Onium-salt-type monomer, monomeric photo-acid generator, polymer, chemically-amplified resist composition, and patterning process

Abstract

The objective of this invention is to provide an onium salt monomer with excellent solvent solubility, high sensitivity, high contrast, excellent EL, LWR, CDU, DOF, resistance to pattern collapse, and excellent etching resistance. The solution of this invention is an onium salt monomer represented by formula (a). n1 represents 0~1, n2 represents 1~4, n3 represents 0~2, n4 represents 0~4; RA represents hydrogen atom, fluorine atom, methyl or trifluoromethyl; RAL represents acid-unstable group; R1 represents halogen atom, nitro, cyano, etc.; LA and LB represent single bond, ester bond, etc.; XL represents single bond or extended hydrocarbon group; Q1 and Q2 represent hydrogen atom, fluorine atom or fluorinated saturated hydrocarbon group; Q3 and Q4 represent fluorine atom or fluorinated saturated hydrocarbon group; Z+ represents onium cation.

Description

Technical Field

[0001] This invention relates to onium salt type monomers, monomer type photoacid generators, polymers, chemical amplification inhibitor compositions, and patterning methods. Prior Technology

[0002] With the increasing integration and speed of LSI (Light Detection and Retina) technology, the miniaturization of patterning is progressing rapidly. In particular, the expansion of the flash memory market and the increase in memory capacity are driving this miniaturization. Regarding the most advanced miniaturization technologies, mass production of 65nm node devices using ArF lithography is underway, and preparations for mass production of 45nm node devices using next-generation ArF immersion lithography are in progress. For next-generation 32nm node devices, immersion lithography using an ultra-high nanometer lens (NA lens) combining 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) using ArF lithography are among the candidates being explored.

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

[0004] With the miniaturization of patterns, the edge roughness (LWR) of line patterns and the dimensional uniformity (CDU) of hole patterns have become problems. It has been pointed out that the uneven distribution of the base polymer, acid-generating agents, the effects of aggregation, and the effects of acid diffusion have all contributed. Furthermore, the tendency for LWR to increase due to the thinning of resist films has led to a significant problem of LWR degradation accompanying miniaturization.

[0005] In EUV lithography resist formulations, high sensitivity, high resolution, and low light-to-weight ratio (LWR) must be achieved simultaneously. Shortening the acid diffusion distance will decrease LWR but decrease sensitivity. For example, lowering the post-exposure baking (PEB) temperature will decrease LWR but decrease sensitivity. Increasing the amount of quencher will also decrease LWR but decrease sensitivity. A trade-off between sensitivity and LWR must be achieved.

[0006] To suppress acid diffusion, inhibitor compounds containing repeating units from onium salts of sulfonic acids with polymerizable unsaturated bonds have been proposed (Patent Documents 1 and 2). These so-called polymer-bonded acid generators are characterized by the generation of polymeric sulfonic acids upon exposure, resulting in very short acid diffusion. Furthermore, sensitivity can be improved by increasing the proportion of the acid generator. In the case of additive acid generators, increasing the amount added also increases sensitivity, but at the same time, the acid diffusion distance also increases. Because the acid system diffuses unevenly, increased acid diffusion degrades LWR and CDU. In terms of balancing sensitivity, LWR, and CDU, polymeric acid generators can be considered to have high capability.

[0007] Iodine atoms exhibit very high absorption at a wavelength of 13.5 nm in EUV, confirming the generation of secondary electrons from iodine atoms during exposure, a phenomenon noteworthy in EUV lithography. Patent Document 3 describes a photoacid generator in which iodine atoms are introduced into anions, and Patent Document 4 describes a photoacid generator containing polymeric groups and iodine atoms introduced into anions. Patent Document 5 describes a photoacid generator in which iodine atoms are introduced into both cations and anions. While this confirms some improvement in lithography performance, the low solubility of iodine atoms in organic solvents poses a risk of precipitation in the solvent.

[0008] Patent document 6 describes a photoacid generator in which multiple fluorine atoms are introduced into the cation. The introduction of multiple fluorine atoms improves the solvent solubility of the photoacid generator, but it is still insufficient from the perspective of EUV absorption and there is room for improvement.

[0009] Patent documents 7-11 describe photoacid generators and quenchers (acid diffusion control agents) containing iodine and fluorine atoms in the cation. Patent documents 12-15 describe onium salt type monomers with iodine atoms and polymerizable groups introduced into the cation. Furthermore, patent documents 16 and 17 describe onium salt type monomers with iodine atoms and polymerizable groups introduced into the anion. While these developments have confirmed improvements in the performance of these inhibitor materials, they are still insufficient from the perspective of acid diffusion control, necessitating the development of inhibitor materials more useful for forming fine patterns. [Previous Technical Documents] [Patent Literature]

[0010] [Patent Document 1] Japanese Patent No. 4425776 [Patent Document 2] International Publication No. 2023 / 063203 [Patent Document 3] Japanese Patent No. 6720926 [Patent Document 4] Japanese Patent No. 6973274 [Patent Document 5] Japanese Patent No. 7041204 [Patent Document 6] Japanese Patent No. 7389562 [Patent Document 7] Japanese Patent Application Publication No. 2021-123579 [Patent Document 8] Japanese Patent Application Publication No. 2021-123580 [Patent Document 9] Japanese Patent Application Publication No. 2022-123839 [Patent Document 10] Japanese Patent Application Publication No. 2023-88869 [Patent Document 11] Japanese Patent Application Publication No. 2023-88870 [Patent Document 12] Japanese Patent Application Publication No. 2022-28615 [Patent Document 13] Japanese Patent Application Publication No. 2023-93372 [Patent Document 14] Japanese Patent Application Publication No. 2023-165660 [Patent Document 15] Japanese Patent Application Publication No. 2023-171323 [Patent Document 16] Japanese Patent No. 6973274 [Patent Document 17] International Publication No. 2024 / 014462 Summary of the Invention

[0011] [The problem that the invention aims to solve] The development of chemical amplification resist compositions that use acids as catalysts requires higher sensitivity and can improve lithography properties such as exposure margin (EL), LWR, CDU, and depth of focus (DOF), as well as excellent etching resistance after patterning.

[0012] In view of the foregoing circumstances, the present invention aims to provide a chemical amplification inhibitor composition that can be used in photolithography, including an onium salt monomer and a monomeric photoacid generator, a polymer containing repeating units from the onium salt monomer, a chemical amplification inhibitor composition containing the polymer, and a patterning method using the chemical amplification inhibitor composition. This composition provides excellent solvent solubility, high sensitivity, high contrast, and excellent photolithography performance such as EL, LWR, CDU, and DOF, while also resisting pattern collapse and exhibiting excellent etching resistance during the formation of fine patterns. [Methods for solving problems]

[0013] To address the aforementioned issues, the present invention provides an onium salt type monomer represented by the following formula (a). [Chemistry 1] In the formula, n1 is 0 or 1, n2 is 1, 2, 3 or 4, n3 is 0, 1 or 2, but when n1 is 0, then 1 ≤ n2 + n3 ≤ 3, when n1 is 1, then 1 ≤ n2 + n3 ≤ 5, and n4 is an integer from 0 to 4. RA series: hydrogen atom, fluorine atom, methyl or trifluoromethyl, RAL series acid unstable groups R1 can be a halogen atom other than iodine, a nitro group, a cyano group, a hydroxyl group, an alkoxy group, a carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms (heteroatomic), an alkoxy group with 1 to 20 carbon atoms (heteroatomic), or a thioalkyl group with 1 to 20 carbon atoms (heteroatomic). When n3 is 2, 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. LA and LB are each independently a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond. XL series single bonds, or may also contain heteroatoms and carbon groups with 1 to 40 carbon atoms, Q1 and Q2 are each independently a hydrogen atom, a methyl group, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Q3 and Q4 are each independently either fluorine atoms or fluorinated saturated hydrocarbon groups having 1 to 6 carbon atoms. Z+ series onium cations.

[0014] If so, then especially when using photolithography with high-energy rays such as KrF excimer laser, ArF excimer laser, electron beam (EB), EUV, etc., it will become a suitable onium salt monomer in chemical amplification inhibitor composition with excellent solvent solubility, high sensitivity, high contrast, and excellent photolithography performance such as EL, LWR, CDU, DOF, while also resisting pattern collapse during the formation of fine patterns and having excellent etching resistance.

[0015] Furthermore, the onium salt type monomer of the present invention is preferably represented by the following formula (a1). [Chemistry 2] In the formula, n1~n4, RA, RAL, R1, LA, Q1~Q4, and Z+ are the same as those mentioned above.

[0016] Furthermore, the onium salt type monomer of the present invention is preferably represented by the following formula (a2). [Chemistry 3] In the formula, n1~n4, RA, RAL, R1, Q1~Q4, and Z+ are the same as those mentioned above.

[0017] The onium salt type monomer of the present invention preferably has such a structure.

[0018] Furthermore, the structure of the acid unstable group represented by RAL should preferably be (AL-1) or (AL-2). [Chemistry 4] In the formula, n6 is either 0 or 1, and n7 is either 0 or 1. RL1, RL2, and RL3 are each independently a hydrocarbon group having 1 to 12 carbon atoms. One portion of the -CH2- group may be replaced by -O- or -S-. When the hydrocarbon group contains an aromatic ring, one or all of the hydrogen atoms in the aromatic ring may be replaced by a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 4 carbon atoms containing a halogen atom, or an alkoxy group having 1 to 4 carbon atoms containing a halogen atom. Furthermore, RL1 and RL2 may also bond to each other and form a ring together with the bonded carbon atoms. One portion of the -CH2- group in this ring may also be replaced by -O- or -S-. RL4 and RL5 are each independently a hydrogen atom or may contain a halogen atom and a hydrocarbon group with 1 to 10 carbon atoms. RL6 may also contain a halogen atom and a hydrocarbon group with 1 to 20 carbon atoms. One portion of the -CH2- group of this hydrocarbon group may be replaced by -O- or -S-. Furthermore, RL5 and RL6 may bond to each other and together with the bonded carbon atoms and LC to form a heterocyclic group with 3 to 20 carbon atoms. One portion of the -CH2- group of this heterocyclic group may also be replaced by -O- or -S-. LC series -O- or -S-, * indicates an atomic bond with an adjacent -O-.

[0019] If the acid-instable group is configured in such a structure, the effects of the present invention can be more fully realized.

[0020] Furthermore, the onium cation represented by Z+ mentioned above should preferably be the strontium cation represented by formula (Z-1) or the monium cation represented by formula (Z-2). [Chemistry 5] In the formula, Rct1 to Rct5 are each independently a halogen atom, or may contain a hydrocarbon group with 1 to 30 carbon atoms of heteroatoms. Furthermore, Rct1 and Rct2 may also be bonded to each other and form a ring together with the sulfur atoms of these bonds.

[0021] Alternatively, the onium cation represented by Z+ mentioned above can also be the strontium cation represented by the following formula (Z-3). [Chemistry 6] In the formula, m1 is 0 or 1, m2 is 0 or 1, m3 is 0 or 1, m4 is 0, 1, 2, 3 or 4, m5 is 0, 1, 2, 3 or 4, m6 is 0, 1, 2, 3, 4, 5 or 6, m7 is 0, 1, 2, 3, 4, 5 or 6, m8 is 0, 1 or 2, m9 is 0, 1 or 2, m10 is 0, 1 or 2, m11 is 0 or 1, m12 is 0, 1, 2, 3 or 4, m13 is 0, 1 or 2, m14 is 0, 1 or 2, only m1 When m1 is 0, then 0 ≤ m6 + m9 ≤ 4; when m1 is 1, then 0 ≤ m6 + m9 ≤ 6; when m2 is 0, then 0 ≤ m7 + m10 ≤ 4; when m2 is 1, then 0 ≤ m7 + m10 ≤ 6; when m3 is 0, then 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, then 1 ≤ m4 + m5 + m8 + m14 ≤ 6; when m11 is 0, then 0 ≤ m12 + m13 ≤ 4; when m11 is 1, then 0 ≤ m12 + m13 ≤ 6; and, m4 + m12 ≥ 1. RF1 to RF3 are each independently 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 m5 is 2 or more, each RF1 can be the same or different from the others. When m6 is 2 or more, each RF2 can be the same or different from the others. When m7 is 2 or more, each RF3 can be the same or different from the others. Rct6~Rct9 can be halogen atoms other than iodine and fluorine atoms, nitro, cyano, or hydrocarbon groups with 1~20 carbon atoms containing heteroatoms, or hydrocarbon oxy groups with 1~20 carbon atoms containing heteroatoms, or hydrocarbon thio groups with 1~20 carbon atoms containing heteroatoms. When m8 is 2, the two Rct6 groups can be the same or different, and the two Rct6 groups can also bond to each other and form a ring with the bonded carbon atoms. When m9 is 2, the two Rct7 groups can be the same or different, and the two Rct7 groups can also bond to each other and form a ring with the bonded carbon atoms. When m10 is 2, the two Rct8 groups can be the same or different, and the two Rct8 groups can also bond to each other and form a ring with the bonded carbon atoms. When m13 is 2, the two Rct9 groups can be the same or different, and the two Rct9 groups can also bond to each other and form a ring with the bonded carbon atoms. Furthermore, the aromatic rings of S+ directly bonded to the strontium cation can also bond to each other and form rings together with S+. LD and LE are each independently formed by single bonds, ether bonds, ester bonds, amide bonds, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. XL2 series single bonds, or may also contain heteroatoms with carbon numbers of 1 to 40 alkyl groups.

[0022] This invention is suitable for using such onium cations.

[0023] Furthermore, the present invention provides a monomeric photoacid generator composed of the above-mentioned onium salt type monomers.

[0024] The onium salt type monomer of the present invention can be used as a photoacid generator.

[0025] Furthermore, the present invention provides a polymer comprising repeating units derived from the aforementioned onium salt type monomers.

[0026] The polymer of this invention is a polymer-bonded photoacid generator that functions as a base polymer and a photoacid generator in a chemical amplification inhibitor composition.

[0027] The polymer of the present invention may further comprise repeating units represented by formula (b1) or (b2). [Chemistry 7] 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. R11 series halogen atoms, cyano, hydroxyl, nitro, may also contain heteroatoms with 1-20 carbon atoms (hydrocarbonyl group), heteroatoms with 1-20 carbon atoms (hydroxyloxy group), heteroatoms with 2-20 carbon atoms (hydrocarbonyl group), heteroatoms with 2-20 carbon atoms (hydrocarbonyloxy group), or heteroatoms with 2-20 carbon atoms (hydroxyloxycarbonyl group). AL1 and AL2 are each independently acid-labile groups. a1 series 0, 1, 2, 3 or 4.

