Onium salt monomer, monomeric photoacid generator, polymer, chemically amplified resist composition, and pattern forming method

Abstract

The present invention relates to onium salt monomers, monomeric photoacid generators, polymers, chemically amplified resist compositions, and pattern forming methods. The present invention is an onium salt monomer characterized by being represented by the following general formula (A). By this, an onium salt monomer used in a chemically amplified resist composition having excellent lithography properties in optical lithography using a high-energy ray is provided.[Chemical Formula 1][In the formula, m4 is an integer of 1 to 4. R A is a hydrogen atom or a methyl group. R 1 is any one of a hydrogen atom, a hydrocarbon group, and an electron-withdrawing group such as a cyano group. L A , L B , and L C are a single bond, a carbonyl group, an ether bond, an ester bond, an amide bond, a sulfonate bond, a sulfonamide bond, a carbonate bond, a carbamate bond, or a hydrocarbylene group. W is a single bond or a hydrocarbylene group. X L1 is a single bond or a hydrocarbylene group. Z + is an onium cation].

Description

Technical Field

[0001] This invention relates to onium salt monomers, monomeric photoacid generators, polymers, chemically amplified resist compositions, and methods for pattern formation. Background Technology

[0002] With the increasing integration and speed of LSI (Light Detection and Ranging) technology, the miniaturization of patterned surfaces is progressing rapidly. In particular, the expansion of the flash memory market and the increase in memory capacity are driving this miniaturization. Regarding cutting-edge miniaturization technologies, mass production of 65nm node devices using ArF lithography is underway, and preparations are underway for mass production of the next generation of 45nm node devices using ArF immersion lithography. For the next generation of 32nm node devices, there are ongoing discussions on immersion lithography using ultra-high nanometer (NA) lenses, combining liquids with higher refractive indices than water with high-refractive-index lenses and high-refractive-index resist films, extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm, and double exposure (double patterning lithography) using ArF lithography.

[0003] With the miniaturization of patterns, the linewidth roughness (LWR) of line patterns and the dimensional uniformity (CDU) of hole patterns or lattice patterns are considered problems. The effects of uneven distribution and aggregation of the base polymer or acid generator, or the influence of acid diffusion, are cited. Furthermore, with the thinning of resist films, there is a tendency for LWR or CDU to increase; the deterioration of LWR and CDU due to the progress in miniaturization has become a serious problem.

[0004] In EUV lithography resist compositions, it is necessary to simultaneously achieve high sensitivity, high resolution, and low light-to-weight ratio (LWR). If the acid diffusion distance is shortened, the LWR decreases, resulting in lower sensitivity. For example, lowering the post-exposure baking (PEB) temperature reduces LWR but lowers sensitivity. Even increasing the amount of quencher reduces LWR but lowers sensitivity. It is necessary to break the trade-off between sensitivity and LWR.

[0005] To suppress acid diffusion, a resist compound containing repeating units from onium salts of sulfonic acids with polymerizable unsaturated bonds has been proposed (Patent Document 1). Such a polymer-bonded acid generator is characterized by the generation of polymeric sulfonic acid upon exposure, resulting in a very short acid diffusion distance. Furthermore, sensitivity can be improved by increasing the ratio of the acid generator. Additive acid generators also increase sensitivity with increased dosage, but in this case, the acid diffusion distance also increases. Since the acid diffuses unevenly, increased acid diffusion degrades the light-to-weight ratio (LWR) or chromatic diffusivity (CDU). In terms of the balance between sensitivity, LWR, and CDU, polymeric acid generators can be considered to have high performance.

[0006] Iodine atoms exhibit very high absorption at a wavelength of 13.5 nm in EUV, thus demonstrating the ability to generate secondary electrons from iodine atoms during exposure, making it a promising candidate for EUV lithography. Patent Document 2 describes a photoacid generator in which iodine atoms are introduced into anions, while Patent Document 3 describes a photoacid generator containing polymerizable groups in which iodine atoms are introduced into anions.

[0007] There have been concerns about the health effects of perfluoroalkyl compounds (PFAS), and the European REACH has imposed restrictions on the manufacture and sale of PFAS compounds. In semiconductor lithography, compounds containing large amounts of PFAS are currently being used. For example, materials containing these are used in surfactants and acid generators. The photoacid generators described in Patent Documents 1, 2, and 3 are all based on fluoroalkyl sulfonic acid units, which have been criticized for having significant health and environmental impacts. Furthermore, recently, not only are these represented non-PFAS materials desired, but also non-F materials that do not contain fluorine atoms.

[0008] Patent documents 4, 5, and 6 describe alkane sulfonic acid type photoacid generators with electron-withdrawing groups as substituents as alternatives to PFAS. Furthermore, patent document 6 describes an attempt to improve acid strength by using carboxylic acids as electron-withdrawing groups. These are suitable as non-F materials, but on the other hand, for practical use as photoresist materials, their high acid diffusion is considered desirable, and further improvements are expected.

[0009] Patent documents 7-11 describe various onium salts that can be used as photoacid generators, and compositions containing onium salts. However, it is desirable to develop novel photoacid generators that exhibit excellent solvent solubility, high sensitivity, and high acid diffusion inhibition performance in chemically amplified resist compositions that use acid as a catalyst, thereby achieving the development of chemically amplified resist compositions that exhibit superior photolithography performance.

[0010] Existing technical documents

[0011] Patent documents

[0012] [Patent Document 1] Japanese Patent Application Publication No. 2006-178317

[0013] [Patent Document 2] Japanese Patent Application Publication No. 2018-5224

[0014] [Patent Document 3] Japanese Patent Application Publication No. 2018-197853

[0015] [Patent Document 4] International Publication No. 2024 / 143131

[0016] [Patent Document 5] International Publication No. 2024 / 241766

[0017] [Patent Document 6] Japanese Patent Application Publication No. 2025-079775

[0018] [Patent Document 7] International Publication No. 2024 / 185543

[0019] [Patent Document 8] International Publication No. 2018 / 168252

[0020] [Patent Document 9] Japanese Patent Application Publication No. 2018-049177

[0021] [Patent Document 10] Japanese Patent Application Publication No. 2015-4967

[0022] [Patent Document 11] International Publication No. 2024 / 225059 Summary of the Invention

[0023] [The problem that the invention aims to solve]

[0024] In the development of chemically amplified resist compositions that use acid as a catalyst, it is desirable to develop resist compositions with high sensitivity and the ability to improve lithographic performance such as LWR, CDU, exposure margin (EL), and depth of focus (DOF), as well as excellent etch resistance after patterning.

[0025] The present invention was made in view of the above circumstances, and its purpose is to provide a chemical amplified resist composition that has excellent solvent solubility, high sensitivity, and excellent lithographic performance such as LWR, EL, and DOF in optical lithography using high-energy rays, including an onium salt monomer, a polymer containing repeating units from the onium salt monomer, a chemical amplified resist composition containing the polymer, and a pattern forming method using the chemical amplified resist composition.

[0026] [Methods for solving the problem]

[0027] To address the aforementioned issues, the present invention provides an onium salt monomer represented by the following general formula (A).

[0028] [Chemistry 1]

[0029]

[0030] [In the formula, m4 is an integer from 1 to 4; R] A It is a hydrogen atom or a methyl group;

[0031] R 1Each group is independently a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms (which may also contain heteroatoms), or an electron-withdrawing group, wherein the electron-withdrawing group is a halogen atom excluding fluorine, a cyano group, a nitro group, or any of the following groups having 1 to 20 carbon atoms: a hydrocarbon oxy group, a hydrocarbon thio group, a hydrocarbon carbonyl group, a hydrocarbon oxycarbonyl group, a hydrocarbon carbonyl oxy group, or a hydrocarbon sulfonyl group. 1 At least one of them is the electron-withdrawing group;

[0032] L A L B and L C Each of the following is independently a single bond, carbonyl group, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, carbamate bond, or may contain a carbonyl group, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond with 1 to 10 carbon atoms.

[0033] W is a single bond or a hydrocarbon group with 1 to 40 carbon atoms that may contain heteroatoms. The hydrocarbon group may also have at least one of oxygen, nitrogen, sulfur and halogen atoms.

[0034] X L1 It is a single bond, or may contain heteroatoms and be a hydrocarbon group with 1 to 40 carbon atoms;

[0035] Z + It is a sulfonium cation represented by the following general formula (Z-1) or a monazine cation represented by the following general formula (Z-2);

[0036] [Chemistry 2]

[0037]

[0038] (where R is in the formula) ct1 ~R ct5 Each is an independent hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms; in addition, R ct1 and R ct2 They can also bond with each other and form rings together with the sulfur atoms they are bonded to.

[0039] If this is the case, then it becomes a chemical amplification resist composition used in optical lithography, especially in the use of high-energy rays such as KrF excimer lasers, ArF excimer lasers, electron beams (EB), EUV, etc., with excellent solvent solubility, high sensitivity, and high contrast. At the same time, it has excellent lithography performance in LWR, CDU, EL, DOF, etc., and even in the formation of fine patterns, it has strong resistance to pattern collapse.

[0040] Furthermore, the onium salt monomer of the present invention is preferably represented by any of the following general formulas (A1) to (A3).

[0041] [Chemistry 3]

[0042]

[0043] (In the formula, m1 is an integer of 0 or 1; m2 is an integer of 1, 2 or 3 when m1 is 0, and an integer of 1, 2, 3, 4 or 5 when m1 is 1; m3 is an integer of 0, 1, 2, 3 or 4 when m1 is 0, and an integer of 0, 1, 2, 3, 4, 5 or 6 when m1 is 1; however, when m1 is 0, 1≤m2+m3≤4, and when m1 is 1, 1≤m2+m3≤6;)

[0044] R 3 It can be a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms; when m3 is 2 or more, each R 3 They can be the same or different, the complex R 3 They can also bond with each other and form rings together with the carbon atoms they bond with;

[0045] m4, R A R 1 X L1 L A L B L C and Z + Same as above.

[0046] In this way, the effects of the present invention can be more fully realized.

[0047] Furthermore, the onium salt monomer of the present invention is preferably a sulfonic acid with the α-position substituted by a cyano or nitro group.

[0048] Such conditions, especially those with high acid strength, result in high sensitivity.

[0049] Furthermore, the present invention provides a monomeric photoacid generator composed of the above-mentioned onium salt monomers.

[0050] The onium salt monomer of the present invention is suitable for use as a monomeric photoacid generator.

[0051] Furthermore, the present invention provides a polymer containing repeating units from the aforementioned monomeric photoacid generator.

[0052] The polymer of this invention functions as both a photoacid generator and a base polymer in chemically amplified resist compositions, thus being a polymer-bonded photoacid generator. The polymer of this invention is suitable for use in chemically amplified resist compositions that exhibit excellent solvent solubility, high sensitivity, high contrast, excellent lithography performance in LWR, CDU, EL, DOF, etc., and strong resistance to pattern collapse even during fine pattern formation.

[0053] In addition, the polymers described above may also contain repeating units represented by formula (b1) or (b2).

