Chemically amplified positive resist composition and resist pattern forming method

Abstract

The invention relates to a chemically amplified positive resist composition and a resist pattern forming method. The present invention addresses the problem of providing, in optical lithography using high-energy rays, excellent solvent solubility and excellent lithography performance such as resolution, LER, and pattern shape, while preventing pattern collapse in the formation of fine patterns, and also providing a method for manufacturing the same. The present invention relates to a chemically amplified positive resist composition having excellent etching resistance, and a method for forming a pattern using the chemically amplified positive resist composition. The solution of the present invention is a chemically amplified positive resist composition comprising: a base polymer (A) which is a polymer having increased solubility in aqueous alkali due to the action of an acid, the present invention relates to a polymer which contains a repeating unit comprising an aromatic sulfonic acid anion represented by formula (A1-1) and a sulfonium cation represented by formula (A1-2), and a repeating unit represented by formula (A2), and which has increased solubility in aqueous alkali due to the action of an acid.

Description

Technical Field

[0001] This invention relates to chemically amplified positive resist compositions and methods for forming resist patterns. Background Technology

[0002] In recent years, the increasing integration of integrated circuits has necessitated the formation of finer patterns. The fabrication of patterns smaller than 0.2 μm primarily utilizes chemically amplified resist compositions using acid as a catalyst. Exposure sources in this process employ high-energy rays such as ultraviolet light, far-ultraviolet light, and electron beams (EB). EB lithography, in particular, is indispensable for the fabrication of blank photomasks in semiconductor manufacturing, especially as it is used in ultra-fine processing techniques. The resist compositions used in such optical lithography include positive resists that dissolve the exposed area to form a pattern, and negative resists that leave the exposed area intact to form a pattern. These can be easily selected by the user according to the desired resist pattern morphology.

[0003] Generally, EB (Edge Electrode) lithography involves sequentially irradiating the area outside the desired resist film with a fine-area EB without using a mask. For positive lithography, the area to be etched with the resist film is irradiated sequentially. For negative lithography, the area to be etched with the resist film is irradiated sequentially. This is a scanning operation across the entire finely segmented area of ​​the processing surface, thus taking longer than a single exposure using a photomask. To avoid reducing throughput, the resist film must have high sensitivity. Furthermore, the longer lithography time makes it easy for differences to arise between the initial and later lithographic areas; the historical stability of the exposed areas in a vacuum is an important performance requirement. Moreover, in the particularly important application of blank photomask processing, surface materials such as chromium compound films (e.g., chromium oxide on the photomask substrate) can easily affect the pattern shape of the chemically amplified resist film. To maintain high resolution and preserve the etched shape, maintaining the rectangular pattern outline of the resist film regardless of the substrate type is also an important performance requirement.

[0004] The sensitivity and pattern profile control of the aforementioned photoresist films have been improved through various modifications, including the selection and combination of materials used in the photoresist composition and processing conditions. One such improvement addresses the issue of acid diffusion, which significantly affects the resolution of chemically amplified photoresist films. Photomask processing requires that the shape of the obtained photoresist pattern does not change over time up to post-exposure heating (PEB). The large time-dependent variation is due to acid diffusion caused by exposure. This acid diffusion problem is not limited to photomask processing; it also has a significant impact on sensitivity and resolution in general photoresist compositions, hence much research has been conducted.

[0005] Patent documents 1 and 2 describe examples of suppressing acid diffusion and reducing roughness by increasing the volume of acid generated by an acid-generating agent. However, in such acid-generating agents, the suppression of acid diffusion is insufficient, and it is desirable to develop acid-generating agents with smaller diffusion.

[0006] Furthermore, Patent Documents 3-6 describe examples of controlling acid diffusion by bonding the sulfonic acid generated during exposure to the resin used in the resist composition. This method of suppressing acid diffusion by introducing repeating units that generate acid during exposure into the base polymer is effective for obtaining patterns with low line edge roughness (LER). However, depending on the structure and introduction rate of such repeating units, there are also cases where the solubility of the base polymer containing the repeating units that generate acid during exposure becomes problematic in organic solvents.

[0007] Additionally, polymers with a large number of aromatic backbones with acidic side chains, such as polyhydroxystyrene, are used as resist compositions for KrF lithography. However, they exhibit significant absorption for light around 200 nm, and therefore are not used as resist compositions for ArF lithography. Nevertheless, for resist compositions for EB lithography and extreme ultraviolet (EUV) lithography, which are powerful techniques for forming patterns with smaller processing limits than ArF lithography, materials with high etch resistance are important considerations.

[0008] For the base polymers of resist compositions for positive EB lithography and EUV lithography, materials soluble in alkaline developers are mainly used. These materials utilize acid generated from a photoacid generator by irradiation with high-energy rays as a catalyst, and deprotect acid-indestructible groups (acid-decomposing protecting groups) that shield the acidic functional groups of the phenol side chains of the base polymer. The aforementioned acid-indestructible groups mainly include tert-alkyl, tert-butoxycarbonyl, and acetal groups. While using protecting groups with lower activation energies, such as acetal groups, for deprotection can yield highly sensitive resist films, insufficient suppression of acid diffusion can lead to deprotection reactions in unexposed areas of the resist film, resulting in LER degradation and decreased dimensional uniformity of pattern linewidth (CDU).

[0009] With the increasing miniaturization of resist patterns in recent years, issues such as resist pattern collapse during development and poor resistance during etching have become problems. While the introduction of repeating units that generate acid during exposure has somewhat suppressed acid diffusion, there is still room for improvement in various photolithographic properties, resist pattern collapse, and etching resistance. To meet future miniaturization requirements, the development of polymer-based acid generators that balance photolithographic performance with resist pattern collapse and etching resistance is also crucial.

[0010] Existing technical documents

[0011] Patent documents

[0012] [Patent Document 1] Japanese Patent Application Publication No. 2009-053518

[0013] [Patent Document 2] Japanese Patent Application Publication No. 2010-100604

[0014] [Patent Document 3] Japanese Patent No. 4425776

[0015] [Patent Document 4] Japanese Patent No. 5201363

[0016] [Patent Document 5] Japanese Patent No. 5231357

[0017] [Patent Document 6] International Publication No. 2008 / 081832 Summary of the Invention

[0018] [The problem that the invention aims to solve]

[0019] In recent years, there has been a demand not only for line spacing (LS), isolated lines (IL), and isolated spacing (IS), but also for resist compositions with excellent hole pattern shape and excellent etching resistance after pattern formation.

[0020] The present invention is based on the foregoing circumstances and aims to provide a chemically amplified positive resist composition that exhibits good solvent solubility, excellent lithographic performance such as resolution, LER, and pattern shape, especially in optical lithography using high-energy rays such as KrF excimer lasers, ArF excimer lasers, EB, and EUV, while also resisting pattern collapse and exhibiting excellent etching resistance during the formation of fine patterns, and a pattern formation method using the chemically amplified resist composition.

[0021] [Methods for solving the problem]

[0022] In order to achieve the aforementioned objectives, the inventors of this application conducted repeated and in-depth research and discovered that, as a polymer-bonded acid generator, a polymer containing repeating units of an onium salt having a polymeric group, an aromatic sulfonic acid anion, and a triarylsulfonium cation having an iodine atom on the aromatic ring, as well as repeating units having phenolic hydroxyl groups, is used as a chemically amplified positive resist composition. This results in good solvent solubility, excellent lithographic performance such as resolution, LER, and pattern shape, especially under EB and EUV lithography. At the same time, it resists pattern collapse during the formation of fine patterns and has excellent etching resistance, thus completing this invention.

[0023] That is, the present invention provides the following chemically amplified positive resist composition and resist patterning method.

[0024] 1. A chemically amplified positive resist composition, comprising:

[0025] The basic polymer (A) is a polymer whose solubility in alkaline aqueous solutions increases due to the action of acid. It comprises repeating units consisting of an aromatic sulfonic acid anion represented by formula (A1-1) and a sulfonium cation represented by formula (A1-2), and repeating units represented by formula (A2), and whose solubility in alkaline aqueous solutions increases due to the action of acid.

[0026] [Chemistry 1]

[0027]

[0028] In the formula, n1 is 0 or 1, and n2 is 0, 1, 2, 3 or 4 when n1 is 0, and 0, 1, 2, 3, 4, 5 or 6 when n1 is 1.

[0029] R A It is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0030] R 1 It can be a halogen atom, nitro group, cyano group, hydroxyl group, or a hydrocarbon 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, and when n2 is 2 or more, each R 1 They can be the same or different; multiple Rs 1 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0031] X 1 It is a single bond, ether bond, ester bond, or amide bond.

[0032] [Chemistry 2]

[0033]

[0034] In the formula, m1 is 0 or 1, m2 is 0 or 1, m3 is 0 or 1, m4 is 0, 1, 2, 3 or 4, m5 is 0, 1, 2, 3 or 4, m6 is 0, 1, 2, 3, 4, 5 or 6, m7 is 0, 1, 2, 3, 4, 5 or 6, m8 is 0, 1 or 2, m9 is 0, 1 or 2, m10 is 0, 1 or 2, m11 is 0 or 1, m12 is 0, 1, 2, 3 or 4, m13 is 0, 1 or 2, m14 is 0, 1 or 2, but m1 When m1 is 0, then 0 ≤ m6 + m9 ≤ 4; when m1 is 1, then 0 ≤ m6 + m9 ≤ 6; when m2 is 0, then 0 ≤ m7 + m10 ≤ 4; when m2 is 1, then 0 ≤ m7 + m10 ≤ 6; when m3 is 0, then 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, then 1 ≤ m4 + m5 + m8 + m14 ≤ 6; when m11 is 0, then 0 ≤ m12 + m13 ≤ 4; when m11 is 1, then 0 ≤ m12 + m13 ≤ 6; and also, m4 + m12 ≥ 1.

[0035] R F1 ~R F3 Each R is independently a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms. When m5 is 2 or more, each R F1 They can be the same or different. When m6 is 2 or more, each R F2 They can be the same or different. When m7 is 2 or more, each R F3 They can be the same or different.

[0036] R 2 ~R 5 It can be a halogen atom other than iodine and fluorine atoms, a nitro group, a cyano group, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms, an hydroxyl group with 1 to 20 carbon atoms that may contain heteroatoms, or a thiol group with 1 to 20 carbon atoms that may contain heteroatoms. When m8 is 2, there are 2 R groups. 2 They can be the same or different, 2 Rs 2 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m9 is 2, there are 2 R atoms. 3 They can be the same or different, 2 Rs 3 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m10 is 2, there are 2 R atoms. 4 They can be the same or different, 2 Rs 4 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m13 is 2, there are 2 R atoms. 5 They can be the same or different, 2 Rs 5 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0037] Furthermore, the S in the sulfonium cation +Directly bonded aromatic rings can also bond to each other and to S + Together they form a ring.

[0038] L A and L B Each bond can be independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond.

[0039] X L It is a single bond, or may contain a heteroatom, a hydrocarbon group with 1 to 40 carbon atoms.

[0040] [Chemistry 3]

[0041]

[0042] In the formula, a1 is 0 or 1, a2 is 0, 1 or 2, a3 is an integer satisfying 0 ≤ a3 ≤ 5 + 2(a2) - a4, and a4 is 1, 2 or 3.

[0043] R A It is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0044] R 11 It is a halogen atom, or a 1-6 carbon saturated hydrocarbon group that can be substituted by a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl group that can be substituted by a halogen atom.

[0045] A 1 It is a single bond or a saturated alkylene group with 1 to 10 carbon atoms, and the -CH2- of the saturated alkylene group can also be replaced by -O-.

[0046] 2. As in 1., a chemically amplified positive resist composition, wherein the sulfonium cation represented by formula (A2) is represented by formula (A1-2-1).

[0047] [Chemistry 4]

[0048]

[0049] In the formula, m4~m10, m12~m14, R F1 ~R F3 R 2 ~R 5 L A L B and X L Same as above.

[0050] 3. The chemically amplified positive resist composition as described in 2, wherein the sulfonium cation represented by formula (A1-2-1) is represented by formula (A1-2-2).

[0051] [Chemistry 5]

[0052]

[0053] In the formula, m4~m10, R F1 ~R F3 and R 2 ~R 5 Same as above.

[0054] 4. A chemically amplified positive resist composition as described in any of 1 to 3, wherein the repeating unit represented by formula (A2) is represented by formula (A2-1).

[0055] [Chemistry 6]

[0056]

[0057] In the formula, R A a4 is the same as described above.

[0058] 5. A chemically amplified positive resist composition as described in any one of 1 to 4, wherein the polymer further comprises at least one repeating unit selected from the repeating units represented by formula (A3-1) and formula (A3-2).

[0059] [Chemistry 7]

[0060]

[0061] In the formula, b1 is 0 or 1, b2 is 0, 1 or 2, b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2(b2) - b4, b4 is 1, 2 or 3, and b5 is 0 or 1.

[0062] R A It is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0063] R 12 It is a halogen atom, or a 1-6 carbon saturated hydrocarbon group that can be substituted by a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl group that can be substituted by a halogen atom.

[0064] A 2 It is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms, and part of the -CH2- of this saturated hydrocarbon group can also be replaced by -O-.

[0065] When b4 is 1, X is an acid-labile group. When b4 is 2 or 3, X is either a hydrogen atom or an acid-labile group independently, but at least one of them is an acid-labile group.

[0066] c1 is 0, 1, or 2; c2 is 0, 1, or 2; c3 is 0, 1, 2, 3, 4, or 5; c4 is 0, 1, or 2.

[0067] R 13 and R 14 Each is independently a hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. 13 and R 14 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0068] R 15 Each is independently a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkoxy group having 1 to 5 carbon atoms.

[0069] R 16 Each can be an independent hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms.

[0070] A 3 It is a single bond, phenylene, naphthylene, or *-C(=O)-OA 31 -, A 31 It is an aliphatic alkylene group, phenylene group, or naphthylene group having 1 to 20 carbon atoms. The aliphatic alkylene group may also include at least one selected from hydroxyl, ether bond, ester bond, and lactone ring. * indicates an atomic bond with a carbon atom of the main chain.

