represented by Rq2 specifically includes, in addition to the substituents exemplified in the specific examples of Rq1, fluorinated saturated hydrocarbon groups such as trifluoromethyl, trifluoroethyl, etc., and fluorinated aryl groups such as pentafluorophenyl, 4-trifluoromethylphenyl, etc.

[0456] Specific examples of the anion of the onium salt represented by formula (1) include those shown below, but are not limited thereto. [Chemical formula 366]

[0457] [Chemical formula 367]

[0458] [[ID=Elementary school]]<00022 >

[0459] [Chemical formula 369] <000 <0 >02213>

[0460] [Chemical formula 370]

[0461] Specific examples of the anion of the onium salt represented by formula (2) include those shown below, but are not limited thereto. [Chemical formula 371]

[0462] [Chemistry 372]

[0463] [Chemistry 373]

[0464] [Chemistry 374]

[0465] [Chemistry 375]

[0466] In formulas (1) and (2), Mq+ is a munonium cation. Examples of the aforementioned munonium cations include strontium cations, monium cations, and ammonium cations. Specific examples of the aforementioned strontium cations include those exemplified in formula (A), those described in paragraphs

[0102] to

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

[0044] to

[0049] of International 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.

[0467] Furthermore, the aforementioned strontium cation should preferably be a strontium cation represented by the following formula (sulfo-1). [Chemistry 376]

[0468] 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 e2 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.

[0469] 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.

[0470] 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.

[0471] 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.

[0472] 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.

[0473] 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.

[0474] 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.

[0475] 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.

[0476] 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.

[0477] 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 group represented by R1 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.

[0478] 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, and adamantane rings. 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.

[0479] 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. [Chemistry 377] In the formula, the dashed lines represent atomic bonds.

[0480] 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.

[0481] 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 (Z) 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.

[0482] The strontium cation represented by formula (sulfo-1) should preferably be represented by the following formula (sulfo-1-1). [Chemistry 378] In the formula, e4~e10, e12~e14, RF1~RF3, Rq11~Rq14, LF, LG and XL3 are the same as those mentioned above.

[0483] The strontium cation represented by formula (sulfo-1-1) should preferably be represented by formula (sulfo-1-2). [Chemistry 379] In the formula, e4~e10, RF1~RF3 and Rq11~Rq13 are the same as those mentioned above.

[0484] 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. [Chemistry 380]

[0485] [Chemistry 381]

[0486] [Chemistry 382]

[0487] [Chemistry 383]

[0488] [Chem. 384]

[0489] [Chem. 385]

[0490] [Chemistry 386]

[0491] [Chemistry 387]

[0492] [Chem.388]

[0493] [Chemistry 389]

[0494] [Chemistry 390]

[0495] [Chemistry 391]

[0496] [Chemistry 392]

[0497] [Chemistry 393]

[0498] [Chem. 394]

[0499] [Chemistry 395]

[0500] [Chemistry 396]

[0501] [Chemistry 397]

[0502] [Chemistry 398]

[0503] [Chemistry 399]

[0504] [Chemical 400]

[0505] [Chemical Engineering 401]

[0506] [Chemical 402]

[0507] [Chemical 403]

[0508] [Chemical 404]

[0509] [Chemical 405]

[0510] [Chemical 406]

[0511] [Chemical 407]

[0512] 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.

[0513] Specific examples of the aforementioned ammonium cations can be represented by the following formula (am-1). [Chemical 408] 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 group represented by R1 in the description of formula (A).

[0514] Specific examples of ammonium cations represented by formula (am-1) are shown below, but are not limited to these. [Chemical 409]

[0515] 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.

[0516] 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.

[0517] 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.

[0518] 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.

[0519] 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.

[0520] 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.

[0521] 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.

[0522] 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.

[0523] [(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. [Chemical 410]

[0524] 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.

[0525] Specific examples of strontium salt cations represented by formula (3) may include those exemplified by the specific examples of strontium cations in formula (A), those described in paragraphs

[0102] to

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

[0044] to

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

[0035] to

[0046] of Japanese Patent Application Publication No. 7491173, and those exemplified by 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 include those described in paragraph

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

[0526] 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 411]

[0527] 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.

[0528] The anion represented by formula (Xa-1) should preferably be represented by the following formula (Xa-1-1). [Chemistry 412]

[0529] 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.