[0028] The polymer of the present invention may further include repeating units represented by the following formula (b3). [Chemistry 8] 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. R12 and R13 are each independently hydrogen atoms, or may contain heteroatoms and be hydrocarbon groups with 1 to 20 carbon atoms. Furthermore, R12 and R13 may also bond to each other and form a ring together with the bonded carbon atoms. R14 can be a halogen atom, hydroxyl group, cyano 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 oxygen carbonyl group with 2-20 carbon atoms, or a hydrocarbon thio group or -N (R14A) (R14B). R14A and R14B are each independently a hydrogen atom or a hydrocarbon group with 1-6 carbon atoms. When b2 is 2 or more, multiple R14 groups can also bond to each other and form a ring together with the carbon atoms of the bonded aromatic ring. 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 an oxygen atom or a sulfur atom, but X4 and X6 are bonded to adjacent carbon atoms in an aromatic ring.

[0029] The polymer of the present invention may further include repeating units represented by formula (c). [Chemistry 9] In the formula, RA represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y1 series single bonds, *-C(=O)-O- or *-C(=O)-NH-, where * indicates an atomic bond with a carbon atom in the main chain. R21 series halogen atoms, nitro, cyano, carboxyl, may also include hydrocarbon groups with 1-20 carbon atoms, hydrocarbon oxygen groups with 1-20 carbon atoms, hydrocarbon carbonyl groups with 2-20 carbon atoms, hydrocarbon carbonyl oxygen groups with 2-20 carbon atoms, or hydrocarbon oxygen carbonyl groups with 2-20 carbon atoms. c1 is 1, 2, 3 or 4, c2 is 0, 1, 2 or 3, but 1≦c1+c2≦5.

[0030] The polymer of the present invention may further include repeating units represented by formula (d). [Chemistry 10] In the formula, RA represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z1 refers to single bonds, pendiphenyl, pendinaphthyl, *-C(=O)-O-Z11-, or *-C(=O)-NH-Z11-. The pendiphenyl or pendinaphthyl group may also be substituted with hydroxyl, nitro, cyano groups, saturated hydrocarbon groups with 1-10 carbon atoms containing fluorine atoms, or saturated hydrocarbon oxygen or halogen atoms containing fluorine atoms. * indicates an atomic bond with a carbon atom in the main chain. Z11 refers to saturated pendialkyl groups with 1-10 carbon atoms, pendiphenyl, or pendinaphthyl groups. These saturated pendialkyl groups may also contain hydroxyl, ether, ester, or lactone rings. R31 is a group consisting of a hydrogen atom or a group containing at least one of the following: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulcinolone ring, and carboxylic anhydride (-C(=O)-OC(=O)-).

[0031] In the polymers of the present invention, various repeating units as described above can be copolymerized as needed.

[0032] Furthermore, the present invention provides a chemical amplification inhibitor composition comprising (A) a base polymer containing the aforementioned polymer.

[0033] The polymer of this invention is a polymer-bonded photoacid generator that functions as a base polymer and a photoacid generator in a chemical amplification inhibitor composition.

[0034] The chemical amplification inhibitor composition of the present invention preferably includes one or more selected from (B) organic solvent, (C) quencher, (D) acid generator, (E) surfactant and (F) anti-solution agent.

[0035] The chemical amplification inhibitor composition of the present invention can be mixed with various additives as needed.

[0036] The present invention also provides a pattern forming method, comprising the following steps: forming a resist film on a substrate using the above-mentioned chemical amplification resist composition, exposing the resist film to high-energy radiation, and developing the exposed resist film using a developing solution.

[0037] The pattern forming method of the present invention can form patterns with high sensitivity and high contrast, especially in photolithography using high-energy rays such as KrF excimer laser, ArF excimer laser, electron beam (EB), and EUV.

[0038] Furthermore, the aforementioned high-energy rays are preferably ArF excimer laser light with a wavelength of 193nm, KrF excimer laser light with a wavelength of 248nm, electron beams, or extreme ultraviolet light with a wavelength of 3~15nm.

[0039] The pattern forming method of the present invention is suitable for using such high-energy rays. [Effects of the Invention]

[0040] Polymers containing repeating units of onium salt monomers that generate acid upon exposure, forming an aromatic ring with a polymerizable group and an iodine atom-substituted aromatic ring, further bonded to a fluorosulfonic acid anion structure and an acid-instable group, exhibit good solvent solubility due to their branched structure. In EUV lithography at 13.5 nm, the absorption of EUV based on the iodine atom is very high, resulting in the generation of secondary electrons from the iodine atom during exposure. The fluorosulfonic acid anion, bonded to the aforementioned polymerizable and iodine-substituted aromatic ring, has a short distance from the polymer backbone to the acid-generating site. The secondary electrons generated by the iodine atom promote the decomposition of cations near the anion, efficiently generating acid, thus achieving high sensitivity. Furthermore, due to the large atomic weight of the iodine atom and its structure bonded to the polymer backbone by the generated acid, it exhibits low acid diffusion. The acid-instable group in the anion is protected by an aromatic hydroxyl group, undergoing deprotection reactions upon acid generation. The aromatic hydroxyl groups generated thereby have increased acidity due to the electron attraction effect of iodine atoms, resulting in high affinity for alkaline developers. Therefore, when the exposed area is developed with an alkaline developer, polymer residues are easily dissolved, improving the dissolution contrast between the exposed and unexposed areas. These additive effects improve LWR and CDU. Furthermore, the aromatic rings in the aforementioned repeating units function as excellent etching-resistant groups, making them suitable for forming fine patterns. Implementation

[0041] As mentioned above, the development of a chemical amplification inhibitor composition is required that has excellent solvent solubility, high sensitivity, high contrast, and excellent lithography performance such as EL, LWR, CDU, and DOF, while also resisting pattern collapse and exhibiting excellent etching resistance in the formation of fine patterns. This includes the development of onium salt monomers, polymers containing repeating units from the onium salt monomers, chemical amplification inhibitor compositions containing the polymers, and patterning methods using these chemical amplification inhibitor compositions.

[0042] In order to achieve the aforementioned objective, the inventors of this invention conducted repeated and in-depth research and discovered that a polymer containing repeating units of onium salt monomers with a polymerizable aromatic ring substituted with iodine atoms, and the aromatic ring further having a structure formed by substituents containing aromatic sulfonic acid anions and acid-instable groups, exhibits good solvent solubility. By using this polymer as a polymer-bonded photoacid generator, a chemical amplification inhibitor composition with high sensitivity, high contrast, high resolution, improved lithography performance such as LWR and CDU, and excellent etching resistance after pattern formation can be obtained, thus completing this invention.

[0043] That is, the present invention is an onium salt type monomer represented by formula (a) above.

[0044] The present invention will now be described in detail, but the present invention is not limited thereto.

[0045] [Onium salt type monomer] The onium salt type single system of the present invention is represented by formula (a). [Chemistry 11]

[0046] 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, 2, 3, or 4. Considering the availability of raw materials, n2 of 1, 2, or 3 is preferred, 1 or 2 is even better, and 1 is still the best. n3 is 0, 1, or 2. However, when n1 is 0, then 1 ≤ n2 + n3 ≤ 3; when n1 is 1, then 1 ≤ n2 + n3 ≤ 5.

[0047] In equation (a), n4 is an integer from 0 to 4, preferably 0, 1, 2 or 3, and even better if it is 1.

[0048] In formula (a), 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.

[0049] In formula (a), RAL is an acid-instable group. The aforementioned acid-instable group should preferably be represented by the following formula (AL-1) or (AL-2). [Chemistry 12] In the formula, * represents an atomic bond with -O-.

[0050] In formula (AL-1), n6 is 0 or 1. RL1, RL2, and RL3 are each independently a hydrocarbon group with 1 to 12 carbon atoms. A portion of the -CH2- group may be substituted with -O- or -S-. When the hydrocarbon group contains an aromatic ring, some or all of the hydrogen atoms in the aromatic ring may be substituted with a halogen atom, a cyano group, a nitro group, an alkyl group with 1 to 4 carbon atoms containing a halogen atom, or an alkoxy group with 1 to 4 carbon atoms containing a halogen atom. Furthermore, RL1 and RL2 may also bond to each other and form a ring with the bonded carbon atoms. A portion of the -CH2- group in this ring may also be substituted with -O- or -S-.

[0051] In formula (AL-2), n7 is 0 or 1. RL4 and RL5 are each independently hydrogen atoms or may contain 1 to 10 carbon-bearing hydrocarbon groups with halogen atoms. RL6 may also contain 1 to 20 carbon-bearing hydrocarbon groups with halogen atoms, and the -CH2- portion of this hydrocarbon group may be substituted with -O- or -S-. Furthermore, RL5 and RL6 may also bond to each other and together with the bonded carbon atoms and LC to form a heterocyclic group with 3 to 20 carbon atoms, and the -CH2- portion of this heterocyclic group may also be substituted with -O- or -S-. LC is -O- or -S-.

[0052] Specific examples of acid unstable groups represented by formula (AL-1) are shown below, but are not limited to these. * indicates an atomic bond with the adjacent -O-.

[0053] [Chemistry 13]

[0054] [Chemistry 14]

[0055] [Chemistry 15]

[0056] [Chemistry 16]

[0057] [Chemistry 17]

[0058] [Chemistry 18]

[0059] [Chemistry 19]

[0060] [Chemistry 20]

[0061] [Chemistry 21]

[0062] [Chemistry 22]

[0063] [Chemistry 23]

[0064] Specific examples of the unstable acid group represented by formula (AL-2) are shown below, but are not limited to these. * indicates an atomic bond with an adjacent -O-.

[0065] [Chemistry 24]

[0066] [Chemistry 25]

[0067] In formula (a), R1 refers to a halogen atom other than iodine, a nitro group, a cyano group, a hydroxyl group, an alkoxy carbonyl group, a carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms (heteroatomic), an alkoxy group with 1 to 20 carbon atoms (heteroatomic), or a thioalkyl group with 1 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, alkoxy group, and thioalkyl group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecyl, octadecyl, nonadecanyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclohexenyl 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 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, each R1 can be the same or different.

[0068] Furthermore, when n3 is 2, the two R1 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 groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, some of the -CH2- groups in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. The result is that the rings may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0069] In formula (a), LA and LB 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 ester or sulfonate bond being more preferred. LB is preferably a single bond, ether bond, ester bond, or sulfonate bond, with ester or sulfonate bond being more preferred.

[0070] LA and -O-RAL should ideally be bonded to adjacent carbon atoms on the aromatic ring. In this case, the substituents and acid-indestructible groups containing the aforementioned aromatic sulfonic acid anion structure will undergo deprotection reactions smoothly due to their closer spatial positions, thereby potentially enhancing the solubility contrast.

[0071] In formula (a), each XL is 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.

[0072] XL can also include specific examples of hydrocarbon groups with 1 to 40 carbon atoms, as shown below, but is not limited to these. Furthermore, in the following formula, * represents the atomic bonds with LA and LB, respectively.

[0073] [Chemistry 26]

[0074] [Chemistry 27]

[0075] [Chemistry 28]

[0076] [Chemistry 29]

[0077] Of these, XL-0~XL-22, XL-29~XL-34, and XL-47~XL-58 are preferred.

[0078] In formula (a), Q1 and Q2 are each independently a hydrogen atom, a methyl group, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Among the aforementioned fluorinated saturated hydrocarbon groups having 1 to 6 carbon atoms, trifluoromethyl is preferred.

[0079] In formula (a), Q3 and Q4 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. A trifluoromethyl group having 1 to 6 carbon atoms is preferred.

[0080] In equation (a), -[C(Q1)(Q2)]n4-C(Q3)(Q4)-SO3 - represents a specific example of the substructure, which is preferably shown below, but is not limited to such examples. Furthermore, in the following equation, * denotes the bond with LB.

[0081] [Chemistry 30]

[0082] Of these, Acid-1 to Acid-7 are preferred, and Acid-1 to Acid-3, Acid-6 and Acid-7 are even better.

[0083] The onium salt type monomer represented by formula (a) should preferably be represented by the following formula (a1). [Chemistry 31] In the formula, n1~n4, RA, RAL, R1, LA, Q1~Q4, and Z+ are the same as those mentioned above.

[0084] The onium salt type monomer represented by formula (a1) should preferably be represented by formula (a2). [Chemistry 32] In the formula, n1~n4, RA, RAL, R1, Q1~Q4, and Z+ are the same as those mentioned above.

[0085] The anions of onium salt type monomers represented by formula (a) can be listed below, but are not limited to these. Furthermore, in the following formulas, RA and Q1 are the same as described above, and Me is a methyl group. Also, the bonding positions of the various substituents on the aromatic ring can be interchanged.

[0086] [Chemistry 33]

[0087] [Chemistry 34]

[0088] [Chemistry 35]

[0089] [Chemistry 36]

[0090] [Chemistry 37]

[0091] [Chemistry 38]

[0092] [Chemistry 39]

[0093] [Chemistry 40]

[0094] [Chemistry 41]

[0095] [Chemistry 42]

[0096] [Chemistry 43]

[0097] [Chemistry 44]

[0098] [Chemistry 45]

[0099] [Chemistry 46]

[0100] [Chemistry 47]

[0101] [Chemistry 48]

[0102] [Chemistry 49]

[0103] [Transformation 50]

[0104] [Chemistry 51]

[0105] [Chemistry 52]

[0106] [Chemistry 53]

[0107] [Chemistry 54]

[0108] [Chemistry 55]

[0109] [Chemistry 56]

[0110] [Chemistry 57]

[0111] [Chem.58]

[0112] [Chemistry 59]

[0113] [Transformation 60]

[0114] [Chemistry 61]

[0115] [Chemistry 62]

[0116] [Chemistry 63]

[0117] [Chemistry 64]

[0118] In formula (a), Z+ represents an onium cation. The aforementioned onium cation is preferably a strontium cation represented by formula (Z-1) or a monium cation represented by formula (Z-2). [Chemistry 65]

[0119] In formulas (Z-1) and (Z-2), Rct1 to Rct5 are each independently a halogen atom, or may contain a hydrocarbon group with 1 to 30 carbon atoms of heteroatoms.

