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: a chemically amplified positive resist composition which can obtain a resist pattern having improved resolution at the time of pattern formation and improved LER, resolution, pattern loyalty, and dose tolerance; and a method for forming a resist pattern. The chemically amplified positive resist composition contains (A) a quenching agent comprising an onium salt represented by the following formula (A), (B) a base polymer comprising a polymer that contains a repeating unit represented by the following formula (B1) and is decomposed by the action of an acid to increase the solubility in an alkali developer, and (C) a photoacid generator. In the formula Z + Xq-(A), Xq-is an anion. However, an acid (XqH) having Xq-as the conjugated base has a boiling point of less than 165 DEG C and a molecular weight of 150 or less.

Description

TECHNICAL FIELD

[0001] The present application relates to a chemically amplified positive resist composition and a resist pattern forming method. BACKGROUND

[0002] In recent years, with the high integration and high speed of LSIs, the miniaturization of pattern rules has also been rapidly progressing. In the processing of patterns of 0.2 μm or less, a chemical amplification resist composition mainly using acid as a catalyst is used. As for the exposure source, high-energy rays such as ultraviolet rays, far ultraviolet rays, and electron beams (EB) are used, and in particular, in the processing method of a blank photomask for manufacturing a photomask for semiconductor manufacturing, EB lithography, which is a super-fine processing technology, has become indispensable.

[0003] A polymer containing a polyacidic side chain-containing aromatic skeleton, such as polyhydroxystyrene, is useful as a material for a KrF resist composition using a KrF excimer laser, but is not used as a material for an ArF resist composition using an ArF excimer laser because it exhibits a large absorption to light around 200 nm. However, in terms of a material for an EB resist composition or an extreme ultraviolet (EUV) resist composition, which is a powerful technology for forming a pattern smaller than the processing limit obtained by an ArF excimer laser, it has become an important material in terms of obtaining high etching resistance.

[0004] Generally, as a base polymer for a positive EB resist composition or an EUV resist composition, a material that uses acid generated from a photoacid generator by irradiation of high-energy rays as a catalyst, and that makes an acid-decomposable protecting group (an acid-labile group) of an acid functional group of a phenolic side chain possessed by the base polymer deprotect, thereby being soluble in an alkali developer, is mainly used.

[0005] The aforementioned acid-decomposable protecting groups mainly use tertiary alkyl groups, tertiary butoxycarbonyl groups, acetal groups, and the like. Here, when a protecting group that has a small activation energy required for deprotection, such as an acetal group, is used, although there is an advantage that a high-sensitivity resist film can be obtained, if the diffusion of the generated acid is not sufficiently suppressed, there is a problem that the deprotection reaction also occurs in the unexposed portions of the resist film, and degradation of line edge roughness (LER) and reduction of the dimensional uniformity (CDU) of the pattern line width occur. Also, especially in the processing of a blank photomask, which is an important use, there are chromium compound films represented by chromium oxide films formed on a photomask substrate, and the like, which have surface materials that easily affect the pattern shape of the chemically amplified resist film, and in order to maintain high resolution and shape after etching, maintaining the pattern profile of the resist film as a rectangle regardless of the type of substrate is also an important performance. Also, in recent years, in order to achieve miniaturization, there are cases where MBMW (Multi-Beam Mask Writing) drawing processing is used in the processing of a blank mask, and at this time, a low-sensitivity resist composition (high-dose area) that is advantageous for roughness is used for the resist composition in the high-dose area, and optimization of the resist composition in the high-dose area is also attracting attention.

[0006] For sensitivity, pattern profile control, various improvements have been made by the selection, combination, and processing conditions of the materials used for the resist composition. As one of the improvements, there is the problem of acid diffusion. For the acid diffusion, since it greatly affects the sensitivity and resolution of the chemically amplified resist composition, many studies have been made.

[0007] Patent Document 1 and Patent Document 2 describe examples in which acid diffusion is suppressed and roughness is reduced by making the volume of benzene sulfonic acid generated from a photo-acid generator by exposure large. However, the suppression of acid diffusion of the aforementioned acid generator has not been sufficient so far, and development of an acid generator with less diffusion is desired.