[0530] 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.

[0531] 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.

[0532] 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.

[0533] 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. [Chemistry 413]

[0534] [Chemistry 414]

[0535] [Chemical 415]

[0536] [Chemistry 416]

[0537] [Chemistry 417]

[0538] [Chemistry 418]

[0539] [Chemistry 419]

[0540] [Chem.420]

[0541] [Chemistry 421]

[0542] [Chemistry 422]

[0543] 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.

[0544] 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.

[0545] 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).

[0546] Specific examples of anions represented by formula (Xa-4) are shown below, but are not limited to these. [Chemistry 423]

[0547] [Chemistry 424]

[0548] 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). [Chemical 425]

[0549] 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.

[0550] In formula (Xa-5), XBI represents iodine or bromine atoms, and when x and / or y are 2 or more, they can be the same or different.

[0551] In formula (Xa-5), L1 represents 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 linear, branched, or cyclic.

[0552] In formula (Xa-5), L2 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.

[0553] 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 group, hydrocarbon oxy group, hydrocarbon carbonyl group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyloxy group, and hydrocarbon sulfonyloxy group 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.

[0554] 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.

[0555] 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.

[0556] 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 426]

[0557] [Chemistry 427]

[0558] [Chemistry 428]

[0559] [Chemistry 429]

[0560] [Chemistry 430]

[0561] [Chemistry 431]

[0562] [Chemistry 432]

[0563] [Chemistry 433]

[0564] [Chemistry 434]

[0565] [Chemistry 435]

[0566] [Chemistry 436]

[0567] [Chemistry 437]

[0568] [Chemistry 438]

[0569] [Chemistry 439]

[0570] [Chemistry 440]

[0571] [Chemistry 441]

[0572] [Chemistry 442]

[0573] [Chemistry 443]

[0574] [Chemistry 444]

[0575] [Chemistry 445]

[0576] [Chemistry 446]

[0577] [Chemistry 447]

[0578] [Chemistry 448]

[0579] 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.

[0580] 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.

[0581] 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.

[0582] Furthermore, component (D), i.e., photoacid generator, should preferably be represented by the following formula (5). [Chemistry 449]

[0583] 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.

[0584] 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.

[0585] 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.

[0586] In formula (5), L11 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.

[0587] 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.

[0588] The photoacid generator represented by formula (5) should preferably be represented by the following formula (5'). [Chemistry 450]

[0589] In formula (5'), L11 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.

[0590] The photoacid generating agent represented by formula (5) may be the same as that exemplified by the photoacid generating agent represented by formula (2) in Japanese Patent Application Publication No. 2017-26980.

[0591] 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.

[0592] 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 the (A) 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), i.e., the 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; therefore, it is ideal. (D) The photoacid generating agent can be used alone or in combination of two or more.

[0593] (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.

[0594] 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 451]

[0595] 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 452] In the formula, the dashed lines represent atomic bonds, which are secondary structures derived from glycerol, trimethylolethane, trimethylolpropane, and neopentyl tertrol, respectively.

[0596] Among these, 1,4-endobutyl and 2,2-dimethyl-1,3-endopropyl are preferred.

[0597] 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.

[0598] 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.

[0599] 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 453]

[0600] 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.

[0601] 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.

[0602] 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.

[0603] 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, other saturated hydrocarbon groups include undecayl, dodecyl, tridecayl, tetradecayl, and decadecyl. Fluorinated hydrocarbon groups represented by Rs3 or Rs6 can be groups where some or all of the hydrogen atoms on 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.

[0604] 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.

[0605] 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.

[0606] 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-decafluoroheptyl, 2-(perfluorobutyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorooctyl)ethyl, 2-(perfluorodecyl)ethyl, etc.

[0607] 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. [Chemistry 454]

[0608] [Chemistry 455]

[0609] [Chemistry 456]

[0610] [Chemistry 457]

[0611] [Chemistry 458]

[0612] [Chemistry 459]

[0613] The aforementioned polymeric surfactants may also include repeating units other than those represented by formulas (6A) to (6E). 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 total repeating units.

[0614] 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.