[0071] 6. A chemically amplified positive resist composition as described in any one of 1 to 5, wherein the polymer further comprises at least one repeating unit selected from the repeating units represented by formula (B3), formula (B4), and formula (B5).

[0072] [Chemistry 8]

[0073]

[0074] In the formula, d is 0, 1, 2, 3, 4, 5, or 6; e is 0, 1, 2, 3, or 4; f1 is 0 or 1; f2 is 0, 1, or 2; and f3 is 0, 1, 2, 3, 4, or 5.

[0075] R A It is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0076] R 17 and R 18 Each can be independently a hydroxyl group, a halogen atom, a 1-6 carbon saturated hydrocarbon group that can be substituted with a halogen atom, a 1-6 carbon saturated hydrocarbon oxygen group that can be substituted with a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl oxygen group that can be substituted with a halogen atom.

[0077] R 19It can be a halogen atom, nitro group, cyano group, saturated hydrocarbon group with 1 to 20 carbon atoms, saturated hydrocarbon oxygen group with 1 to 20 carbon atoms, saturated hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms, saturated hydrocarbon oxygen hydrocarbon group with 2 to 20 carbon atoms, or saturated hydrocarbon thioalkyl hydrocarbon group with 2 to 20 carbon atoms. When f2 is 1 or 2, it can also be a hydroxyl group.

[0078] A 4 It is a single bond or a saturated alkylene group with 1 to 10 carbon atoms, and the -CH2- of the saturated alkylene group can also be replaced by -O-.

[0079] 7. A chemically amplified positive resist composition as described in any one of 1 to 6, wherein the content of repeating units having an aromatic ring backbone in the (A) base polymer is 60 mol% or more.

[0080] 8. A chemically amplified positive resist composition as described in any of 1 to 7, further comprising (B) a quencher.

[0081] 9. A chemically amplified positive resist composition as described in any of 1 to 8, further comprising (C) an organic solvent.

[0082] 10. A chemically amplified positive resist composition as described in any one of 1 to 9, further comprising (D) a polymer containing fluorine atoms, the (D) fluorine-containing polymer comprising:

[0083] The repeating unit is selected from at least one of the repeating units represented by the following formula (D1), the repeating unit represented by the following formula (D2), the repeating unit represented by the following formula (D3), and the repeating unit represented by the following formula (D4).

[0084] [Chemistry 9]

[0085]

[0086] In the formula, h is 1, 2, or 3.

[0087] R B Each is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0088] R 201 R 202 R 204 and R 205 Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms.

[0089] R 203 R 206 R 207 and R 208 Each is independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, a fluorinated hydrocarbon group having 1 to 15 carbon atoms, or an acid-labile group, R 203 R206 R 207 and R 208 When the group is a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond or a carbonyl group can also be inserted between the carbon-carbon bonds.

[0090] Z 1 It is a (h+1) valence hydrocarbon group with 1 to 20 carbon atoms or a (h+1) valence fluorinated hydrocarbon group with 1 to 20 carbon atoms.

[0091] 11. A chemically amplified positive resist composition as described in 10, wherein the fluorine-containing polymer further comprises at least one repeating unit selected from the repeating units represented by formula (D5) and formula (D6).

[0092] [Chemistry 10]

[0093]

[0094] In the formula, x is 1, 2, or 3, y is an integer satisfying 0 ≤ y ≤ 5 + 2z - x, and z is 0 or 1.

[0095] R C Each can be independently a hydrogen atom or a methyl group.

[0096] R 209 It is a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, which may also have hydrogen atoms or groups containing heteroatoms inserted between carbon-carbon bonds.

[0097] R 210 It can also be a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, into which heteroatoms can be inserted between carbon-carbon bonds.

[0098] R 211 It is a saturated hydrocarbon group with 1 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom. Part of the -CH2- of this saturated hydrocarbon group may also be replaced by an ester bond or an ether bond.

[0099] Z 2 It is a single bond, *-C(=O)-O- or *-C(=O)-NH-.

[0100] Z 3 It is a single bond, -O-, *-C(=O)-OZ 31 -Z 32 -or *-C(=O)-NH-Z 31 -Z 32 -, Z 31 It is a single bond or a saturated alkylene group with 1 to 10 carbon atoms, Z 32 It is a single bond, ester bond, ether bond, or sulfonamide bond.

[0101] * represents an atomic bond with a carbon atom in the main chain.

[0102] 12. A chemically amplified positive resist composition as described in any of 1 to 11, further comprising (E) an acid generating agent.

[0103] 13. A method for forming a resist pattern, comprising the following steps:

[0104] A resist film is formed on a substrate using a chemically amplified positive resist composition as described in any of 1 to 12, the resist film is patterned using high-energy rays, and the patterned resist film is developed using an alkaline developer.

[0105] 14. The method for forming a resist pattern as in 13, wherein the high-energy ray is a KrF excimer laser, an ArF excimer laser, extreme ultraviolet light, or an electron beam.

[0106] 15. A method for forming a resist pattern as described in 13 or 14, wherein the outermost surface of the substrate is composed of a material containing at least one selected from chromium, silicon, tantalum, molybdenum, cobalt, nickel, tungsten, and tin.

[0107] 16. A method for forming a resist pattern as described in any one of 13 to 15, wherein the substrate is a transmissive or reflective blank mask.

[0108] 17. A transmissive or reflective blank mask, coated with a chemically amplified positive resist composition as described in any one of 1 to 12.

[0109] [The effects of the invention]

[0110] The chemically amplified positive resist composition of the present invention exhibits extremely high resolution in microfabrication technologies, especially EB lithography and EUV lithography, and can provide patterns with small LER (Low Etching Resistant). Furthermore, since the resist pattern also exhibits excellent etch resistance after formation, it is suitable as a chemically amplified positive resist material. Attached Figure Description

[0111] [ Figure 1 [ ] is the nuclear magnetic resonance spectrum of the onium salt type monomer A1-1 synthesized in Synthesis Example 1-1. 1 H-NMR / DMSO-d6). Detailed Implementation

[0112] The present invention will now be described in detail. Furthermore, in the following description, depending on the structure represented by the chemical formula, there may be asymmetric carbons, and thus mirror-image isomers and non-mirror-image isomers may exist. In such cases, a single formula is used to represent these isomers. These isomers may be used individually or as a mixture of two or more.

[0113] [Chemical amplification positive resist composition]

[0114] [(A) Basic Polymer]

[0115] The resist composition of the present invention comprises a base polymer as component (A), which contains a polymer that decomposes under the action of acid and has increased solubility in alkaline developer.

[0116] The aforementioned polymer comprises repeating units (hereinafter also referred to as repeating unit A1) of onium salts consisting of aromatic sulfonic acid anions having polymerizable groups and triarylsulfonium cations having iodine atoms on the aromatic rings.

[0117] The anion of repeating unit A1 is represented by the following formula (A1-1).

[0118] [Chemistry 11]

[0119]

[0120] In formula (A1-1), n1 is 0 or 1. When n1 is 0, it is a benzene ring; when n1 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with n1 of 0 is preferred. n2 is 0, 1, 2, 3, or 4 when n1 is 0, and 0, 1, 2, 3, 4, 5, or 6 when n1 is 1. Considering the availability of raw materials, n2 of 0, 1, 2, 3, or 4 is preferred, with 0, 1, or 2 being even better.

[0121] In equation (A1-1), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Among these, hydrogen atoms and methyl groups are preferred, with hydrogen atoms being the most desirable.

[0122] In equation (A1-1), R 1It can be a halogen atom, nitro group, cyano group, hydroxyl group, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms, or a hydrocarbon oxy group with 1 to 20 carbon atoms that may contain heteroatoms. The aforementioned halogen atom is preferably a fluorine atom, chlorine atom, bromine atom, or iodine atom, with fluorine or iodine atom being more preferred. Furthermore, the hydrocarbon portion of the aforementioned hydrocarbon group, hydrocarbon oxy group, and hydrocarbon sulfide group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, decadecyl, heptadecyl, octadecyl, nonadecanyl, and icosyl; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these. Among these, aryl is preferred. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. This results in the possible inclusion of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), and haloalkyl groups. Also, when n2 is 2 or more, each R... 1 They can be the same or different.

[0123] Furthermore, when n² is 2 or more, multiple R... 1 They can also bond to each other and form rings together with the carbon atoms they are bonded to. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and part of the -CH2- in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, etc. As a result, they can also contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0124] In formula (A1-1), X 1It can be a single bond, an ether bond, an ester bond, or an amide bond. Among these, single bonds or ester bonds are preferred, with single bonds being even better.

[0125] Specific examples of aromatic sulfonic acid anions represented by formula (A1-1) are shown below, but are not limited to these. Furthermore, in the following formula, R... A Same as above.

[0126] [Chemistry 12]

[0127]

[0128] [Chemistry 13]

[0129]

[0130] The sulfonium cation of repeating unit A1 is represented by the following formula (A1-2).

[0131] [Chemistry 14]

[0132]

[0133] In formula (A1-2), m1 is 0 or 1. When m1 is 0, it is a benzene ring; when m1 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m1 = 0 is preferred. m2 is 0 or 1. When m2 is 0, it is a benzene ring; when m2 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m2 = 0 is preferred. m3 is 0 or 1. When m3 is 0, it is a benzene ring; when m3 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m3 = 0 is preferred.

[0134] In formula (A1-2), m4 is 0, 1, 2, 3, or 4. The more iodine atoms in the cationic structure, the less solvent-soluble it becomes, and there is a risk of precipitation in the resist composition. Therefore, it is preferable for m4 to be 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0135] In formula (A1-2), m5 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, m5 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better. m6 is 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, m6 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better. m7 is 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, m7 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0136] In formula (A1-2), m8 is 0, 1, or 2. Considering the availability of raw materials, m8 is preferably 0 or 1. m9 is 0, 1, or 2. Considering the availability of raw materials, m9 is preferably 0 or 1. m10 is 0, 1, or 2. Considering the availability of raw materials, m10 is preferably 0 or 1.

[0137] In formula (A1-2), m11 is 0 or 1. When m11 is 0, it is a benzene ring; when m11 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m11 of 0 is preferred.

[0138] In formula (A1-2), m12 is 0, 1, 2, 3, or 4. Since the more iodine atoms in the cationic structure, the less solvent-soluble it becomes and the more likely it is to precipitate in the resist composition, m12 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0139] In formula (A1-2), m13 is 0, 1, or 2. Considering the availability of raw materials, m13 is preferably 0 or 1. m14 is 0, 1, or 2. Considering the synthesis, m14 is preferably 0 or 1.

[0140] However, when m1 is 0, then 0 ≤ m6 + m9 ≤ 4; when m1 is 1, then 0 ≤ m6 + m9 ≤ 6. When m2 is 0, then 0 ≤ m7 + m10 ≤ 4; when m2 is 1, then 0 ≤ m7 + m10 ≤ 6. When m3 is 0, then 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, then 1 ≤ m4 + m5 + m8 + m14 ≤ 6. When m11 is 0, then 0 ≤ m12 + m13 ≤ 4; when m11 is 1, then 0 ≤ m12 + m13 ≤ 6. Also, m4 + m12 ≥ 1.

[0141] In equation (A1-2), R F1 ~R F3 Each R is independently a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms. Among these, trifluoromethyl, trifluoromethoxy, and trifluorothiomethoxy are preferred. When m5 is 2 or more, each R F1 They can be the same or different. When m6 is 2 or more, each R F2 They can be the same or different. When m7 is 2 or more, each R F3 They can be the same or different.

[0142] In equation (A1-2), R 2 ~R 5 Each group can be independently composed of a halogen atom other than iodine or fluorine, a nitro group, a cyano group, a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms, an alkyloxy group with 1 to 20 carbon atoms that may contain heteroatoms, or an alkylthio group with 1 to 20 carbon atoms that may contain heteroatoms. The hydrocarbon portion of the aforementioned hydrocarbon group, alkyloxy group, and alkylthio group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be cited in the description of formula (A1-1) under R. 1The same applies to the hydrocarbon groups exemplified above. Furthermore, some or all of the hydrogen atoms in the hydrocarbon portions of the aforementioned hydrocarbon groups, hydroxyl groups, and thiol groups may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned hydrocarbon groups may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, the hydrocarbon groups may also include hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0143] Also, when m8 is 2, there are 2 Rs. 2 They can be the same or different, 2 Rs 2 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m9 is 2, there are 2 R atoms. 3 They can be the same or different, 2 Rs 3 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m10 is 2, the two R atoms... 4 They can be the same or different, 2 Rs 4 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m13 is 2, there are 2 R atoms. 5 They can be the same or different, 2 Rs 5 They can also bond to each other and form rings together with the carbon atoms they are bonded to. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and part of the -CH2- in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, etc. As a result, they can also contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0144] Furthermore, S is directly bonded to the sulfonium cation represented by formula (A1-2). + The aromatic rings can also bond with each other and with S. + Together they form a ring. Specific examples of the aforementioned ring structure can be exemplified by the following formulas, etc.

[0145]

[0146] In the formula, the dashed lines represent atomic bonds.

[0147] In formula (A1-2), L A and L BEach bond can be independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Among these, L... A Single bonds, ether bonds, ester bonds, or sulfonate bonds are preferred, with ester bonds or sulfonate bonds being even more preferred. L B Single bonds, ether bonds, or ester bonds are preferred, with single bonds being even better.

[0148] In formula (A1-2), X L It is a single-bonded, or possibly heteroatom-containing, hydrocarbon group with 1 to 40 carbon atoms. The aforementioned hydrocarbon group can be straight-chain, branched, or cyclic; specific examples include alkane diols and divalent saturated cyclic hydrocarbon groups. The aforementioned heteroatom can include oxygen, nitrogen, and sulfur atoms.

[0149] X L The expression may also include a hydrocarbon group with 1 to 40 carbon atoms containing heteroatoms, preferably as shown below. Furthermore, in the following formula, * indicates a group related to L. A and L B The key.