[0120] Specific examples of halogen atoms represented by Rct1~Rct5 include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.

[0121] Rct1 to Rct5 represent hydrocarbon groups, 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, and tributyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 30 carbon atoms such as vinyl, allyl, 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; aralkyl groups with 7 to 30 carbon atoms such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these, preferably aryl. 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.

[0122] Furthermore, Rct1 and Rct2 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 shown by the following formulas.

[0123] [Chemistry 66] In the formula, the dashed lines represent the atomic bonds between the atoms of Rct3 and Rct3.

[0124] A specific example of a strontium cation represented by formula (Z-1) can be found in paragraph

[0102] of Japanese Patent Application Publication No. 2024-003744.

[0125] The authors recorded in the Japanese Patent Application Publication No. 2023-169812, paragraphs

[0070] to

[0085] , etc., but not limited to those.

[0125] Specific examples of citric acid represented by formula (Z-2) can be cited from paragraph

[0181] of Japanese Patent Application Publication No. 2024-000259, but are not limited to such examples.

[0126] The Z+ cation should preferably be the strontium cation represented by the formula (Z-3). [Chemistry 67]

[0127] In formula (Z-3), m1 is either 0 or 1. When m1 is 0, it is a benzene ring; when m1 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m1=0 is preferred. m2 is either 0 or 1. When m2 is 0, it is a benzene ring; when m2 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m2=0 is preferred. m3 is either 0 or 1. When m3 is 0, it is a benzene ring; when m3 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m3=0 is preferred.

[0128] In formula (Z-3), m4 is 0, 1, 2, 3, or 4. The more iodine atoms in the cation structure, the higher the absorption, especially for EUV. The fewer iodine atoms, the higher the solvent solubility and the less concern about precipitation in the inhibitor composition. Therefore, m4 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0129] In formula (Z-3), m5 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, m5 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better. m6 is 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, m6 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better. m7 is 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, m7 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0130] In formula (Z-3), m8 is 0, 1, or 2. Considering the availability of raw materials, m8 being 0 or 1 is preferred. m9 is 0, 1, or 2. Considering the availability of raw materials, m9 being 0 or 1 is preferred. m10 is 0, 1, or 2. Considering the availability of raw materials, m10 being 0 or 1 is preferred.

[0131] In formula (Z-3), m11 is either 0 or 1. When m11 is 0, it is a benzene ring; when m11 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m11 of 0 is preferred.

[0132] In formula (Z-3), m12 is 0, 1, 2, 3, or 4. The more iodine atoms in the cation structure, the higher the absorption, especially for EUV. The fewer iodine atoms, the higher the solvent solubility and the less concern about precipitation in the inhibitor composition. Therefore, m12 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0133] In formula (Z-3), m13 is 0, 1, or 2. From the perspective of raw material acquisition, m13 being 0 or 1 is preferred. m14 is 0, 1, or 2. From the perspective of synthesis, m14 being 0 or 1 is preferred.

[0134] However, when m1 is 0, then 0 ≤ m6 + m9 ≤ 4; when m1 is 1, then 0 ≤ m6 + m9 ≤ 6. When m2 is 0, then 0 ≤ m7 + m10 ≤ 4; when m2 is 1, then 0 ≤ m7 + m10 ≤ 6. When m3 is 0, then 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m13 is 1, then 1 ≤ m4 + m5 + m8 + 14 ≤ 6. When m11 is 0, then 0 ≤ m12 + m13 ≤ 4; when m11 is 1, then 0 ≤ m12 + m13 ≤ 6. Also, m4 + m12 ≥ 1.

[0135] In formula (Z-3), 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 m5 is 2 or more, each RF1 may be the same or different from each other; when m6 is 2 or more, each RF2 may be the same or different from each other; when m7 is 2 or more, each RF3 may be the same or different from each other.

[0136] In formula (Z-3), Rct6 to Rct9 represent halogen atoms other than iodine and fluorine atoms, nitro groups, cyano groups, and may also include hydrocarbon groups with 1 to 20 carbon atoms (heteroatomic), hydroxyl groups with 1 to 20 carbon atoms (heteroatomic), or thiol groups with 1 to 20 carbon atoms (heteroatomic). The hydrocarbon portion of the aforementioned hydrocarbon groups, hydroxyl groups, and thiol 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 explanation 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.

[0137] Furthermore, when m8 is 2, the two Rct6 atoms can be the same or different, and the two Rct6 atoms can also bond to each other and form a ring together with the carbon atoms of these bonds. When m9 is 2, the two Rct7 atoms can be the same or different, and the two Rct7 atoms can also bond to each other and form a ring together with the carbon atoms of these bonds. When m10 is 2, the two Rct8 atoms can be the same or different, and the two Rct8 atoms can also bond to each other and form a ring together with the carbon atoms of these bonds. When m13 is 2, the two Rct9 atoms can be the same or different, and the two Rct9 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, 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.

[0138] Furthermore, the aromatic rings of S+ in the strontium cation represented by formula (Z-3) can also bond to each other and form a ring together with S+. In this case, specific examples of the aforementioned ring structure can be listed in the following formulas.

[0139] [Chemistry 68] In the formula, the dashed lines represent atomic bonds.

[0140] In formula (Z-3), LD and LE are each independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Of these, LD is preferably a single bond, ether bond, ester bond, or sulfonate bond, with ester bond or sulfonate bond being more preferred. LE is preferably a single bond, ether bond, or ester bond, with single bond being more preferred.

[0141] In formula (Z-3), XL2 is a single bond, or may contain a heteroatom of 1 to 40 carbon atoms in an extended hydrocarbon group. Specific examples of extended hydrocarbon groups of 1 to 40 carbon atoms that may also contain heteroatoms can be illustrated as those exemplified by the specific examples of extended hydrocarbon groups of 1 to 40 carbon atoms represented by XL, but are not limited to these.

[0142] The strontium cation represented by formula (Z-3) should preferably be represented by the following formula (Z-3-1).

[0143] [Chemistry 69] In the formula, m4~m10, m12~m14, RF1~RF3, Rct6~Rct9, LD, LE and XL2 are the same as those mentioned above.

[0144] The cation represented by formula (Z-3-1) should preferably be represented by formula (Z-3-2).

[0145] [Chemistry 70] In the formula, m4~m10, RF1~RF3 and Rct6~Rct8 are the same as those mentioned above.

[0146] Specific examples of strontium cations represented by formula (Z-3) are shown below, but are not limited to these. Furthermore, in the following formula, Me is a methyl group.

[0147] [Chemistry 71]

[0148] [Chemistry 72]

[0149] [Chemistry 73]

[0150] [Chemistry 74]

[0151] [Chemistry 75]

[0152] [Chemistry 76]

[0153] [Chemistry 77]

[0154] [Chemistry 78]

[0155] [Chemistry 79]

[0156] [Chemistry 80]

[0157] [Chemistry 81]

[0158] [Chemistry 82]

[0159] [Chemistry 83]

[0160] [Chemistry 84]

[0161] [Chemistry 85]

[0162] [Chemistry 86]

[0163] [Chemistry 87]

[0164] [Chemistry 88]

[0165] [Chemistry 89]

[0166] [Chemistry 90]

[0167] [Chemistry 91]

[0168] [Chemistry 92]

[0169] [Chemistry 93]

[0170] [Chemistry 94]

[0171] [Chemistry 95]

[0172] [Chemistry 96]

[0173] [Chemistry 97]

[0174] [Chem. 98]

[0175] Specific examples of the onium salts of the present invention can be listed as any combination of the aforementioned anions and cations.

[0176] The onium salt type monomer of this invention can be synthesized using known methods. Specifically, for the following intermediate (In-1-ex) that can be synthesized using known organic synthesis reactions, the corresponding chloromethyl alkyl ether can be reacted under basic conditions to introduce an acetal-type acid unstable group. Alternatively, a carbonate-type acid unstable group can be introduced by reacting a chloroformate derived from a tertiary alcohol under basic conditions.

[0177] [Chemistry 99] In the formula, n1~n4, RA, R1, LA, LB, XL, Q1~Q4, and Z+ are the same as those mentioned above.

[0178] Furthermore, the aforementioned manufacturing method is merely one example, and the manufacturing method of the onium salt type monomer of the present invention is not limited to such methods.

[0179] Furthermore, the onium salt type monomer of the present invention can be used as a monomeric photoacid generator.

[0180] [polymer] The polymer of the present invention comprises repeating units (hereinafter also referred to as repeating unit a) derived from the onium salt type monomer represented by formula (a).

[0181] The polymer of this invention is a polymer-bonded photoacid generator in which the chemical amplification inhibitor component functions as a base polymer and as a photoacid generator. The onium salt monomer of this invention is characterized by an acid-indestructible group in the anion, which increases the carbon number and thus provides good solvent solubility. The acid-indestructible group in the anion undergoes a deprotection reaction upon acid generation, resulting in the formation of aromatic hydroxyl groups. This provides solubility contrast. Furthermore, the iodine atom in the anion exhibits very high EUV absorption at a wavelength of 13.5 nm, thus generating secondary electrons during exposure. Due to the aforementioned aromatic ring substituted with polymeric groups and iodine atoms and bonded to the anionic structure, the secondary electrons generated by the iodine atom promote the decomposition of cations near the anion, efficiently generating acid, thereby increasing sensitivity. Moreover, due to the large atomic weight of the iodine atom, the generated acid is bonded to the polymer backbone, resulting in low acid diffusion. Polymerizable groups composed of styrene and vinylnaphthalene structures are more rigid than those of methacrylates, thus increasing the glass transition temperature (Tg) of the polymer. It is believed that the interaction (π-π stacking effect) of aromatic rings within or between the base polymers ensures a regular and correct arrangement of the base polymers, exhibiting resistance to pattern collapse in the developer 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. The use of triarylstrontium cations containing fluorine atoms is preferred, as the electron attraction effect of fluorine atoms lowers the LUMO energy level in the leading-edge molecular orbital theory, making it easier to accept secondary electrons and thus promoting cation decomposition and effectively generating acid. This addition effect results in high sensitivity. This prevents the decrease in resolution caused by acid diffusion blurring, thereby improving LWR and CDU. Therefore, the polymer of the present invention is particularly suitable as a material for chemically amplified positive inhibitor components.

[0182] The aforementioned polymer may further include 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.).

[0183] [Chemistry 100]

[0184] In formulas (b1) and (b2), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0185] In formula (b1), X1 refers to a single bond, an phenyl group, an anhydride group, *-C(=O)-O-X11-, or *-C(=O)-NH-X11-. This phenyl or anhydride group may be substituted with a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, or a saturated hydrocarbon oxygen group containing fluorine atoms with 1 to 10 carbon atoms, or a halogen atom. X11 refers to a saturated hydrocarbon group with 1 to 10 carbon atoms, an phenyl group, or an anhydride 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.

[0186] In formula (b2), X2 represents a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * indicates an atomic bond with a carbon atom in the main chain. R11 represents 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 represents 0, 1, 2, 3, or 4, preferably 0 or 1.

[0187] In formulas (b1) and (b2), AL1 and AL2 are each independently acid-indestructible groups. Specific examples of the aforementioned acid-indestructible groups may be listed, for example, those described in Japanese Patent Application Publication Nos. 2013-80033 and 2013-83821, but are not limited to these.

[0188] Generally speaking, specific examples of the aforementioned unstable acid groups can be represented by the following formulas (AL-1) to (AL-3).

[0189] [Chemistry 101] In the formula, * represents an atomic bond.

[0190] 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, fluorine, and iodine atoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Preferably, the aforementioned hydrocarbon groups have 1 to 20 carbon atoms.

[0191] In formula (AL-1), a2 is an integer from 0 to 10, and should preferably be 1, 2, 3, 4 or 5.

[0192] 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, fluorine, and iodine atoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Furthermore, any two of RL2, RL3, and RL4 can bond to each other and form a ring with 3 to 20 carbon atoms together with the bonded carbon atoms or carbon and oxygen atoms. The aforementioned rings are preferably rings with 4 to 16 carbon atoms, and alicyclic rings are particularly preferred.

[0193] 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, fluorine, and iodine. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. 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 alicyclic rings are particularly preferred.

[0194] Specific examples of repeating unit b1 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.

[0195] [Chemistry 102]

[0196] [Chemistry 103]

[0197] [Chemistry 104]

[0198] [Chemistry 105]

[0199] [Chemistry 106]

[0200] [Chemistry 107]

[0201] [Chemistry 108]

[0202] Specific examples of repeating unit b2 may be listed below, but are not limited to these. Furthermore, in the following formula, RA and AL2 are the same as described above.

[0203] [Chemistry 109]

[0204] [Chemical 110]

[0205] [Chemistry 111]

[0206] The aforementioned polymer may also further include repeating units represented by the following formula (b3) (hereinafter also referred to as repeating unit b3).

[0207] [Chemistry 112]

[0208] In formula (b3), 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.

[0209] In formula (b3), RA refers to a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Among these, a hydrogen atom is preferred, a methyl group is more preferred, and a hydrogen atom is even more preferred.

[0210] In formula (b3), 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, a single bond and *-C(=O)-O- are preferred, with a single bond being even more preferred.

[0211] In formula (b3), R12 and R13 are each independently hydrogen atoms, or may contain heteroatoms and hydrocarbon groups with 1 to 20 carbon atoms. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, 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, allyl, propenyl, butenyl, and hexenyl; cyclounsaturated cycloalkyl groups with 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups with 2 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.

[0212] Furthermore, R12 and R13 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.

[0213] In formula (b3), R14 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(R14A)(R14B). R14A and R14B are each independently a hydrogen atom or a hydrocarbon group with 1 to 6 carbon atoms. The aforementioned halogen atom is preferably a fluorine atom, chlorine atom, bromine atom, or iodine atom, with fluorine or iodine atom being more preferred. The hydrocarbon 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 R12 and R13. 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 b2 is 2 or more, each R14 can be the same or different.

[0214] Furthermore, when b2 is 2 or more, multiple R14 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.

[0215] In formula (b3), 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.

[0216] In formula (b3), X5 and X6 are each independently an oxygen atom or a sulfur atom. However, X4 and X6 are bonded to adjacent carbon atoms of the aromatic ring. X5 and X6 can be the same or different. From the perspective of reactivity, it is better if X5 and X6 are both oxygen atoms.