[0054] [Chemistry 4]

[0055]

[0056] (where R is in the formula) A Each can be independently a hydrogen atom or a methyl group;

[0057] Y 1 It is a single bond, a phenylene or naphthylene group, or a linking group having 1 to 12 carbon atoms selected from ester bonds, ether bonds, and lactone rings. The phenylene, naphthylene group, and the linking group may also have at least one of the following: hydroxyl group, halogen atom, saturated hydrocarbon oxygen group having 1 to 8 carbon atoms, and saturated hydrocarbon carbonyl oxygen group having 2 to 8 carbon atoms.

[0058] Y 2 It is a single bond or an ester bond;

[0059] Y 3 It is a single bond, an ether bond, or an ester bond;

[0060] R 11 and R 12 Each is an independent acid-labile group;

[0061] R 13 It is a saturated hydrocarbon group with 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group with 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group with 2 to 5 carbon atoms;

[0062] R 14 It is a single bond or an alkane diene with 1 to 6 carbon atoms, and the alkane diene may also contain at least one selected from hydroxyl, saturated hydrocarbon oxygen with 1 to 8 carbon atoms, saturated hydrocarbon carbonyl oxygen with 2 to 8 carbon atoms, ether bond and ester bond;

[0063] (a is an integer between 0 and 4.)

[0064] In this way, the effects of the present invention can be more fully realized.

[0065] Furthermore, the present invention provides chemically amplified resist compositions containing the aforementioned polymer as a base polymer.

[0066] If such a composition is found, it becomes a chemically amplified resist composition that exhibits excellent solvent solubility, high sensitivity, and high contrast, especially in optical lithography using high-energy rays such as KrF excimer lasers, ArF excimer lasers, electron beams (EB), and EUV. It also provides excellent lithography performance in LWR, CDU, EL, and DOF, and is highly resistant to pattern collapse even during the formation of fine patterns.

[0067] The chemically amplified resist composition of the present invention may also contain at least one selected from organic solvents, quenchers, acid generators, surfactants, and dissolution inhibitors.

[0068] In addition to the aforementioned base polymer, the chemically amplified resist composition of the present invention may also contain such components as required.

[0069] Furthermore, the present invention provides a pattern forming method, comprising: a step of forming a resist film on a substrate using the above-described chemically amplified resist composition; a step of exposing the resist film to high-energy radiation; and a step of developing the exposed resist film using a developing solution.

[0070] By using the chemically amplified resist composition of the present invention, a pattern formation method can be developed that provides high sensitivity, high contrast, and strong resistance to pattern collapse, especially in optical lithography using high-energy rays such as KrF excimer lasers, ArF excimer lasers, electron beams (EB), and EUV, while also achieving high lithography performance in LWR, CDU, EL, and DOF processes, even in the formation of fine patterns.

[0071] In addition, it is preferable to use ArF excimer laser with a wavelength of 193nm or KrF excimer laser with a wavelength of 248nm, electron beam or extreme ultraviolet light with a wavelength of 3~15nm.

[0072] The pattern forming method of the present invention is particularly suitable for use with such high-energy rays.

[0073] [The effects of the invention]

[0074] Polymers containing repeating units of acid generated by exposure from onium salt monomers of the present invention are materials with high sensitivity to sulfonic acid anions with electron-withdrawing groups substituted and low environmental impact due to the characteristics of polymer-bonded photoacid generators, which can suppress acid diffusion and improve the photolithography performance of LWR, CDU, EL, DOF, etc. Detailed Implementation

[0075] As mentioned above, there is a search for onium salt monomers, polymers containing repeating units from the onium salt monomers, chemically amplified resist compositions containing the polymers, and patterning methods using the chemically amplified resist compositions that offer excellent solvent solubility, high sensitivity, high contrast, and excellent lithographic performance, particularly in optical lithography using high-energy rays such as KrF excimer lasers, ArF excimer lasers, electron beams (EB), and EUV.

[0076] As a result of repeated and in-depth research in order to achieve the above-mentioned objectives, the inventors of this application discovered that by using a polymer containing repeating units as a polymer-bonded photoresist generator, wherein the repeating units are derived from onium salt monomers composed of sulfonic acids having polymerizable groups and aromatic rings and being replaced by electron-withdrawing groups that do not contain fluorine atoms, a chemically amplified resist composition with improved photolithography performance such as LWR, CDU, EL, and DOF can be obtained, thus completing the present invention.

[0077] That is, the present invention is an onium salt monomer represented by the following general formula (A).

[0078] [Chemistry 5]

[0079]

[0080] [In the formula, m4 is an integer from 1 to 4; R] A It is a hydrogen atom or a methyl group;

[0081] R 1 Each group is independently a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms (which may also contain heteroatoms), or an electron-withdrawing group, wherein the electron-withdrawing group is a halogen atom excluding fluorine, a cyano group, a nitro group, or any of the following groups having 1 to 20 carbon atoms: a hydrocarbon oxy group, a hydrocarbon thio group, a hydrocarbon carbonyl group, a hydrocarbon oxycarbonyl group, a hydrocarbon carbonyl oxy group, or a hydrocarbon sulfonyl group. 1 At least one of them is the electron-withdrawing group;

[0082] L A L B and L C Each of the following is independently a single bond, carbonyl group, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, carbamate bond, or may contain a carbonyl group, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond with 1 to 10 carbon atoms.

[0083] W is a single bond or a hydrocarbon group with 1 to 40 carbon atoms that may contain heteroatoms. The hydrocarbon group may also have at least one of oxygen, nitrogen, sulfur and halogen atoms.

[0084] X L1 It is a single bond, or may contain heteroatoms and be a hydrocarbon group with 1 to 40 carbon atoms;

[0085] Z + It is a sulfonium cation represented by the following general formula (Z-1) or a monazine cation represented by the following general formula (Z-2);

[0086] [Chemistry 6]

[0087]

[0088] (where R is in the formula) ct1 ~R ct5 Each is an independent hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms; in addition, R ct1 and R ct2 They can also bond with each other and form rings together with the sulfur atoms they are bonded to.

[0089] The present invention will now be described in detail, but the present invention is not limited thereto.

[0090] [Onium salt monomer]

[0091] The onium salt monomer of the present invention is represented by the following general formula (A).

[0092] [Chemistry 7]

[0093]

[0094] [In the formula, m4 is an integer from 1 to 4; R] A It is a hydrogen atom or a methyl group;

[0095] R 1 Each group is independently a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms (which may also contain heteroatoms), or an electron-withdrawing group, wherein the electron-withdrawing group is a halogen atom excluding fluorine, a cyano group, a nitro group, or any of the following groups having 1 to 20 carbon atoms: a hydrocarbon oxy group, a hydrocarbon thio group, a hydrocarbon carbonyl group, a hydrocarbon oxycarbonyl group, a hydrocarbon carbonyl oxy group, or a hydrocarbon sulfonyl group. 1 At least one of them is the electron-withdrawing group;

[0096] L A L B and L C Each of the following is independently a single bond, carbonyl group, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, carbamate bond, or may contain a carbonyl group, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond with 1 to 10 carbon atoms.

[0097] W is a single bond or a hydrocarbon group with 1 to 40 carbon atoms that may contain heteroatoms. The hydrocarbon group may also have at least one of oxygen, nitrogen, sulfur and halogen atoms.

[0098] X L1 It is a single bond, or may contain heteroatoms and be a hydrocarbon group with 1 to 40 carbon atoms;

[0099] Z + It is a sulfonium cation represented by the following general formula (Z-1) or a monazine cation represented by the following general formula (Z-2);

[0100] [Chemistry 8]

[0101]

[0102] (where R is in the formula) ct1 ~R ct5 Each is an independent hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms; in addition, R ct1 and R ct2 They can also bond with each other and form rings together with the sulfur atoms they are bonded to.

[0103] <Anion section>

[0104] As indicated by general formula (A), the onium salt monomer of the present invention has a sulfonate ion (SO3) in the anionic portion. - The sulfonic acid ion is substituted by at least one electron-withdrawing group and has a polymerizable double bond. The anionic portion will be explained in detail below.

[0105] In general formula (A), m4 is an integer from 1 to 4. m4 is preferably 1 to 2, and more preferably 1. In this case, the mobility of the sulfonic acid anion is reduced, which can inhibit acid diffusion.

[0106] In general formula (A), R 1 Each of the following is independently a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms (which may also contain heteroatoms), or an electron-withdrawing group, wherein the electron-withdrawing group is a halogen atom excluding fluorine, a cyano group, a nitro group, or any of the following hydrocarbon groups having 1 to 20 carbon atoms (which may also contain heteroatoms): a hydrocarbon oxy group, a hydrocarbon thio group, a hydrocarbon carbonyl group, a hydrocarbon oxycarbonyl group, a hydrocarbon carbonyl oxy group, or a hydrocarbon sulfonyl group. 1 At least one of them is the aforementioned electron-withdrawing group. By replacing the vicinity of the sulfonic acid anion with an electron-withdrawing group other than a fluorine atom, the photoacid generator can reduce the fluorine atom content in the resist component while maintaining the acid strength of the photoacid generator, thereby reducing the environmental impact.

[0107] For electron-withdrawing groups, the m-position substituent constant σ in the Hammett equation described in Chem. Rev. 1991, 91, 165-169 is preferable. m For groups larger than 0, it is preferable to have a value larger than 0.35, and further preferably nitro, cyano, hydrocarbon carbonyl (especially acetyl), hydrocarbon oxy carbonyl, and hydrocarbon carbonyl oxy, with cyano being the most desirable. Electron-withdrawing groups, by bonding near the sulfonic acid anion, can increase the acid strength of the sulfonic acid through an inductive effect. On the other hand, as the aforementioned electron-withdrawing groups, it is preferable to have groups that do not contain amino, mercapto, carboxylic acid, sulfonic acid, or aldehyde groups, and especially preferably, these groups that serve as hydrogen bond preforms do not substitute the α-position of the sulfonic acid. Because they exist near the sulfonic acid, the nucleophilicity of the hydrogen bond preform, which is robbed of a hydrogen atom by the sulfonic acid anion due to intramolecular hydrogen bonding, increases, and the sensitivity decreases. The Hammett substituent constants σ for each group in this specification are as follows: m The values ​​used are those described in Chem. Rev. 1991, 91, 165-169. For those not described, the pKa of benzoic acid was calculated using the software ACD / ChemSketch (ACD / Labs 8.00 Release Product Version: 8.08), and the difference between the pKa of benzoic acid and the pKa of benzoic acid derivatives with a substituent at the m-position was used to obtain σ. m value.

[0108] In particular, it is preferable to substitute the α- or β-position of the sulfonic acid anion with an electron-withdrawing group, and even more preferable to substitute the α-position. In this case, the acid strength is the highest, indicating high sensitivity. In particular, it is preferable to substitute the α-position of the sulfonic acid with a cyano or nitro group.

[0109] As for the substitution positions of the electron-withdrawing groups, more specifically, examples include (1) having only one electron-withdrawing group at the α-position of the sulfonic acid anion and no electron-withdrawing group at the β-position; (2) having two electron-withdrawing groups at the α-position of the sulfonic acid anion and no electron-withdrawing group at the β-position; (3) having only one electron-withdrawing group at the β-position of the sulfonic acid anion and no electron-withdrawing group at the α-position; and (4) having only one electron-withdrawing group at the α-position of the sulfonic acid anion and only one electron-withdrawing group at the β-position, etc. Furthermore, in cases where there are two or more electron-withdrawing groups, the electron-withdrawing groups may be the same or different.