[0150] [Chemistry 16]

[0151]

[0152] [Chemistry 17]

[0153]

[0154] [Chemistry 18]

[0155]

[0156] Among these, X L -0~X L -3, X L -29~X L -34 and X L -47~X L -49 is better, X L -0~X L -2、X L -29 and X L -47 is better.

[0157] The sulfonium cation represented by formula (A1-2) should preferably be represented by the following formula (A1-2-1).

[0158] [Chemistry 19]

[0159]

[0160] In the formula, m4~m10, m12~m14, R F1 ~R F3 R2 ~R 5 L A L B and X L Same as above.

[0161] The sulfonium cation represented by formula (A1-2-1) should preferably be represented by formula (A1-2-2).

[0162] [Chemistry 20]

[0163]

[0164] In the formula, m4~m10, R F1 ~R F3 and R 2 ~R 5 Same as above.

[0165] Specific examples of sulfonium cations represented by formula (A1-2) are shown below, but are not limited to these. Furthermore, in the following formula, Me is a methyl group.

[0166] [Chemistry 21]

[0167]

[0168] [Chemistry 22]

[0169]

[0170] [Chemistry 23]

[0171]

[0172] [Chemistry 24]

[0173]

[0174] [Chemistry 25]

[0175]

[0176] [Chemistry 26]

[0177]

[0178] [Chemistry 27]

[0179]

[0180] [Chemistry 28]

[0181]

[0182] [Chemistry 29]

[0183]

[0184] [Chemistry 30]

[0185]

[0186] [Chemistry 31]

[0187]

[0188] [Chemistry 32]

[0189]

[0190] [Chemistry 33]

[0191]

[0192] [Chemistry 34]

[0193]

[0194] [Chemistry 35]

[0195]

[0196] [Chemistry 36]

[0197]

[0198] [Chemistry 37]

[0199]

[0200] [Chemistry 38]

[0201]

[0202] [Chemistry 39]

[0203]

[0204] [Chemistry 40]

[0205]

[0206] [Chemistry 41]

[0207]

[0208] [Chemistry 42]

[0209]

[0210] [Chemistry 43]

[0211]

[0212] [Chemistry 44]

[0213]

[0214] [Chemistry 45]

[0215]

[0216] [Chemistry 46]

[0217]

[0218] [Chemistry 47]

[0219]

[0220] [Chemistry 48]

[0221]

[0222] Specific examples of repeating unit A1 can be any combination of the aforementioned anions and cations.

[0223] Methods for synthesizing monomers from repeating unit A1 include those described in Japanese Patent Application Publication No. 2010-155824 and Japanese Patent No. 7067271. The aforementioned manufacturing method is only one example, and the manufacturing method of monomers from repeating unit A1 is not limited to these.

[0224] The structural features of repeating unit A1 can be exemplified by the onmium salt composed of aromatic sulfonic acid anions with polymerizable groups directly bonded to the aromatic ring and triarylsulfonium cations containing iodine atoms. Aromatic sulfonic acid anions with polymerizable groups directly bonded to the aromatic ring will generate acid upon exposure; since the aromatic sulfonic acid is directly bonded to the polymer backbone, acid diffusion can be controlled to a high degree. Furthermore, the aromatic ring interacts with other copolymerizing units containing aromatic rings (π-π stacking interaction), exhibiting a regular and close arrangement, thus suppressing pattern collapse. On the other hand, aromatic sulfonic acid anions with polymerizable groups directly bonded to the aromatic ring do not have very high organic solvent solubility. Furthermore, due to the presence of iodine atoms in the triarylsulfonium cation, solubility further decreases; however, by introducing multiple fluorine atoms onto the aromatic ring of the cation, organic solvent solubility can be ensured. Furthermore, the iodine and fluorine atoms in the cations possess electron attraction, thus lowering the energy level of the lowest unoccupied molecular orbital (LUMO) in frontier molecular orbital theory. This makes the cations more receptive to secondary electrons, promoting cation decomposition and efficient acid generation, thereby increasing sensitivity. In the exposed section, due to the efficient decomposition of the cations, sufficient acid is generated, allowing for efficient deprotection of the protecting groups of the base polymer. The aromatic sulfonic acid bonded to the main chain of the base polymer is readily soluble in the alkaline developer, thus increasing the dissolution rate. On the other hand, in the unexposed section, the iodine atoms in the triarylsulfonium cation exhibit resistance to dissolution in the alkaline developer, reducing film loss in the unexposed section. Therefore, the dissolution contrast is improved. Through these synergistic effects, the chemically amplified positive resist composition of the present invention exhibits high sensitivity and low acid diffusion, resulting in good resolution and LER, and enabling the formation of patterns resistant to pattern collapse, making it suitable for the formation of fine patterns.

[0225] The repeating unit A1 is suitable for use as a polymer-bonded photoacid generator.

[0226] The aforementioned polymer further comprises a repeating unit A2 having phenolic hydroxyl groups, represented by the formula (A2).

[0227] [Chemistry 49]

[0228]

[0229] In formula (A2), a1 is 0 or 1. a2 is 0, 1, or 2; 0 represents the benzene skeleton, 1 represents the naphthalene skeleton, and 2 represents the anthracene skeleton. a3 is an integer satisfying 0 ≤ a3 ≤ 5 + 2(a2) - a4. a4 is 1, 2, or 3. When a2 is 0, it is preferable that a3 is 0, 1, 2, or 3, and a4 is preferably 1, 2, or 3. When a2 is 1 or 2, it is preferable that a3 is 0, 1, 2, 3, or 4, and a4 is preferably 1, 2, or 3.

[0230] In equation (A2), RA It is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0231] In equation (A2), R 11 It can be a halogen atom, nitro group, cyano group, or a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted with a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that can be substituted with a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that can be substituted with a halogen atom. The aforementioned saturated hydrocarbon group, as well as the saturated hydrocarbon oxygen group and the saturated hydrocarbon carbonyl oxygen group, can be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, butyl, pentyl, hexyl, and their structural isomers; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; and groups obtained by combining these. If the number of carbon atoms is below the upper limit, the solubility in alkaline developing solutions is good. When a3 is 2 or more, each R... 11 They can be the same or different.

[0232] In formula (A2), A 1 It is a single bond or a saturated alkylene group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated alkylene group can also be replaced by -O-. The aforementioned saturated alkylene group can be linear, branched, or cyclic. Specific examples include alkylene groups with 1 to 10 carbon atoms such as methylene, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, and their structural isomers; cyclic saturated alkylene groups with 3 to 10 carbon atoms such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and groups obtained by combining these. When the aforementioned saturated alkylene group contains an ether bond, when a1 in formula (A2) is 1, it can be inserted anywhere except between the carbon atom at the α-position and the carbon atom at the β-position for the ester oxygen atom. Furthermore, when a1 is 0, the atom bonded to the main chain becomes an ether oxygen atom, and a second ether bond can be inserted at any position except between the carbon atom at the α-position and the carbon atom at the β-position for this ether oxygen atom. Also, if the number of carbon atoms in the aforementioned saturated hydrocarbon group is 10 or less, sufficient solubility in alkaline developing solution can be obtained, thus it is ideal.

[0233] a1 is 0 and A 1 When it is a single bond, that is, the aromatic ring is directly bonded to the polymer backbone (i.e., it does not have a linking group (-C(=O)-OA)). 1 When repeating unit A2, preferred examples include units derived from 3-hydroxystyrene, 4-hydroxystyrene, 5-hydroxy-2-vinylnaphthalene, 6-hydroxy-2-vinylnaphthalene, etc. In particular, repeating units represented by the following formula (A2-1) are preferred.

[0234] [Transformation 50]

[0235]

[0236] In the formula, R A a4 is the same as described above.

[0237] a1 is 0 and A 1 It is a single bond (i.e., it does not have a linking group (-C(=O)-OA)). 1 When repeating unit A2, preferred examples are listed below, but are not limited to these. Furthermore, in the following formula, R... A Same as above.

[0238] [Chemistry 51]

[0239]

[0240] [Chemistry 52]

[0241]

[0242] [Chemistry 53]

[0243]

[0244] [Chemistry 54]

[0245]

[0246] [Chemistry 55]

[0247]

[0248] a1 is 1 (i.e., having -C(=O)-OA as a linking group). 1 When -), preferred examples of repeating unit A2 include those shown below, but are not limited to these. Furthermore, in the following formula, R... A Same as above.

[0249] [Chemistry 56]

[0250]

[0251] [Chemistry 57]

[0252]

[0253] [Chem.58]

[0254]

[0255] [Chemistry 59]

[0256]

[0257] [Transformation 60]

[0258]

[0259] [Chemistry 61]

[0260]

[0261] The content of repeating unit A2 in the aforementioned polymer is preferably 30-90 mol%, and more preferably 40-85 mol%. However, if the polymer described later contains at least one of the repeating units represented by formula (A4) and formula (A5) that provides higher etch resistance, and this unit has a phenolic hydroxyl group as a substituent, then the ratio is also preferably within the aforementioned range. Repeating unit A2 can be used alone or in combination of two or more.

[0262] The aforementioned polymer provides the characteristic that the exposed portion of the positive resist component is soluble in alkaline developer. Therefore, it is preferable to include repeating units with acidic functional groups protected by acid-insecure groups, that is, repeating units protected by acid-insecure groups and soluble in alkali due to the action of acid (hereinafter also referred to as repeating unit A3).

[0263] The best repeating unit A3 can be represented by the following formula (A3-1) (hereinafter also referred to as repeating unit A3-1).

[0264] [Chemistry 62]

[0265]

[0266] In equation (A3-1), b1 is 0 or 1. b2 is 0, 1, or 2, where 0 represents the benzene skeleton, 1 represents the naphthalene skeleton, and 2 represents the anthracene skeleton. b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2(b2) - b4. b4 is 1, 2, or 3. b5 is 0 or 1. When b2 is 0, preferably b3 is 0, 1, 2, or 3, and b4 is 1, 2, or 3. When b2 is 1 or 2, preferably b3 is 0, 1, 2, 3, or 4, and b4 is 1, 2, or 3.

[0267] In equation (A3-1), R A It is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0268] In equation (A3-1), R 12It is a halogen atom, or a 1-6 carbon saturated hydrocarbon group that can be substituted with a halogen atom, a 1-6 carbon saturated hydrocarbon oxygen group that can be substituted with a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl oxygen group that can be substituted with a halogen atom. The aforementioned saturated hydrocarbon group, as well as the saturated hydrocarbon oxygen group and the saturated hydrocarbon carbonyl oxygen group, can be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, butyl, pentyl, hexyl, and their structural isomers; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; and groups obtained by combining these. If the number of carbon atoms is below the upper limit, the solubility in alkaline developing solutions is good. If b3 is 2 or more, each R... 12 They can be the same or different.

[0269] In formula (A3-1), A 2 It is a single bond or a saturated alkylene group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated alkylene group can also be replaced by -O-. The aforementioned saturated alkylene group can be linear, branched, or cyclic. Specific examples include alkylene groups with 1 to 10 carbon atoms such as methylene, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, and their structural isomers; cyclic saturated alkylene groups with 3 to 10 carbon atoms such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and groups obtained by combining these. When the aforementioned saturated alkylene group contains an ether bond, when b1 in formula (A3-1) is 1, it can be inserted anywhere except between the carbon atom at the α-position and the carbon atom at the β-position for the ester oxygen atom. Furthermore, when b1 is 0, the atom bonded to the main chain becomes an ether oxygen atom, and a second ether bond can be inserted at any position except between the carbon atom at the α-position and the carbon atom at the β-position for this ether oxygen atom. Moreover, if the number of carbon atoms in the aforementioned saturated hydrocarbon group is 10 or less, sufficient solubility in alkaline developing solution can be obtained, thus it is ideal.

[0270] In formula (A3-1), when b4 is 1, X is an acid-labile group. When b4 is 2 or 3, X is either a hydrogen atom or an acid-labile group, with at least one being an acid-labile group. That is, the repeating unit A3-1 is either a phenolic hydroxyl group bonded to an aromatic ring that is protected by an acid-labile group, or a carboxyl group bonded to an aromatic ring that is protected by an acid-labile group. The aforementioned acid-labile groups are widely used in a large number of known chemically amplified positive resist compositions, and there are no particular limitations as long as they provide an acidic group through acid removal.

[0271] The aforementioned acid-labile groups may include, for example, tertiary saturated hydrocarbon groups. For obtaining the monomers used in polymerization by distillation, tertiary saturated hydrocarbon groups with 4 to 18 carbon atoms are preferred.

[0272] The saturated hydrocarbon groups bonded to the tertiary carbon atoms of the aforementioned tertiary saturated hydrocarbon groups are preferably those with 1 to 15 carbon atoms. These saturated hydrocarbon groups with 1 to 15 carbon atoms can be linear, branched, or cyclic, and may also contain oxygen-containing functional groups such as ether bonds or carbonyl groups between the carbon-carbon bonds. Furthermore, the saturated hydrocarbon groups bonded to the tertiary carbon atoms can also bond to each other and form rings together with the tertiary carbon atoms to which they are bonded.

[0273] Saturated hydrocarbon groups bonded to the aforementioned tertiary carbon atoms can be listed as methyl, ethyl, propyl, adamantyl, norbornel, tetrahydrofuran-2-yl, 7-oxanorborne-2-yl, cyclopentyl, 2-tetrahydrofuranyl, tricyclic [5.2.1.0] 2,6 ] Decyl, 8-ethyl-8-tricyclo[5.2.1.0 2,6 Decyl, 3-methyl-3-tetracyclo[4.4.0.1] 2,5 .1 7,10 [12 bases, 4 rings [4.4.0.1]] 2,5 .1 7,10 Dodecayl, 3-oxo-1-cyclohexyl, etc.