[0615] Methods for synthesizing the aforementioned polymeric surfactants include: adding a free radical initiator to a monomer containing unsaturated bonds, representing repeating units of formulas (6A) to (6E) and providing other repeating units as needed, in an organic solvent, and heating to polymerize it. Examples of organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, and dialkylene. 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-independent unstable groups can be directly introduced into the monomer, or they can be protected or partially protected after polymerization.

[0616] 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.

[0617] 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.

[0618] [(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 solubility of Mw3000 or less that change due to the action of acid (solution inhibitors). The aforementioned acid-increasing compounds can be found in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608. When the aforementioned acid-increasing compounds are included, their content relative to 80 parts by mass of the base polymer 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 found in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608.

[0619] [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.

[0620] The aforementioned substrate, for example, can be a substrate used for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective film, etc.) or a substrate used for masking circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.).

[0621] 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.

[0622] 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.

[0623] 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.

[0624] 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.

[0625] 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.

[0626] 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.

[0627] 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.

[0628] 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.

[0629] 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.

[0630] 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]

[0631] 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.

[0632] [1] Synthesis of strontium salt type monomers [Example 1-1] Synthesis of monomer PAG-1 (1) Synthesis of intermediate In-1 [Chemistry 460]

[0633] Under nitrogen atmosphere, SM-1 (34.7 g), SM-2 (85.0 g), and copper acetate (8.24 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 recrystallized with diisopropyl ether to obtain 42.5 g of yellow crystalline intermediate In-1 (62% yield).

[0634] (2) Synthesis of monomer PAG-1 [Chemistry 461]

[0635] Under nitrogen atmosphere, intermediates In-1 (37.7 g), In-2 (76.7 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 84.2 g of the monomer PAG-1 in oily form (95% yield).

[0636] The TOF-MS results of PAG-1 are shown below. MALDI TOF-MS: POSITIVE M+308 (equivalent to C18H14NO2S+) NEGATIVE M-873 (equivalent to C22H8F4I7O7S-)

[0637] [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 462]

[0638] [Chemistry 463]

[0639] [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. [Chemistry 464]

[0640] [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 465]

[0641] [Chemistry 466]

[0642] [Chemistry 467]

[0643] [Example 2-1] Synthesis of Polymer P-1 Under nitrogen atmosphere, monomer-polymerization initiator solution was prepared by taking monomer a1-1 (18.3 g), monomer b1-1 (5.4 g), monomer PAG-1 (26.4 g), V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) 1.72 g, and MEK 70 g in a flask. In another flask under nitrogen atmosphere, MEK 23 g 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 1000 g of hexane after vigorous stirring, and the precipitated polymer was filtered. The obtained polymer was then washed twice with 300 g of hexane and vacuum dried at 50°C for 20 hours to obtain a white powder polymer P-1 (yield 49.1 g, 98% yield). The Mw ratio of polymer P-1 is 9700, 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 468]

[0644] [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.

[0645] [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 - - - - 9700 1.61 P-2 2 15 a1-1 55 b1-1 30 - - - - 9400 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 - - - - 9300 1.61 P-5 5 15 a1-1 55 b1-1 30 - - - - 9200 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 1.62 P-8 PAG-8 15 a1-1 55 b1-1 30 - - - - 9400 1.61 P-9 PAG-9 15 a1-1 55 b1-1 30 - - - - 9500 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 - - - - 9300 1.62 P-13 PAG-1 15 a3-1 45 b1-1 40 - - - - 8800 1.63 P-14 2 15 a1-1 55 b1-2 30 - - - - 9100 1.61 P-15 2 15 a1-1 55 b1-3 30 - - - - 9200 1.62 P-16 PAG-2 15 a1-1 55 b1-4 30 - - - - 9100 1.62 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 - - 9300 1.61 P-19 PAG-4 15 a1-2 30 a2-1 15 b1-3 40 - - 9200 1.62 P-20 PAG-6 10 a1-1 35 a2-1 15 b1-1 30 b2-1 10 9200 1.63 P-21 PAG-7 15 a1-2 35 a3-1 15 b1-2 25 b2-2 10 9100 1.61 P-22 PAG-9 15 a1-1 50 b1-1 30 b2-3 5 - - 9000 1.61 P-23 PAG-1 5 a1-1 55 b1-2 40 - - - - 9500 1.63 P-24 PAG-2 5 a1-1 30 a1-3 25 b1-2 40 - - 9500 1.62 P-25 PAG-3 5 a1-2 30 a2-1 20 b1-4 35 b2-1 10 9300 1.61 P-26 PAG-7 5 a1-1 35 a3-1 15 b1-1 30 b2-2 15 9600 1.62