[0110] The hydrocarbon groups mentioned above, as well as the hydrocarbon groups of hydrocarbon oxy, hydrocarbon thio, hydrocarbon carbonyl, hydrocarbon oxy carbonyl, hydrocarbon carbonyl oxy, and hydrocarbon sulfonyl groups, can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; cyclosyl saturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclounsaturated hydrocarbon 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, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned hydrocarbon group can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0111] Examples of halogen atoms that exclude fluorine atoms include chlorine, bromine, and iodine atoms.

[0112] In general formula (A), R A It is a hydrogen atom or a methyl group.

[0113] L A L B and L C Each of these groups is independently a single bond, carbonyl group, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, carbamate bond, or may contain a carbonyl group, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond, and has 1 to 10 carbon atoms as an L group. A The bond should ideally be a single bond or an ester bond, with a single bond being more preferable. In this case, sulfonic acid has low degrees of freedom, which can further inhibit acid diffusion. As an L... B It is best to form ester bonds or sulfonate bonds. As L... C It is best to use an ester bond ( -OC(=O)- ,or -C(=O)-O- ), ether bonds, are more suitable for -OC(=O)- Representer ( and Each is with X L1 SO 3- (Atomic bonds on the side). In this case, the acid strength of the sulfonic acid anion is higher, thus increasing sensitivity.

[0114] In general formula (A), W and X L1 It is a "single bond, or may contain a heteroatom, of 1 to 40 carbon atoms, and is a hydrocarbon group". However, it is preferable to use W and X. L1 At least one of them contains an aromatic ring, preferably W is an aromatic ring, and L is an aromatic ring. A It is a single bond. In this case, the rigidity of the onium salt monomer is further increased, improving LWR and CDU. Specific examples include alkane diols, cyclic saturated alkylene groups, and arylene groups. As heteroatoms mentioned above, examples include oxygen atoms, nitrogen atoms, and sulfur atoms.

[0115] As W and X L1 Specific examples of hydrocarbon groups with 1 to 40 carbon atoms that may also contain heteroatoms can be listed below, but are not limited to these. Furthermore, in the following formula, Each is different from L A and L B L B and L C Atomic bonds.

[0116] [Chemistry 9]

[0117]

[0118] [Chemistry 10]

[0119]

[0120] [Chemistry 11]

[0121]

[0122] [Chemistry 12]

[0123]

[0124] [Chemistry 13]

[0125]

[0126] Of these, X is the most suitable. L -0~X L -22, X L -29~XL -34, and X L -47~X L -63, W or X would be more appropriate. L1 At least one of the aromatic rings in the photoresist is an iodine-substituted aromatic ring, preferably W. In this case, the sensitivity is good due to the high EUV absorption of the iodine-substituted aromatic ring. The number of iodine atoms substituting the aromatic ring is preferably 1 to 2, more preferably 2. Although the higher the number of iodine atoms, the higher the EUV absorption and the higher the sensitivity, on the other hand, sometimes the solubility of the photoresist solvent decreases. Therefore, in cases where the photoresist does not contain units such as triiodobenzene or tetraiodobenzene, higher solubility in the photoresist solvent is preferable.

[0127] The onium salt monomer represented by the general formula (A) of the present invention is preferably represented by any of the following general formulas (A1) to (A3).

[0128] [Chemistry 14]

[0129]

[0130] (In the formula, m1 is an integer of 0 or 1. m2 is an integer of 1, 2 or 3 when m1 is 0, and an integer of 1, 2, 3, 4 or 5 when m1 is 1. m3 is an integer of 0, 1, 2, 3 or 4 when m1 is 0, and an integer of 0, 1, 2, 3, 4, 5 or 6 when m1 is 1. However, when m1 is 0, 1 ≤ m2 + m3 ≤ 4, and when m1 is 1, 1 ≤ m2 + m3 ≤ 6.)

[0131] R 3 It can be a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms that may contain heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms that may contain heteroatoms. When m3 is 2 or more, each R 3 They can be the same or different, the complex R 3 They can also bond with each other and form rings together with the carbon atoms they bond with.

[0132] m4, R A R 1 X L1 L A L B L C and Z + Same as above.

[0133] Specific examples of onium salt anions represented by general formula (A) are shown below, but are not limited to these. In addition, the bonding positions of various substituents on the aromatic ring can also be interchanged.

[0134] [Chemistry 15]

[0135]

[0136] [Chemistry 16]

[0137]

[0138] [Chemistry 17]

[0139]

[0140] [Chemistry 18]

[0141]

[0142] [Chemistry 19]

[0143]

[0144] [Chemistry 20]

[0145]

[0146] [Chemistry 21]

[0147]

[0148] [Chemistry 22]

[0149]

[0150] [Chemistry 23]

[0151]

[0152] [Chemistry 24]

[0153]

[0154] [Chemistry 25]

[0155]

[0156] <Cation portion>

[0157] In general formula (A), Z + It is a sulfonium cation represented by the following general formula (Z-1) or a monazine cation represented by the following general formula (Z-2).

[0158] [Chemistry 26]

[0159]

[0160] In general formulas (Z-1) and (Z-2), R ct1 ~R ct5Each is an independent hydrocarbon group consisting of halogen atoms or may contain heteroatoms, and has 1 to 30 carbon atoms.

[0161] As R ct1 ~R ct5 Specific examples of halogen atoms can be listed, such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0162] R ct1 ~R ct5 The hydrocarbon group represented can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 30 carbon atoms such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclohexenyl; aryl groups with 6 to 30 carbon atoms such as phenyl, naphthyl, and thiophene; and aralkyl groups with 7 to 30 carbon atoms such as benzyl, 1-phenylethyl, and 2-phenylethyl. Groups obtained by combining these groups are preferably aryl. Furthermore, some 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. A portion of the -CH2- group in the aforementioned hydrocarbon group can also be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), or haloalkyl groups, etc.

[0163] In addition, R ct1 and R ct2 They can also bond with each other to form rings together with the sulfur atoms they bond with. In this case, specific examples of the above-mentioned ring structures can be listed, such as those represented by the following formulas.

[0164] [Chemistry 27]

[0165]

[0166] (In the formula, the dashed line is connected to R) ct3 (Atomic bonds.)

[0167] Specific examples of sulfonium cations represented by the general formula (Z-1) are shown below, but are not limited to these.

[0168] [Chemistry 28]

[0169]

[0170] [Chemistry 29]

[0171]

[0172] [Chemistry 30]

[0173]

[0174] [Chemistry 31]

[0175]

[0176] [Chemistry 32]

[0177]

[0178] [Chemistry 33]

[0179]

[0180] [Chemistry 34]

[0181]

[0182] [Chemistry 35]

[0183]

[0184] [Chemistry 36]

[0185]

[0186] [Chemistry 37]

[0187]

[0188] [Chemistry 38]

[0189]

[0190] [Chemistry 39]

[0191]

[0192] [Chemistry 40]

[0193]

[0194] [Chemistry 41]

[0195]

[0196] [Chemistry 42]

[0197]

[0198] [Chemistry 43]

[0199]

[0200] [Chemistry 44]

[0201]

[0202] [Chemistry 45]

[0203]

[0204] [Chemistry 46]

[0205]

[0206] [Chemistry 47]

[0207]

[0208] [Chemistry 48]

[0209]

[0210] [Chemistry 49]

[0211]

[0212] [Transformation 50]

[0213]

[0214] [Chemistry 51]

[0215]

[0216] [Chemistry 52]

[0217]

[0218] [Chemistry 53]

[0219]

[0220] [Chemistry 54]

[0221]

[0222] [Chemistry 55]

[0223]

[0224] [Chemistry 56]

[0225]

[0226] [Chemistry 57]

[0227]

[0228] [Chem.58]

[0229]

[0230] [Chemistry 59]

[0231]

[0232] [Transformation 60]

[0233]

[0234] [Chemistry 61]

[0235]

[0236] [Chemistry 62]

[0237]

[0238] [Chemistry 63]

[0239]

[0240] Specific examples of monazine cations represented by the general formula (Z-2) are shown below, but are not limited to these.

[0241] [Chemistry 64]

[0242]

[0243] [Chemistry 65]

[0244]

[0245] As a specific example of the onium salt monomer of the present invention, any combination of the above-mentioned anion and the above-mentioned cation can be listed.

[0246] The onium salt monomer of the present invention can be synthesized, for example, by the same method as that described in Japanese Patent No. 5201363 for a sulfonium salt having a polymerizable anion, but the method for manufacturing the onium salt monomer of the present invention is not limited to this method.

[0247] [Monomer-type photoacid generator]

[0248] The monomeric photoacid generator of the present invention is composed of the onium salt monomer of the present invention.

[0249] As long as the monomeric photoacid generator of the present invention is as described above, it exhibits excellent solvent solubility, high sensitivity, and high acid diffusion inhibition performance when used in chemically amplified resist compositions that use acid as a catalyst, thereby achieving chemically amplified resist compositions that exhibit excellent photolithography performance.

[0250] [polymer]

[0251] The polymer of the present invention contains repeating units (hereinafter also referred to as repeating unit a) from the onium salt monomer (the monomeric photoacid generator of the present invention) represented by the above general formula (A).

[0252] The polymer of the present invention is a polymer-bonded photoacid generator that functions as both a photoacid generator and a base polymer in a chemically amplified resist composition. Structurally, the polymer of the present invention contains repeating units from onium salt monomers having a benzenesulfonic acid structure substituted with electron-withdrawing groups. The benzenesulfonic acid anion substituted with electron-withdrawing groups enhances the acid strength of the sulfonic acid, further increasing the acid strength compared to the case where only fluorine atoms are substituted, not only through induction but also through resonance effects. Because it can form patterns with excellent LWR, CDU, EL, and DOF, and strong resistance to pattern collapse, the polymer of the present invention is particularly suitable as a material for chemically amplified resist compositions.

[0253] The polymers of the present invention can, for example, be included as a base polymer in chemically amplified resist compositions.

[0254] When the polymer of the present invention is contained in a positive resist composition, it comprises repeating units containing acid-labile groups. The repeating units containing acid-labile groups are preferably 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.).

[0255] [Chemistry 66]

[0256]

[0257] In equations (b1) and (b2),

[0258] R A Each can be a hydrogen atom or a methyl group independently.

[0259] Y 1It is a single bond, a phenylene or naphthylene group, or a linking group having 1 to 12 carbon atoms selected from the group consisting of ester bonds, ether bonds, and lactone rings. The phenylene, naphthylene group, and the linking group may also have at least one of the group consisting of hydroxyl groups, halogen atoms, saturated hydrocarbon oxygen groups having 1 to 8 carbon atoms, and saturated hydrocarbon carbonyl oxygen groups having 2 to 8 carbon atoms.

[0260] Y 2 It is a single bond or an ester bond.

[0261] Y 3 It is a single bond, an ether bond, or an ester bond.

[0262] R 11 and R 12 Each is an acid-labile group.

[0263] R 13 It is a saturated hydrocarbon group with 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group with 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group with 2 to 5 carbon atoms.

[0264] R 14 It is a single bond or an alkane diene having 1 to 6 carbon atoms, and the alkane diene may also contain at least one of the following groups: hydroxyl group, saturated hydrocarbon oxy group having 1 to 8 carbon atoms, saturated hydrocarbon carbonyl oxy group having 2 to 8 carbon atoms, ether bond, and ester bond.