[0217] Specific examples of repeating unit b3 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.

[0218] [Chemistry 113]

[0219] [Chemistry 114]

[0220] [Chemistry 115]

[0221] [Chemistry 116]

[0222] [Chemistry 117]

[0223] [Chemistry 118]

[0224] [Chemistry 119]

[0225] [Chemistry 120]

[0226] [Chemistry 121]

[0227] [Chemistry 122]

[0228] [Chemistry 123]

[0229] [Chemistry 124]

[0230] [Chemistry 125]

[0231] [Chemistry 126]

[0232] [Chemistry 127]

[0233] [Chemistry 128]

[0234] [Chemistry 129]

[0235] [Chemistry 130]

[0236] [Chemistry 131]

[0237] [Chemistry 132]

[0238] [Chemistry 133]

[0239] [Chemistry 134]

[0240] [Chemistry 135]

[0241] [Chemistry 136]

[0242] [Chemistry 137]

[0243] [Chemistry 138]

[0244] [Chemistry 139]

[0245] [Chemistry 140]

[0246] [Chemistry 141]

[0247] [Chemistry 142]

[0248] [Chemistry 143]

[0249] [Chemistry 144]

[0250] [Chemistry 145]

[0251] [Chemistry 146]

[0252] [Chemistry 147]

[0253] [Chemistry 148]

[0254] [Chemistry 149]

[0255] [Chemistry 150]

[0256] [Chemistry 151]

[0257] [Chemistry 152]

[0258] [Chemistry 153]

[0259] [Chemistry 154]

[0260] [Chemistry 155]

[0261] [Chemistry 156]

[0262] [Chemistry 157]

[0263] [Chemistry 158]

[0264] [Chemistry 159]

[0265] [Chemistry 160]

[0266] [Chemistry 161]

[0267] [Chemistry 162]

[0268] The aforementioned polymer preferably includes a repeating unit represented by the following formula (c) (hereinafter also referred to as repeating unit c). [Chemistry 163]

[0269] In formula (c), RA represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y1 represents a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * indicates an atomic bond with a carbon atom in the main chain. R21 represents a halogen atom, a nitro group, a cyano group, a carboxyl group, or may contain a hydrocarbon group with 1 to 20 carbon atoms of a heteroatom, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms of a heteroatom, or a hydrocarbon carbonyloxy group with 2 to 20 carbon atoms of a heteroatom, or a hydrocarbon carbonyloxy group with 2 to 20 carbon atoms of a heteroatom. c1 represents 1, 2, 3, or 4. c2 represents 0, 1, 2, or 3. However, 1 ≤ c1 + c2 ≤ 5.

[0270] Specific examples of repeating unit c may be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above.

[0271] [Chemistry 164]

[0272] [Chemistry 165]

[0273] [Chemistry 166]

[0274] [Chemistry 167]

[0275] [Chemistry 168]

[0276] The aforementioned polymer preferably includes a repeating unit represented by the following formula (d) (hereinafter also referred to as repeating unit d). [Chemistry 169]

[0277] In formula (d), RA represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z1 represents a single bond, an phenyl group, an anatase group, *-C(=O)-O-Z11-, or *-C(=O)-NH-Z11-. This phenyl or anatase 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, or a saturated hydrocarbon oxygen group containing fluorine atoms with 1 to 10 carbon atoms, or a halogen atom. * indicates an atomic bond with a carbon atom in the main chain. Z11 represents a saturated hydrocarbon group with 1 to 10 carbon atoms, an phenyl group, or an anatase group. This saturated hydrocarbon group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. R31 is a group consisting of 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, sulcinolone ring, and carboxylic anhydride (-C(=O)-OC(=O)-).

[0278] Specific examples of repeating unit d may be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above.

[0279] [Chemistry 170]

[0280] [Chemistry 171]

[0281] [Chemistry 172]

[0282] [Chemistry 173]

[0283] [Chemistry 174]

[0284] [Chemistry 175]

[0285] [Chemistry 176]

[0286] [Chemistry 177]

[0287] [Chemistry 178]

[0288] [Chemistry 179]

[0289] [Chemistry 180]

[0290] [Chemistry 181]

[0291] [Chemistry 182]

[0292] [Chemistry 183]

[0293] [Chemistry 184]

[0294] [Chemistry 185]

[0295] For repeating units d, in ArF lithography, those with lactone rings as polar groups are preferred, and in KrF lithography, EB lithography, and EUV lithography, those with phenolic sites are preferred.

[0296] The aforementioned polymer may further include repeating units (hereinafter also referred to as repeating unit e) having a structure in which hydroxyl groups are protected by acid-insecure groups. Repeating unit e is not particularly limited as long as it has a structure in which one or more hydroxyl groups are protected, and the protecting group decomposes and generates hydroxyl groups due to the action of acid. It is preferred to use the following formula (e).

[0297] [Chemistry 186]

[0298] In formula (e1), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R41 is a (d + 1)-valent hydrocarbon group having 1 to 30 carbon atoms which may also contain heteroatoms. R42 is an acid-labile group. d is 1, 2, 3, or 4.

[0299] In formula (e), the acid-labile group represented by R42 is not particularly limited as long as it is deprotected by the action of an acid to generate a hydroxyl group. The structure of R42 is preferably an acetal structure, a ketal structure, an alkoxycarbonyl group, an alkoxymethyl group, etc., and particularly preferably an alkoxymethyl group represented by the following formula (e1).

[0300] [Chemical formula 187] In the formula, * represents an atomic bond. R43 is a hydrocarbon group having 1 to 15 carbon atoms.

[0301] Specific examples of the acid-labile group represented by R42, the alkoxymethyl group represented by formula (e1), and the repeating unit e can be the same as those exemplified in the description of the repeating unit d in Japanese Patent Application Laid-Open No. 2020-111564.

[0302] The aforementioned polymer may further contain a repeating unit f derived from indene, benzofuran, benzothiophene, acenaphthylene, chromone, coumarin, norbornadiene, or derivatives thereof. Specific examples of the monomer providing the repeating unit f include those shown below, but are not limited thereto.

[0303] [Chemical formula 188]

[0304] The aforementioned polymer may further contain a repeating unit g derived from styrene, indan, vinylpyridine, or vinylcarbazole.

[0305] In the polymer of the present invention, the content ratios of the repeating units a, b1, b2, b3, c, d, e, f, and g are preferably 0 < a ≤ 0.5, 0 ≤ b1 ≤ 0.8, 0 ≤ b2 ≤ 0.8, 0 ≤ b3 ≤ 0.6, 0 ≤ c ≤ 0.8, 0 ≤ d ≤ 0.5, 0 ≤ e ≤ 0.3, 0 ≤ f ≤ 0.3, and 0 ≤ g ≤ 0.3, more preferably 0 < a ≤ 0.4, 0 ≤ b1 ≤ 0.7, 0 ≤ b2 ≤ 0.7, 0 ≤ b3 ≤ 0.5, 0 ≤ c ≤ 0.7, 0 ≤ d ≤ 0.4, 0 ≤ e ≤ 0.2, 0 ≤ f ≤ 0.2, and 0 ≤ g ≤ 0.2. However, a + b1 + b2 + b3 + c + d + e + f + g ≤ 1.0.

[0306] The weight-average molecular weight (Mw) of the aforementioned polymer is preferably between 1,000 and 500,000, and more preferably between 3,000 and 100,000. If Mw is within this range, sufficient etch resistance will be achieved, without concerns about a decrease in resolution due to the difference in dissolution rates before and after exposure. Furthermore, in this invention, Mw is a polystyrene-converted value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or N,N-dimethylformamide (DMF) as a solvent. GPC measurements are typically performed at room temperature around 23 degrees Celsius, but can also be performed at higher or lower temperatures.

[0307] Furthermore, regarding the aforementioned polymer molecular weight distribution (Mw / Mn), since the influence of Mw / Mn tends to increase as the pattern becomes more regular and refined, a narrow dispersion of Mw / Mn of 1.0 to 2.0 is preferable to obtain a resist composition suitable for fine pattern sizes. If it is within the aforementioned range, there will be fewer low-molecular-weight and high-molecular-weight polymers, and after exposure, there will be no risk of foreign matter being observed on the pattern or the pattern shape deteriorating.

[0308] For example, a method for synthesizing the aforementioned polymer may be described as follows: a monomer that provides the aforementioned repeating unit is placed in an organic solvent, a free radical polymerization initiator is added, and the mixture is heated to polymerize it.

[0309] 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.

[0310] The aforementioned polymerization initiator can be added to the monomer solution and supplied to the reactor, or the monomer solution and initiator solution can be prepared separately and supplied to the reactor independently. During the standby time, there is a possibility that polymerization may occur due to free radicals generated by the initiator, resulting in ultra-high molecular weight polymers. Therefore, from a quality management perspective, it is preferable to prepare the monomer solution and initiator solution independently and add them dropwise. Acid-labile groups can be used directly introduced into the monomer, or they can be protected or partially protected after polymerization. Furthermore, to adjust the molecular weight, known chain transfer agents such as dodecyl mercaptan and 2-mercaptoethanol can be used concurrently. In this case, the amount of such chain transfer agents added relative to the total amount of monomers to be polymerized should preferably be 0.01~20 mol%.

[0311] When monomers contain hydroxyl groups, the hydroxyl groups can be replaced with acetal groups such as ethoxy or ethoxy, which are easily deprotected by acids, during polymerization. After polymerization, the hydroxyl groups can be deprotected with weak acids and water. Alternatively, they can be replaced with acetyl, methyl, or neopentyl groups before polymerization and then subjected to alkaline hydrolysis.

[0312] 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.

[0313] Specific examples of alkali used in alkaline hydrolysis include ammonia and triethylamine. Furthermore, the reaction temperature should preferably be -20 to 100°C, more preferably 0 to 60°C. The reaction time should preferably be 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0314] Furthermore, the amount of each monomer in the aforementioned monomer solution can be appropriately set, for example, in a manner that results in a preferred content ratio for the aforementioned repeating unit.

[0315] The polymer obtained by the aforementioned manufacturing method can be used as the final product, either as the reaction solution obtained by polymerization or as the final product, which is obtained by purification steps such as adding the polymer solution to a lean solvent to obtain the powder and then reprecipitating it. Considering the perspectives of work efficiency and quality stability, it is better to use the polymer solution in which the powder obtained by purification steps is dissolved in the solvent as the final product.

[0316] Specific examples of solvents used at this time can be cited from paragraphs

[0144] to

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

[0317] In the aforementioned polymer solution, the polymer concentration is preferably 0.01~30% by mass, and more preferably 0.1~20% by mass.

[0318] The aforementioned reaction solutions and polymer solutions are best filtered. Filtering removes foreign matter and colloids that may cause defects, which is effective in stabilizing quality.

[0319] The materials used in the aforementioned filters include fluorocarbon-based, cellulose-based, nylon-based, polyester-based, and hydrocarbon-based materials. For filtration steps involving chemically amplified inhibitors, filters made of fluorocarbon-based materials such as Teflon (a registered trademark), polyethylene, polypropylene, or nylon are preferred. The pore size of the filter can be appropriately selected according to the target cleanliness level, preferably below 100 nm, and more preferably below 20 nm. Furthermore, these filters can be used individually or in combination. The filtration method can preferably involve passing the solution through only once, or circulating the solution for multiple filtrations. The filtration steps can be performed in any order and number of times during the polymer manufacturing process, preferably filtering the reaction solution, polymer solution, or both after the polymerization reaction.

[0320] [Chemical Amplification Inhibitor Composition] [(A) Basic Polymer] The chemical amplification inhibitor composition of the present invention comprises a base polymer containing the aforementioned polymer as component (A).

[0321] 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 may include, in addition to the aforementioned polymers, hydrides of ring-opening shift polymers; in this case, those described in Japanese Patent Application Publication No. 2003-66612 may be used.

[0322] Furthermore, there is no particular limitation on the amount of component (A) in the chemical amplification inhibitor composition of the present invention. For example, it can be set to 0.1 to 10 parts by mass relative to 100 parts by mass of the total composition, preferably 0.5 to 5 parts by mass.

[0323] [(B) Organic solvents] The chemical amplification inhibitor composition of the present invention may also include an organic solvent as component (B). As for the organic solvent (B), it is not particularly limited as long as it can dissolve the aforementioned components and the components described below. Specific examples of such organic solvents include ketones such as cyclopentanone, cyclohexanone, and methyl-2-n-pentanone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ketols such as DAA; ethers such as PGME, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tributyl acetate, tributyl propionate, and propylene glycol monotert-butyl ether acetate; lactones such as GBL; and mixtures thereof.

[0324] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, cyclohexanone, GBL, DAA, and mixed solvents thereof, which have particularly good solubility in component (A), i.e., the base polymer, are preferred.

[0325] 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 200-5000 parts by mass, and more preferably 400-3500 parts by mass. (B) Organic solvent can be used alone or in combination with two or more.

[0326] [(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 the desired pattern.

[0327] (C) Specific examples of quenching agents can be listed as onion salts represented by formula (1) or (2).

[0328] [Chemistry 189]

[0329] In formula (1), Rq1 is a hydrogen atom, or may contain a hydrocarbon group with 1 to 40 carbon atoms of heteroatoms, except that the hydrogen atom at the α-position of the sulfonic acid group is replaced by a fluorine atom or a fluoroalkyl group. In formula (2), Rq2 is a hydrogen atom, or may contain a hydrocarbon group with 1 to 40 carbon atoms of heteroatoms.

[0330] Rq1 represents hydrocarbon groups with 1 to 40 carbon atoms. Specifically, examples include alkyl groups with 1 to 40 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, tripentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclo[5.2.1.02,6]decyl, and adamantylalkyl; and aryl groups with 6 to 40 carbon atoms such as phenyl, naphthyl, and anthracene. Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Similarly, one part of the -CH2- group in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it can also contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0331] Specifically, the hydrocarbon group represented by Rq2, in addition to the substituents exemplified in the specific examples of Rq1, can also include fluorinated saturated hydrocarbon groups such as trifluoromethyl and trifluoroethyl, and fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

[0332] Specific examples of the anions of the onium salts represented by formula (1) are shown below, but are not limited to these.

[0333] [Chemistry 190]

[0334] [Chemistry 191]

[0335] [Chemistry 192]

[0336] [Chemistry 193]

[0337] [Chemistry 194]

[0338] Specific examples of the anions of the onium salts represented by equation (2) are shown below, but are not limited to these.