[0008] Patent Document 3 describes an example in which acid diffusion is controlled by making a sulfonic acid generated by exposure bind to a polymer used for a resist composition to suppress diffusion. This method of suppressing acid diffusion by making a repeating unit that generates an acid by exposure contained in a base polymer is effective in obtaining a pattern with small LER. However, depending on the structure and introduction rate of the repeating unit, there are cases where the solubility of the base polymer in which the repeating unit that generates an acid by exposure has been bound to an organic solvent becomes a problem.

[0009] Further, when a sulfonium salt that generates an acid such as a fluorinated alkane sulfonic acid having high acid strength is used with a polymer having a repeating unit having an acetal group, there is a problem that a pattern having a large LER is formed. In the deprotection of an acetal group having a small activation energy for deprotection, since the acid strength of the fluorinated alkane sulfonic acid is too high, even if the diffusion of the acid is suppressed, the deprotection reaction proceeds due to a trace amount of the acid that diffuses to the unexposed portion. The same applies to a sulfonium salt that generates a benzenesulfonic acid described in Patent Documents 1 and 2. Thus, it is desirable to develop an acid generator that generates an acid having a more desirable strength for the deprotection of an acetal group.

[0010] It is considered that, in order to suppress the diffusion of the acid, in addition to the aforementioned method of making the volume of the generated acid large, there is a method of improving the quencher (acid diffusion controller). The quencher is an agent that suppresses the diffusion of the acid, and is actually a necessary component in order to improve the performance of the resist composition. Quenchers have been variously investigated to date, and generally, an amine or a weak acid onium salt is used. In the case of a weak acid onium salt, Patent Document 5 describes that by adding triphenylsulfonium acetate, a good resist pattern having no T-top formation, no isolated pattern and line width difference, and no standing wave can be formed. Patent Document 6 describes that by adding an ammonium sulfonate or an ammonium carboxylate, the sensitivity, resolution, and exposure latitude are improved. Further, Patent Document 7 describes a KrF lithography and EB lithography resist composition containing a combination of a photoacid generator that generates a carboxylic acid containing a fluorine atom, which has excellent resolution, and improves the process latitude such as exposure latitude, depth of focus, and the like. They are used in KrF lithography, EB lithography, or F2 lithography.

[0011] Patent Document 8 describes an ArF lithography positive photosensitive composition containing a carboxylic acid onium salt. They exchange and generate a weak acid and a strong acid onium salt from a strong acid (sulfonic acid) and a weak acid onium salt generated from a photoacid generator by exposure, thereby suppressing the acid decomposition reaction of an acid-labile group by replacing the strong acid (sulfonic acid) having high acidity with a weak acid (carboxylic acid), and reducing (controlling) the acid diffusion distance, and function as a quencher on the surface.

[0012] Patent Document 9 describes the use of a sulfonium salt containing a heterocycle containing nitrogen as a quencher, but does not make a detailed investigation into a low sensitivity resist composition (high dose region) of 50 μC or more.

[0013] However, when the aforementioned resist composition containing a carboxylic acid onium salt, a fluorocarboxylic acid onium salt is used to perform patterning, in terms of the further miniaturization that has progressed in recent years, the LER and resolution are still insufficient to date, and thus it is desirable to develop a quencher that further reduces the LER, and improves the resolution, pattern fidelity, and dose latitude.

[0014] Prior Art Documents

[0015] Patent Documents

[0016] [Patent Document 1] Japanese Patent Application Publication No. 2009-53518

[0017] [Patent Document 2] Japanese Patent Application Publication No. 2010-100604

[0018] [Patent Document 3] Japanese Patent Application Publication No. 2011-22564

[0019] [Patent Document 4] Japanese Patent No. 5083528

[0020] [Patent Document 5] Japanese Patent No. 3955384

[0021] [Patent Document 6] Japanese Patent Application Publication No. 11-327143

[0022] [Patent Document 7] Japanese Patent No. 4231622

[0023] [Patent Document 8] Japanese Patent No. 4226803

[0024] [Patent Document 9] Japanese Patent No. 6512049 Summary of the Invention

[0025] [The problem that the invention aims to solve]

[0026] The present invention is made in view of the foregoing circumstances, and aims to provide a chemically amplified positive resist composition that can obtain improved resolution during pattern formation, and improved LER, resolution, pattern fidelity and dose tolerance, as well as a method for forming resist patterns.