[0265] a is an integer from 0 to 4 (0, 1, 2, 3 or 4).

[0266] Specific examples of a single entity given as a repeating unit b1 can be listed below, but are not limited to these. Furthermore, in the following formula, R... A and R 11 Same as above.

[0267] [Chemistry 67]

[0268]

[0269] [Chemistry 68]

[0270]

[0271] Specific examples of a single entity given as a repeating unit b2 can be listed below, but are not limited to such entities. Furthermore, in the following formula, R... A and R 12 Same as above.

[0272] [Chemistry 69]

[0273]

[0274] As R 11 Or R12 The unstable acid group can be represented in various ways, and examples can be given by formulas (AL-1) to (AL-3).

[0275] [Chemistry 70]

[0276]

[0277] In equation (AL-1), b is 0, 1, 2, 3, 4, 5, or 6. R L1 It refers to a tertiary hydrocarbon group with 4 to 20 carbon atoms, preferably 4 to 15; a trialkylsilyl group where each hydrocarbon group is a saturated hydrocarbon group with 1 to 6 carbon atoms; a saturated hydrocarbon group with 4 to 20 carbon atoms containing a carbonyl group, an ether bond, or an ester bond; or a group represented by formula (AL-3). Furthermore, tertiary hydrocarbon group refers to a group obtained by removing a hydrogen atom from a tertiary carbon atom of a hydrocarbon.

[0278] R L1 The tertiary hydrocarbon group can be saturated or unsaturated, and can be branched or cyclic. Specific examples include tert-butyl, tert-pentyl, 1,1-diethylpropyl, 1-ethylcyclopentyl, 1-butylcyclopentyl, 1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl, and 2-methyl-2-adamantyl. Specific examples of the above trialkylsilyl groups include trimethylsilyl, triethylsilyl, and dimethyl-tert-butylsilyl. The aforementioned saturated hydrocarbon groups containing carbonyl, ether, or ester bonds can be linear, branched, or cyclic, but are preferably cyclic. Specific examples include 3-oxocyclohexyl, 4-methyl-2-oxocyclohexane-4-yl, 5-methyl-2-oxocyclopentane-5-yl, 2-tetrahydropyranyl, and 2-tetrahydrofuranyl.

[0279] Specific examples of acid-instable groups represented by formula (AL-1) include tert-butoxycarbonyl, tert-butoxycarbonylmethyl, tert-pentyloxycarbonyl, tert-pentyloxycarbonylmethyl, 1,1-diethylpropyloxycarbonyl, 1,1-diethylpropyloxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyloxycarbonylmethyl, 1-ethyl-2-cyclopentenyloxycarbonyl, 1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl, 2-tetrahydropyranyloxycarbonylmethyl, 2-tetrahydrofuranyloxycarbonylmethyl, etc.

[0280] Furthermore, as acid-instable groups represented by formula (AL-1), groups represented by formulas (AL-1)-1 to (AL-1)-10 can also be listed below.

[0281] [Chemistry 71]

[0282]

[0283] (In the formula, the dashed lines represent atomic bonds.)

[0284] In equations (AL-1)-1 to (AL-1)-10, b is the same as above. R L8 Each is independently a saturated hydrocarbon group with 1 to 10 carbon atoms or an aryl group with 6 to 20 carbon atoms. R L9 It is a hydrogen atom or a saturated hydrocarbon group with 1 to 10 carbon atoms. R L10 It is a saturated hydrocarbon group with 2 to 10 carbon atoms or an aryl group with 6 to 20 carbon atoms. The above-mentioned saturated hydrocarbon group can be any of the following: straight-chain, branched, or cyclic.

[0285] In equation (AL-2), R L2 and R L3 Each saturated hydrocarbon group is independently composed of hydrogen atoms or has 1 to 18 carbon atoms, preferably 1 to 10. These saturated hydrocarbon groups can be linear, branched, or cyclic. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl, and n-octyl.

[0286] In equation (AL-2), R L4 It may also contain heteroatoms and be a hydrocarbon group with 1 to 18 carbon atoms, preferably 1 to 10. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples of the aforementioned hydrocarbon group include saturated hydrocarbon groups with 1 to 18 carbon atoms, some of which may be substituted by hydroxyl, alkoxy, oxo, amino, or alkylamino groups. Specific examples of such substituted saturated hydrocarbon groups include those shown below.

[0287] [Chemistry 72]

[0288]

[0289] (In the formula, the dashed lines represent atomic bonds.)

[0290] R L2 and R L3 R L2 and R L4 、or R L3 and R L4 They can also bond with each other and form rings together with the carbon atoms they bond with, or with carbon and oxygen atoms. In this case, the R related to ring formation... L2 and R L3 R L2 and R L4 、or R L3 and R L4 Each is an alkane dimethyl group with 1 to 18 carbon atoms, preferably 1 to 10. The ring formed by their bonding preferably has 3 to 10 carbon atoms, and more preferably 4 to 10.

[0291] Among the acid-labile groups represented by formula (AL-2), specific examples of linear or branched structures can be listed as those represented by formulas (AL-2)-1 to (AL-2)-69, but are not limited to these. Furthermore, in the following formulas, dashed lines represent atomic bonds.

[0292] [Chemistry 73]

[0293]

[0294] [Chemistry 74]

[0295]

[0296] [Chemistry 75]

[0297]

[0298] [Chemistry 76]

[0299]

[0300] Among the acid-unstable groups represented by formula (AL-2), specific examples of cyclic groups include tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, tetrahydropiperan-2-yl, and 2-methyltetrahydropiperan-2-yl.

[0301] Furthermore, groups represented by formulas (AL-2a) or (AL-2b) can be listed as acid-indestructible groups. Through these acid-indestructible groups, the polymer can be cross-linked intermolecularly or intramolecularly.

[0302] [Chemistry 77]

[0303]

[0304] (In the formula, the dashed lines represent atomic bonds.)

[0305] In formula (AL-2a) or (AL-2b), R L11 and R L12 Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms. These saturated hydrocarbon groups can be linear, branched, or cyclic. Furthermore, R... L11 With R L12 They can also bond with each other and form rings together with the carbon atoms they bond with; in this case, R L11 and R L12 Each is an independent alkane diol with 1 to 8 carbon atoms. R L13Each is an independent saturated hydrocarbon group having 1 to 10 carbon atoms. The aforementioned saturated hydrocarbon groups can be linear, branched, or cyclic. c and d are each independent integers from 0 to 10, preferably 0, 1, 2, 3, 4, or 5, and e is an integer from 1 to 7, preferably 1, 2, or 3.

[0306] In formula (AL-2a) or (AL-2b), L A These are aliphatic saturated hydrocarbon groups with 1 to 50 carbon atoms (e+1), alicyclic saturated hydrocarbon groups with 3 to 50 carbon atoms (e+1), aromatic hydrocarbon groups with 6 to 50 carbon atoms (e+1), or heterocyclic groups with 3 to 50 carbon atoms (e+1). Furthermore, a portion of the -CH2- group can be substituted by a group containing a heteroatom, and a portion of the hydrogen atom in these groups can be substituted by a hydroxyl, carboxyl, acyl, or fluorine atom. As L A The saturated hydrocarbon group should preferably be a saturated hydrocarbon group with 1-20 carbon atoms, a trivalent saturated hydrocarbon group, a tetravalent saturated hydrocarbon group, or an aryl group with 6-30 carbon atoms. The aforementioned saturated hydrocarbon group can be linear, branched, or cyclic. B It is -C(=O)-O-, -NH-C(=O)-O-, or -NH-C(=O)-NH-.

[0307] Specific examples of cross-linked acetal groups represented by formula (AL-2a) or (AL-2b) include groups represented by formulas (AL-2)-70 to (AL-2)-77.

[0308] [Chemistry 78]

[0309]

[0310] (In the formula, the dashed lines represent atomic bonds.)

[0311] In equation (AL-3), R L5 It is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. This hydrocarbon group may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. R L6 and R L7 Each group is independently a hydrocarbon group having 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 20 carbon atoms, cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms, and aryl groups having 6 to 10 carbon atoms. Furthermore, R... L5 With R L6 Combination, R L5 With R L7 Combinations, or R L6 With R L7The combinations can also bond to each other individually and together with the carbon atoms they bond to form alicyclic rings with 3 to 20 carbon atoms.

[0312] Specific examples of groups represented by formula (AL-3) include tert-butyl, 1,1-diethylpropyl, 1-ethylnorbornel, 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-isopropylcyclopentyl, 1-methylcyclohexyl, 2-(2-methyl)adamantyl, 2-(2-ethyl)adamantyl, and tert-pentyl.

[0313] Furthermore, as specific examples of groups represented by formula (AL-3), groups represented by formulas (AL-3)-1 to (AL-3)-22 can also be listed below.

[0314] [Chemistry 79]

[0315]

[0316] (In the formula, the dashed lines represent atomic bonds.)

[0317] In equations (AL-3)-1 to (AL-3)-22, R L14 Each is independently a hydrogen atom, an aliphatic hydrocarbon group with 1 to 8 carbon atoms, or an aryl group with 6 to 20 carbon atoms. L15 and R L17 Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 20 carbon atoms. R L16 It is an aryl group with 6 to 20 carbon atoms. The aforementioned saturated hydrocarbon group can be linear, branched, or cyclic. Furthermore, phenyl or similar compounds are preferred as the aforementioned aryl group. R L18 It is a fluorine atom, an iodine atom, a nitro group, or a trifluoromethyl group. R L19 Each of the following can be independently a hydrogen atom, a fluorine atom, an iodine atom, a nitro group, a saturated hydrocarbon group with 1 to 8 carbon atoms, or a hydrocarbon oxygen group with 1 to 8 carbon atoms. f is 1, 2, 3, 4, or 5.

[0318] Furthermore, groups represented by formulas (AL-3)-23 or (AL-3)-24 can be listed as acid-indestructible groups. Through these acid-indestructible groups, the polymer can be intramolecularly or intermolecularly crosslinked.

[0319] [Chemistry 80]

[0320]

[0321] (In the formula, the dashed lines represent atomic bonds.)

[0322] In equations (AL-3)-23 and (AL-3)-24, R L14 Same as above. R L20It is a saturated or unsaturated alkylene group with a carbon number of 1 to 20 and a (g+1) valence, or an arylene group with a carbon number of 6 to 20 and a (g+1) valence, and may also contain heteroatoms such as oxygen, sulfur, and nitrogen atoms. The aforementioned saturated or unsaturated alkylene groups can be linear, branched, or cyclic. g is 1, 2, or 3.

[0323] In addition to these acid-instable groups, acid-instable groups containing aromatic groups as described in Japanese Patent Nos. 5565293, 5434983, 5407941, 5655756 and 5655755 may also be used.

[0324] The polymer of the present invention may further contain a repeating unit c comprising a phenolic hydroxyl group as a close-knit group. Specific examples of monomers providing the repeating unit c include, but are not limited to, those shown below. Furthermore, in the following formula, R... A Same as above.