[0646] [Table 2] 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 CP-1 A 15 a1-1 55 b1-1 30 - - - - 9500 1.62 CP-2 b 15 a1-1 55 b1-1 30 - - - - 9100 1.61 CP-3 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 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 PAG-B 15 a1-2 55 b1-1 30 - - - - 9600 1.61 CP-8 PAG-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 PAG-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

[0647] [3] Preparation of chemical amplification inhibitor composition [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).

[0648] [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)

[0649] [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)

[0650] 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)

[0651] Photoacid generators: PAG-X, PAG-Y [Chemistry 469]

[0652] Quenching agents: Q-1~Q-4 [Chemistry 470]

[0653] Surfactant A: 3-Methyl-3-(2,2,2-trifluoroethoxymethyl)oxetane / tetrahydrofuran / 2,2-dimethyl-1,3-propanediol copolymer (manufactured by OMNOVA). [Chemistry 471] a:(b+b'):(c+c')=1:4~7:0.01~1 (Morbies) Mw=1500

[0654] [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 varied (exposure amount pitch: 1 mJ / cm2, focal length pitch: 0.020 μm). After exposure, PEB was performed at the temperatures shown in Tables 5 and 6 for 60 seconds. Subsequently, the model was immersed in a 2.38% TMAH aqueous solution for 30 seconds for development, rinsed with a washing material containing surfactant, and then rotated to dry, thus obtaining a positive pattern. The obtained LS patterns were observed using a Hitachi Advanced Semiconductor Critical Dimension SEM (CG6300), and the sensitivity, EL, LWR, depth of focus (DOF), and collapse limit were evaluated according to the methods described below. Furthermore, the development defects of the obtained LS patterns were evaluated. The results are shown in Tables 5 and 6.

[0655] [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.

[0656] [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.

[0657] [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.

[0658] [DOF Rating] In terms of depth of focus evaluation, the focal length range is determined by the range of ±10% (16.2~19.8nm) of the 18nm dimension in the aforementioned LS pattern. The larger this value, the wider the depth of focus.

[0659] [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.

[0660] [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.

[0661] [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 95 32 18 2.2 120 10.8 A Example 4-2 R-2 100 32 19 2.4 110 10.7 A Example 4-3 R-3 100 33 17 2.3 120 10.6 A Example 4-4 R-4 95 32 18 2.3 110 11.1 A Examples 4-5 R-5 105 33 17 2.3 100 11.2 A Examples 4-6 R-6 100 32 17 2.4 120 11.2 A Examples 4-7 R-7 95 33 18 2.2 110 11.1 A Examples 4-8 R-8 95 33 19 2.4 100 11.3 A Examples 4-9 R-9 100 34 17 2.3 110 11.2 A Examples 4-10 R-10 100 32 18 2.3 120 11.0 A Example 4-11 R-11 100 33 19 2.4 120 11.1 A Example 4-12 R-12 95 33 17 2.2 110 10.9 A Example 4-13 R-13 105 34 18 2.4 120 11.0 A Example 4-14 R-14 100 35 17 2.5 100 10.8 A Examples 4-15 R-15 95 32 17 2.3 110 10.9 A Example 4-16 R-16 95 33 18 2.2 120 11.2 A Example 4-17 R-17 100 33 17 2.3 110 11.1 A Example 4-18 R-18 95 32 18 2.3 110 11.1 A Example 4-19 R-19 95 34 18 2.3 120 11.2 A Example 4-20 R-20 100 33 17 2.3 110 10.8 A Example 4-21 R-21 100 33 19 2.3 110 10.9 A Example 4-22 R-22 100 34 17 2.4 110 11.0 A Example 4-23 R-23 95 32 18 2.2 110 11.2 A Example 4-24 R-24 95 34 18 2.3 120 11.1 A Example 4-25 R-25 100 33 17 2.4 110 11.2 A Example 4-26 R-26 100 33 19 2.3 110 10.9 A