[0339] [Chemistry 195]

[0340] [Chemistry 196]

[0341] [Chemistry 197]

[0342] [Chemistry 198]

[0343] [Chemistry 199]

[0344] In formulas (1) and (2), Mq+ is a ium cation. The aforementioned ium cation is preferably a strontium cation represented by formulas (Z-1) and (Z-3), a monium cation represented by formula (Z-2), or an ammonium cation represented by formula (am-1).

[0345] [Chemistry 200]

[0346] In formula (am-1), Rq11 to Rq14 are each independently a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. Furthermore, Rq11 and Rq12 may also bond to each other and form a ring together with the nitrogen atoms of these bonds. Specific examples of the aforementioned hydrocarbon groups can be listed as those exemplified by the hydrocarbon groups represented by Rct1 to Rct5 in the descriptions of formulas (Z-1) and (Z-2).

[0347] Specific examples of ammonium cations represented by formula (am-1) are shown below, but are not limited to these.

[0348] [Chemical Engineering 201]

[0349] 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 readily 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.

[0350] 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, "weak acid" means an acidity that cannot be protected by the acid unstable group of the unit containing the acid unstable group used in the base polymer. When the onium salts represented by formula (1) or (2) are used in combination with the conjugate base of 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.

[0351] 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, an onium salt having strontium cation and carboxylate anion sites in the same molecule as described in Japanese Patent No. 6583136 and 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.

[0352] 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.

[0353] 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.

[0354] 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, particularly 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 Application Publication No. 3790649 may also be included. Moreover, compounds in which an acid-instable group is present in the molecule as described in Japanese Patent Application Publication No. 2009-109595 may also be included.

[0355] 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.

[0356] 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.

[0357] [(D) Acid generating agent] The chemical amplification inhibitor composition of the present invention may also include an acid generating agent. Examples of such acid generating agents include compounds that generate acid in response to active light or radiation (photoacid generating agents). There are no particular limitations on photoacid generating agents, as long as they are compounds that generate acid upon exposure to high-energy rays; those that generate sulfonic acid, amide acid, or methyl acid are preferred. Preferred photoacid generating agents include strontium salts, ferrous salts, sulfonated diazomethanes, N-sulfonoxyamides, and oxime-O-sulfonate type acid generating agents. Specific examples of acid generating agents can be found in paragraphs

[0122] to

[0142] of Japanese Patent Application Publication No. 2008-111103.

[0358] Furthermore, photoacid generators are also suitable to use strontium salts represented by formula (3-1) and ferrous salts represented by formula (3-2).

[0359] [Chemical Engineering 202]

[0360] In formulas (3-1) and (3-2), R101 to R105 are each independently a halogen atom, or may contain a hydrocarbon group with 1 to 20 carbon atoms and heteroatoms. Specific examples of the aforementioned halogen atoms and hydrocarbon groups can be listed as those exemplified by the halogen atoms and hydrocarbon groups represented by Rct1 to Rct5 in the descriptions of formulas (Z-1) and (Z-2). Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups may be replaced by heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- group in the aforementioned hydrocarbon groups may also be replaced by heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may also contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonyl lactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc. Furthermore, R101 and R102 can also bond to each other and form a ring together with the sulfur atoms of such bonds. Specific examples of the rings formed in this case can be illustrated by the same examples shown in the description of formula (Z-1) where Rct1 and Rct2 are bonded to each other and can form a ring together with the sulfur atoms of such bonds.

[0361] Specific examples of strontium salt cations represented by formula (3-1) can be listed as those exemplified by strontium cations represented by formulas (Z-1) and (Z-3). Similarly, specific examples of zirconia salt cations represented by formula (3-2) can be listed as those exemplified by zirconia cations represented by formula (Z-2).

[0362] In formulas (3-1) and (3-2), Xa- is selected from the anions in formulas (3A) to (3D).

[0363] [Chemical Engineering 203]

[0364] In formula (3A), Rfa is a fluorine atom, or may contain a hydrocarbon group with 1 to 40 carbon atoms, which may also include heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed as those illustrated in the description of Rfa1 in formula (3A') described later.

[0365] The anion represented by formula (3A) should preferably be represented by formula (3A').

[0366] [Chemical 204]

[0367] In formula (3A'), RHF is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group.

[0368] In formula (3A'), the Rfa1 system may also include hydrocarbon groups with 1 to 38 carbon atoms of heteroatoms. The aforementioned heteroatoms are preferably oxygen, nitrogen, sulfur, or halogen atoms, with oxygen atoms being more preferred. Considering the need for high resolution in the formation of fine patterns, hydrocarbon groups with 6 to 30 carbon atoms are particularly desirable.

[0369] Rfa1 represents a hydrocarbon group with 1 to 38 carbon atoms, which can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 38 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, norbornel, norbornelmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups with 2 to 38 carbon atoms, such as allyl and 3-cyclohexenyl; aryl groups with 6 to 38 carbon atoms, such as phenyl, 1-naphthyl, and 2-naphthyl; aralkyl groups with 7 to 38 carbon atoms, such as benzyl and diphenylmethyl; and groups obtained by combining these.

[0370] Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, halogen, or other heteroatoms. Similarly, the -CH2- portion of the aforementioned hydrocarbon group can also be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, or other heteroatoms. This results in the possible inclusion of hydroxyl, fluorine, chlorine, bromine, iodine, cyano, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. Preferably, the aforementioned heteroatom is an oxygen atom. 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.

[0371] For details on the synthesis of strontium salts containing anions represented by formula (3A'), please refer to Japanese Patent Application Publication Nos. 2007-145797, 2008-106045, 2009-7327, and 2009-258695. Furthermore, strontium salts described in Japanese Patent Application Publication Nos. 2010-215608, 2012-41320, 2012-106986, and 2012-153644 are also suitable.

[0372] Specific examples of anions represented by formula (3A) are shown below, but are not limited to these. Furthermore, in the following formula, Ac is an acetyl group.

[0373] [Chemical Engineering 205]

[0374] [Chemical Engineering 206]

[0375] [Chemical 207]

[0376] [Chemical Engineering 208]

[0377] In formula (3B), 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 (3A'). 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 bond of Rfb1 and Rfb2 to each other is preferably fluorinated ethyl or fluorinated propyl.

[0378] In formula (3C), 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 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 (3A'). Rfc1, Rfc2, and Rfc3 are preferably fluorine atoms or linear fluorinated alkyl groups with 1 to 4 carbon atoms. Furthermore, Rfc1 and Rfc2 may also be bonded to each other and form a ring together with the bonded group (-CF2-SO2-C--SO2-CF2-). In this case, the group obtained by the bond of Rfc1 and Rfc2 is preferably fluorinated ethyl or fluorinated propyl.

[0379] In formula (3D), 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 (3A').

[0380] For details on the synthesis of strontium salts containing anions represented by formula (3D), please refer to Japanese Patent Application Publication No. 2010-215608 and Japanese Patent Application Publication No. 2014-133723.

[0381] Specific examples of anions represented by formula (3D) are shown below, but are not limited to these.

[0382] [Chemical Engineering 209]

[0383] [Chemical 210]

[0384] Furthermore, photoacid generators containing anions represented by formula (3D) possess sufficient acidity to cleave the acid-indestabilizing groups in the base polymer because they do not have a fluorine atom at the α-position of the sulfonic acid group, but have two trifluoromethyl groups at the β-position. Therefore, they can be used as photoacid generators.

[0385] The aforementioned photoacid generator is suitable to be represented by the following formula (4).

[0386] [Chemistry 211]

[0387] In formula (4), R201 and R202 are each independently a hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. R203 is an extended hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. Furthermore, any two of R201, R202, and R203 may bond to each other and form a ring together with the sulfur atoms of such bonds. In this case, specific examples of the aforementioned rings can be given as those illustrated in the description of formula (Z-1) where Rct1 and Rct2 are bonded to each other and can form a ring together with the sulfur atoms of such bonds.

[0388] 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, n-pentyl, tripentyl, 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 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.

[0389] R203 represents an extended hydrocarbon group with 1 to 30 carbon atoms, which can be saturated or unsaturated, and can be straight-chain, 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, and heptadecane-1,17-diyl. Dimethyl alkane groups with 1 to 30 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norcamphenediyl, and adamantanediyl; phenyl groups with 6 to 30 carbon atoms, such as methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, dibutylphenyl, tributylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, dibutylnaphthyl, and tributylnaphthyl; and other aryl groups obtained by combining these groups. Furthermore, some or all of the hydrogen atoms in the aforementioned alkyl group can be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, halogen, or other heteroatoms. Similarly, the -CH2- group in the aforementioned alkyl group can also be replaced by heteroatom groups containing oxygen, sulfur, nitrogen, or other heteroatoms. This results in the possible inclusion of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), and haloalkyl groups. The aforementioned heteroatoms should preferably be oxygen atoms.

[0390] In formula (4), L1 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.

[0391] In formula (4), Xa, Xb, Xc and Xd are each independently a hydrogen atom, a fluorine atom or a trifluoromethyl atom. However, at least one of Xa, Xb, Xc and Xd is a fluorine atom or a trifluoromethyl atom.

[0392] In equation (4), k is 0, 1, 2 or 3.

[0393] The photoacid generator represented by formula (4) should preferably be represented by the following formula (4').

[0394] [Chemistry 212]

[0395] In formula (4'), L1 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 hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon group represented by Rfa1 in formula (3A'). x and y are each independently 0, 1, 2, 3, 4, or 5. z is 0, 1, 2, 3, or 4.

[0396] Specific examples of photoacid generators represented by formula (4) can be listed as those similar to those exemplified by the photoacid generators represented by formula (2) in Japanese Patent Application Publication No. 2017-26980.

[0397] Among the aforementioned photoacid generators, those containing anions represented by formula (3A') or (3D) exhibit low acid diffusion and excellent solvent solubility, which is particularly desirable. Furthermore, those represented by formula (4') exhibit extremely low acid diffusion, which is also particularly desirable.

[0398] Furthermore, other acid-generating agents may also be strontium salts and ferric salts containing anions with an iodine-substituted aromatic rings, represented by formulas (5-1) or (5-2).

[0399] [Chemistry 213]

[0400] In equations (5-1) and (5-2), p is 1, 2, or 3. q is 1, 2, 3, 4, or 5. r is 0, 1, 2, or 3. However, 1 ≤ q + r ≤ 5. It is preferable for q to be 1, 2, or 3, with 2 or 3 being even better. It is preferable for r to be 0, 1, or 2.

[0401] In formulas (5-1) and (5-2), L11 is a single bond, ether bond, or ester bond, or may contain a saturated alkyl group with 1 to 6 carbon atoms of an ether bond or ester bond. The aforementioned saturated alkyl group may be straight-chain, branched, or cyclic.

[0402] In equations (5-1) and (5-2), L12 is a single bond or a divalent linker with 1 to 20 carbon atoms when p is 1, and a (p+1) valent linker with 1 to 20 carbon atoms when p is 2 or 3. The linker may also contain oxygen, sulfur or nitrogen atoms.

[0403] In formulas (5-1) and (5-2), R401 refers to a hydroxyl, carboxyl, fluorine, chlorine, bromine, or amino group, or may contain a fluorine, chlorine, or bromine atom, a hydroxyl, an amino group, or an ether bond of a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxy group with 1 to 20 carbon atoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms, a hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms, or a hydrocarbon sulfonyl oxy group with 1 to 20 carbon atoms, or -N(R401A)(R401B), -N(R401C)-C(=O)-R401D or -N(R401C)-C(=O)-O-R401D. R401A and R401B are each independently a hydrogen atom or a saturated hydrocarbon group with 1 to 6 carbon atoms. R401C consists of hydrogen atoms or saturated hydrocarbon groups with 1 to 6 carbon atoms, and may also contain halogen atoms, hydroxyl groups, saturated hydrocarbon oxy groups with 1 to 6 carbon atoms, saturated hydrocarbon carbonyl groups with 2 to 6 carbon atoms, or saturated hydrocarbon carbonyloxy groups with 2 to 6 carbon atoms. R401D consists of aliphatic hydrocarbon groups with 1 to 16 carbon atoms, aryl groups with 6 to 14 carbon atoms, or aralkyl groups with 7 to 15 carbon atoms, and may also contain halogen atoms, hydroxyl groups, saturated hydrocarbon oxy groups with 1 to 6 carbon atoms, saturated hydrocarbon carbonyl groups with 2 to 6 carbon atoms, or saturated hydrocarbon carbonyloxy groups with 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. The aforementioned hydrocarbon groups, hydrocarbon oxy groups, hydrocarbon carbonyl groups, hydrocarbon oxycarbonyl groups, hydrocarbon carbonyloxy groups, and hydrocarbon sulfonyloxy groups may be linear, branched, or cyclic. When p and / or r are 2 or more, each R401 may be the same or different from the others.

[0404] Among these, R401 should preferably be a hydroxyl group, -N(R401C)-C(=O)-R401D, -N(R401C)-C(=O)-O-R401D, a fluorine atom, a chlorine atom, a bromine atom, a methyl group, a methoxy group, etc.

[0405] In formulas (5-1) and (5-2), Rf1 to Rf4 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, Rf1 and Rf2 can also form a carbonyl group together. In particular, it is preferable that both Rf3 and Rf4 are fluorine atoms.

[0406] In formulas (5-1) and (5-2), R402 to R406 are each independently a halogen atom, or may contain heteroatoms and be a hydrocarbon group with 1 to 20 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 groups represented by Rct1 to Rct5 in the descriptions of formulas (Z-1) and (Z-2). Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups may be replaced by hydroxyl, carboxyl, halogen, cyano, nitro, mercapto, sulfonyl lactone ring, sulfonic acid group, or a strontium-containing group; and some of the -CH2- group in the aforementioned hydrocarbon groups may be replaced by ether, ester, carbonyl, amide, carbonate, or sulfonate bonds. Additionally, R402 and R403 may also bond to each other and form a ring together with the sulfur atoms of these bonds. At this point, specific examples of the aforementioned rings can be listed as those illustrated in the description of formula (Z-1) where Rct1 and Rct2 are bonded to each other and can form a ring together with the sulfur atoms of such bonds.