[0325] [Chemistry 81]

[0326]

[0327] The polymers of the present invention may also contain repeating units d, including hydroxyl groups other than phenolic hydroxyl groups, lactone rings, sulfonyl rings, ether bonds, ester bonds, sulfonate bonds, carbonyl groups, sulfonyl groups, cyano groups, or carboxyl groups as other closely related groups. Specific examples of monomers providing repeating units d are shown below, but are not limited to these. Furthermore, in the following formula, R... A Same as above.

[0328] [Chemistry 82]

[0329]

[0330] [Chemistry 83]

[0331]

[0332] [Chemistry 84]

[0333]

[0334] [Chemistry 85]

[0335]

[0336] [Chemistry 86]

[0337]

[0338] [Chemistry 87]

[0339]

[0340] [Chemical Formula 88]

[0341]

[0342] [Chemical Formula 89]

[0343]

[0344] The polymer of the present invention may further contain a repeating unit e derived from indene, benzofuran, benzothiophene, vinylnaphthalene, chromone, coumarin, norbornadiene, or derivatives thereof. Specific examples of the monomer that provides the repeating unit e include, but are not limited to, those shown below.

[0345] [Chemical Formula 90]

[0346]

[0347] The polymer of the present invention may further contain a repeating unit f derived from styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methyleneindane, vinylpyridine, or vinylcarbazole.

[0348] The base polymer for a positive resist composition contains, in addition to the repeating unit a, a repeating unit containing an acid-labile group, for example, the repeating unit b1 or b2. In this case, the content ratios of the repeating units a, b1, b2, c, d, e and f are preferably 0<a≤0.5, 0≤b1<1.0, 0≤b2<1.0, 0<b1+b2<1.0, 0≤c≤0.9, 0≤d≤0.9, 0≤e≤0.8 and 0≤f≤0.8, more preferably 0.02≤a≤0.4, 0≤b1≤0.9, 0≤b2≤0.9, 0.1≤b1+b2≤0.9, 0≤c≤0.8, 0≤d≤0.8, 0≤e≤0.7, 0≤f≤0.7, and even more preferably 0.05≤a≤0.35, 0≤b1≤0.8, 0≤b2≤0.8, 0.1≤b1+b2≤0.8, 0≤c≤0.75, 0≤d≤0.75, 0≤e≤0.6 and 0≤f≤0.6. In addition, a+b1+b2+c+d+e+f=1.0.

[0349] On the other hand, the base polymer for the negative resist composition does not necessarily require acid-labile groups. Examples of such a base polymer include those further containing the repeating unit c in addition to the repeating unit a, and optionally those further containing repeating units d, e and / or f. The content ratio of these repeating units is preferably 0<a≤0.5, 0<c≤1.0, 0≤d≤0.9, 0≤e≤0.8 and 0≤f≤0.8, more preferably 0.02≤a≤0.4, 0.2≤c≤1.0, 0≤d≤0.8, 0≤e≤0.7 and 0≤f≤0.7, and still more preferably 0.05≤a≤0.35, 0.3≤c≤1.0, 0≤d≤0.75, 0≤e≤0.6 and 0≤f≤0.6. In addition, a+c+d+e+f=1.0.

[0350] Examples of the method for synthesizing the polymer of the present invention include a method of polymerizing the monomers that provide the above repeating units by adding a radical polymerization initiator in an organic solvent and heating the mixture.

[0351] Specific examples of the organic solvent used during polymerization include toluene, benzene, tetrahydrofuran (THF), methyl ethyl ketone (MEK), diethyl ether, dioxane and the like. Specific examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, lauroyl peroxide and the like. The temperature during polymerization is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

[0352] When copolymerizing a hydroxyl group-containing monomer, the hydroxyl group may be substituted with an acid-labile acetal group such as ethoxyethoxy group during polymerization, followed by deprotection with a weak acid and water after polymerization; or the hydroxyl group may be substituted with an acetyl group, formyl group, pivaloyl group or the like, followed by alkaline hydrolysis after polymerization.

[0353] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, acetoxystyrene or acetoxyvinylnaphthalene may be used instead of hydroxystyrene or hydroxyvinylnaphthalene, and the acetoxy group is deprotected by the above alkaline hydrolysis after polymerization to form hydroxystyrene or hydroxyvinylnaphthalene.

[0354] As the base for alkaline hydrolysis, ammonia water, triethylamine and the like can be used. In addition, the reaction temperature is preferably -20 to 100°C, more preferably 0 to 60°C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0355] The polymer of the present invention, when used in gel permeation chromatography (GPC) with THF as a solvent, preferably has a polystyrene equivalent weight-average molecular weight (Mw) of 1,000 to 500,000, more preferably 2,000 to 30,000, and even more preferably 5,000 to 20,000. As long as Mw is within the above range, the heat resistance or solubility of the resist film in alkaline developer is good.

[0356] Furthermore, when the molecular weight distribution (Mw / Mn) in the polymer of the present invention is narrow, suppressing the presence of low or high molecular weight polymers can suppress the appearance of foreign matter on the pattern or the deterioration of the pattern shape after exposure. As the pattern regularity becomes finer, the influence of Mw or Mw / Mn tends to increase. Therefore, in order to obtain a resist composition suitable for use with fine pattern sizes, the Mw / Mn of the polymer of the present invention is preferably 1.0 to 2.0, and more preferably a narrow dispersion of 1.0 to 1.5.

[0357] The polymer of the present invention may also contain two or more polymers with different composition ratios, Mw, and Mw / Mn.

[0358] [Chemical amplification resist composition]

[0359] The chemically amplified resist composition of the present invention contains the polymer of the present invention as the base polymer.

[0360] The chemically amplified resist composition of the present invention, containing the polymer of the present invention as the base polymer, exhibits excellent solvent solubility, high sensitivity, and high acid diffusion inhibition performance, thereby exhibiting better photolithography performance.

[0361] The chemically amplified resist composition of the present invention may further contain at least one selected from the group consisting of organic solvents, quenchers, acid generators, surfactants, and dissolution inhibitors.

[0362] The chemically amplified resist composition of the present invention may contain the above-mentioned components depending on the application.

[0363] Hereinafter, any component other than the base polymer in the composition of the chemically amplified resist of the present invention will be described.

[0364] <Organic solvents>

[0365] The chemically amplified resist composition of the present invention may also contain organic solvents. There are no particular limitations on the organic solvents, as long as they are capable of dissolving the polymer of the present invention and any of the components described below. Specific examples of the organic solvents mentioned above include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone, as described in paragraphs

[0144] to

[0145] of Japanese Patent Application Publication No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; propylene glycol monomethyl ether, ethylene glycol monomethyl ether, etc. Ethers such as monomethyl alcohol ether, monoethyl propylene glycol ether, monoethyl ethylene glycol ether, dimethyl propylene glycol ether, and dimethyl diethylene glycol ether; esters such as monomethyl propylene glycol ether acetate, monoethyl propylene glycol ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and mono-tert-butyl propylene glycol ether acetate; and lactones such as γ-butyrolactone.

[0366] In the chemically amplified resist composition of the present invention, the content of the aforementioned organic solvent relative to 100 parts by weight of the base polymer is preferably 100 to 10,000 parts by weight, more preferably 200 to 8,000 parts by weight. One of the aforementioned organic solvents may be used alone, or two or more may be used in combination.

[0367] <Quenching Agent>

[0368] The chemically amplified resist composition of the present invention may also contain a quencher, depending on the requirements. In this invention, a quencher refers to a compound that can prevent diffusion to unexposed areas by capturing acid generated from a photoacid generator.

[0369] Specific examples of the aforementioned quenching agents include amine compounds, sulfonates, or carboxylates. The aforementioned amine compounds are primary, secondary, or tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Publication No. 2008-111103, and are particularly suitable as amine compounds having any one of a hydroxyl group, ether bond, ester bond, lactone ring, cyano group, or sulfonate bond. Furthermore, compounds in which the primary or secondary amine is protected as a carbamate group, as described in Japanese Patent No. 3790649, are also suitable. Such protected amine compounds are effective when the resist composition contains components that are unstable to alkalis.

[0370] As specific examples of the above-mentioned sulfonates, compounds represented by formula (1) can be listed. Furthermore, as specific examples of the above-mentioned carboxylates, compounds represented by formula (2) can be listed.

[0371] [Chemistry 91]

[0372]

[0373] In equation (1), R 101 It is a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms, but excludes those bonded to SO3. - The hydrogen atom of the carbon atom at the α position of the radical is replaced by a fluorine atom or a fluorinated alkyl group.

[0374] R 101 The hydrocarbon group representing 1 to 40 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 40 carbon atoms such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclic [5.2.1.0] 2，6 Cyclic saturated hydrocarbon groups with 3 to 40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; alkenyl groups with 2 to 40 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; unsaturated aliphatic cyclic hydrocarbon groups with 3 to 40 carbon atoms, such as cyclohexenyl; aryl groups with 6 to 40 carbon atoms, such as phenyl, naphthyl, alkylphenyl (e.g., 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, and 4-n-butylphenyl), dialkylphenyl (e.g., 2,4-dimethylphenyl, and 2,4,6-triisopropylphenyl), alkylnaphthyl (e.g., methylnaphthyl, and ethylnaphthyl), and dialkylnaphthyl (e.g., dimethylnaphthyl, and diethylnaphthyl); and aralkyl groups with 7 to 40 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl.

[0375] Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, or halogen atoms. A portion of the -CH2- group in the aforementioned hydrocarbon group may also be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, or nitrogen atoms. As a result, the hydrocarbon group may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), or haloalkyl groups, etc. Examples of hydrocarbon groups containing heteroatoms include heteroaryl groups such as thiophene; alkoxyphenyl groups such as 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-tert-butoxyphenyl, and 3-tert-butoxyphenyl; alkoxynaphthyl groups such as methoxynaphthyl, ethoxynaphthyl, n-propoxynaphthyl, and n-butoxynaphthyl; dialkoxynaphthyl groups such as dimethoxynaphthyl and diethoxynaphthyl; and aryloxoalkyl groups such as 2-aryl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl.

[0376] R 102 It can also contain hydrocarbon groups with 1 to 40 carbon atoms and heteroatoms. As R 102 The hydrocarbon group represented can be listed as R. 101 The hydrocarbon groups represented are the same as those shown. In addition, as other specific examples, fluorinated alkyl groups such as trifluoromethyl, trifluoroethyl, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl, and 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl, as well as fluorinated aryl groups such as pentafluorophenyl or 4-trifluoromethylphenyl, can also be listed.

[0377] Specific examples of anions of sulfonates represented by formula (1) are listed below, but are not limited to these.

[0378] [Chemistry 92]

[0379]

[0380] [Chemistry 93]

[0381]

[0382] Specific examples of the anions of carboxylate salts represented by formula (2) are shown below, but are not limited to these. Furthermore, in the following formula, Me is a methyl group.

[0383] [Chemistry 94]

[0384]

[0385] [Chemistry 95]

[0386]

[0387] [Chemistry 96]

[0388]

[0389] [Chemistry 97]

[0390]

[0391] [Chem. 98]

[0392]

[0393] In equations (1) and (2), Mq + It is an onium cation. Examples of onium cations include sulfonium cations, monium cations, and ammonium cations. The sulfonium cation is preferably represented by formula (Z-1), and examples of this formula are those identical to those exemplified as examples of sulfonium cations represented by formula (Z-1). The monium cation is preferably represented by formula (Z-2), and examples of this formula are those identical to those exemplified as examples of monium cations represented by formula (Z-2).