[0662] [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 41 13 3.0 90 12.6 B Comparative Example 4-2 CR-2 100 38 14 2.9 80 12.8 C Comparative Example 4-3 CR-3 100 37 14 2.8 80 13.3 C Comparative Example 4-4 CR-4 100 38 15 2.8 90 13.2 B Comparative Examples 4-5 CR-5 95 39 13 2.8 80 12.6 C Comparative Examples 4-6 CR-6 100 35 11 3.4 60 12.7 B Comparative Examples 4-7 CR-7 100 38 14 2.9 90 12.8 C Comparative Examples 4-8 CR-8 100 38 13 2.8 80 12.4 C Comparative Examples 4-9 CR-9 95 37 15 2.7 90 13.4 B Comparative Example 4-10 CR-10 100 39 14 2.9 80 12.6 B Comparative Example 4-11 CR-11 100 37 14 2.9 80 12.4 B Comparative Example 4-12 CR-12 100 38 14 2.9 80 13.6 B Comparative Example 4-13 CR-13 95 39 13 2.8 90 12.2 B Comparative Example 4-14 CR-14 105 36 11 3.3 50 12.6 C Comparative Example 4-15 CR-15 100 42 13 3.2 70 12.2 C Comparative Example 4-16 CR-16 95 39 15 2.8 80 13.2 B Comparative Example 4-17 CR-17 95 41 10 3.2 60 12.3 B Comparative Example 4-18 CR-18 100 40 10 3.1 60 12.3 B

[0663] 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.

[0664] [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.

[0665] [Table 7] inhibitor Composition PEB temperature (°C) Optimal exposure (mJ / cm2) CDU (nm) Example 5-1 R-1 95 twenty two 2.2 Example 5-2 R-2 95 twenty three 2.2 Example 5-3 R-3 90 twenty three 2.3 Example 5-4 R-4 90 twenty three 2.3 Example 5-5 R-5 90 twenty three 2.2 Examples 5-6 R-6 95 twenty three 2.3 Examples 5-7 R-7 95 twenty two 2.3 Examples 5-8 R-8 90 twenty three 2.4 Examples 5-9 R-9 95 twenty three 2.2 Examples 5-10 R-10 95 twenty four 2.5 Examples 5-11 R-11 95 twenty three 2.3 Examples 5-12 R-12 90 twenty two 2.4 Examples 5-13 R-13 90 twenty three 2.3 Examples 5-14 R-14 90 twenty three 2.3 Examples 5-15 R-15 90 twenty three 2.5 Examples 5-16 R-16 85 twenty four 2.4 Examples 5-17 R-17 95 twenty three 2.3 Example 5-18 R-18 95 twenty three 2.3 Example 5-19 R-19 90 twenty four 2.2 Example 5-20 R-20 95 twenty three 2.3 Example 5-21 R-21 95 twenty three 2.3 Example 5-22 R-22 95 twenty three 2.4 Example 5-23 R-23 95 twenty two 2.3 Example 5-24 R-24 90 twenty three 2.3 Example 5-25 R-25 95 twenty two 2.3 Example 5-26 R-26 95 twenty four 2.2

[0666] [Table 8] inhibitor Composition PEB temperature (°C) Optimal exposure (mJ / cm2) CDU (nm) Comparative Example 5-1 CR-1 95 32 3.0 Comparative Example 5-2 CR-2 95 28 2.9 Comparative Example 5-3 CR-3 95 28 2.9 Comparative Example 5-4 CR-4 90 27 2.7 Comparative Example 5-5 CR-5 90 29 2.8 Comparative Examples 5-6 CR-6 95 25 3.3 Comparative Examples 5-7 CR-7 90 29 2.9 Comparative Examples 5-8 CR-8 90 28 2.7 Comparative Examples 5-9 CR-9 90 27 2.9 Comparative Examples 5-10 CR-10 95 27 2.8 Comparative Example 5-11 CR-11 95 29 2.8 Comparative Example 5-12 CR-12 95 27 2.8 Comparative Example 5-13 CR-13 85 28 2.9 Comparative Example 5-14 CR-14 95 25 3.5 Comparative Example 5-15 CR-15 95 30 3.1 Comparative Example 5-16 CR-16 90 28 2.8 Comparative Example 5-17 CR-17 95 31 3.2 Comparative Example 5-18 CR-18 95 32 3.1

[0667] The results shown in Tables 7 and 8 confirm that the chemical amplification inhibitor composition containing polymers composed of strontium salt type monomers of the present invention has good sensitivity and excellent CDU.