[0274] The aforementioned tertiary saturated hydrocarbon groups include tert-butyl, tert-pentyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1,2-trimethylpropyl, 1-adamantane-1-methylethyl, 1-methyl-1-(2-norborneol)ethyl, 1-methyl-1-(tetrahydrofuran-2-yl)ethyl, 1-methyl-1-(7-oxanorborneol-2-yl)ethyl, 1-methylcyclopentyl, 1-ethyl Cyclopentyl, 1-propylcyclopentyl, 1-cyclopentylcyclopentyl, 1-cyclohexylcyclopentyl, 1-(2-tetrahydrofuranyl)cyclopentyl, 1-(7-oxanorbornen-2-yl)cyclopentyl, 1-methylcyclohexyl, 1-ethylcyclohexyl, 1-cyclopentylcyclohexyl, 1-cyclohexylcyclohexyl, 2-methyl-2-norbornenyl, 2-ethyl-2-norbornenyl, 8-methyl-8-tricyclo[5.2.1.0] 2,6 ] Decyl, 8-ethyl-8-tricyclo[5.2.1.0 2,6 Decyl, 3-methyl-3-tetracyclo[4.4.0.1] 2,5 .1 7,10 Dodecayl, 3-ethyl-3-tetracyclo[4.4.0.1] 2, 5 .1 7,10 Dodecyl, 2-methyl-2-adamantyl, 2-ethyl-2-adamantyl, 1-methyl-3-oxo-1-cyclohexyl, 1-methyl-1-(tetrahydrofuran-2-yl)ethyl, 5-hydroxy-2-methyl-2-adamantyl, 5-hydroxy-2-ethyl-2-adamantyl, but not limited to these.

[0275] Furthermore, the aforementioned acid-indestructible groups can be exemplified by groups represented by formula (A3-1-1). Groups represented by formula (A3-1-1) are commonly used as acid-indestructible groups and are a useful option for providing a more rectangular pattern at the interface between the pattern and the substrate. When X is a group represented by formula (A3-1-1), an acetal structure is formed.

[0276] [Chemistry 63]

[0277]

[0278] In the formula, the dashed lines represent atomic bonds.

[0279] In equation (A3-1-1), R L1 It is a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. The aforementioned saturated hydrocarbon group can be straight-chain, branched, or cyclic.

[0280] R L1 The appropriate group can be selected based on its sensitivity to acid decomposition. For example, if a design is intended to ensure high stability and decomposition by strong acids, then groups with hydrogen atoms or tertiary carbon atoms bonded to the acetal carbon are preferable. R groups bonded to the acetal carbon via tertiary carbon atoms... L1 Examples include tert-butyl, tert-pentyl, and 1-adamantyl, but these are not the only possibilities. For designs requiring high reactivity and high sensitivity to pH changes, straight-chain alkyl groups are preferable. The specific choice also depends on the combination of acid-generating and quenching agents incorporated into the resist composition. L2 In designs where a larger alkyl group is chosen at the end, and the solubility changes significantly due to decomposition, R L1 It is preferable that the carbon atom bonded to the acetal carbon be a secondary carbon atom. L1 Examples include isopropyl, sec-butyl, cyclopentyl, cyclohexyl, etc., but are not limited to these.

[0281] In equation (A3-1-1), R L2 It is a hydrocarbon group with 1 to 30 carbon atoms. This hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. A portion of the -CH2- group can also be replaced by heteroatoms such as oxygen or sulfur atoms, resulting in ether bonds, thioether bonds, etc. Specific examples of the aforementioned hydrocarbon group include saturated hydrocarbon groups with 1 to 30 carbon atoms and aryl groups with 6 to 30 carbon atoms. Especially in the formation of fine patterns, in order to obtain higher resolution, R... L2 It is preferable to use a hydrocarbon group with 1 to 6 carbon atoms. R L2 When the hydrocarbon group has 1 to 6 carbon atoms, the alcohol produced after the deprotection reaction using acid is water-soluble. Therefore, when forming a positive pattern with an alkaline developer, it will dissolve in the developer, thus suppressing residue defects in the exposed area.

[0282] Preferred examples of the groups represented by formula (A3-1-1) are shown below, but are not limited to these. Furthermore, in the following formula, R... L1 As mentioned above, dashed lines represent atomic bonds.

[0283] [Chemistry 64]

[0284]

[0285] [Chemistry 65]

[0286]

[0287] In addition to the aforementioned acid-unstable groups, phenolic hydroxyl groups can also be replaced by -CH2COO- (tertiary saturated hydrocarbon group). In this case, the aforementioned tertiary saturated hydrocarbon group can be the same as the tertiary saturated hydrocarbon group used in the protection of the aforementioned phenolic hydroxyl group.

[0288] Furthermore, repeating unit A3 can also be represented by the following formula (A3-2) (hereinafter also referred to as repeating unit A3-2). Repeating unit A3-2 is a useful option as a unit containing acid-insecure groups that provides good performance for linewidth variation under developing load, since the dissolution rate of the exposed section will increase.

[0289] [Chemistry 66]

[0290]

[0291] In equation (A3-2), c1 is 0, 1, or 2. c2 is 0, 1, or 2. c3 is 0, 1, 2, 3, 4, or 5. c4 is 0, 1, or 2.

[0292] In equation (A3-2), R A It is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0293] In equation (A3-2), R 13 and R 14 Each is independently a hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. 13 With R 14 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0294] In equation (A3-2), R 15 Each is independently a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkoxy group having 1 to 5 carbon atoms.

[0295] In equation (A3-2), R 16 Each can be an independent hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms.

[0296] In equation (A3-2), A 3 It is a single bond, phenylene, naphthylene, or *-C(=O)-OA 31 -. A 31 It is an aliphatic alkylene group, phenylene group, or naphthylene group having 1 to 20 carbon atoms. The aliphatic alkylene group may also include at least one selected from hydroxyl, ether bond, ester bond, and lactone ring. * indicates an atomic bond with a carbon atom of the main chain.

[0297] Preferred examples of repeating unit A3-2 may be listed below, but are not limited to these. Furthermore, in the following formula, R... A Same as above.

[0298] [Chemistry 67]

[0299]

[0300] [Chemistry 68]

[0301]

[0302] The content of repeating unit A3, among all repeating units constituting the aforementioned polymer, is preferably 5–95 mol%, and more preferably 20–80 mol%. Repeating unit A3 can be used alone or in combination of two or more types.

[0303] The aforementioned polymer may also include at least one selected from the repeating unit represented by formula (A4) (hereinafter also referred to as repeating unit A4.), the repeating unit represented by formula (A5) (hereinafter also referred to as repeating unit A5.), and the repeating unit represented by formula (A6) (hereinafter also referred to as repeating unit A6.).

[0304] [Chemistry 69]

[0305]

[0306] In equations (A4) and (A5), d is 0, 1, 2, 3, 4, 5, or 6. e is 0, 1, 2, 3, or 4.

[0307] In equations (A4) and (A5), R 17 and R 18 Each R is independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group with 1 to 6 carbon atoms that may be substituted with a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that may be substituted with a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that may be substituted with a halogen atom. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxygen group, and saturated hydrocarbon carbonyl oxygen group can be linear, branched, or cyclic. When d is 2 or more, each R 17 They can be the same or different. When e is 2 or more, each R... 18 They can be the same or different.

[0308] In formula (A6), f1 is 0 or 1. f2 is 0, 1, or 2; 0 represents the benzene skeleton, 1 represents the naphthalene skeleton, and 2 represents the anthracene skeleton. f3 is 0, 1, 2, 3, 4, or 5. When f2 is 0, f3 should preferably be 0, 1, 2, or 3; when f2 is 1 or 2, f3 should preferably be 0, 1, 2, 3, or 4.

[0309] In equation (A6), R A It is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0310] In equation (A6), R 19 It can be a halogen atom, nitro group, cyano group, saturated hydrocarbon group with 1 to 20 carbon atoms, saturated hydrocarbon oxy group with 1 to 20 carbon atoms, saturated hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms, saturated hydrocarbon oxyalkyl group with 2 to 20 carbon atoms, or saturated hydrocarbon thioalkyl group with 2 to 20 carbon atoms. When f2 is 1 or 2, it can be a hydroxyl group. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyl oxy group, saturated hydrocarbon oxyalkyl group, and saturated hydrocarbon thioalkyl group can be straight-chain, branched, or cyclic. When f3 is 2 or more, each R 19 They can be the same or different.

[0311] In formula (A6), A 4 It is a single bond or a saturated alkylene group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated alkylene group may also be replaced by -O-. The aforementioned saturated alkylene group can be linear, branched, or cyclic; specific examples can be listed with A in formula (A2). 1 The same as those exemplified in the description.

[0312] When at least one of the repeating units A4 to A6 is used as a constituent unit of the aforementioned polymer, in addition to the etching resistance of the aromatic ring, the effect of improving etching resistance and EB irradiation resistance during pattern inspection can also be obtained by adding a ring structure to the main chain.

[0313] To improve etching resistance, the content of repeating units A4 to A6 should preferably be 5 mol% or more of all repeating units constituting the aforementioned polymer. Furthermore, the content of repeating units A4 to A6 should preferably be 25 mol% or less, and more preferably 20 mol% or less, of all repeating units constituting the aforementioned polymer. Ideally, if the amount of repeating units A4 to A6 is 25 mol% or less (in the case of units lacking functional groups or whose functional groups are other than hydroxyl groups), there will be no risk of developing defects. Repeating units A4 to A6 can be used alone or in combination of two or more.

[0314] In the aforementioned polymer, the content of repeating units having an aromatic ring skeleton is preferably 65 mol% or more, more preferably 75 mol% or more, and even more preferably 85 mol% or more.

[0315] The aforementioned polymer may also contain commonly used (meth)acrylate units protected by acid-insecure groups, (meth)acrylate units with lactone structures, hydroxyl groups other than phenolic hydroxyl groups, or other tightly bound groups. These repeating units allow for fine-tuning of the properties of the resist film; the polymer may also be omitted.

[0316] Examples of the aforementioned (meth)acrylate units with binding groups include repeating units represented by formula (A7) (hereinafter also referred to as repeating unit A7.), repeating units represented by formula (A8) (hereinafter also referred to as repeating unit A8.), and repeating units represented by formula (A9) (hereinafter also referred to as repeating unit A9.). These units do not exhibit acidity and can be used as auxiliary units that provide binding to the substrate or adjust solubility.

[0317] [Chemistry 70]

[0318]

[0319] In equations (A7) to (A9), R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 21 It is -O- or methylene. R 22 It is a hydrogen atom or a hydroxyl group. R 23 It is a saturated hydrocarbon group with 1 to 4 carbon atoms. g is 0, 1, 2 or 3.

[0320] When repeating units A7 to A9 are included, their content in the aforementioned polymer is preferably 0 to 20 mol%, and more preferably 0 to 10 mol%. Repeating units B14 to B16 can be used alone or in combination of two or more.

[0321] The aforementioned polymer can be synthesized by copolymerizing monomers requiring protection groups using known methods, followed by a deprotection reaction as needed. The copolymerization reaction is not particularly limited, but is preferably free radical polymerization or anionic polymerization. For these methods, please refer to Japanese Patent Application Publication No. 2004-115630.

[0322] For the aforementioned polymers, a weight-average molecular weight (Mw) of 1000 to 50000 is preferred, and 2000 to 20000 is even more preferred. If Mw is 1000 or higher, as is known in the past, there is no risk of pattern dome-shaped ...

[0323] For the aforementioned polymer, a narrow dispersion with a molecular weight distribution (Mw / Mn) of 1.0–2.0, preferably 1.0–1.9, and more preferably 1.0–1.8, is preferred. This narrow dispersion prevents the formation of foreign matter on the pattern or deterioration of the pattern shape after development.

[0324] Furthermore, regarding the aforementioned basic polymer design, the dissolution rate of the alkaline developer is preferably below 10 nm / min, more preferably below 7 nm / min, and even more preferably below 5 nm / min. In advanced generations, when the substrate coating is a thin film region (below 100 nm), the impact on pattern film loss during alkaline development becomes greater. When the polymer's alkaline dissolution rate exceeds 10 nm / min, the pattern will break down, and fine patterns cannot be formed. In particular, when fabricating photomasks requiring defect-free properties, there is a significant tendency for drastic development. Moreover, the dissolution rate of the basic polymer in the alkaline developer in this invention is calculated from the film loss after developing a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution at 23°C for 100 seconds on an 8-inch silicon wafer with a polymer solution (polymer concentration: 16.7% by mass, solvent: propylene glycol monomethyl ether acetate (PGMEA)) for 1000 nm thickness, followed by baking at 100°C for 90 seconds.

[0325] (A) The base polymer may also include other polymers besides those mentioned above. Other polymers may be those known as base polymers used as components of the resist. The content of other polymers is not particularly limited, as long as it does not impair the effects of the invention.

[0326] [(B) Quenching agent]

[0327] The chemically amplified positive resist composition of the present invention may, as needed, include a quencher as component (B). Furthermore, in the present invention, a quencher refers to a compound that captures the acid generated by the acid-generating agent. This suppresses the diffusion rate of the acid generated by the acid-generating agent within the resist film, thus suppressing the effect of the acid generated within the resist film on the chromium-containing material even when using a substrate with its outermost surface made of a chromium-containing material.

[0328] The aforementioned quenching agents may include known basic compounds. Known basic compounds may include primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds with carboxyl groups, nitrogen-containing compounds with sulfonyl groups, nitrogen-containing compounds with hydroxyl groups, nitrogen-containing compounds with hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amides, imides, and carbamates. In particular, primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Publication No. 2008-111103, especially amine compounds with hydroxyl groups, ether bonds, ester bonds, lactone rings, cyano groups, or sulfonate bonds, or compounds with carbamate groups described in Japanese Patent No. 3790649, are preferred. Preferred alternatives include tris[2-(methoxymethoxy)ethyl]amine, tris[2-(methoxymethoxy)ethyl]amine-N-oxide, dibutylaminobenzoic acid, morpholine derivatives, imidazole derivatives, etc. By adding such basic compounds, for example, the diffusion rate of acid in the resist film can be further suppressed, or the shape can be corrected.

[0329] Furthermore, the aforementioned quenchers include, for example, onium salts such as sulfonium salts, uranium salts, and ammonium salts of α-unfluorinated carboxylic acids, as described in Japanese Patent Application Publication No. 2008-158339. α-fluorinated sulfonic acids, imide acids, or methyl acids require deprotection of unstable acid groups, and this is achieved through salt exchange with α-unfluorinated onium salts, releasing the α-unfluorinated carboxylic acid. Since the α-unfluorinated carboxylic acid hardly undergoes a deprotection reaction, it functions as a quencher.