[0407] Specific examples of strontium salt cations represented by formula (5-1) can be listed as those exemplified by strontium cations represented by formula (Z-1). Similarly, specific examples of zirconia salt cations represented by formula (5-2) can be listed as those exemplified by zirconia cations represented by formula (Z-2).

[0408] Specific examples of onium salt anions represented by formula (5-1) or (5-2) are shown below, but are not limited to these.

[0409] [Chemistry 214]

[0410] [Chemical 215]

[0411] [Chemistry 216]

[0412] [Chemistry 217]

[0413] [Chemistry 218]

[0414] [Chemistry 219]

[0415] [Chem.220]

[0416] [Chemistry 221]

[0417] [Chemistry 222]

[0418] [Chemistry 223]

[0419] [Chemistry 224]

[0420] [Chemistry 225]

[0421] [Chemistry 226]

[0422] [Chemistry 227]

[0423] [Chemistry 228]

[0424] [Chemistry 229]

[0425] [Chemistry 230]

[0426] [Chemistry 231]

[0427] [Chemistry 232]

[0428] [Chemistry 233]

[0429] [Chemistry 234]

[0430] [Chemistry 235]

[0431] When the chemical amplification inhibitor composition of the present invention includes (D) an acid-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 component (D), i.e., the acid-generating agent, added is within the aforementioned range, the resolution is good, and there is no concern about the generation of foreign matter after the inhibitor film is developed or peeled off, which is ideal. The (D) acid-generating agent can be used alone or in combination of two or more.

[0432] (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.

[0433] 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).

[0434] [Chemistry 236]

[0435] 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.

[0436] [Chemistry 237] In the formula, the dashed lines represent atomic bonds, which are secondary structures derived from glycerol, trimethylolethane, trimethylolpropane, and neopentyl tertrol, respectively.

[0437] Among these, 1,4-endobutyl and 2,2-dimethyl-1,3-endopropyl are preferred.

[0438] 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.

[0439] 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.

[0440] Specific examples of such polymeric surfactants include those containing at least one of the repeating units represented by formulas (6A) to (6E).

[0441] [Chemistry 238]

[0442] 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 (u+1) valence hydrocarbon group or a fluorinated hydrocarbon group with 1 to 20 carbon atoms. u represents 1, 2, or 3. Rs5 is independently a hydrogen atom or a group represented by -C(=O)-O-Rsa. Rsa is a fluorinated hydrocarbon group with 1 to 20 carbon atoms. Rs6 series hydrocarbon groups or fluorinated hydrocarbon groups with 1 to 15 carbon atoms can also have ether bonds or carbonyl groups inserted between the carbon-carbon bonds.

[0443] 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.

[0444] 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.

[0445] 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 examples of saturated hydrocarbon groups include undecayl, dodecyl, tridecayl, tetradecayl, and decadecyl. Specific examples of fluorinated hydrocarbon groups represented by Rs3 or Rs6 include groups where some or all of the hydrogen atoms of the carbon atom bonded to the aforementioned hydrocarbon group are replaced by fluorine atoms. As mentioned earlier, ether bonds or carbonyl groups can also be inserted between these carbon-carbon bonds.

[0446] Specific examples of acid-instable groups represented by Rs3 include groups represented by the aforementioned formulas (AL-1) to (AL-3), 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.

[0447] Rs4 represents a (u+1) valence hydrocarbon group or fluorinated hydrocarbon group, which can be straight-chain, branched, or cyclic. Specific examples can be listed as groups obtained by removing u hydrogen atoms from the aforementioned hydrocarbon group or fluorinated hydrocarbon group.

[0448] 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.

[0449] 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.

[0450] [Chemistry 239] [ ]

[0451] [Chemistry 240]

[0452] [Chemistry 241]

[0453] [Chemistry 242]

[0454] [Chemistry 243]

[0455] The aforementioned polymeric surfactants may also include repeating units other than those represented by formulas (6A) to (6E). Specific examples of other repeating units include repeating units derived from methacrylic acid, α-trifluoromethacrylic acid derivatives, etc. In polymeric surfactants, the content of repeating units represented by formulas (6A) to (6E) is preferably 20 mol% or more, more preferably 60 mol% or more, and even more preferably 100 mol% in all repeating units.

[0456] 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.

[0457] A method for synthesizing the aforementioned polymeric surfactants can be exemplified by adding a free radical initiator to an organic solvent and heating the monomer containing unsaturated bonds, along with repeating units represented by formulas (6A) to (6E) and other repeating units as needed, to polymerize the monomer. Specific examples of organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, and dialkylene. Specific examples of polymerization initiators include AIBN, 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid), benzoyl peroxide, and lauryl peroxide. The reaction temperature is preferably 50–100°C. The reaction time is preferably 4–24 hours. Acid-unstable groups can be directly introduced into the monomer, or they can be protected or partially protected after polymerization.

[0458] 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.

[0459] 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.

[0460] [(F) Anti-solubilizer] The chemical amplification inhibitor composition of the present invention may further include a solvent resist as component (F). When the chemical amplification inhibitor composition of the present invention is positive, by incorporating a solvent resist, the difference in dissolution rate between the exposed and unexposed areas can be further increased, thereby further improving the resolution.

[0461] Specific examples of the aforementioned solvent inhibitors include compounds containing two or more phenolic hydroxyl groups, preferably with a molecular weight of 100-1000, more preferably 150-800, in which the hydrogen atoms of the phenolic hydroxyl groups are replaced by acid-unstable groups at a ratio of 0-100 mol% of the total; or compounds containing carboxyl groups, in which the hydrogen atoms of the carboxyl groups are replaced by acid-unstable groups at an average ratio of 50-100 mol% of the total. Specifically, examples include compounds in which the hydrogen atoms of the hydroxyl and carboxyl groups of bisphenol A, triphenol, phenolphthalein, cresol phenolic varnish, naphtholic acid, adamantane carboxylic acid, and cholic acid are replaced by acid-unstable groups, such as those described in paragraphs

[0155] to

[0178] of Japanese Patent Application Publication No. 2008-122932.

[0462] When the chemical amplification inhibitor composition of the present invention includes (F) solvent inhibitor, its content relative to 80 parts by weight of (A) base polymer is preferably 0 to 50 parts by weight, and more preferably 5 to 40 parts by weight. (F) Solvent inhibitor can be used alone or in combination of two or more.

[0463] [(G) Other ingredients] The chemical amplification inhibitor composition of this invention may also include compounds that decompose to produce acid (acid-increasing compounds), organic acid derivatives, fluorinated alcohols, water-repellent enhancers, etc., as other components in (G). 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 weight of the base polymer in (A) is preferably 0 to 5 parts by weight, and more preferably 0 to 3 parts by weight. If the content is within this range, acid diffusion is easily controlled, and degradation of resolution and pattern shape can be suppressed. The aforementioned organic acid derivatives and fluorinated alcohols can be found in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608.

[0464] The aforementioned water-repellent enhancer can be used in immersion lithography without a surface coating. The aforementioned water-repellent enhancer is preferably a polymer containing fluorinated alkyl groups, or a polymer containing a specific structure, namely 1,1,1,3,3,3-hexafluoro-2-propanol residues, as exemplified in Japanese Patent Application Publication Nos. 2007-297590 and 2008-111103. The aforementioned water-repellent enhancer must be soluble in alkaline or organic solvent developing solutions. Water-repellent enhancers having the aforementioned specific 1,1,1,3,3,3-hexafluoro-2-propanol residues exhibit good solubility in developing solutions. Polymers containing repeating units containing amine or ammonium salts as water-repellent enhancers are highly effective in preventing the evaporation of acid in PEB and in preventing poor opening of the hole pattern after development. When the chemical amplification inhibitor composition of the present invention contains the aforementioned water-repellent enhancer, its content relative to 80 parts by weight of (A) base polymer is preferably 0 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight.

[0465] [Pattern Formation Method] When the chemically amplified resist composition of the present invention is used in the manufacture of various integrated circuits, it is applicable to known lithography techniques. For example, in terms of pattern formation methods, a method comprising the following steps can be listed: forming a resist film on a substrate using the aforementioned chemically amplified resist composition, exposing the aforementioned resist film to high-energy radiation, and developing the exposed resist film using a developing solution.

[0466] First, the chemically amplifying resist composition of the present invention is coated onto a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective film, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.) using appropriate coating methods such as spin coating, roll coating, flow coating, dip coating, spray coating, or blade coating to achieve a coating film thickness of 0.01~2.0μm. The coating is then placed on a hot plate and preheated at 60~150℃ for 10 seconds~30 minutes, more preferably 80~120℃ for 30 seconds~20 minutes, to form a resist film.

[0467] Then, the aforementioned resist film is exposed using high-energy radiation. Examples of such high-energy radiation include ultraviolet light, far-ultraviolet light, EB, EUV with wavelengths of 3-15 nm, X-rays, soft X-rays, excimer laser light, gamma rays, and synchrotron radiation. When using ultraviolet light, far-ultraviolet light, EUV, X-rays, soft X-rays, excimer laser light, gamma rays, or synchrotron radiation, irradiation is performed directly or using a mask used to form the target pattern, with an exposure dose preferably of approximately 1-200 mJ / cm², and more preferably approximately 10-100 mJ / cm². When using EB radiation, the pattern is drawn directly or using a mask used to form the target pattern, with an exposure dose preferably of approximately 0.1-100 μC / cm², and more preferably approximately 0.5-50 μC / cm². The chemical amplification inhibitor composition of the present invention is particularly suitable for micro-patterning in high-energy radiation using ArF excimer laser light with a wavelength of 193 nm, KrF excimer laser light with a wavelength of 248 nm, EB (electron beam) or EUV (extreme ultraviolet), X-rays, soft X-rays, gamma rays or synchrotron radiation with a wavelength of 3~15 nm.

[0468] After exposure, PEB can also be performed on a hot plate, preferably at 60~150℃ for 10 seconds to 30 minutes, more preferably at 80~120℃ for 30 seconds to 20 minutes.

[0469] After exposure or PEB, a developer solution containing 0.1-10% by mass, preferably 2-5% by mass, of an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, or tetrabutylammonium hydroxide is used. The development is performed using conventional methods such as dip, immersion, or spray for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes. In this way, the exposed areas dissolve in the developer solution, while the unexposed areas do not dissolve, thus forming a positive pattern of the target on the substrate.

[0470] Negative patterns can also be obtained by using an organic solvent developer instead of the aforementioned alkaline aqueous solution. Specific examples of developers used in this case include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methyl acetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl valerate, methyl crotonate, and crotonic acid. 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, benzyl formate, ethyl phenyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in mixtures of two or more.

[0471] Rinsing can also be performed at the end of development. For the rinsing solution, a solvent that is miscible with the developer and does not dissolve the resist film is preferred. Such solvents should preferably be alcohols with 3-10 carbon atoms, ether compounds with 8-12 carbon atoms, alkanes with 6-12 carbon atoms, alkenes, alkynes, or aromatic solvents.

[0472] Specific examples of alcohols with 3 to 10 carbon atoms include n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tributanol, 1-pentanol, 2-pentanol, 3-pentanol, neopentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 3, 3-Dimethyl-1-butanol, 3,3-Dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, 1-octanol, etc.

[0473] Specific examples of the aforementioned ether compounds with 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, didi-dibutyl ether, di-n-pentyl ether, diisopentyl ether, didi-dipentyl ether, didi-dipentyl ether, and di-n-hexyl ether.

[0474] Specific examples of alkanes with 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, and cyclononane. Specific examples of alkenes with 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Specific examples of alkynes with 6 to 12 carbon atoms include hexyne, heptyne, and octyne.

[0475] Specific examples of the aforementioned aromatic solvents include toluene, xylene, ethylbenzene, isopropylbenzene, tributylbenzene, and mesitylene.

[0476] Rinsing can reduce the collapse of resist patterns and the formation of defects. However, rinsing is not always necessary, and omitting rinsing can reduce the amount of solvent used.

[0477] Alternatively, the developed hole and groove patterns can be shrunk using heat flow, RELACS, or DSA techniques. A shrinkage agent is applied to the hole pattern. During baking, the diffusion of the acid catalyst from the resist film causes cross-linking of the shrinkage agent on the surface of the resist film, and the shrinkage agent adheres to the sidewalls of the hole pattern. The baking temperature should be 70~180℃, more preferably 80~170℃, and the baking time should be 10~300 seconds. This removes excess shrinkage agent and reduces the size of the hole pattern. [Example]

[0478] The present invention will be specifically described below with examples of synthesis, embodiments, and comparative examples. The present invention is not limited to the embodiments described below. The apparatus used is as follows. MALDI TOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[0479] [1] Synthesis of onium salt type monomers [Example 1-1] Synthesis of onium salt type monomer a-1 [Chemistry 244]

[0480] Under nitrogen atmosphere, 38.4 g of starting material SM-1 and 6.1 g of triethylamine were dissolved in 200 g of dichloromethane in a reaction vessel, which was then cooled in an ice bath. While maintaining the temperature inside the reaction vessel below 20°C, 6.7 g of starting material SM-2 was added dropwise. After addition, the temperature was raised to room temperature and allowed to mature for 4 hours. After maturation, the reaction vessel was cooled in an ice bath, water was added to stop the reaction, and aqueous work-up was performed. After distilling off the solvent, diisopropyl ether was added to wash away the residue, thereby obtaining 39.3 g of onium salt monomer a-1 in oily form (92% yield). MALDI TOF-MS: POSITIVE M+335 (equivalent to C18H11F4S+) Negative M-519 (equivalent to C16H18F2IO7S-)

[0481] [Examples 1-2~1-8] Synthesis of onium salt type monomers a-2~a-8 Using the corresponding raw materials and known organic synthesis reactions, onium salt type monomers a-2 to a-8 represented by the following formulas are synthesized.

[0482] [Chemistry 245]

[0483] [Comparative Examples 1-1 to 1-4] Comparison of the synthesis of onium salt type monomers Ca-1 to Ca-4 Using the corresponding raw materials and known organic synthesis reactions, comparative onium salt monomers ca-1 to ca-4 represented by the following formulas were synthesized.

[0484] [Chemistry 246]

[0485] [2] Synthesis of basic polymers Among the monomers used in the synthesis of basic polymers, those other than monomers a-1 to a-8 and comparative monomers ca-1 to ca-4 are as follows.