[0668] [6] Evaluation of dry etching resistance [Examples 6-1 to 6-26, Comparative Examples 6-1 to 6-18] A polymer solution containing 2g of each of the polymers shown in Tables 1 and 2 (polymers P-1 to P-26 and comparative polymers CP-1 to CP-18) dissolved in 10g of cyclohexanone and filtered through a 0.2μm filter was spin-coated onto a Si substrate to form a film with a thickness of 300nm. The film was evaluated under the following conditions. Etching experiments using CHF3 / CF4 based gases: The thickness difference of the polymer film before and after etching was determined using the TE-8500P dry etching apparatus manufactured by Tokyo Power Technology Co., Ltd. The etching conditions are as follows. Chamber pressure 40 Pa RF power 1000W 9mm interval CHF3 gas flow rate 30 mL / min CF4 gas flow rate 30 mL / min Ar gas flow rate 100 mL / min 60 seconds In this evaluation, those with smaller film thickness differences, i.e., smaller reductions, exhibit higher etching resistance. The results of dry etching resistance are shown in Tables 9 and 10.

[0669] [Table 9] polymer CHF3 / CF4-based gas etching rate (nm / min) Example 6-1 P-1 96 Example 6-2 P-2 96 Example 6-3 P-3 95 Example 6-4 P-4 95 Example 6-5 P-5 96 Example 6-6 P-6 95 Examples 6-7 P-7 96 Examples 6-8 P-8 95 Examples 6-9 P-9 95 Examples 6-10 P-10 95 Examples 6-11 P-11 96 Examples 6-12 P-12 96 Examples 6-13 P-13 95 Examples 6-14 P-14 96 Examples 6-15 P-15 95 Examples 6-16 P-16 95 Examples 6-17 P-17 97 Examples 6-18 P-18 96 Examples 6-19 P-19 95 Examples 6-20 P-20 96 Example 6-21 P-21 96 Example 6-22 P-22 95 Example 6-23 P-23 96 Example 6-24 P-24 96 Example 6-25 P-25 95 Example 6-26 P-26 96

[0670] [Table 10] polymer CHF3 / CF4-based gas etching rate (nm / min) Comparative Example 6-1 CP-1 112 Comparative Example 6-2 CP-2 98 Comparative Example 6-3 CP-3 97 Comparative Example 6-4 CP-4 98 Comparative Example 6-5 CP-5 108 Comparative Example 6-6 CP-6 111 Comparative Examples 6-7 CP-7 99 Comparative Examples 6-8 CP-8 98 Comparative Examples 6-9 CP-9 99 Comparative Examples 6-10 CP-10 103 Comparative Example 6-11 CP-11 99 Comparative Examples 6-12 CP-12 97 Comparative Example 6-13 CP-13 99 Comparative Example 6-14 CP-14 112 Comparative Example 6-15 CP-15 109 Comparative Example 6-16 CP-16 99 Comparative Example 6-17 CP-17 103 Comparative Example 6-18 CP-18 102

[0671] The results shown in Tables 9 and 10 confirm that the polymer of the present invention has excellent dry etching resistance to CHF3 / CF4 gases.