[0394] As another example of the aforementioned quenching agents, the polymer-type quenching agent described in Japanese Patent Application Publication No. 2008-239918 can be cited. It improves the rectangularity of the resist pattern by aligning with the resist surface. The polymer-type quenching agent also has the effect of preventing film reduction or rounding of the top of the pattern when applied to a protective film for impregnation and exposure.

[0395] In addition, as a quenching agent, onium salts having sulfonium cations and benzene oxide anions within the same molecule as described in Japanese Patent No. 6848776 can also be used. Furthermore, onium salts having sulfonium cations and carboxylate anions within the same molecule as described in Japanese Patent No. 6583136, Japanese Patent Application Publication No. 2020-200311, or onium salts having monium cations and carboxylate anions within the same molecule as described in Japanese Patent No. 6274755 can also be used.

[0396] In the case where the chemically amplified resist composition of the present invention contains a quencher, its content relative to 80 parts by weight of the base polymer is preferably 0.001 to 12 parts by weight, more preferably 0.01 to 8 parts by weight. By incorporating the quencher, the sensitivity of the resist film becomes easier to adjust, and the diffusion of acid in the resist film can be suppressed to improve resolution, suppress sensitivity changes after exposure, reduce substrate or environmental dependence, or improve exposure latitude or pattern outline, etc. Furthermore, the addition of the aforementioned quencher can also improve substrate adhesion. One type of quencher can be used alone, or two or more can be used in combination.

[0397] As the aforementioned acid generating agent, compounds that generate acid in response to active light or radiation (photoacid generating agents) can be listed. Any compound that generates acid by irradiation with high-energy rays is acceptable as a component of the photoacid generating agent, and preferably an acid generating agent that generates sulfonic acid, imine acid, or methyl acid. Specific examples of suitable photoacid generating agents include sulfonium salts, sulfonium salts, sulfonyl diazomethanes, N-sulfonyloxyimide, and oxime-O-sulfonate type acid generating agents. Specific examples of the aforementioned acid generating agents include those described in paragraphs

[0122] to

[0142] of Japanese Patent Application Publication No. 2008-111103, Japanese Patent Application Publication No. 2018-5224, and Japanese Patent Application Publication No. 2018-25789. When the resist composition of the present invention contains the above-mentioned acid generating agent, its content relative to 100 parts by weight of the base polymer is preferably 0 to 200 parts by weight, and preferably 0.1 to 100 parts by weight. Furthermore, since the polymer of the present invention contains a base polymer that functions as a photoacid generating agent, it is not necessary to additionally incorporate an acid generating agent.

[0398] Specific examples of the aforementioned surfactants can be found in paragraphs

[0165] to

[0166] of Japanese Patent Application Publication No. 2008-111103. By adding surfactants, the coatability of the resist composition can be further improved or controlled. In the case where the resist composition of the present invention contains the aforementioned surfactant, its content is preferably 0.0001 to 10 parts by mass relative to 100 parts by mass of the base polymer. The aforementioned surfactants can be used alone or in combination of two or more.

[0399] When the resist composition of the present invention is positive, by incorporating a dissolution inhibitor, the difference in dissolution rate between the exposed and unexposed areas can be further increased, and the resolution can be further improved. Specific examples of the dissolution inhibitors mentioned above include compounds in which the hydrogen atoms of the phenolic hydroxyl groups of a compound having a molecular weight preferably of 100 to 1000, more preferably 150 to 800, and containing two or more phenolic hydroxyl groups in the molecule are substituted by acid-indestructible groups at a ratio of 0 to 100 mol% in all respects; or compounds in which the hydrogen atoms of the carboxyl groups of a compound containing carboxyl groups in the molecule are substituted by acid-indestructible groups at an average ratio of 50 to 100 mol% in all respects. 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 substituted by acid-indestructible groups, as described, for example, in paragraphs

[0155] to

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

[0400] When the chemically amplified resist composition of the present invention is positive and contains the above-mentioned dissolution inhibitor, its content relative to 100 parts by weight of the base polymer is preferably 0 to 50 parts by weight, more preferably 5 to 40 parts by weight. As the above-mentioned dissolution inhibitor, one type can be used alone, or two or more types can be used in combination.

[0401] <Other Ingredients>

[0402] The chemically amplified resist composition of the present invention may also contain crosslinking agents, water repellency improvers, or alkynyl alcohols, etc.

[0403] On the other hand, when the chemically amplified resist composition of the present invention is negative, a negative pattern can be obtained by adding a crosslinking agent to reduce the dissolution rate of the exposed portion. Specific examples of such crosslinking agents include epoxy compounds, melamine compounds, guanidine compounds, acetylenoid compounds or urea compounds, isocyanate compounds, nitrogen compounds, and compounds containing double bonds such as olefins, substituted with groups selected from at least one of hydroxymethyl, alkoxymethyl, and acyloxymethyl groups. These can be used as additives or introduced into the polymer side chains as dangling groups. Furthermore, compounds containing hydroxyl groups can also be used as crosslinking agents.

[0404] Specific examples of the aforementioned epoxy compounds include tris(2,3-epoxypropyl)isocyanurate, trimethylolpropane trioxypropyl ether, trimethylolpropane trioxypropyl ether, and triethylolethane trioxypropyl ether.

[0405] Specific examples of the aforementioned melamine compounds include hexahydroxymethyl melamine, hexamethoxymethyl melamine, compounds or mixtures thereof in which 1 to 6 hydroxymethyl groups of hexahydroxymethyl melamine are methoxymethylated, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, and compounds or mixtures thereof in which 1 to 6 hydroxymethyl groups of hexahydroxymethyl melamine are acyloxymethylated.

[0406] Specific examples of the aforementioned guanidine compounds include tetrahydroxymethylguanidine, tetramethoxymethylguanidine, compounds of tetrahydroxymethylguanidine with 1 to 4 hydroxymethyl groups methoxymethylated, or mixtures thereof, tetramethoxyethylguanidine, tetraacyloxyguanidine, and compounds of tetrahydroxymethylguanidine with 1 to 4 hydroxymethyl groups acyloxymethylated, or mixtures thereof.

[0407] Specific examples of the aforementioned acetylenoid compounds include tetrahydroxymethylacetylenoid, tetramethoxyacetylenoid, tetramethoxymethylacetylenoid, compounds in which 1 to 4 of the hydroxymethyl groups of tetrahydroxymethylacetylenoid are methoxymethylated, or mixtures thereof, and compounds in which 1 to 4 of the hydroxymethyl groups of tetrahydroxymethylacetylenoid are acyloxymethylated, or mixtures thereof. Specific examples of the aforementioned urea compounds include tetrahydroxymethylurea, tetramethoxymethylurea, compounds in which 1 to 4 of the hydroxymethyl groups of tetrahydroxymethylurea are methoxymethylated, or mixtures thereof, and tetramethoxyethylurea, etc.

[0408] Specific examples of the aforementioned isocyanate compounds include toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0409] Specific examples of the aforementioned azide compounds include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylene bisazide, and 4,4'-oxybisazide.

[0410] Specific examples of the compounds containing olefins mentioned above include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylenediol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, neopentyltetraethylenedivinyl ether, neopentyltetraethylenedivinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0411] In the case where the chemically amplified resist composition of the present invention is negative and contains the above-mentioned crosslinking agent, its content relative to 100 parts by weight of the base polymer is preferably 0.1 to 50 parts by weight, more preferably 1 to 40 parts by weight. As the above-mentioned crosslinking agent, one type can be used alone, or two or more types can be used in combination.

[0412] The aforementioned water-repellent improver enhances the water repellency of the resist film surface and can be used in immersion lithography without a surface coating. As the aforementioned water-repellent improver, polymers containing fluorinated alkyl groups, polymers containing 1,1,1,3,3,3-hexafluoro-2-propanol residues with a specific structure, etc., are preferable, especially those exemplified in Japanese Patent Application Publication No. 2007-297590 and Japanese Patent Application Publication No. 2008-111103. The aforementioned water-repellent improver needs to be soluble in alkaline or organic solvent developing solutions. The aforementioned water-repellent improver having specific 1,1,1,3,3,3-hexafluoro-2-propanol residues exhibits good solubility in developing solutions. As the water-repellent improver, polymers containing repeating units containing amino or amine salts are highly effective in preventing the evaporation of acid in PEB, thereby preventing poor opening of the hole pattern after development. When the chemically amplified resist composition of the present invention contains the above-mentioned water-repellent improver, its content relative to 100 parts by weight of the base polymer is preferably 0 to 20 parts by weight, more preferably 0.5 to 10 parts by weight. The above-mentioned water-repellent improver can be used alone or in combination of two or more.

[0413] Specific examples of the aforementioned alkynyl alcohols can be cited from paragraphs

[0179] to

[0182] of Japanese Patent Application Publication No. 2008-122932. When the chemically amplified resist composition of the present invention contains the aforementioned alkynyl alcohols, their content is preferably 0 to 5 parts by mass relative to 100 parts by mass of the base polymer. The aforementioned alkynyl alcohols can be used alone or in combination of two or more.

[0414] [Pattern Formation Method]

[0415] When the chemically amplified resist composition of the present invention is used in the manufacture of various integrated circuits, known photolithography techniques can be applied. For example, as a specific example of a patterning method, a method comprising the steps of: forming a resist film on a substrate using the chemically amplified resist composition of the present invention; exposing the resist film to high-energy radiation; and developing the exposed resist film using a developer. This example of a patterning method is the patterning method of the present invention.

[0416] As long as it is the pattern forming method of the present invention, because the chemically amplified resist composition of the present invention is used, pattern forming can be performed in an excellent state such as LWR, CDU, EL, DOF, that is, with excellent photolithography performance.

[0417] The pattern forming method of the present invention will be described in more detail below, but the pattern forming method of the present invention is not limited to the examples shown below.

[0418] First, the chemically amplified resist composition of the present invention is applied to a substrate for integrated circuit manufacturing (e.g., Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, and organic antireflective films, etc.) or a substrate for mask circuit manufacturing (e.g., Cr, CrO, CrON, MoSi2, and SiO2, etc.) using a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, and doctor blade coating, with a coating thickness preferably of 0.01 to 2 μm. The resulting coating is then pre-baked on a hot plate, preferably at 60 to 150°C for 10 to 30 seconds, more preferably at 80 to 120°C for 30 to 20 seconds, to form a resist film.

[0419] Then, the resist film is exposed using high-energy radiation. Specific examples of such high-energy radiation include ultraviolet light, far ultraviolet light, EB, EUV (wavelength 3-15 nm), X-rays, soft X-rays, excimer lasers, gamma rays, and synchrotron radiation. For example, ArF excimer lasers with a wavelength of 193 nm, KrF excimer lasers with a wavelength of 248 nm, electron beams, or extreme ultraviolet light with a wavelength of 3-15 nm can be used as high-energy radiation. When using ultraviolet light, far ultraviolet light, EUV, X-rays, soft X-rays, excimer lasers, gamma rays, or synchrotron radiation as high-energy radiation, the exposure dose is preferably about 1-200 mJ / cm², either directly or using a mask to form the desired pattern. 2 It is more appropriate to have a concentration of approximately 10~100 mJ / cm. 2 Irradiation is performed in a manner that allows for exposure. When using EB as a high-energy ray, the exposure dose should be approximately 0.1~300 μC / cm. 2 The optimal temperature range is approximately 0.5~200 μC / cm. 2 The pattern can be drawn directly or using a mask to form the desired pattern. Furthermore, the chemically amplified resist composition of the present invention is particularly suitable for fine patterning using KrF excimer lasers, ArF excimer lasers, EB, EUV, X-rays, soft X-rays, gamma rays, and synchrotron radiation in high-energy radiation, and is especially suitable for fine patterning using EB or EUV.