[0027] [Methods for solving the problem]

[0028] After repeated and in-depth explorations to achieve the aforementioned objectives, the inventors of this application have obtained the following insights, which led to the completion of this invention: By utilizing a chemically amplified resist composition containing (A) a quencher composed of an onium salt containing a conjugate acid (XqH) with a boiling point below 165°C and a molecular weight below 150, (B) a base polymer containing a predetermined polymer, and (C) a photoacid generator, patterns exhibiting good resolution, pattern shape, and improved LER, pattern fidelity, and dose tolerance can be obtained.

[0029] That is, the present invention provides the following chemically amplified positive resist composition and resist patterning method.

[0030] 1. A chemically amplified positive resist composition, comprising:

[0031] (A) Quenching agent, composed of onium salts represented by the following formula (A),

[0032] (B) A basic polymer comprising repeating units represented by the following formula (B1), and a polymer that decomposes under the action of acid and increases its solubility in alkaline developing solutions, and

[0033] (C) Photoacid generator.

[0034] [Chemistry 1]

[0035] z + xq - (A)

[0036] In the formula, Xq - It is an anion. However, with Xq - The acid (XqH) that is a conjugate base has a boiling point below 165°C and a molecular weight below 150.

[0037] Z + The sulfonium cation represented by formula (Z-1), the monium cation represented by formula (Z-2), the ammonium cation represented by formula (Z-3), or the sulfonium cation represented by formula (Z-4) are all sulfonium cations.

[0038] [Chemistry 2]

[0039]

[0040] In the formula, R 1 ~R 9 Each group is a hydrocarbon group with 1 to 30 carbon atoms, which may be independently composed of halogen atoms or may also contain heteroatoms. Also, R 1 ~R 3 Any two atoms in R can also bond to each other and form a ring together with the sulfur atoms they are bonded to. 6 ~R 9 Any two atoms in the atom can also bond to each other and form a ring together with the nitrogen atoms they are bonded to.

[0041] [Chemistry 3]

[0042]

[0043] 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. However, when m1 is 0, 0 ≤ m6 + m9 ≤ 4; when m1 is 1, 0 ≤ m6 + m9 ≤ 6. When m2 is 0, 0 ≤ m7 + m10 ≤ 4; when m2 is 1, 0 ≤ m7 + m10 ≤ 6. When m3 is 0, 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, 1 ≤ m4 + m5 + m8 + m14 ≤ 6. When m11 is 0, 0 ≤ m12 + m13 ≤ 4; when m11 is 1, 0 ≤ m12 + m13 ≤ 6. Also, m4 + m12 ≥ 1.

[0044] 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 group having 1 to 6 carbon atoms with an oxygen atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms with a thio group. 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.

[0045] R 10 ~R 13 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 containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. When m8 is 2, there are 2 R groups. 10 They can be the same or different, and there are 2 Rs. 10 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. 11 They can be the same or different, and there are 2 Rs. 11 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... 12 They can be the same or different, and there are 2 Rs. 12 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. 13 They can be the same or different, and there are 2 Rs. 13 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0046] Furthermore, S directly bonded to the sulfonium cation +The aromatic rings can also bond with each other and with S + Together they form a ring.

[0047] 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.

[0048] X L It is a single bond, or may contain a heteroatom and a hydrocarbon group with 1 to 40 carbon atoms.

[0049] [Chemistry 4]

[0050]

[0051] In the formula, a1 is 0 or 1. a2 is 0, 1 or 2. a3 is an integer that satisfies 0 ≤ a3 ≤ 5 + 2(a2) - a4. a4 is 1, 2 or 3.