[0330] Onium salts of carboxylic acids that are not fluorinated at the α-position, for example, can be represented by the following formula (B1).

[0331] [Chemistry 71]

[0332] R 101 -CO2 - Mq A + (B1)

[0333] In equation (B1), R 101 It is a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms, but excludes the case where the hydrogen atom at the α-position of the carboxyl group is replaced by a fluorine atom or a fluoroalkyl group.

[0334] R 101The hydrocarbon group represented can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, and 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, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated aliphatic hydrocarbon groups with 3 to 40 carbon atoms, such as cyclohexenyl; aryl groups with 6 to 40 carbon atoms, such as phenyl, naphthyl, alkylphenyl (2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butylphenyl, etc.), di- or trialkylphenyl (2,4-dimethylphenyl, 2,4,6-triisopropylphenyl, etc.), alkylnaphthyl (methylnaphthyl, ethylnaphthyl, etc.), and dialkylnaphthyl (dimethylnaphthyl, diethylnaphthyl, etc.); and aralkyl groups with 7 to 40 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl.]

[0335] 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 can also include hydroxyl groups, cyano groups, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc. Hydrocarbon groups containing heteroatoms can 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-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl.

[0336] In equation (B1), Mq A +It is an onium cation. The aforementioned onium cation is preferably a sulfonium cation, a monium cation, or an ammonium cation, with sulfonium cation or monium cation being more preferred. Specific examples of the aforementioned sulfonium cation may be listed in paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-003744, paragraphs

[0070] to

[0085] of Japanese Patent Application Publication No. 2023-169812, and those expressed by formula (A2), but are not limited to these. Specific examples of the aforementioned monium cation may be listed in paragraph

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

[0337] The anions of onium salts represented by formula (B1) can be listed below, but are not limited to these.

[0338] [Chemistry 72]

[0339]

[0340] [Chemistry 73]

[0341]

[0342] [Chemistry 74]

[0343]

[0344] The aforementioned quenching agents are also suitable for the use of sulfonium salts of carboxylic acids containing iodinated benzene rings, represented by the following formula (B2).

[0345] [Chemistry 75]

[0346]

[0347] In equation (B2), s is 1, 2, 3, 4, or 5. t is 0, 1, 2, or 3. However, 1 ≤ s + t ≤ 5. u is 1, 2, or 3.

[0348] In equation (B2), R 111 It is a 1-6 carbon saturated hydrocarbon group, a 1-6 carbon saturated hydrocarbon oxygen group, a 2-6 carbon saturated hydrocarbon carbonyl oxygen group, or a 1-4 carbon saturated hydrocarbon sulfonyl oxygen group, or a hydroxyl group, fluorine atom, chlorine atom, bromine atom, amino group, nitro group, cyano group, or hydrogen atom, which may be substituted by halogen atoms. 111A )-C(=O)-R 111B or -N(R) 111A )-C(=O)-OR 111B R 111A It is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 111B It is a saturated hydrocarbon group with 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbon group with 2 to 8 carbon atoms. When t and / or u is 2 or more, each R 111They can be the same or different.

[0349] In equation (B2), L 1 It is a single bond or a (u+1) valence linking group having 1 to 20 carbon atoms, and may also include at least one selected from ether bonds, carbonyl groups, ester bonds, amide bonds, sulfonyl lactone rings, lactam rings, carbonate bonds, halogen atoms, hydroxyl groups, and carboxyl groups. The aforementioned saturated hydrocarbon groups, saturated hydrocarbon oxy groups, saturated hydrocarbon carbonyl oxy groups, and saturated hydrocarbon sulfonyl oxy groups may be linear, branched, or cyclic.

[0350] In equation (B2), R 112 R 113 and R 114 Each group consists of a halogen atom or may contain heteroatoms and has 1 to 20 carbon atoms. These alkyl groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, alkenyl groups with 2 to 20 carbon atoms, aryl groups with 6 to 20 carbon atoms, and aralkyl groups with 7 to 20 carbon atoms. Furthermore, some or all of the hydrogen atoms in the aforementioned alkyl groups may be replaced by hydroxyl, carboxyl, halogen, oxo, cyano, nitro, sulfonyl lactone ring, sulfonic acid group, or sulfonium salt-containing groups. A portion of the -CH2- group in the aforementioned alkyl groups may also be replaced by ether, ester, carbonyl, amide, carbonate, or sulfonate bonds. Also, R... 112 and R 113 They can also bond to each other and form rings together with the sulfur atoms they are bonded to.

[0351] Specific examples of compounds represented by formula (B2) can be found in Japanese Patent Application Publication No. 2017-219836. Compounds represented by formula (B2) exhibit high absorption, high sensitization effect, and high acid diffusion control effect.

[0352] The aforementioned quenching agent may also be a nitrogen-containing carboxylate compound represented by the following formula (B3).

[0353] [Chemistry 76]

[0354]

[0355] In formula (B3), R 121 ~R 124 Each is independently a hydrogen atom, -L 2 -CO2 - Or it may contain a hydrocarbon group with 1 to 20 carbon atoms that are heteroatoms. R 121 With R 122 R 122 With R 123 、or R 123 With R 124 They can also bond to each other and form rings together with the carbon atoms they are bonded to. 2It is a single bond or may contain heteroatoms and consist of 1 to 20 carbon-containing hydrocarbon groups. R 125 It is a hydrocarbon group with 1 to 20 carbon atoms, which may contain hydrogen atoms or heteroatoms.

[0356] In equation (B3), ring R r It is a 2-6 carbon ring containing carbon and nitrogen atoms in the formula. Some or all of the hydrogen atoms bonded to the carbon atoms in this ring may also be hydrocarbon groups with 1-20 carbon atoms, or -L... 2 -CO2 - Alternatively, a portion of the carbon atom in the ring may be replaced by a sulfur atom, an oxygen atom, or a nitrogen atom. The aforementioned ring can be an alicyclic or aromatic ring; 5-membered or 6-membered rings are preferred. Specific examples include pyridine rings, pyrrole rings, pyrrolidine rings, piperidine rings, pyrazole rings, imidazoline rings, pyridazine rings, pyrimidine rings, pyrazine rings, imidazoline rings, oxazole rings, thiazole rings, morpholine rings, thiazine rings, triazole rings, etc.

[0357] The carboxylic acid onium salt represented by formula (B3) has at least one -L 2 -CO2 - Base. That is, R 121 ~R 124 At least one of them is -L 2 -CO2 - At least one of the hydrogen atoms bonded to the carbon atom of ring R is -L 2 -CO2 - Replacement.

[0358] In formula (B3), Mq B + It is a sulfonium cation, a monazine cation, or an ammonium cation, with a sulfonium cation being preferred. Specific examples of the aforementioned sulfonium cations may be listed in paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-003744, paragraphs

[0070] to

[0085] of Japanese Patent Application Publication No. 2023-169812, and those expressed by formula (A2), but are not limited to these.

[0359] The anions of compounds represented by formula (B3) may be listed below, but are not limited to these.

[0360] [Chemistry 77]

[0361]

[0362] [Chemistry 78]

[0363]

[0364] [Chemistry 79]

[0365]

[0366] [Chemistry 80]

[0367]

[0368] [Chemistry 81]

[0369]

[0370] [Chemistry 82]

[0371]

[0372] Furthermore, the aforementioned quenching agent may also be a weak acid betaine-type compound. Specific examples are listed below, but are not limited to these.

[0373] [Chemistry 83]

[0374]

[0375] The aforementioned quenching agents include, for example, polymer-type quenching agents described in Japanese Patent Application Publication No. 2008-239918. These quenching agents improve the rectangularity of the resist pattern by aligning with the surface of the resist film. Polymer-type quenching agents also prevent film loss and dome-shaped formation of the pattern when using a protective film for immersion exposure.

[0376] When the chemically amplified positive resist composition of the present invention includes a quencher, its content relative to 80 parts by weight of the aforementioned base polymer is preferably 0 to 50 parts by weight, and more preferably 0.1 to 40 parts by weight. The aforementioned quencher may be used alone or in combination of two or more.

[0377] [(C) Organic solvent]

[0378] The resist composition of the present invention may also include an organic solvent as component (C). The aforementioned organic solvent is not particularly limited as long as it can dissolve each component. Examples of such organic solvents include, for example, ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentanone, 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; and propylene glycol monomethyl ether (PGME). Ethers such as ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate (EL), ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate; lactones such as γ-butyrolactone; and mixed solvents thereof. When using the acid-labile groups of acetals, high-boiling-point alcohol solvents can be added to accelerate the deprotection reaction of the acetal, specifically diethylene glycol, propylene glycol, glycerol, 1,4-butanediol, and 1,3-butanediol.

[0379] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, and their mixed solvents are preferred.

[0380] When the chemically amplified positive resist composition of the present invention contains (C) organic solvent, its content relative to 80 parts by mass of (A) base polymer is preferably 200 to 10,000 parts by mass, and more preferably 400 to 5,000 parts by mass. (C) organic solvent may be used alone or in combination with two or more.

[0381] [(D) Polymers containing fluorine atoms]

[0382] The chemically amplified positive resist composition of the present invention, for the purposes of high contrast, suppression of chemical flash of acid under high-energy radiation, blocking the mixing of acid from the antistatic film during the processing of antistatic film material on the resist film, and suppressing unintended pattern degradation, may also include a polymer containing fluorine atoms as component (D) containing at least one of the repeating units represented by formula (D1) (hereinafter also referred to as repeating unit D1.), repeating units represented by formula (D2) (hereinafter also referred to as repeating unit D2.), repeating units represented by formula (D3) (hereinafter also referred to as repeating unit D3.), and repeating units represented by formula (D4) (hereinafter also referred to as repeating unit D4.). The aforementioned polymer containing fluorine atoms also has the function of a surfactant, thus preventing the re-adhesion of insoluble substances that may be generated during the development process to the substrate, and thus also being effective against development defects.

[0383] [Chemistry 84]

[0384]

[0385] In equations (D1) to (D4), h is 1, 2, or 3. R B Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 201 R 202 R 204 and R 205 Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. R 203 R 206 R 207 and R 208 Each is independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, a fluorinated hydrocarbon group having 1 to 15 carbon atoms, or an acid-labile group, R 203 R 206 R 207 and R 208 When the group is a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond or a carbonyl group can also be inserted between the carbon-carbon bonds. 1 It is a (h+1) valence hydrocarbon group with 1 to 20 carbon atoms or a (h+1) valence fluorinated hydrocarbon group with 1 to 20 carbon atoms. * indicates an atomic bond with a carbon atom in the main chain.

[0386] R 201 R 202 R 204 and R 205 The saturated hydrocarbon group representing 1 to 10 carbon atoms can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and cyclic saturated hydrocarbon groups with 3 to 10 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornel. Among these, saturated hydrocarbon groups with 1 to 6 carbon atoms are preferred.

[0387] R 203 R 206 R 207 and R 208The hydrocarbon group representing 1 to 15 carbon atoms can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 15 carbon atoms, alkenyl groups with 2 to 15 carbon atoms, and alkynyl groups with 2 to 15 carbon atoms, with alkyl groups with 1 to 15 carbon atoms being preferred. In addition to the aforementioned alkyl groups, other examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, and n-pentadecayl. Furthermore, fluorinated hydrocarbon groups can be groups in which some or all of the hydrogen atoms of the carbon atoms bonded to the aforementioned hydrocarbon groups are replaced by fluorine atoms.

[0388] Z 1 The (h+1) valence hydrocarbon groups representing 1 to 20 carbon atoms can be categorized as alkyl groups with 1 to 20 carbon atoms or cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, excluding groups with k hydrogen atoms. Also, Z 1 The (h+1) valence fluorinated hydrocarbon group representing carbon numbers from 1 to 20 can be exemplified by groups in which at least one hydrogen atom of the aforementioned (h+1) valence hydrocarbon group is replaced by a fluorine atom.

[0389] Specific examples of repeating units D1 to D4 can be listed below, but are not limited to these. Furthermore, in the following formula, R... B Same as above.

[0390] [Chemistry 85]

[0391]

[0392] [Chemistry 86]

[0393]

[0394] [Chemistry 87]

[0395]

[0396] Furthermore, the aforementioned fluorine-containing polymer is preferably a polymer that further comprises at least one of the repeating units represented by formula (D5) (hereinafter also referred to as repeating unit D5.) and the repeating units represented by formula (D6) (hereinafter also referred to as repeating unit D6.).

[0397] [Chemistry 88]

[0398]

[0399] In equations (D5) and (D6), x is 1, 2, or 3. y is an integer satisfying 0 ≤ y ≤ 5 + 2z - x. z is 0 or 1. R C Each can be independently a hydrogen atom or a methyl group. R 209It is a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, which may also have hydrogen atoms or groups containing heteroatoms inserted between carbon-carbon bonds. R 210 It can also be a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, into which heteroatoms can be inserted between carbon-carbon bonds. R 211 It is a saturated hydrocarbon group with 1 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom, and part of the -CH2- of the aforementioned saturated hydrocarbon group may also be replaced by an ester bond or an ether bond. 2 It is a single bond, *-C(=O)-O- or *-C(=O)-NH-. Z 3 It is a single bond, -O-, *-C(=O)-OZ 31 -Z 32 -or *-C(=O)-NH-Z 31 -Z 32 -. Z 31 It is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms. Z 32 It is a single bond, ester bond, ether bond, or sulfonamide bond. * is an atomic bond with a carbon atom in the main chain.

[0400] R 209 and R 210 The hydrocarbon group representing 1 to 5 carbon atoms can include alkyl, alkenyl, ynyl, etc., with alkyl being preferred. Examples of the aforementioned alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, etc. Furthermore, groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms can also be inserted between the carbon-carbon bonds of the aforementioned hydrocarbon groups.