Claims

1. A strontium salt type monomer, represented by the following formula (A), wherein p is 1, n1 is 0, n2 is 1 or 2, n3 is 0, 1, 2 or 3, 1≦n2+n3≦5, R1 is a halogen atom, cyano group, hydroxyl group, carboxyl group, or may contain a hydrocarbon group with 1 to 20 carbon atoms of heteroatoms, or may contain a hydrocarbon oxy group with 1 to 20 carbon atoms of heteroatoms, or may contain a hydrocarbon thio group with 1 to 20 carbon atoms of heteroatoms, or may contain a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms of heteroatoms. When n3 is 2 or 3, each R1 can be the same or different from each other, and two R1s can also be bonded to each other and form a ring together with the bonded carbon atoms. R2 refers to vinyl or phenyl groups, where some or all of the hydrogen atoms of the vinyl or phenyl group may be substituted with a group containing heteroatoms. Two R2 groups may be the same or different. Furthermore, two of the three substituents bonded to S+ may bond to each other and form a ring with the sulfur atoms of these bonds. Z- refers to the anion represented by the formula (Z), where 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 or 1, m11 is 0, 1, 2, 3 or 4, m12 is 0, 1, 2 or 3, m13 is 0 or 1, m14 is 0 or 1, m15 is 0 or 1, however, m When 1 is 0, then 0 ≤ m2 + m3 + m14 ≤ 4; when m1 is 1, then 0 ≤ m2 + m3 + m14 ≤ 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; when m10 is 0, then 0 ≤ m11 + m12 ≤ 4; when m10 is 1, then 0 ≤ m11 + m12 ≤ 6; and also, 1 ≤ m2 + m5 + m8 ≤ 4. RA represents hydrogen, fluorine, methyl, or trifluoromethyl. R11, R12, and R13 are each independently a halogen atom other than iodine, a nitro, cyano, hydroxyl, or carboxyl group. They may also include hydrocarbon groups with 1-20 carbon atoms (heteroatomic), hydroxyl groups with 1-20 carbon atoms (heteroatomic), thiol groups with 1-20 carbon atoms (heteroatomic), or carbonyl groups with 2-20 carbon atoms (heteroatomic). When m3 is 2 or 3, each R11 may be the same or different. Two R11s may also bond to each other and form a ring with the bonded carbon atoms. When m6 is 2 or 3, each R12 may be the same or different. Two R12s may also bond to each other and form a ring with the bonded carbon atoms. When m9 is 2 or 3, each R13 may be the same or different. Two R13s may also bond to each other and form a ring with the bonded carbon atoms. R14 series includes halogen atoms other than fluorine and iodine atoms, nitro groups, hydroxyl groups, and may also include hydrocarbon groups with 1 to 20 carbon atoms (heteroatomic), hydroxyl groups with 1 to 20 carbon atoms (heteroatomic), or hydrocarbon thiol groups with 1 to 20 carbon atoms (heteroatomic).When m12 is 2 or 3, each R14 can be the same or different. Two R14s can also bond to each other and form a ring with the carbon atoms of these bonds. RF is a fluorine atom, a fluorinated saturated hydrocarbon group with 1 to 6 carbons, a fluorinated saturated hydrocarbon oxygen group with 1 to 6 carbons, or a fluorinated saturated hydrocarbon thio group with 1 to 6 carbons. When m11 is 2, 3, or 4, each RF can be the same or different. 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 hydrocarbon group with 1 to 40 carbons. However, m13 and m14 cannot both be 0, and LA, LB, LC, LD, XL1, and XL2 cannot both be single bonds.

2. The strontium salt type monomer of claim 1 is represented by the following formula (A1), in which p, n1~n3, R1 and Z- are the same as in claim 1, n4 is 0, n5 is 0, 1, 2, 3, 4 or 5, R3 is a halogen atom, cyano, hydroxyl, carboxyl, or may contain a hydrocarbon group with 1~20 carbon atoms of heteroatoms, or may contain a hydrocarbon oxy group with 1~20 carbon atoms of heteroatoms, or may contain a hydrocarbon thio group with 1~20 carbon atoms of heteroatoms, or may contain a hydrocarbon oxy carbonyl group with 2~20 carbon atoms of heteroatoms. When n5 is 2, 3, 4 or 5, each R3 may be the same or different from each other, and two R3s may also be bonded to each other and form a ring together with the carbon atoms of such bonds.

3. As in request item 1, strontium salt type monomers, wherein, m15 is 1.

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, phenyl group, naphthyl group, *-C(=O)-O-X11-, or *-C(=O)-NH-X11-, wherein the phenyl group or naphthyl group may also 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, phenyl group, or naphthyl group, wherein the saturated hydrocarbon group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring; X2 is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * indicates an atomic bond with a carbon atom in the main chain. R21 can be a halogen atom, cyano, hydroxyl, nitro, 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. AL1 and AL2 are each independently acid-labile groups. a1 can be 0, 1, 2, 3, or 4. In the formula, b1 can be 0 or 1, and 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-, where * 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, but 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 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. 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, and 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 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 carbonyl oxygen group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms containing heteroatoms. When c2 is 2, 3 or 4, each R32 can be the same or different from the others. c1 is 1, 2, 3 or 4, and 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.