[0420] After exposure, PEB can be performed on a heating plate or in an oven at 30-150°C for 10-30 seconds, or more preferably at 50-120°C for 30-20 seconds, or PEB can be omitted.

[0421] After exposure or PEB, a developer solution containing 0.1-10% by mass, more preferably 2-5% by mass, of an alkaline aqueous solution of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, etc., is used to develop the resist film by exposure using conventional methods such as dip, immersion, or spraying for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, thereby forming the desired pattern on the resist film. In the case of positive chemically amplified resist compositions, the exposed portions dissolve in the developer solution, while the unexposed portions do not dissolve, thus forming the desired positive pattern on the substrate. In the case of negative chemically amplified resist compositions, the opposite is true; the exposed portions become insoluble in the developer solution, while the unexposed portions dissolve.

[0422] Negative patterns can also be obtained by developing with organic solvents using a positive chemically amplified resist composition containing a base polymer with acid-instable groups. Specific examples of developers used in this process 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, butyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, methyl valerate, methyl valerate, methyl crotonate, croton... Ethyl propionate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenyl acetate, benzyl formate, ethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, and 2-phenylethyl acetate, etc. These organic solvents can be used alone or in mixtures of two or more.

[0423] At the end of development, a rinse is performed. The rinse solution should preferably be a solvent that is miscible with the developer but does not dissolve the resist film. Such a solvent is preferably an alcohol with 3 to 10 carbon atoms, an ether compound with 8 to 12 carbon atoms, an alkane with 6 to 12 carbon atoms, an alkene, an alkyne, or an aromatic solvent.

[0424] Specific examples of alcohols with 3 to 10 carbon atoms include n-propyl alcohol, isopropyl alcohol, 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentyl alcohol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, and 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, as well as cyclohexanol, 1-octanol, etc.

[0425] Specific examples of the ether compounds having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, disec-butyl ether, di-n-pentyl ether, diisopentyl ether, disec-pentyl ether, ditert-pentyl ether, and di-n-hexyl ether.

[0426] Specific examples of alkanes having 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 having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Specific examples of alkynes having 6 to 12 carbon atoms include hexyne, heptyne, and octyne.

[0427] Specific examples of the aforementioned aromatic solvents include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, and mesitylene.

[0428] Rinsing can reduce the collapse or defects of the resist pattern. Furthermore, rinsing is not always necessary; it can be omitted to reduce solvent usage.

[0429] The developed hole or groove pattern can also be shrunk, for example, by heat transfer, RELACS, or DSA techniques. A shrinking agent is applied to the hole pattern, and during baking, the diffusion of the acid catalyst from the resist film causes cross-linking of the shrinking agent on the surface of the resist film, allowing the shrinking agent to adhere to the sidewalls of the hole pattern. The baking temperature is preferably 70–180°C, more preferably 80–170°C, and the baking time is preferably 10–300 seconds to remove excess shrinking agent and shrink the hole pattern.

[0430] [Example]

[0431] The present invention will be specifically described below with examples of synthesis, embodiments, and comparative examples, but the present invention is not limited to the embodiments described below. Furthermore, the apparatus used is the same as described below.

[0432] MALDI TOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[0433] [1] Synthesis of onium salt monomers

[0434] [Example 1-1] Synthesis of onium salt monomer a-1

[0435] [Chemistry 99]

[0436]

[0437] (1) Synthesis of intermediate In-1

[0438] Under nitrogen atmosphere, starting materials SM-1 (17.8 g), SM-2 (37.8 g), DMAP (0.75 g), and dichloromethane (300 g) were added to a reaction vessel and cooled in an ice bath. While maintaining the temperature inside the reaction vessel below 20°C, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (21.2 g) was added directly as a powder. After addition, the mixture was heated to room temperature and allowed to mature for 12 hours. After maturation, water was added to stop the reaction. The solvent was distilled off from the collected material obtained by conventional aqueous work-up and silica gel column chromatography. Diisopropyl ether was added to wash the residue, thereby obtaining 42.6 g of intermediate In-1 as a white solid (90% yield).

[0439] (2) Synthesis of onium salt type monomer a-1

[0440] Under nitrogen atmosphere, intermediate In-1 (42.6 g), starting material SM-3 (39.3 g), dichloromethane (200 g), and water (150 g) were added to a reaction vessel. After stirring for 30 minutes, the organic layer was separated, washed with water, and then concentrated under reduced pressure. The concentrate was purified by silica gel chromatography, and diisopropyl ether was added for recrystallization, thereby obtaining 62.6 g of the onium salt monomer a-1 of the target compound as white crystals (yield 95%).

[0441] MALDI TOF-MS:

[0442] POSITIVE M + 335 (equivalent to C) 18 H 11 F4S + )

[0443] NEGATIVE M - 324 (equivalent to C)13 H 10 NO7S - )

[0444] [Examples 1-2~1-12] Synthesis of onium salt monomers a-2~a-12

[0445] Using the corresponding raw materials and known organic synthesis reactions, onium salt monomers a-2 to a-12 represented by the following formula were synthesized.

[0446] [Chemistry 100]

[0447]

[0448] [Chemistry 101]

[0449]

[0450] [Comparative Examples 1-1 to 1-6] Comparison of the synthesis of onium salt monomers Ca-1 to Ca-6

[0451] Using the corresponding raw materials and known organic synthesis reactions, comparative onium salt monomers ca-1 to ca-6 represented by the following formulas were synthesized.

[0452] [Chemistry 102]

[0453]

[0454] [2] Synthesis of basic polymers

[0455] Among the monomers used in the synthesis of the basic polymer, those other than monomers a-1 to a-12 and comparative monomers ca-1 to ca-6 are as follows.

[0456] [Chemistry 103]

[0457]

[0458] [Chemistry 104]

[0459]

[0460] [Chemistry 105]

[0461]

[0462] [Example 2-1] Synthesis of Polymer P-1

[0463] Using the previously synthesized onium salt monomer a-1, monomers b1-1 and c-1 as shown in Table 1 below, and taking 3.34 g of V-601 (manufactured by Fujifilm and Koimitsu Chemical Co., Ltd.) and 139 g of MEK, a monomer-polymerization initiator solution was prepared. In another flask under nitrogen atmosphere, 46 g of MEK was added dropwise over 4 hours while stirring and heating to 80°C. After the addition was complete, the polymerization solution was stirred continuously for 2 hours while maintaining the temperature at 80°C, and then cooled to room temperature. The obtained polymerization solution was added dropwise to 3000 g of vigorously stirred hexane, and the precipitated polymer was separated by filtration. The obtained polymer was washed twice with 600 g of hexane and then vacuum dried at 50°C for 20 hours to obtain a white powder polymer P-1 (yield 85.2 g, 96% yield). The Mw of polymer P-1 is 9200, and the Mw / Mn ratio is 1.70. In addition, Mw is the converted value of styrene using DMF as a solvent.

[0464] [Examples 2-2~2-17, Comparative Examples 2-1~2-11] Synthesis of polymers P-2~P-17 and comparative polymers CP-1~CP-11

[0465] 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.

[0466] The solubility of each polymer in a 10% PGMEA solution was evaluated by turbidity measurement. Values ​​higher than 1 NTU were denoted as ×, and lower values ​​as 0. The results are shown in Tables 1 and 2.

[0467] [Table 1]

[0468]

[0469] [Table 2]

[0470]

[0471] [3] Preparation of chemically amplified resist composition

[0472] [Examples 3-1 to 3-24, Comparative Examples 3-1 to 3-18]

[0473] A solution was prepared by dissolving the predetermined components of the base polymers (P-1 to P-17) selected from the present invention, the comparative base polymers (CP-1 to CP-11), the acid generators (PAG-1 to PAG-4), and the quenchers (SQ-1 to SQ-3, AQ-1) as shown in Tables 3 and 4 below in a solvent containing 0.01% by mass of 3M FC-4430 as a surfactant. The solution was then filtered through a 0.2 μm Teflon (registered trademark) filter to prepare chemically amplified resist compositions (R-1 to R-24, CR-1 to CR-18).

[0474] [Table 3]

[0475]

[0476] [Table 4]

[0477]

[0478] In Tables 3 and 4, the solvents, quenchers (SQ-1~SQ-3, AQ-1) and acid generators (PAG-1~PAG-4) are as described below.

[0479] Solvent:

[0480] PGMEA (Propylene Glycol Monomethyl Ether Acetate)

[0481] DAA (diacetone alcohol)

[0482] Quenching agents: SQ-1~SQ-3, AQ-1

[0483] [Chemistry 106]

[0484]

[0485] • Acid generating agents: PAG-1~PAG-4

[0486] [Chemistry 107]

[0487]

[0488] [4] Evaluation of EUV lithography (1)

[0489] [Examples 4-1 to 4-24, Comparative Examples 4-1 to 4-18]

[0490] The chemically amplified resist compositions (R-1~R-24, CR-1~CR-18) shown in Tables 3 and 4 were spin-coated onto a Si substrate with a 20 nm thick silicon-containing spin-coated hard mask SHB-A940 (silicon content 43% by mass) manufactured by Shin-Etsu Chemical Industry Co., Ltd. A 50 nm thick resist film was fabricated by pre-baking at 100°C for 60 seconds using a hot plate. For the above resist film, an ASML EUV scanning exposure machine NXE3300 (NA 0.33, σ 0.9 / 0.6, dipole illumination) was used, while varying the exposure dose and focus (exposure pitch: 1 mJ / cm). 2 An LS pattern with a focal pitch of 0.020 μm was exposed on the wafer at an edge size of 18 nm and a pitch of 36 nm. After exposure, PEB was applied for 60 seconds at the temperatures shown in Tables 5 and 6. Then, immersion development was performed for 30 seconds with a 2.38% (w / w) TMAH aqueous solution, followed by rinsing with a surfactant-containing washing material and spin drying to obtain a positive LS pattern.

[0491] The obtained LS patterns were observed using a Hitachi Advanced Technology Co., Ltd. critical dimension SEM (CG6300), and the sensitivity, EL, LWR, and DOF were evaluated according to the methods described below. The results are shown in Tables 5 and 6.

[0492] [Sensitivity Evaluation]

[0493] Calculate the optimal exposure Eop (mJ / cm) for obtaining an LS pattern with a linewidth of 18nm and a pitch of 36nm. 2 This value is used as the sensitivity. The smaller the value, the higher the sensitivity.

[0494] [EL Review]

[0495] The exposure amount formed within ±10% (16.2~19.8nm) of the 18nm spacing width in the above LS pattern is calculated using the following formula (unit: %). The larger this value, the better the performance.

[0496] EL(%) = (|E1-E2| / Eop) × 100

[0497] E1: Optimal exposure for an LS pattern with a linewidth of 16.2nm and a pitch of 36nm.