[0401] -OR in equation (D5) 209 It is preferable to have a hydrophilic group. In this case, R 209 Suitable for hydrogen atoms, alkyl groups with 1 to 5 carbon atoms with oxygen atoms inserted between carbon-carbon bonds, etc.

[0402] R 211 The saturated hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom can be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 20 carbon atoms or cyclic saturated hydrocarbon groups having at least one hydrogen atom replaced by a fluorine atom.

[0403] Z 2 *-C(=O)-O- or *-C(=O)-NH- are preferable. Furthermore, R C Methyl is preferable. (By Z) 2 The presence of a carbonyl group enhances the acid-trapping ability of the antistatic membrane. Furthermore, if R... C If the methyl group is used, it becomes a rigid polymer with a higher glass transition temperature (Tg), thus inhibiting acid diffusion. As a result, the resist film exhibits good historical stability, and its resolution and pattern shape do not deteriorate.

[0404] Z 3 The saturated alkylene groups representing carbon atoms from 1 to 10 can be linear, branched, or cyclic. Specific examples include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, propane-2,2-diyl, butane-1,1-diyl, butane-1,2-diyl, butane-1,3-diyl, butane-2,3-diyl, butane-1,4-diyl, and 1,1-dimethylethane-1,2-diyl.

[0405] Repeating unit D5 can be listed as shown below, but is not limited to these. Furthermore, in the following formula, R... C Same as above.

[0406] [Chemistry 89]

[0407]

[0408] [Chemistry 90]

[0409]

[0410] Repeating unit D6 can be listed as shown below, but is not limited to these. Furthermore, in the following formula, R... C Same as above.

[0411] [Chemistry 91]

[0412]

[0413] [Chemistry 92]

[0414]

[0415] [Chemistry 93]

[0416]

[0417] [Chemistry 94]

[0418]

[0419] The content of repeating units D1 to D4 in the aforementioned polymer containing fluorine atoms is preferably 15 to 95 mol%, and more preferably 20 to 85 mol%. The content of repeating units D5 and / or D6 in the aforementioned polymer containing fluorine atoms is preferably 5 to 85 mol%, and more preferably 15 to 80 mol%. Repeating units D1 to D6 can be used alone or in combination of two or more.

[0420] (D) The polymer containing fluorine atoms may also contain other repeating units besides the aforementioned repeating units. Such repeating units can be exemplified by those described in paragraphs

[0046] to

[0078] of Japanese Patent Application Publication No. 2014-177407. (D) When the polymer containing fluorine atoms contains other repeating units, their content in all the repeating units of the aforementioned polymer containing fluorine atoms should preferably be 50 mol% or less.

[0421] (D) Fluorine-containing polymers can be synthesized by copolymerizing monomers requiring protection groups using known methods, followed by a deprotection reaction as needed. The copolymerization reaction is not particularly limited, but free radical polymerization or anionic polymerization is preferred. For these methods, please refer to Japanese Patent Application Publication No. 2004-115630.

[0422] (D) For polymers containing fluorine atoms, a Mw of 2000–50000 is preferred, and 3000–20000 is even better. If Mw is above 2000, acid will not diffuse, resolution will not deteriorate, and historical stability will not be compromised. If Mw is below 50000, solubility in solvents is sufficient, and coating defects will not occur. Furthermore, for polymers containing fluorine atoms in (D), an Mw / Mn ratio of 1.0–2.2 is preferred, and 1.0–1.7 is even better.

[0423] When the chemically amplified positive resist composition of the present invention contains (D) a polymer containing fluorine atoms, its content relative to 80 parts by mass of the base polymer (A) is preferably 0.01 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass. The polymer containing fluorine atoms (D) can be used alone or in combination of two or more.

[0424] [(E) Photoacid Generator]

[0425] The chemically amplified positive resist composition of the present invention may also include a photoacid generator as component (E). The aforementioned photoacid generator is not particularly limited to compounds that generate acid when irradiated with high-energy rays. Preferred photoacid generators include sulfonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, and oxime-O-sulfonate type acid generators.

[0426] Specific examples of the aforementioned photoacid generators include nonafluorobutyrate, partially fluorinated sulfonates described in paragraphs

[0247] to

[0251] of Japanese Patent Application Publication No. 2012-189977, partially fluorinated sulfonates described in paragraphs

[0261] to

[0265] of Japanese Patent Application Publication No. 2013-101271, partially fluorinated sulfonates described in paragraphs

[0122] to

[0142] of Japanese Patent Application Publication No. 2008-111103, and partially fluorinated sulfonates described in paragraphs

[0080] to

[0081] of Japanese Patent Application Publication No. 2010-215608. Among the aforementioned specific examples, the photoacid generators of the aromatic hydrocarbon sulfonate type or the alkane sulfonate type produce an acid of appropriate strength for deprotecting the acid-instable group of the repeating unit A3, which is ideal.

[0427] Such photoacid generators are preferably salt compounds containing the anions shown below.

[0428] [Chemistry 95]

[0429]

[0430] [Chemistry 96]

[0431]

[0432] [Chemistry 97]

[0433]

[0434] [Chem. 98]

[0435]

[0436] [Chemistry 99]

[0437]

[0438] [Chemistry 100]

[0439]

[0440] [Chemistry 101]

[0441]

[0442] [Chemistry 102]

[0443]

[0444] [Chemistry 103]

[0445]

[0446] [Chemistry 104]

[0447]

[0448] [Chemistry 105]

[0449]

[0450] [Chemistry 106]

[0451]

[0452] [Chemistry 107]

[0453]

[0454] [Chemistry 108]

[0455]

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[0842] [Chemical 302]

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[0902] [Chemistry 332]

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[0904] [Chemistry 333]

[0905]

[0906] [Chemistry 334]

[0907]

[0908] [Chemistry 335]

[0909]

[0910] [Chemistry 336]

[0911]

[0912] Furthermore, the aforementioned photoacid generator should preferably be a salt compound containing an anion represented by the following formula (E1).

[0913] [Chemistry 337]

[0914]

[0915] In equation (E1), m1 is 0 or 1. p is 1, 2 or 3. q is 1, 2, 3, 4 or 5. r is 0, 1, 2 or 3. However, 1 ≤ q + r ≤ 5.

[0916] In formula (E1), L 11 It is a single bond, ether bond, ester bond, sulfonate bond, carbonate bond, or carbamate bond.

[0917] In formula (E1), L 12 It is an ether bond, ester bond, sulfonate bond, carbonate bond, or carbamate bond.

[0918] In formula (E1), L CWhen p is 1, it is a single bond or a hydrocarbon group with 1 to 20 carbon atoms; when p is 2 or 3, it is a (p+1) valence hydrocarbon group with 1 to 20 carbon atoms. The hydrocarbon group and the (p+1) valence hydrocarbon group may also include at least one selected from ether bond, carbonyl group, ester bond, amide bond, sulcinolone ring, lactam ring, carbonate bond, halogen atom, hydroxyl group and carboxyl group.

[0919] L C The alkylene group representing 1 to 20 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkane diyl groups with 1 to 20 carbon atoms, such as methane-diyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; cyclic saturated alkylene groups with 3 to 20 carbon atoms, such as cyclopentane-diyl, cyclohexane-diyl, norcamphene-diyl, and adamantane-diyl; unsaturated aliphatic alkylene groups with 2 to 20 carbon atoms, such as vinylene and propylene-1,3-diyl; aryl groups with 6 to 20 carbon atoms, such as phenylene and naphthylene; and groups obtained by combining these. Also, L C The (p+1) valence hydrocarbon group representing 1 to 20 carbon atoms can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples can be given by further eliminating one or two hydrogen atoms from the aforementioned examples of hydrocarbon groups representing 1 to 20 carbon atoms.

[0920] In equation (E1), Rf 1 and Rf 2 Each is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom, with at least one being a fluorine atom or a trifluoromethyl atom.

[0921] In equation (E1), R 301 It includes hydroxyl, carboxyl, saturated hydrocarbon groups with 1 to 6 carbon atoms, saturated hydrocarbon oxygen groups with 1 to 6 carbon atoms, saturated hydrocarbon carbonyl oxygen groups with 2 to 6 carbon atoms, fluorine atoms, chlorine atoms, bromine atoms, and -N(R) groups. 301A (R) 301B ), -N(R 301C )-C(=O)-R 301D or -N(R) 301C )-C(=O)-OR 301D R 301A and R 301B Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 301C It is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 301D It is a saturated hydrocarbon group with 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbon group with 2 to 8 carbon atoms.

[0922] R 301 R 301A R 301B and R 301C The saturated hydrocarbon group representing 1 to 6 carbon atoms can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 6 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, and n-hexyl; and cyclic saturated hydrocarbon groups with 3 to 6 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Also, R... 301 The saturated hydrocarbon portion of a saturated hydrocarbon group with 1 to 6 carbon atoms can be exemplified by examples similar to the aforementioned saturated hydrocarbon groups, R. 301 The saturated hydrocarbon portion of the carbonyl group of a saturated hydrocarbon with 2 to 6 carbon atoms can be exemplified by those with 1 to 5 carbon atoms among the specific examples of the aforementioned saturated hydrocarbon groups with 1 to 6 carbon atoms.

[0923] R 301D The unsaturated aliphatic hydrocarbon group with 2 to 8 carbon atoms can be linear, branched, or cyclic. Specific examples include alkenyl groups with 2 to 8 carbon atoms such as vinyl, propenyl, butenyl, and hexenyl; alkynyl groups with 2 to 8 carbon atoms such as ethynyl, propynyl, and butynyl; and cyclic unsaturated aliphatic hydrocarbon groups with 3 to 8 carbon atoms such as cyclohexenyl and norcamphenyl.

[0924] In equation (E1), R 302 It is a saturated hydrocarbon group with 1 to 20 carbon atoms or an aryl group with 6 to 20 carbon atoms. Some or all of the hydrogen atoms of the saturated hydrocarbon group may be replaced by halogen atoms other than fluorine atoms. Some or all of the hydrogen atoms of the aryl group may also be replaced by substituents selected from saturated hydrocarbon groups with 1 to 20 carbon atoms, saturated hydrocarbon oxygen groups with 1 to 20 carbon atoms, aryl groups with 6 to 20 carbon atoms, halogen atoms and hydroxyl groups.

[0925] R 302 The alkylene group representing 1 to 20 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed with L... C The same applies to the alkylene groups representing carbon numbers from 1 to 20.

[0926] R 302Specific examples of arylene groups having 6 to 20 carbon atoms include phenylene, naphthylene, phenanthrenediyl, and anthracenediyl. The saturated hydrocarbon group having 1 to 20 carbon atoms and the hydrocarbon part of the hydroxyl group having 1 to 20 carbon atoms that are substituents of the aforementioned arylene groups can be straight-chain, branched, or cyclic. Specific examples include alkyl groups having 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, decadecyl, heptadecyl, octadecyl, nonadecanyl, and icosyl; and cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl. Specific examples of arylene substituents with 6 to 14 carbon atoms include phenylene, naphthylene, phenanthrenediyl, anthracenediyl, etc.

[0927] The anion represented by formula (E1) should preferably be the anion represented by formula (E2).

[0928] [Chemistry 338]

[0929]

[0930] In equation (E2), p, q, r, and L 11 L C and R 301 Same as above. m2 is 1, 2, 3, or 4. R 302A It is a saturated hydrocarbon group with 1 to 20 carbon atoms, a saturated hydroxyl group with 1 to 20 carbon atoms, an aryl group with 6 to 14 carbon atoms, a halogen atom, or a hydroxyl group. Furthermore, when m2 is 2, 3, or 4, each R... 302A They can be the same or different.

[0931] Specific examples of anions represented by formula (E1) are shown below, but are not limited to these.

[0932] [Chemistry 339]

[0933]

[0934] [Transformation 340]

[0935]

[0936] [Chemistry 341]

[0937]

[0938] [Chemistry 342]

[0939]

[0940] [Chemistry 343]

[0941]

[0942] [Chemistry 344]

[0943]

[0944] [Chemistry 345]

[0945]

[0946] [Chemistry 346]

[0947]

[0948] [Chemistry 347]

[0949]

[0950] [Chemistry 348]

[0951]

[0952] [Chemistry 349]

[0953]

[0954] [Chemical 350]

[0955]

[0956] [Chemistry 351]

[0957]

[0958] [Chemistry 352]

[0959]

[0960] [Chemistry 353]

[0961]

[0962] [Chemistry 354]

[0963]

[0964] [Chemistry 355]

[0965]

[0966] [Chemistry 356]

[0967]

[0968] [Chemistry 357]

[0969]

[0970] [Chemical formula 358]

[0971]

[0972] [Chemical formula 359]

[0973]

[0974] [Chemical formula 360]

[0975]

[0976] [Chemical formula 361]

[0977]

[0978] [Chemical formula 362]

[0979]

[0980] [Chemical formula 363]

[0981]

[0982] [Chemical formula 364]

[0983]

[0984] [Chemical formula 365]

[0985]

[0986] [Chemical formula 366]

[0987]

[0988] [Chemical formula 367]

[0989]

[0990] [Chemical formula 368]

[0991]

[0992] [Chemical formula 369]

[0993]

[0994] [[ID=​​​​​​

[0997]

[0998] [Chemistry 372]

[0999]

[1000] [Chemistry 373]

[1001]

[1002] [Chemistry 374]

[1003]

[1004] [Chemistry 375]

[1005]

[1006] (E) In the photoacid generating agent, the cation paired with the aforementioned anion is preferably a sulfonium cation or a monazine cation. Specific examples of the aforementioned sulfonium cation may be cited in paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-003744, paragraphs

[0070] to

[0085] of Japanese Patent Application Publication No. 2023-169812, and those expressed by formula (A2), but are not limited to these. Specific examples of the aforementioned monazine cation may be cited in paragraph

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

[1007] For the acids generated by the aforementioned photoacid generators, a pKa of -2.0 or higher is preferred, and -1.0 or higher is even better. Furthermore, an upper limit of 2.0 for the pKa is preferable. The pKa value is calculated using pKa DB in the software ACD / Chemsketch ver: 9.04 manufactured by Advanced Chemistry Development, Inc.