[0052] R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0053] R 21 It can be a halogen atom, a nitro group, a carboxyl group, or a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted by a halogen atom, or a saturated hydrocarbon carbonyl group with 2 to 8 carbon atoms that can be substituted by a halogen atom.

[0054] A 1 It is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated hydrocarbon group can also be replaced by -O-.

[0055] 2. As in 1., a chemically amplified positive resist composition, wherein the anion Xq - The conjugate acid XqH is formic acid, acetic acid, propionic acid, butyric acid, trifluoroacetic acid, 3,3,3-trifluoropropionic acid, trimethylacetic acid, or nitric acid.

[0056] 3. A chemically amplified positive resist composition as in 1. or 2, wherein the aforementioned polymer further contains a repeating unit represented by the following formula (B2-1).

[0057] [Chemistry 5]

[0058]

[0059] In the formula, R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0060] 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.

[0061] R 31 It is a halogen atom, or a saturated hydrocarbon group having 1 to 6 carbon atoms that can be substituted by a halogen atom, or a saturated hydrocarbon carbonyl group having 2 to 8 carbon atoms that can be substituted by a halogen atom.

[0062] A 2 It is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated hydrocarbon group can also be replaced by -O-.

[0063] X is an acid-labile group when b4 is 1, and is a hydrogen atom or an acid-labile group when b4 is 2 or 3, but at least one of them is an acid-labile group.

[0064] 4. A chemically amplified positive resist composition as described in any one of 1. to 3, wherein the aforementioned polymer further contains a repeating unit represented by the following formula (B2-2).

[0065] [Chemistry 6]

[0066]

[0067] In the formula, 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.

[0068] R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0069] R 32 and R 33 Each can be independently a hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms, and R 32 and R 33 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0070] R 34 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.

[0071] R 35 Each can be an independent hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms.

[0072] A 3 It is a single bond, phenylene, naphthylene, or *-C(=O)-OA 31 -. A 31 It may also contain an aliphatic alkylene group, or a phenylene or naphthylene group, with 1 to 20 carbon atoms, and may also contain a hydroxyl group, ether bond, ester bond, or lactone ring. * indicates an atomic bond with the carbon atom of the main chain.

[0073] 5. A chemically amplified positive resist composition as described in any one of 1 to 4, wherein the aforementioned polymer contains at least one repeating unit selected from the repeating unit represented by formula (B3), the repeating unit represented by formula (B4), and the repeating unit represented by formula (B5).

[0074] [Chemistry 7]

[0075]

[0076] 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.

[0077] R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0078] R 41 and R 42 Each can be independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group with 1 to 6 carbon atoms that can also be substituted by a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that can also be substituted by a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that can also be substituted by a halogen atom.

[0079] R 43 It can be a saturated hydrocarbon group with 1 to 20 carbon atoms, a saturated hydrocarbon oxygen group with 1 to 20 carbon atoms, a saturated hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms, a saturated hydrocarbon oxy hydrocarbon group with 2 to 20 carbon atoms, a saturated hydrocarbon thioalkyl group with 2 to 20 carbon atoms, a halogen atom, a nitro group, or a cyano group, and can also be a hydroxyl group when f2 is 1 or 2.

[0080] A 4 It is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated hydrocarbon group can also be replaced by -O-.

[0081] 6. A chemically amplified positive resist composition as described in any one of 1 to 5, wherein the polymer contains at least one repeating unit selected from the following formula (B6), the following formula (B7), the following formula (B8), the following formula (B9), and the following formula (B10).

[0082] [Chemistry 8]

[0083]

[0084] In the formula, g1 and g2 are independently 0, 1, 2 or 3. h1 is 0 or 1. h2 is 0, 1, 2, 3 or 4. h3 is 0, 1, 2, 3 or 4. However, when h1 is 0, 0 ≤ h2 + h3 ≤ 4, and when h1 is 1, 0 ≤ h2 + h3 ≤ 6.