[0486] [Chemistry 247]

[0487] [Chemistry 248]

[0488] [Chemistry 249]

[0489] [Example 2-1] Synthesis of Polymer P-1 Under nitrogen atmosphere, monomer-polymerization initiator solution was prepared by taking monomer a-1 (22.4 g), monomer b1-1 (21.4 g), monomer c-1 (6.3 g), V-601 (manufactured by Fujifilm and Koei Tecmo Chemicals Co., Ltd.) 2.0 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 resulting polymerization solution was added dropwise to 1500 g of vigorously stirred hexane, and the precipitated polymer was filtered. The obtained polymer was washed twice with 300 g of hexane and then vacuum dried at 50°C for 20 hours to obtain a white powder polymer P-1 (yield 47.5 g, 95% yield). The Mw ratio of polymer P-1 is 9200, and the Mw / Mn ratio is 1.63. Furthermore, the Mw ratio is the polystyrene equivalent value obtained by GPC using DMF as a solvent. [Chemistry 250]

[0490] [Examples 2-2~2-21, Comparative Examples 2-1~2-11] Synthesis of polymers P-2~P-21 and comparative polymers CP-1~CP-11 The polymers shown in Tables 1 and 2 were manufactured using the same method as in Example 2-1, except that the types and blending ratios of the monomers were changed.

[0491] [Table 1]

[0492] [Table 2]

[0493] [3] Preparation of chemical amplification inhibitor composition [Examples 3-1 to 3-21, Comparative Examples 3-1 to 3-11] A solution was prepared by dissolving the predetermined components selected from the basic polymers (P-1 to P-21), the comparative basic polymers (CP-1 to CP-11), the acid generators (PAG-1, PAG-2), and the quenchers (SQ-1 to SQ-3, AQ-1) of the present invention, as shown in Tables 3 and 4 below, in a solvent containing 0.01% by mass of 3M FC-4430 as a surfactant. The chemical amplification inhibitor components (R-1 to R-21, CR-1 to CR-11) were prepared by filtering the solution through a 0.2 μm Teflon (registered trademark) filter.

[0494] [Table 3]

[0495] [Table 4]

[0496] Tables 3 and 4 list the solvents, quenchers (SQ-1~SQ-3, AQ-1), and acid generators (PAG-1, PAG-2) as follows. Solvent: PGMEA (Propylene Glycol Monomethyl Ether Acetate) EL (ethyl lactate) DAA (diacetone alcohol)

[0497] Quenching agents: SQ-1~SQ-3, AQ-1 [Chemistry 251]

[0498] • Acid generating agents: PAG-1, PAG-2 [Chemistry 252]

[0499] [4] Evaluation of EUV lithography (1) [Examples 4-1 to 4-21, Comparative Examples 4-1 to 4-11] The chemical amplification resist compositions (R-1~R-21, CR-1~CR-11) shown in Tables 3 and 4 were spin-coated onto a Si substrate with a silicon spin-coating hard mask SHB-A940 (silicon content 43% by mass) manufactured by Shin-Etsu Chemical Industry Co., Ltd., which had 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 size of 18 nm and a pitch of 36 nm on the wafer was exposed using an EUV scanning exposure machine manufactured by ASML NXE3300 (NA 0.33, σ 0.9 / 0.6, dipole illumination) while changing the exposure amount and focal length (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 developed by immersion in a 2.38% TMAH aqueous solution for 30 seconds, rinsed with a washing material containing surfactant, and then rotated and dried to obtain a positive pattern.

[0500] The obtained LS patterns were observed using a Hitachi Advanced Semiconductor Spectrometer (SEM) (CG6300), and the sensitivity, EL, LWR, DOF, and collapse limit were evaluated according to the methods described below. The results are shown in Tables 5 and 6.

[0501] [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.

[0502] [EL Review] The exposure amount formed within ±10% (16.2~19.8nm) of the 18nm spacing in the aforementioned LS pattern is calculated using the following formula (unit: %). 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.

[0503] [LWR Evaluation] The dimensions of the LS pattern obtained by Eop irradiation are measured at 10 points along the long side of the line. The standard deviation (σ) is calculated as 3 times the value (3σ) and taken as the LWR. The smaller this value, the less roughness and the more uniform the line width of the pattern will be.

[0504] [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.

[0505] [Collapse Limit Assessment of Line Patterns] The line dimensions of the aforementioned LS pattern at various exposures at the optimal focal length were measured along the long side at 10 locations. The finest line dimension obtained without collapse was defined as the collapse limit dimension. The smaller this value, the better the collapse limit.

[0506] [Table 5]

[0507] [Table 6]

[0508] As shown in Tables 5 and 6, the chemical amplification inhibitor composition using a base polymer containing repeating units of the onium salt monomer from this invention exhibits good sensitivity and excellent EL, LWR, and DOF. Furthermore, a small collapse limit value was confirmed, indicating resistance to pattern collapse even during fine pattern formation. Therefore, the chemical amplification inhibitor composition of this invention demonstrates its ideal suitability as a material for EUV lithography. On the other hand, the comparative example not using the onium salt monomer of this invention showed poor sensitivity, EL, LWR, DOF, and pattern collapse performance.

[0509] [5] Evaluation of EUV lithography (2) [Examples 5-1 to 5-21, Comparative Examples 5-1 to 5-11] The chemically amplified resist compositions (R-1~R-21, CR-1~CR-11) 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 film was then exposed using an ASML EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, mask with a pitch of 46 nm on the wafer, and a +20% deviation hole pattern). A hole pattern with a size of 23 nm was formed by PEB for 60 seconds using a hot plate at the temperatures recorded in Tables 7 and 8, followed by development for 30 seconds with a 2.38% by mass TMAH aqueous solution.

[0510] Using a Hitachi Advanced Semiconductor Dimensioning SEM (CG6300), the exposure was measured when the hole size was 23 nm, and this was defined as the sensitivity. Furthermore, the dimensions of 50 holes at this size were measured, and the standard deviation (σ) calculated from these results was tripled (3σ), which was defined as the dimensional standard deviation (CDU). The results are shown in Tables 7 and 8.

[0511] [Table 7]

[0512] [Table 8]

[0513] The results shown in Tables 7 and 8 confirm that the chemical amplification inhibitor composition of the present invention exhibits good sensitivity and excellent CDU. On the other hand, the comparative examples that did not use the onium salt monomer of the present invention showed poor sensitivity and CDU.

[0514] [6] Evaluation of dry etching resistance [Examples 6-1 to 6-21, Comparative Examples 6-1 to 6-11] 2g of each of the polymers shown in Tables 1 and 2 (polymers P-1 to P-21, comparative polymers CP-1 to CP-11) were dissolved in 10g of cyclohexanone. The polymer solutions were then spin-coated onto a Si substrate through a 0.2μm filter to form a film with a thickness of 300nm. The film was evaluated under the following conditions.

[0515] 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 spacing CHF3 gas flow rate 30 mL / min CF4 gas flow rate 30 mL / min Ar gas flow rate 100 mL / min 60 seconds

[0516] The evaluation shows that films with smaller thickness differences, i.e. smaller reductions, have higher etching resistance.

[0517] The results of dry etching resistance are shown in Tables 9 and 10.

[0518] [Table 9]

[0519] [Table 10]

[0520] The results shown in Tables 9 and 10 confirm that the polymer of the present invention exhibits excellent dry etching resistance to CHF3 / CF4-based gases. On the other hand, comparative examples that did not use the onium salt monomer of the present invention all showed poor dry etching resistance.

[0521] This specification includes the following inventions.

[0522] [1]: A type of onium salt monomer, characterized by the following formula (a), [Chemistry 253] In the formula, n1 is 0 or 1, n2 is 1, 2, 3 or 4, n3 is 0, 1 or 2, but when n1 is 0, then 1 ≤ n2 + n3 ≤ 3, when n1 is 1, then 1 ≤ n2 + n3 ≤ 5, and n4 is an integer from 0 to 4. RA series: hydrogen atom, fluorine atom, methyl or trifluoromethyl, RAL series acid unstable groups R1 can be a halogen atom other than iodine, a nitro group, a cyano group, a hydroxyl group, an alkoxy group, a carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms (heteroatomic), an alkoxy group with 1 to 20 carbon atoms (heteroatomic), or a thioalkyl group with 1 to 20 carbon atoms (heteroatomic). When n3 is 2, 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. LA and LB are each independently a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond. XL series single bonds, or may also contain heteroatoms and carbon groups with 1 to 40 carbon atoms, Q1 and Q2 are each independently a hydrogen atom, a methyl group, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Q3 and Q4 are each independently either fluorine atoms or fluorinated saturated hydrocarbon groups having 1 to 6 carbon atoms. Z+ series onium cations.

[0523] [2]: The onium salt type monomers mentioned above [1] are represented by the following formula (a1), [Chemistry 254] In the formula, n1~n4, RA, RAL, R1, LA, Q1~Q4, and Z+ are the same as those mentioned above.

[0524] [3]: The onium salt type monomers mentioned in [1] or [2] above are represented by the following formula (a2), [Chemistry 255] In the formula, n1~n4, RA, RAL, R1, Q1~Q4, and Z+ are the same as those mentioned above.

[0525] [4]: As in any of [1] to [3] above, the structure of the acid unstable group represented by RAL is (AL-1) or (AL-2). [Chemistry 256] In the formula, n6 is either 0 or 1, and n7 is either 0 or 1. RL1, RL2, and RL3 are each independently a hydrocarbon group having 1 to 12 carbon atoms. One portion of the -CH2- group may be replaced by -O- or -S-. When the hydrocarbon group contains an aromatic ring, one or all of the hydrogen atoms in the aromatic ring may be replaced by a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 4 carbon atoms containing a halogen atom, or an alkoxy group having 1 to 4 carbon atoms containing a halogen atom. Furthermore, RL1 and RL2 may also bond to each other and form a ring together with the bonded carbon atoms. One portion of the -CH2- group in this ring may also be replaced by -O- or -S-. RL4 and RL5 are each independently a hydrogen atom or may contain a halogen atom and a hydrocarbon group with 1 to 10 carbon atoms. RL6 may also contain a halogen atom and a hydrocarbon group with 1 to 20 carbon atoms. One portion of the -CH2- group of this hydrocarbon group may be replaced by -O- or -S-. Furthermore, RL5 and RL6 may bond to each other and together with the bonded carbon atoms and LC to form a heterocyclic group with 3 to 20 carbon atoms. One portion of the -CH2- group of this heterocyclic group may also be replaced by -O- or -S-. LC series -O- or -S-, * indicates an atomic bond with an adjacent -O-.

[0526] [5]: As in any of [1] to [4] above, the onium salt type monomer, wherein the onium cation represented by Z+ is the strontium cation represented by formula (Z-1) or the monazine cation represented by formula (Z-2), [Chemistry 257] In the formula, Rct1 to Rct5 are each independently a halogen atom, or may contain a hydrocarbon group with 1 to 30 carbon atoms of heteroatoms. Furthermore, Rct1 and Rct2 may also be bonded to each other and form a ring together with the sulfur atoms of these bonds.

[0527] [6]: The onium salt type monomer of any one of [1] to [4] above, wherein the onium cation represented by Z+ is the strontium cation represented by the following formula (Z-3), [Chemistry 258] In the formula, m1 is 0 or 1, m2 is 0 or 1, m3 is 0 or 1, m4 is 0, 1, 2, 3 or 4, m5 is 0, 1, 2, 3 or 4, m6 is 0, 1, 2, 3, 4, 5 or 6, m7 is 0, 1, 2, 3, 4, 5 or 6, m8 is 0, 1 or 2, m9 is 0, 1 or 2, m10 is 0, 1 or 2, m11 is 0 or 1, m12 is 0, 1, 2, 3 or 4, m13 is 0, 1 or 2, m14 is 0, 1 or 2, only m1 When m1 is 0, then 0 ≤ m6 + m9 ≤ 4; when m1 is 1, then 0 ≤ m6 + m9 ≤ 6; when m2 is 0, then 0 ≤ m7 + m10 ≤ 4; when m2 is 1, then 0 ≤ m7 + m10 ≤ 6; when m3 is 0, then 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, then 1 ≤ m4 + m5 + m8 + m14 ≤ 6; when m11 is 0, then 0 ≤ m12 + m13 ≤ 4; when m11 is 1, then 0 ≤ m12 + m13 ≤ 6; and, m4 + m12 ≥ 1. RF1 to RF3 are each independently 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 m5 is 2 or more, each RF1 can be the same or different from the others. When m6 is 2 or more, each RF2 can be the same or different from the others. When m7 is 2 or more, each RF3 can be the same or different from the others. Rct6~Rct9 can be halogen atoms other than iodine and fluorine atoms, nitro, cyano, or hydrocarbon groups with 1~20 carbon atoms containing heteroatoms, or hydrocarbon oxy groups with 1~20 carbon atoms containing heteroatoms, or hydrocarbon thio groups with 1~20 carbon atoms containing heteroatoms. When m8 is 2, the two Rct6 groups can be the same or different, and the two Rct6 groups can also bond to each other and form a ring with the bonded carbon atoms. When m9 is 2, the two Rct7 groups can be the same or different, and the two Rct7 groups can also bond to each other and form a ring with the bonded carbon atoms. When m10 is 2, the two Rct8 groups can be the same or different, and the two Rct8 groups can also bond to each other and form a ring with the bonded carbon atoms. When m13 is 2, the two Rct9 groups can be the same or different, and the two Rct9 groups can also bond to each other and form a ring with the bonded carbon atoms. Furthermore, the aromatic rings of S+ directly bonded to the strontium cation can also bond to each other and form rings together with S+. LD and LE are each independently formed by single bonds, ether bonds, ester bonds, amide bonds, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. XL2 series single bonds, or may also contain heteroatoms with carbon numbers of 1 to 40 alkyl groups.

[0528] [7]: A monomeric photoacid generator, characterized by being composed of any one of the onium salt monomers described above [1] to [6].

[0529] [8]: A polymer characterized by comprising repeating units from any of the onium salt monomers described above [1] to [6].

[0530] [9]: The polymer described above [8] further comprises repeating units represented by formula (b1) or (b2), [Chemistry 259] 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. R11 series halogen atoms, cyano, hydroxyl, nitro, may also contain heteroatoms with 1-20 carbon atoms (hydrocarbonyl group), heteroatoms with 1-20 carbon atoms (hydroxyloxy group), heteroatoms with 2-20 carbon atoms (hydrocarbonyl group), heteroatoms with 2-20 carbon atoms (hydrocarbonyloxy group), or heteroatoms with 2-20 carbon atoms (hydroxyloxycarbonyl group). AL1 and AL2 are each independently acid-labile groups. a1 series 0, 1, 2, 3 or 4.