[1008] When the chemically amplified positive resist composition of the present invention includes an (E) photoacid generator, its content relative to 80 parts by weight of the aforementioned base polymer is preferably 1 to 10 parts by weight, and more preferably 1 to 5 parts by weight. By including the (E) photoacid generator, the amount of acid generated in the exposed portion and the solvent resistance of the unexposed portion can be appropriately adjusted. The (E) photoacid generator can be used alone or in combination of two or more.

[1009] When the chemically amplified positive resist composition of the present invention simultaneously contains (E) a photoacid generator and (B) a quencher, the content ratio of the photoacid generator to the quencher (photoacid generator / quencher) is preferably such that the mass ratio is less than 3, more preferably less than 2.5, and even more preferably less than 2. If the content ratio of the photoacid generator to the quencher in the aforementioned chemically amplified positive resist composition is within the aforementioned range, acid diffusion can be sufficiently suppressed, and excellent resolution and dimensional uniformity can be obtained.

[1010] [(F) Surfactant]

[1011] To improve the coating properties of the substrate, the chemically amplified positive resist composition of the present invention may also include a conventional surfactant as component (F). The aforementioned surfactants are widely known, as described in International Publication No. 2006 / 121096, Japanese Patent Application Publication No. 2008-102383, Japanese Patent Application Publication No. 2008-304590, Japanese Patent Application Publication No. 2004-115630, and Japanese Patent Application Publication No. 2005-8766, and may be referenced and selected from these.

[1012] When the chemically amplified positive resist composition of the present invention contains surfactant (F), its content relative to 80 parts by mass of the base polymer (A) is preferably 2 parts by mass or less, more preferably 1 part by mass or less, and preferably 0.01 parts by mass or more. Surfactant (F) may be used alone or in combination of two or more.

[1013] [Resist Pattern Formation Method]

[1014] The resist pattern forming method of the present invention includes the steps of forming a resist film on a substrate using the aforementioned chemically amplified positive resist composition, exposing the aforementioned resist film using high-energy rays, and developing the aforementioned patterned resist film using an alkaline developer to obtain a resist pattern.

[1015] The aforementioned substrate can be, for example, a substrate used for integrated circuit manufacturing (Si, SiO, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective film, etc.) or a substrate used for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, Si, SiO, SiO2, etc.). The aforementioned chemically amplified positive resist composition is coated onto the substrate using a spin-coating or similar method to achieve a film thickness of 0.03–2 μm. The substrate is then placed on a heating plate and pre-baked, preferably at 60–150°C for 1–20 minutes, more preferably at 80–140°C for 1–10 minutes, to form a resist film.

[1016] Then, the aforementioned resist film is exposed to high-energy rays to irradiate the pattern. Examples of such high-energy rays include ultraviolet light, far-ultraviolet light, excimer lasers (KrF, ArF, etc.), EB, EUV, X-rays, gamma rays, and synchrotron radiation.

[1017] When using ultraviolet light, far ultraviolet light, excimer lasers, EUV, X-rays, gamma rays, or synchrotron radiation, the aforementioned high-energy rays utilize a mask to form the target pattern, with an optimal exposure dose of 1–300 mJ / cm². 2 It is even better to achieve 10-200 mJ / cm 2 Irradiation in this manner. When using EB (Extracorporeal Electron Microwave Oxide) for high-energy radiation, the optimal exposure level is 1–300 μC / cm. 2 It is better to achieve a temperature of 10–200 μC / cm 2 The method directly depicts the image. Furthermore, the chemically amplified positive resist composition of this invention is particularly useful in EUV or EB lithography.

[1018] In addition to the usual exposure method, exposure can also be achieved by wetting the mask and the resist film with a liquid between them, depending on the circumstances. In this case, a water-insoluble protective film can also be used.

[1019] Then, on a heated plate, preferably at 60–150°C, perform post-exposure baking (PEB) for 1–20 minutes, more preferably at 80–140°C for 1–10 minutes.

[1020] Subsequently, a developer solution containing an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) of preferably 0.1 to 5% by mass, more preferably 2 to 3% by mass, is used to develop the substrate using conventional methods such as dip, immersion, or spraying for 0.1 to 3 minutes, preferably 0.5 to 2 minutes, thereby forming the target pattern on the substrate.

[1021] The chemically amplified positive resist composition of the present invention is particularly useful when high etch resistance is required, and when the pattern linewidth variation remains small even with prolonged time from exposure to PEB, and the LER remains low. Furthermore, the resist composition of the present invention is particularly useful for use on substrates made of materials where it is difficult to achieve a tight adherence to the resist pattern, thus easily leading to pattern peeling and pattern breakage. Examples of such substrates include substrates formed by sputtering metallic chromium or chromium compounds containing one or more light elements selected from oxygen, nitrogen, and carbon. The chemically amplified positive resist composition of the present invention is particularly useful in pattern formation using a blank photomask as a substrate.

[1022] [Example]

[1023] The present invention will be specifically described below by illustrating synthesis examples, embodiments, and comparative examples. The present invention is not limited to the embodiments described below. Furthermore, the copolymerization composition ratio is a molar ratio, and Mw is a polystyrene conversion value obtained using GPC. The apparatus used is as follows.

[1024] •IR: NICOLET 6700, Thermo Fisher Scientific

[1025] · 1 H-NMR: ECA-500 manufactured by Nippon Electronics Co., Ltd.

[1026] MALDI TOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[1027] [1] Synthesis of onium salt monomers

[1028] [Synthetic Example 1-1] Synthesis of Onium Salt Monomer A1-1

[1029] [Chemistry 376]

[1030]

[1031] Under nitrogen atmosphere, an aqueous solution of raw material SM-1 (1046.2 g, equivalent to 47.1 g of pure substance), raw material SM-2 (21.6 g), and dichloromethane (300 g) were added, and the mixture was stirred at room temperature for 30 minutes. The organic layer was separated, washed with water, and then concentrated under reduced pressure to obtain onium salt monomer A1-1 as an oily substance (yield 56.7 g, 93% yield).

[1032] The IR spectrum data and TOF-MS results of the onium salt type monomer A1-1 are shown below. Also, the nuclear magnetic resonance spectrum ( 1 The results of H-NMR / DMSO-d6 showed that Figure 1 .

[1033] IR(D-ATR):ν=3436,3060,1706,1599,1560,1495,1443,1387,1294,1200,1134,112 3,1055,1033,1009,999,912,864,844,733,719,699,675,581,555,539,508,491cm -1 .

[1034] MALDI TOF-MS:POSITIVE M + 461 (equivalent to C) 18 H 10 F4IS + )

[1035] NEGATIVE M - 183 (equivalent to C8H7O3S) - )

[1036] [2] Polymer synthesis

[1037] [Synthetic Example 2-1] Synthesis of Polymer P-1

[1038] Under nitrogen atmosphere, monomer-polymerization initiator solution was prepared by taking monomer A1-1 (19.2 g), monomer A2-1 (50.1 g), monomer A3-1-1 (30.7 g), V-601 (manufactured by Fujifilm and Koei Tecmo Chemicals Co., Ltd.) 6.86 g, and MEK 139 g in a flask. In another flask under nitrogen atmosphere, MEK 46 g was taken and heated to 80°C with stirring. The aforementioned monomer-polymerization initiator solution was then added dropwise over 4 hours. After the addition was complete, the polymerization solution was maintained at 80°C and stirred for another 2 hours, then cooled to room temperature. The obtained polymerization solution was added dropwise to 3000 g of hexane under vigorous stirring. The precipitated polymer was filtered. 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 97.1 g, 97% yield). The Mw of polymer P-1 is 9700, and the Mw / Mn ratio is 1.62. Furthermore, Mw is a polystyrene conversion value obtained using GPC with DMF as the solvent.

[1039] [Chemistry 377]

[1040]

[1041] [Synthetic Examples 2-2 to 2-60, Comparative Synthetic Examples 1-1 to 1-38] Synthesis of polymers P-2 to P-60 and comparative polymers CP-1 to CP-38

[1042] By changing the types and blending ratios of the monomers, polymers P-2 to P-60 shown in Tables 1 and 2, and comparative polymers CP-1 to CP-38 shown in Table 3, were synthesized using the same method as in Synthesis Example 2-1. In Tables 1 to 3, the induction ratios are shown as molar ratios.

[1043] [Table 1]

[1044]

[1045] [Table 2]

[1046]

[1047] [Table 3]

[1048]

[1049] The monomers used in the synthesis of the polymer are as follows.

[1050] [Chemistry 378]

[1051]

[1052] [Chemistry 379]

[1053]

[1054] [Chemistry 380]

[1055]

[1056] [Chemistry 381]

[1057]

[1058] [Chemistry 382]

[1059]

[1060] [Chemistry 383]

[1061]

[1062] [Chem. 384]

[1063]

[1064] The dissolution rate of the aforementioned polymers in the alkaline developer was calculated by spin-coating a polymer solution (polymer concentration: 16.7% by mass, solvent: PGME) onto an 8-inch silicon wafer, baking it at 100°C for 90 seconds to form a film with a thickness of 1000 nm, developing it with a 2.38% by mass TMAH aqueous solution at 23°C for 100 seconds, and measuring the film loss. The results showed that the dissolution rate of polymers P-1 to P-60 was less than 10 nm / min. Furthermore, the dissolution rate of polymers CP-1 to CP-38 was also less than 10 nm / min.

[1065] [Synthetic Examples 3-1 to 3-16] Synthesis of Polymers AP-1 to AP-16

[1066] By changing the raw material compounds used, but otherwise using the same method as in Synthesis Example 1-1, polymers AP-1 to AP-16 as shown below were synthesized.

[1067] [Chem. 385]

[1068]

[1069] [Chemistry 386]

[1070]

[1071] [Chemistry 387]

[1072]

[1073] [Chem.388]

[1074]

[1075] The dissolution rate of polymers AP-1 to AP-16 is below 10 nm / min.

[1076] [2] Preparation of chemically amplified positive resist composition

[1077] [Examples 1-1 to 1-100, Comparative Examples 1-1 to 1-60]

[1078] The components shown in Tables 4-8 below were dissolved in an organic solvent. The resulting solution was filtered through a 5 nm nylon filter and a sub-1 nm UPE filter to prepare a chemically amplified positive resist composition. The aforementioned organic solvent was 920 parts by weight of PGMEA, 1850 parts by weight of EL, or a mixture of 1850 parts by weight of diacetone alcohol and 1850 parts by weight of PGME.

[1079] [Table 4]

[1080]

[1081] [Table 5]

[1082]

[1083] [Table 6]

[1084]

[1085] [Table 7]

[1086]

[1087] [Table 8]

[1088]

[1089] Furthermore, the structures of quenchers Q-1 to Q-5, photoacid generators PAG-1 to PAG-6, and polymers FP-1 to FP-5 in Tables 4 to 8 are as follows.

[1090] [Chemistry 389]

[1091]

[1092] [Chemistry 390]

[1093]

[1094] [Chemistry 391]

[1095]

[1096] [3] Evaluation of EB lithography

[1097] [Examples 2-1 to 2-100, Comparative Examples 2-1 to 2-60]

[1098] Various chemically amplified positive resist compositions (R-1 to R-100, CR-1 to CR-60) were spin-coated onto a 152 mm square EUV exposure mask with a chromium compound outermost surface using an ACT-M spin-coating machine. The mask was then pre-baked at 110°C for 600 seconds on a heated plate to create a resist film with a thickness of 80 nm. The thickness of the obtained resist film was measured using an optical measuring instrument, Nanospec (Nanometrics). Measurements were taken at 81 points within the plane of the blank substrate, excluding the outer edge portion extending 10 mm inwards from the outer perimeter, and the average and range of the film thickness were calculated.

[1099] Then, exposure was performed using an electron beam exposure apparatus (EBM-5000plus manufactured by NuFlare Technology Co., Ltd., with an accelerating voltage of 50kV), and PEB was applied at 110°C for 600 seconds. Development was then performed with a 2.38% by mass TMAH aqueous solution to obtain a positive pattern.

[1100] The obtained resist patterns were evaluated as follows. The patterned blank mask was observed using an overhead SEM (scanning electron microscope). The optimal exposure (μC / cm²) was defined as the exposure at which the 1:1 line-to-space (LS) ratio at 200 nm was resolved at a 1:1 ratio. 2 The resolution (limiting resolution) was defined as the smallest size among the exposures with a 1:1 resolution for 200nm LS, and the LER of the 200nm LS was measured by SEM. For the limiting resolution of isolation spacing (IS), the smallest size among the exposures with a 9:1 line-to-spacing (LS) ratio at 200nm was defined as the limiting resolution. For pattern shape, whether it was rectangular was determined visually. The results are shown in Tables 9–13.

[1101] [Table 9]

[1102]

[1103] [Table 10]

[1104]

[1105] [Table 11]

[1106]

[1107] [Table 12]

[1108]

[1109] [Table 13]

[1110]

[1111] [4] Evaluation of etching resistance

[1112] [Examples 3-1 to 3-6, Comparative Examples 3-1 to 3-4]

[1113] Various chemically amplified positive resist compositions (R-2, R-7 to R-11, CR-2, CR-7 to CR-9) were spin-coated onto a 152 mm square EUV exposure mask with a chromium compound outermost surface using an ACT-M spin-coating machine. The mask was then pre-baked at 110°C for 600 seconds on a heated plate to create a 120 nm thick resist film. The thickness of the obtained resist film was measured using an optical measuring instrument, Nanospec (Nanometrics). Measurements were taken at 81 points within the plane of the blank substrate, excluding the outer edge portion extending 10 mm inwards from the outer perimeter, and the average and range of the film thickness were calculated. The coated substrate was then dry-etched using a UNAXIS G4 dry etching apparatus under the following conditions, and the film loss rate (A / sec) derived from the etched residual film was calculated. The results are shown in Table 11.