[0498] E2: Optimal exposure for an LS pattern with a linewidth of 19.8 nm and a pitch of 36 nm.

[0499] Eop: Optimal exposure for LS patterns with a linewidth of 18nm and a pitch of 36nm.

[0500] [LWR Evaluation]

[0501] The dimensions of the LS pattern obtained by Eop irradiation are measured at 10 points along the length of the line. The value of three times the standard deviation (σ) (3σ) is taken as the LWR. The smaller this value, the more uniform the line width of the pattern with less roughness can be obtained.

[0502] [DOF Rating]

[0503] As an evaluation of focal depth, the focal range is determined within ±10% (16.2~19.8nm) of the 18nm dimension in the aforementioned LS pattern. The larger this value, the wider the focal depth.

[0504] [Table 5]

[0505]

[0506] [Table 6]

[0507]

[0508] As shown in Table 5, the chemically amplified resist composition using a base polymer containing repeating units from the onium salt monomer of the present invention exhibits good sensitivity and excellent EL, LWR, and DOF. Therefore, the chemically amplified resist composition of the present invention demonstrates its suitability as a material for EUV lithography.

[0509] On the other hand, according to the results shown in Table 6, when using onium salt monomers ca-1 to ca-6 (ca-1: the electron-withdrawing group substituted at the α-position of the sulfonic acid ion is a fluorine atom, ca-2: there is no electron-withdrawing group near the sulfonic acid ion, ca-3: the benzene ring is directly bonded to the sulfonic acid, ca-4: the electron-withdrawing group substituted at the β-position of the sulfonic acid ion is a fluorine atom, ca-5: the benzene ring is directly bonded to the sulfonic acid, and ca-6: the electron-withdrawing group substituted at the α-position of the sulfonic acid ion is a carboxyl group) that are different from those of the inventors, good photolithography properties cannot be obtained.

[0510] This specification includes the following inventions.

[0511] [1]: An onium salt monomer, characterized in that it is represented by the following general formula (A);

[0512] [Chemistry 108]

[0513]

[0514] [In the formula, m4 is an integer from 1 to 4; R] A It is a hydrogen atom or a methyl group;

[0515] R 1Each group is independently a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms (which may also contain heteroatoms), or an electron-withdrawing group, wherein the electron-withdrawing group is a halogen atom excluding fluorine, a cyano group, a nitro group, or any of the following groups having 1 to 20 carbon atoms: a hydrocarbon oxy group, a hydrocarbon thio group, a hydrocarbon carbonyl group, a hydrocarbon oxycarbonyl group, a hydrocarbon carbonyl oxy group, or a hydrocarbon sulfonyl group. 1 At least one of them is the electron-withdrawing group;

[0516] L A L B and L C Each of the following is independently a single bond, carbonyl group, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, carbamate bond, or may contain a carbonyl group, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond with 1 to 10 carbon atoms.

[0517] W is a single bond or a hydrocarbon group with 1 to 40 carbon atoms that may contain heteroatoms. The hydrocarbon group may also have at least one of oxygen, nitrogen, sulfur and halogen atoms.

[0518] X L1 It is a single bond, or may contain a heteroatom and a hydrocarbon group with 1 to 40 carbon atoms;

[0519] Z + It is a sulfonium cation represented by the following general formula (Z-1) or a monazine cation represented by the following general formula (Z-2);

[0520] [Chemistry 109]

[0521]

[0522] (where R is in the formula) ct1 ~R ct5 Each is an independent hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms; in addition, R ct1 and R ct2 They can also bond with each other and form rings together with the sulfur atoms they are bonded to.

[0523] [2]: Onium salt monomers such as [1], wherein is represented by any of the following general formulas (A1) to (A3);

[0524] [Chemical 110]

[0525]

[0526] (In the formula, m1 is an integer of 0 or 1; m2 is an integer of 1, 2 or 3 when m1 is 0, and an integer of 1, 2, 3, 4 or 5 when m1 is 1; m3 is an integer of 0, 1, 2, 3 or 4 when m1 is 0, and an integer of 0, 1, 2, 3, 4, 5 or 6 when m1 is 1; however, when m1 is 0, 1≤m2+m3≤4, and when m1 is 1, 1≤m2+m3≤6;)

[0527] R 3 It can be a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms; when m3 is 2 or more, each R 3 They can be the same or different, the complex R 3 They can also bond with each other and form rings together with the carbon atoms they bond with;

[0528] m4, R A R 1 X L1 L A L B L C and Z + Same as above.

[0529] [3]: Onium salt monomers such as [1] or [2], wherein the α-position of the sulfonic acid is substituted by a cyano or nitro group.

[0530] [4]: A monomeric photoacid generator composed of any one of the onium salt monomers in [1] to [3].

[0531] [5]: A polymer containing repeating units from monomeric photoacid generators such as [4].

[0532] [6]: Polymers such as [5], wherein the polymer further contains repeating units represented by the following formula (b1) or (b2);

[0533] [Chemistry 111]

[0534]

[0535] (where R is in the formula) A Each can be independently a hydrogen atom or a methyl group;

[0536] Y 1 It is a single bond, a phenylene or naphthylene group, or a linking group having 1 to 12 carbon atoms selected from ester bonds, ether bonds, and lactone rings. The phenylene, naphthylene group, and the linking group may also have at least one of the following: hydroxyl group, halogen atom, saturated hydrocarbon oxygen group having 1 to 8 carbon atoms, and saturated hydrocarbon carbonyl oxygen group having 2 to 8 carbon atoms.

[0537] Y 2 It is a single bond or an ester bond;

[0538] Y 3 It is a single bond, an ether bond, or an ester bond;

[0539] R 11 and R 12 Each is an unstable acid group;

[0540] R 13 It is a saturated hydrocarbon group with 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group with 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group with 2 to 5 carbon atoms;

[0541] R 14 It is a single bond or an alkane diene with 1 to 6 carbon atoms, and the alkane diene may also contain at least one selected from hydroxyl, saturated hydrocarbon oxygen with 1 to 8 carbon atoms, saturated hydrocarbon carbonyl oxygen with 2 to 8 carbon atoms, ether bond and ester bond;

[0542] (a is an integer between 0 and 4.)

[0543] [7]: A chemically amplified resist composition containing a polymer such as [6] as a base polymer.

[0544] [8]: The chemically amplified resist composition of [7] also contains at least one selected from organic solvents, quenchers, acid generators, surfactants and dissolution inhibitors.

[0545] [9]: A method for forming a pattern, comprising the following steps:

[0546] A resist film is formed on the substrate using a chemically amplified resist composition such as [7] or [8].

[0547] The resist film was exposed to high-energy rays and

[0548] The exposed resist film was developed using a developer.

[0549]

[10] : The pattern forming method of [9], 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.

[0550] Furthermore, the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any embodiment having a substantially the same structure as the technical concept described in the claims of the present invention, and performing the same effect, is included within the technical scope of the present invention.

Claims

1. A ononium salt monomer, characterized in that, It is represented by the following general formula (A); In the formula, m4 is an integer from 1 to 2; R A It is a hydrogen atom or a methyl group; R 1 Each is independently a hydrogen atom and an electron-withdrawing group, wherein the electron-withdrawing group is any one of cyano, nitro, alkyl carbonyl with 1 to 20 carbon atoms, alkyloxy carbonyl with 1 to 20 carbon atoms, and alkyl carbonyloxy with 1 to 20 carbon atoms. 1 At least one of them is the electron-withdrawing group; L A L B and L C Each can be independently a single bond, carbonyl group, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond; W is an alkylene group containing 1 to 40 carbon atoms, which may be an alkanediol, a cyclic saturated alkylene group, or an aryl group. Or, W is , , , or Where * represents L A and L B atomic bonds; X L1 It is a single bond or an alkylene group with 1 to 40 carbon atoms that optionally contains a halogen atom, and the alkylene group is an alkane dimethyl, a cyclic saturated alkylene group or an aryl group; Z + It is a sulfonium cation represented by the following general formula (Z-1); In the formula, R ct1 ~R ct3 Each is independently an aryl group containing halogen atoms with 6 to 30 carbon atoms; furthermore, R ct1 and R ct2 They can be arbitrarily bonded together with each other, and together with the sulfur atoms bonded to them, they form a ring.

2. The ononium salt monomer according to claim 1, wherein, is Any of the following general formulas (A1) to (A3) represents the following: In the formula, m1 is an integer of 0 or 1; m2 is an integer of 1, 2 or 3 when m1 is 0, and an integer of 1, 2, 3, 4 or 5 when m1 is 1; m3 is an integer of 0, 1, 2, 3 or 4 when m1 is 0, and an integer of 0, 1, 2, 3, 4, 5 or 6 when m1 is 1; however, when m1 is 0, 1≤m2+m3≤4, and when m1 is 1, 1≤m2+m3≤6; R 3 It is a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or an optional hydrocarbon group containing a halogen atom with 1 to 20 carbon atoms; when m3 is 2 or more, each R 3 They are the same or different from each other; m4, R A R 1 X L1 L A L B L C and Z + Same as above; Alternatively, the onium salt monomer is .

3. The onium salt monomer according to claim 1, wherein, The α-position of sulfonic acid is replaced by a cyano or nitro group.

4. A monomeric photoacid generator, comprising an onium salt monomer according to any one of claims 1 to 3.

5. A polymer comprising repeating units from the monomeric photoacid generator according to claim 4.

6. The polymer according to claim 5, wherein, The polymer also contains repeating units represented by formula (b1) or (b2); In the formula, R A Each can be independently a hydrogen atom or a methyl group; Y 1 It is a single bond, a phenylene or naphthylene group, or a linking group having 1 to 12 carbon atoms selected from ester bonds, ether bonds, and lactone rings, wherein the phenylene, naphthylene group, and the linking group optionally have at least one selected from hydroxyl, halogen atom, saturated hydrocarbon oxygen group having 1 to 8 carbon atoms, and saturated hydrocarbon carbonyl oxygen group having 2 to 8 carbon atoms. Y 2 It is a single bond or an ester bond; Y 3 It is a single bond, an ether bond, or an ester bond; R 11 and R 12 Each is an unstable acid group; R 13 It is a saturated hydrocarbon group with 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group with 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group with 2 to 5 carbon atoms; R 14 It is a single bond or an alkane diene with 1 to 6 carbon atoms, wherein the alkane diene may optionally contain at least one selected from hydroxyl, saturated hydrocarbon oxygen with 1 to 8 carbon atoms, saturated hydrocarbon carbonyl oxygen with 2 to 8 carbon atoms, ether bond and ester bond; a is an integer between 0 and 4.

7. A chemically amplified resist composition comprising the polymer according to claim 6 as a base polymer.

8. The chemically amplified resist composition according to claim 7 further comprises at least one selected from organic solvents, quenchers, acid generators, surfactants, and dissolution inhibitors.

9. A method for forming a pattern, comprising the following steps: A resist film is formed on a substrate using the chemically amplified resist composition according to claim 7. The resist film was exposed to high-energy rays and The exposed resist film was developed using a developer.

10. The pattern forming method according to claim 9, wherein, The high-energy ray can be an ArF excimer laser with a wavelength of 193 nm, a KrF excimer laser with a wavelength of 248 nm, an electron beam, or extreme ultraviolet light with a wavelength of 3-15 nm.

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