[0531]

[10] : Polymers such as those in [8] or [9] above further include repeating units represented by the following formula (b3), [Chemistry 260] 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. R12 and R13 are each independently hydrogen atoms, or may contain heteroatoms and be hydrocarbon groups with 1 to 20 carbon atoms. Furthermore, R12 and R13 may also bond to each other and form a ring together with the bonded carbon atoms. R14 can be a halogen atom, hydroxyl group, cyano 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 oxygen carbonyl group with 2-20 carbon atoms, or a hydrocarbon thio group or -N (R14A) (R14B). R14A and R14B are each independently a hydrogen atom or a hydrocarbon group with 1-6 carbon atoms. When b2 is 2 or more, multiple R14 groups can also bond to each other and form a ring together with the carbon atoms of the bonded aromatic ring. 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 an oxygen atom or a sulfur atom, but X4 and X6 are bonded to adjacent carbon atoms in an aromatic ring.

[0532]

[11] : The polymer of any one of [8] to

[10] above further comprises a repeating unit represented by the following formula (c), [Chemistry 261] In the formula, RA represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y1 series single bonds, *-C(=O)-O- or *-C(=O)-NH-, where * indicates an atomic bond with a carbon atom in the main chain. R21 series halogen atoms, nitro, cyano, carboxyl, may also include hydrocarbon groups with 1-20 carbon atoms, hydrocarbon oxygen groups with 1-20 carbon atoms, hydrocarbon carbonyl groups with 2-20 carbon atoms, hydrocarbon carbonyl oxygen groups with 2-20 carbon atoms, or hydrocarbon oxygen carbonyl groups with 2-20 carbon atoms. c1 is 1, 2, 3 or 4, c2 is 0, 1, 2 or 3, but 1≦c1+c2≦5.

[0533]

[12] : The polymer of any one of [8] to

[11] above further comprises a repeating unit represented by the following formula (d), [Chemistry 262] In the formula, RA represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z1 refers to single bonds, pendiphenyl, pendinaphthyl, *-C(=O)-O-Z11-, or *-C(=O)-NH-Z11-. The pendiphenyl or pendinaphthyl group may also be substituted with hydroxyl, nitro, cyano groups, saturated hydrocarbon groups with 1-10 carbon atoms containing fluorine atoms, or saturated hydrocarbon oxygen or halogen atoms containing fluorine atoms. * indicates an atomic bond with a carbon atom in the main chain. Z11 refers to saturated pendialkyl groups with 1-10 carbon atoms, pendiphenyl, or pendinaphthyl groups. These saturated pendialkyl groups may also contain hydroxyl, ether, ester, or lactone rings. R31 is a group consisting of a hydrogen atom or a group containing at least one of the following: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulcinolone ring, and carboxylic anhydride (-C(=O)-OC(=O)-).

[0534]

[13] : A chemical amplification inhibitor composition characterized by comprising (A) a base polymer comprising any one of the polymers described above [8] to

[12] .

[0535]

[14] : The chemical amplification inhibitor composition as described in

[13] above further includes one or more selected from (B) organic solvents, (C) quenchers, (D) acid generators, (E) surfactants and (F) anti-solution agents.

[0536]

[15] : A method for forming a pattern, characterized by comprising the following steps: A resist film is formed on a substrate using the chemical amplification resist composition as described in

[13] or

[14] above, the resist film is exposed to high-energy rays, and the exposed resist film is developed using a developer.

[0537]

[16] : The pattern forming method described in

[15] above, wherein the high-energy ray is an ArF excimer laser with a wavelength of 193 nm or a KrF excimer laser with a wavelength of 248 nm, an electron beam or extreme ultraviolet light with a wavelength of 3~15 nm.

[0538] Furthermore, the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and those having a substantially identical structure to the technical concept described in the claims of the present invention, and which will perform the same effect, are all covered by the technical scope of the present invention.

[0539] none

Claims

1. A onium salt type monomer, characterized by the following formula (a), wherein n1 is 0 or 1, n2 is 1, 2, 3 or 4, n3 is 0, 1 or 2, except that when n1 is 0, then 1 ≤ n2 + n3 ≤ 3, and when n1 is 1, then 1 ≤ n2 + n3 ≤ 5, n4 is an integer from 0 to 4, RA is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, RAL is an acid-unstable group, R1 is a halogen atom other than an iodine atom, a nitro group, a cyano group, a hydroxyl group, an alkoxy group, a carboxyl group, or may contain a hydrocarbon group with 1 to 20 carbon atoms of heteroatoms, or may contain a hydrocarbon thio group with 1 to 20 carbon atoms of heteroatoms, and when n3 is 2, each R1 may be the same or different from each other, and two R1s may also be bonded to each other and form a ring together with the bonded carbon atoms. LA and LB are each independently a single bond, ether bond, ester bond, or sulfonate bond; XL is a single bond, or may contain a heteroatom of a hydrocarbon group with 1 to 40 carbon atoms; Q1 and Q2 are each independently a hydrogen atom, methyl, fluorine atom, or a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms; Q3 and Q4 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms; Z+ is an onium cation, which is a strontium cation represented by the following formula (Z-1) or a monium cation represented by the following formula (Z-2); in the formula, Rct1 to Rct5 are each independently a halogen atom, or may contain a heteroatom of a hydrocarbon group with 1 to 30 carbon atoms; furthermore, Rct1 and Rct2 may also bond to each other and form a ring together with the sulfur atoms of these bonds.

2. If the onium salt type monomer of Request 1 is represented by the following formula (a1), in which n1~n4, RA, RAL, R1, LA, Q1~Q4, and Z+ are the same as in Request 1.

3. If the onium salt type monomer of claim 2 is represented by the following formula (a2), in which n1~n4, RA, RAL, R1, Q1~Q4, and Z+ are the same as in claim 2.

4. As in request item 1, the onium salt type monomer, wherein, The structure of the unstable acid group represented by RAL is as follows: (AL-1) or (AL-2), where n6 is 0 or 1, n7 is 0 or 1, RL1, RL2, and RL3 are each independently a hydrocarbon group with 1 to 12 carbon atoms. One portion of the -CH2- group of this hydrocarbon group can be substituted with -O- or -S-. When the hydrocarbon group contains an aromatic ring, one or all of the hydrogen atoms in the aromatic ring can be substituted with a halogen atom, a cyano group, a nitro group, an alkyl group with 1 to 4 carbon atoms containing a halogen atom, or an alkoxy group with 1 to 4 carbon atoms containing a halogen atom. Furthermore, RL1 and RL2 can also bond to each other and form a ring together with the bonded carbon atoms. One portion of the -CH2- group in this ring can also be substituted with -O- or -S-. RL4 and RL5 are each independently hydrogen atoms or may contain halogen atoms in hydrocarbon groups with 1 to 10 carbon atoms. RL6 may also contain halogen atoms in hydrocarbon groups with 1 to 20 carbon atoms. A portion of the -CH2- of this hydrocarbon group may be replaced by -O- or -S-. Furthermore, RL5 and RL6 may bond to each other and together with the bonded carbon atoms and LC to form heterocyclic groups with 3 to 20 carbon atoms. A portion of the -CH2- of this heterocyclic group may also be replaced by -O- or -S-. LC is -O- or -S-. * indicates an atomic bond with an adjacent -O-.

5. As in request item 1, the onium salt type monomer, wherein, The Z+ ion represents the strontium ion represented by the following formula (Z-3), where m1 is 0 or 1, m2 is 0 or 1, m3 is 0 or 1, m4 is 0, 1, 2, 3 or 4, m5 is 0, 1, 2, 3 or 4, m6 is 0, 1, 2, 3, 4, 5 or 6, m7 is 0, 1, 2, 3, 4, 5 or 6, m8 is 0, 1 or 2, m9 is 0, 1 or 2, m10 is 0, 1 or 2, m11 is 0 or 1, m12 is 0, 1, 2, 3 or 4, m13 is 0, 1 or 2, m14 is 0, 1 or 2, except that m1 When m1 is 0, then 0 ≤ m6 + m9 ≤ 4; when m1 is 1, then 0 ≤ m6 + m9 ≤ 6; when m2 is 0, then 0 ≤ m7 + m10 ≤ 4; when m2 is 1, then 0 ≤ m7 + m10 ≤ 6; when m3 is 0, then 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, then 1 ≤ m4 + m5 + m8 + m14 ≤ 6; when m11 is 0, then 0 ≤ m12 + m13 ≤ 4; when m11 is 1, then 0 ≤ m12 + m13 ≤ 6; and also, m4 + m12 ≥ 1. RF1 to RF3 are each independently 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 m5 is 2 or more, each RF1 can be the same or different from the others. When m6 is 2 or more, each RF2 can be the same or different from the others. When m7 is 2 or more, each RF3 can be the same or different from the others. Rct6~Rct9 can be halogen atoms other than iodine and fluorine atoms, nitro, cyano, or hydrocarbon groups with 1~20 carbon atoms containing heteroatoms, or hydrocarbon oxy groups with 1~20 carbon atoms containing heteroatoms, or hydrocarbon thio groups with 1~20 carbon atoms containing heteroatoms. When m8 is 2, the two Rct6 groups can be the same or different, and the two Rct6 groups can also bond to each other and form a ring with the bonded carbon atoms. When m9 is 2, the two Rct7 groups can be the same or different, and the two Rct7 groups can also bond to each other and form a ring with the bonded carbon atoms. When m10 is 2, the two Rct8 groups can be the same or different, and the two Rct8 groups can also bond to each other and form a ring with the bonded carbon atoms. When m13 is 2, the two Rct9 groups can be the same or different, and the two Rct9 groups can also bond to each other and form a ring with the bonded carbon atoms. Furthermore, the aromatic rings of S+ directly bonded to the strontium cation can also bond to each other and form a ring together with S+. LD and LE are each independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond or carbamate bond. XL2 is a single bond, or may also contain a hydrocarbon group with 1 to 40 carbon atoms of heteroatoms.

6. A monomeric photoacid generator, characterized in that it is composed of an onium salt type monomer as claimed in any one of claims 1 to 5.

7. A polymer characterized by comprising repeating units from any one of claims 1 to 5 of a monium salt monomer.

8. The polymer of claim 7 further comprises repeating units represented by formula (b1) or (b2), wherein RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; 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 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-, where * represents an atomic bond with a carbon atom of the main chain. R11 can be a halogen atom, cyano, hydroxyl, nitro, or may contain a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms, a hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms, or a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms. AL1 and AL2 are each independently acid-labile groups, and a1 can be 0, 1, 2, 3, or 4.

9. The polymer of claim 7 further comprises repeating units represented by the following formula (b3), wherein b1 is 0 or 1, b2 is 0, 1, 2 or 3 when b1 is 0, and 0, 1, 2, 3, 4 or 5 when b1 is 1, RA is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, X3 is a single bond, *-C(=O)-O- or *-C(=O)-NH-, * represents an atomic bond with a carbon atom of the main chain, R12 and R13 are each independently hydrogen atoms, or may also contain hydrocarbon groups with 1 to 20 carbon atoms of heteroatoms, and R12 and R13 may also be bonded to each other and form a ring together with the bonded carbon atoms. R14 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 oxy 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(R14A)(R14B). R14A and R14B are each independently a hydrogen atom or a hydrocarbon group with 1 to 6 carbon atoms. When b2 is 2 or more, multiple R14s can also bond to each other and form a ring together with the carbon atoms of the aromatic rings that are bonded. X4 is a single bond, an aliphatic hydrocarbon group with 1 to 4 carbon atoms, a carbonyl group, a sulfonyl group, or a group obtained by combining these. X5 and X6 are each independently an oxygen atom or a sulfur atom. However, X4 and X6 are bonded to adjacent carbon atoms of the aromatic ring.

10. The polymer of claim 7 further comprises repeating units represented by the following formula (c), wherein RA is a hydrogen atom, a fluorine atom, a methyl or trifluoromethyl group, Y1 is a single bond, *-C(=O)-O- or *-C(=O)-NH-, * represents an atomic bond with a carbon atom of the main chain, R21 is a halogen atom, a nitro group, a cyano group, a carboxyl group, or may include a hydrocarbon group with 1 to 20 carbon atoms of a heteroatom, or may include a hydrocarbon oxygen group with 1 to 20 carbon atoms of a heteroatom, or may include a hydrocarbon carbonyl group with 2 to 20 carbon atoms of a heteroatom, or may include a hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms of a heteroatom, or may include a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms of a heteroatom, c1 is 1, 2, 3 or 4, c2 is 0, 1, 2 or 3, but 1 ≤ c1 + c2 ≤ 5.

11. The polymer of claim 7 further comprises repeating units represented by the following formula (d), wherein RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; Z1 is a single bond, a phenyl group, a naphthyl group, *-C(=O)-O-Z11-, or *-C(=O)-NH-Z11-, and the phenyl or naphthyl group may also be substituted by a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, a saturated hydrocarbon oxygen group containing fluorine atoms with 1 to 10 carbon atoms, or a halogen atom; * represents an atomic bond with a carbon atom of the main chain; and Z11 is a saturated hydrocarbon group with 1 to 10 carbon atoms, a phenyl group, or a naphthyl group, and the saturated hydrocarbon group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. R31 is a group consisting of a hydrogen atom or a group containing at least one of the following: hydroxyl group (other than phenolic hydroxyl group), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulcinolone ring, and carboxylic anhydride (-C(=O)-OC(=O)-).

12. A chemical amplification inhibitor composition characterized by comprising (A) a base polymer comprising the polymer as claimed in claim 7.

13. The chemical amplification inhibitor composition of claim 12 further includes one or more selected from (B) organic solvents, (C) quenchers, (D) acid generators, (E) surfactants, and (F) anti-solution agents.

14. A pattern forming method, characterized by comprising the following steps: forming a resist film on a substrate using a chemical amplifying resist composition as claimed in claim 12, exposing the resist film to high-energy radiation, and developing the exposed resist film using a developing solution.

15. The pattern forming method as described in claim 14, wherein, The high-energy rays are ArF excimer laser light with a wavelength of 193nm or KrF excimer laser light with a wavelength of 248nm, electron beams, or extreme ultraviolet light with a wavelength of 3~15nm.