[1114] RF1(RIE): Pulse 700V

[1115] RF2(ICP): CW 400W

[1116] Pressure: 6mTorr

[1117] Cl2: 185 sccm

[1118] O2: 55sccm

[1119] He: 9.25 sccm

[1120] Etching time: 75 seconds

[1121] [Table 14]

[1122] Anti-corrosion composition Speed ​​(A / sec) Example 3-1 R-2 6.5 Example 3-2 R-7 6.5 Example 3-3 R-8 6.6 Examples 3-4 R-9 6.6 Examples 3-5 R-10 6.5 Examples 3-6 R-11 6.6 Comparative Example 3-1 CR-2 8.9 Comparative Example 3-2 CR-7 8.8 Comparative Example 3-3 CR-8 7.9 Comparative Examples 3-4 CR-9 7.4

[1123] The chemically amplified positive resist compositions (R-1 to R-100) of the present invention all exhibit good resolution, LER, and pattern rectangularity. On the other hand, the resist compositions of the comparative examples (CR-1 to CR-60) have insufficient optimization of acid diffusion, and deterioration in resolution, LER, and pattern rectangularity can be observed. Furthermore, in the dry etching evaluation using R-2, R-7 to R-11, the etching resistance is better than that of CR-2, CR-7 to CR-9, demonstrating that the presence of the (A1) framework of the present invention in the polymer is effective in mask processing.

[1124] The resist patterning method using the chemically amplified positive resist composition of the present invention is useful in the manufacture of semiconductor devices, especially in the optical lithography of transmissive and reflective blank photomasks.

Claims

1. A chemically amplified positive resist composition, comprising: a base polymer (A) which is a polymer whose solubility in an aqueous alkali increases due to the action of an acid, which comprises a repeating unit composed of an aromatic sulfonic acid anion represented by the following formula (Al-1) and a sulfonium cation represented by the following formula (Al-2), and a repeating unit represented by the following formula (A2), and which is a polymer whose solubility in an aqueous alkali increases due to the action of an acid, in the formula, n1 is 0 or 1, n2 is 0, 1, 2, 3 or 4 when n1 is 0, and is 0, 1, 2, 3, 4, 5 or 6 when n1 is 1, R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R 1 is a halogen atom, a nitro group, a cyano group, a hydroxyl group, a hydrocarbon group having 1 to 20 carbons which can also contain a hetero atom, a hydrocarbon oxy group having 1 to 20 carbons which can also contain a hetero atom, or a hydrocarbon thio group having 1 to 20 carbons which can also contain a hetero atom, and when n2 is 2 or more, each R 1 may be the same as or different from each other, and a plurality of R 1 may also be bonded to each other and form a ring together with the carbon atom to which they are bonded, X 1 is a single bond, ether bond, ester bond or amide bond, in the formula, m1 is 0 or 1, m2 is 0 or 1, m3 is 0 or 1, m4 is 0, 1, 2, 3 or 4, m5 is 0, 1, 2, 3 or 4, m6 is 0, 1, 2, 3, 4, 5 or 6, m7 is 0, 1, 2, 3, 4, 5 or 6, m8 is 0, 1 or 2, m9 is 0, 1 or 2, m10 is 0, 1 or 2, m11 is 0 or 1, m12 is 0, 1, 2, 3 or 4, m13 is 0, 1 or 2, m14 is 0, 1 or 2, but, 0≤m6+m9≤4 when m1 is 0, 0≤m6+m9≤6 when m1 is 1, 0≤m7+m10≤4 when m2 is 0, 0≤m7+m10≤6 when m2 is 1, 1≤m4+m5+m8+m14≤4 when m3 is 0, 1≤m4+m5+m8+m14≤6 when m3 is 1, 0≤m12+m13≤4 when m11 is 0, 0≤m12+m13≤6 when m11 is 1, and, m4+m12≥1, R F1 ~R F3 each independently is a fluorine atom, a fluorinated saturated hydrocarbon group having a carbon number of 1 to 6, a fluorinated saturated hydrocarbon oxy group having a carbon number of 1 to 6, or a fluorinated saturated hydrocarbon thio group having a carbon number of 1 to 6, and when m5 is 2 or more, each R F1 may be the same as or different from each other, and when m6 is 2 or more, each R F2 may be the same as or different from each other, and when m7 is 2 or more, each R F3 may be the same as or different from each other, R 2 ~R 5 is a halogen atom other than an iodine atom and a fluorine atom, a nitro group, a cyano group, a hydrocarbon group having a carbon number of 1 to 20 which can include a hetero atom, a hydrocarbon oxy group having a carbon number of 1 to 20 which can include a hetero atom, or a hydrocarbon thio group having a carbon number of 1 to 20 which can include a hetero atom, when m8 is 2, 2 R 2 may be the same as or different from each other, 2 R 2 may be bonded to each other and form a ring together with the carbon atom to which they are bonded, when m9 is 2, 2 R 3 may be the same as or different from each other, 2 R 3 may be bonded to each other and form a ring together with the carbon atom to which they are bonded, when m10 is 2, 2 R 4 may be the same as or different from each other, 2 R 4 may be bonded to each other and form a ring together with the carbon atom to which they are bonded, when m13 is 2, 2 R 5 may be the same as or different from each other, 2 R 5 may be bonded to each other and form a ring together with the carbon atom to which they are bonded, Further, the S in the stannum cation + The directly bonded aromatic rings can also be bonded to each other and to the S + together form a ring, L A and L B each independently is a single bond, ether bond, ester bond, amide bond, sulfonate ester bond, sulfonamide bond, carbonate ester bond, or carbamate ester bond, X L is a single bond, or a hydrocarbylene group having a carbon number of 1 to 40 which can also contain heteroatoms, in the formula, a1 is 0 or 1, a2 is 0, 1 or 2, a3 is an integer satisfying 0≤a3≤5+2(a2)-a4, a4 is 1, 2 or 3, R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R 11 is a halogen atom, a saturated hydrocarbon group having a carbon number of 1 to 6 which can be substituted with a halogen atom, a saturated hydrocarbon oxy group having a carbon number of 1 to 6 which can be substituted with a halogen atom, or a saturated hydrocarbon carbonyloxy group having a carbon number of 2 to 8 which can be substituted with a halogen atom, A 1 is a single bond or a saturated hydrocarbylene group having a carbon number of 1 to 10, and -CH2- of the saturated hydrocarbylene group can be substituted with -O-.

2. The chemically amplified positive resist composition according to claim 1, wherein, the sulfonium cation represented by the formula (A2) is represented by the following formula (Al-2-1), in the formula, m4to m10, m12to m14, R F1 to R F3 , R 2 to R 5 , L A , L B , and X L are the same as described above.

3. The chemically amplified positive resist composition according to claim 2, wherein, the sulfonium cation represented by the formula (Al-2-1) is represented by the following formula (Al-2-2), wherein m4to m10, R F1 to R F3 and R 2 to R 5 are the same as described previously.

4. The chemically amplified positive resist composition according to claim 1, wherein, the repeating unit represented by the formula (A2) is represented by the following formula (A2-1), wherein R A and a4 are the same as previously described.

5. The chemically amplified positive resist composition according to claim 1, wherein, the polymer further comprises at least one selected from the group consisting of a repeating unit represented by the following formula (A3-1) and a repeating unit represented by the following formula (A3-2), in the formula, b1 is 0 or 1, b2 is 0, 1 or 2, b3 is an integer satisfying 0≤b3≤5+2(b2)-b4, b4 is 1, 2 or 3, b5 is 0 or 1, R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R 12 is a halogen atom, a saturated hydrocarbon group having a carbon number of 1 to 6 which can be substituted with a halogen atom, a saturated hydrocarbon oxy group having a carbon number of 1 to 6 which can be substituted with a halogen atom, or a saturated hydrocarbon carbonyloxy group having a carbon number of 2 to 8 which can be substituted with a halogen atom, A 2 is a single bond or a saturated hydrocarbylene group having a carbon number of 1 to 10, a part of -CH2- of which can also be replaced by -O-, X is an acid-labile group when b4 is 1, X are each independently a hydrogen atom or an acid-labile group when b4 is 2 or 3, but at least one is an acid-labile group, c1 is 0, 1 or 2, c2 is 0, 1 or 2, c3 is 0, 1, 2, 3, 4 or 5, c4 is 0, 1 or 2, R 13 and R 14 each independently is a hydrocarbon group of carbon number 1 to 10 which can also contain heteroatoms, R 13 and R 14 may also be bonded to each other and form a ring together with the carbon atom to which they are bonded, R 15 each independently a fluorine atom, a fluorinated alkyl group having a carbon number of 1 to 5, or a fluorinated alkoxy group having a carbon number of 1 to 5, R 16 each independently a hydrocarbon group of carbon number 1 to 10 which can also contain heteroatoms, A 3 is a single bond, phenylene, naphthylene or *-C(=O)-O-A 31 -, A 31 is an aliphatic hydrocarbylene group having a carbon number of 1 to 20, which aliphatic hydrocarbylene group can also contain at least one selected from a hydroxyl group, an ether bond, an ester bond and a lactone ring, and * represents a bond to a carbon atom of the main chain.

6. The chemically amplified positive resist composition according to claim 1, wherein, the polymer further comprises at least one selected from the group consisting of a repeating unit represented by the following formula (B3), a repeating unit represented by the following formula (B4) and a repeating unit represented by the following formula (B5), in the formula, d is 0, 1, 2, 3, 4, 5 or 6, e is 0, 1, 2, 3 or 4, f1 is 0 or 1, f2 is 0, 1 or 2, f3 is 0, 1, 2, 3, 4 or 5, R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R 17 and R 18 each independently is a hydroxyl group, a halogen atom, a saturated hydrocarbon group having 1 to 6 carbons which can be substituted with a halogen atom, a saturated hydrocarbon oxy group having 1 to 6 carbons which can be substituted with a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbons which can be substituted with a halogen atom, R 19 is a halogen atom, a nitro group, a cyano group, a saturated hydrocarbon group having a carbon number of 1 to 20, a saturated hydrocarbon oxy group having a carbon number of 1 to 20, a saturated hydrocarbon carbonyl oxy group having a carbon number of 2 to 20, a saturated hydrocarbon oxy hydrocarbon group having a carbon number of 2 to 20, or a saturated hydrocarbon thiohydrocarbon group having a carbon number of 2 to 20, and f2may also be a hydroxyl group when f2is 1 or 2, A 4 is a single bond or a saturated hydrocarbylene group having a carbon number of 1 to 10, and -CH2- in the saturated hydrocarbylene group can be substituted with -O-.

7. The chemically amplified positive resist composition according to claim 1, wherein The content ratio of the repeating unit having an aromatic ring skeleton in all repeating units of the polymer contained in the (A) base polymer is 60 mol% or more.

8. The chemically amplified positive resist composition according to claim 1, further comprising (B) a quencher.

9. The chemically amplified positive resist composition according to claim 1, further comprising (C) an organic solvent.

10. The chemically amplified positive resist composition according to claim 1, further comprising (D) a fluorine atom-containing polymer, The (D) fluorine atom-containing polymer comprises: at least one selected from the group consisting of a repeating unit represented by the following formula (D1), a repeating unit represented by the following formula (D2), a repeating unit represented by the following formula (D3), and a repeating unit represented by the following formula (D4), in the formula, h is 1, 2, or 3, R B each independently is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R 201 , R 202 , R 204 and R 205 are each independently a hydrogen atom or a saturated hydrocarbon group having a carbon number of 1 to 10, R 203 , R 206 , R 207 and R 208 are each independently a hydrogen atom, a hydrocarbon group having a carbon number of 1 to 15, a fluorinated hydrocarbon group having a carbon number of 1 to 15 or an acid labile group, R 203 , R 206 , R 207 and R 208 may also be inserted with an ether bond or a carbonyl group between the carbon-carbon bonds when they are a hydrocarbon group or a fluorinated hydrocarbon group, Z 1 is a (h+1)-valent hydrocarbon group having a carbon number of 1 to 20 or a (h+1)-valent fluorinated hydrocarbon group having a carbon number of 1 to 20.

11. The chemically amplified positive resist composition according to claim 10, wherein, The fluorine atom-containing polymer further comprises at least one selected from the group consisting of a repeating unit represented by the following formula (D5) and a repeating unit represented by the following formula (D6), in the formula, x is 1, 2, or 3, y is an integer satisfying 0≤y≤5+2z-x, and z is 0 or 1, R C each independently is a hydrogen atom or a methyl group, R 209 is a hydrogen atom, or a linear or branched hydrocarbon group having 1 to 5 carbon atoms which can also insert a hetero atom-containing group between carbon-carbon bonds, R 210 is a linear or branched hydrocarbon group having 1 to 5 carbons which can also insert a hetero atom-containing group between carbon-carbon bonds, R 211 is a saturated hydrocarbon group having 1 to 20 carbon atoms, in which at least one hydrogen atom is replaced with a fluorine atom, and a part of -CH2- in the saturated hydrocarbon group can be replaced with an ester bond or an ether bond, Z 2 is a single bond, *-C(=O)-O- or *-C(=O)-NH-, Z 3 is a single bond, -O-, -C(=O)-O-Z 31 -Z 32 - or -C(=O)-NH-Z 31 -Z 32 -, Z 31 is a single bond or a saturated hydrocarbylene group having a carbon number of 1 to 10, Z 32 is a single bond, an ester bond, an ether bond or a sulfonamide bond, * is an atomic bond with a carbon atom of the main chain.

12. The chemically amplified positive resist composition according to claim 1, further comprising (E) an acid generator.

13. A resist pattern forming method comprising the steps of: forming a resist film on a substrate using the chemically amplified positive resist composition according to any one of claims 1 to 12, irradiating the resist film with a high-energy ray in a pattern, and developing the resist film irradiated in the pattern using an alkali developer.

14. The resist pattern forming method according to claim 13, wherein, The high-energy ray is a KrF excimer laser, an ArF excimer laser, extreme ultraviolet rays, or an electron beam.

15. The resist pattern forming method according to claim 13, wherein The topmost surface of the substrate is composed of a material containing at least one selected from the group consisting of chromium, silicon, tantalum, molybdenum, cobalt, nickel, tungsten, and tin.

16. The resist pattern forming process according to claim 13, wherein, The substrate is a transmissive or reflective blank mask.

17. A transmissive or reflective blank mask coated with the chemically amplified positive resist composition according to any one of claims 1 to 12.

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