[0085] R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0086] Z 1 It is a single bond or may have substituents.

[0087] Z 2 For single bonds, **-C(=O)-OZ 21 -、**-C(=O)-NH-Z 21 -or**-OZ 21 -. Z 21 It is an aliphatic alkylene group, phenylene group, or a divalent group obtained by combining them, having 1 to 6 carbon atoms, and may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups.

[0088] Z 3 It can be a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond.

[0089] Z 4 It is a single bond, or an aliphatic alkylene group with 1 to 6 carbon atoms, a phenylene group, or a divalent group obtained by combining them, and may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups.

[0090] Z 5 Each can be a single bond, or may have substituents such as phenylene, naphthylene, or *-C(=O)-OZ. 51 -. Z 51 It is an aliphatic alkylene group, phenylene group, or naphthylene group with 1 to 10 carbon atoms, and the aliphatic alkylene group may also contain halogen atoms, hydroxyl groups, ether bonds, ester bonds, or lactone rings.

[0091] Z 6 It can be a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond.

[0092] Z 7 Each is independently a single bond, ***-Z 71 -C(=O)-O-、***-C(=O)-NH-Z 71 -or ***-OZ 71 -. Z 71 It may also contain heteroatoms and alkylene groups with 1 to 20 carbon atoms.

[0093] Z 8 Each is independently a single bond, ****-Z 81 -C(=O)-O-、****-C(=O)-NH-Z 81 -or ****-OZ 81 -. Z81 It may also contain heteroatoms and alkylene groups with 1 to 20 carbon atoms.

[0094] Z 9 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, *-C(=O)-OZ 91 -、*-C(=O)-N(H)-Z 91 -or *-OZ 91 -. Z 91 It is an aliphatic alkylene group, phenylene, fluorinated phenylene, or phenylene substituted with trifluoromethyl, having 1 to 6 carbon atoms, and may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group.

[0095] * indicates an atomic bond with a carbon atom in the main chain. ** indicates an atomic bond with Z. 1 The atomic bonds. *** indicates the relationship between Z and 6 Atomic bonds. **** represents the bond between Z and Z. 7 Atomic bonds.

[0096] L 1 It can be a single bond, ether bond, ester bond, carbonyl group, sulfonate bond, sulfonamide bond, carbonate bond or carbamate bond.

[0097] Rf 1 and Rf 2 Each is independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms.

[0098] Rf 3 and Rf 4 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms.

[0099] Rf 5 and Rf 6 Each can be independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. However, all Rf 5 and Rf 6 It cannot be both hydrogen atoms at the same time.

[0100] Rf 7 It is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkyl thio group having 1 to 6 carbon atoms.

[0101] R 51 and R 52 Each can be independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. Also, R 51 and R 52 They can also bond to each other and form rings together with the sulfur atoms they are bonded to.

[0102] R 53It is a halogen atom other than fluorine, or may contain a hydrocarbon group with 1 to 20 carbon atoms and heteroatoms. When h3 is 2, 3, or 4, multiple R 53 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0103] M - It is a non-nucleophilic relative ion.

[0104] A + It is a ium cation.

[0105] 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 skeleton in all repeating units of the aforementioned base polymer is 60 mol% or more.

[0106] 8. Any chemically amplified positive resist composition as described in any of 1. to 7, further contains (D) an organic solvent.

[0107] 9. The chemically amplified positive resist composition of any one of 1. to 8. further contains (E) a polymer containing fluorine atoms, which contains at least one repeating unit selected from the repeating unit represented by formula (E1), the repeating unit represented by formula (E2), the repeating unit represented by formula (E3) and the repeating unit represented by formula (E4), and may also contain at least one repeating unit selected from the repeating unit represented by formula (E5) and the repeating unit represented by formula (E6).

[0108] [Chemistry 9]

[0109]

[0110] In the formula, j1 is 1, 2, or 3. j2 is an integer satisfying 0 ≤ j2 ≤ 5 + 2(j3) - j1. j3 is 0 or 1. k is 1, 2, or 3.

[0111] R B Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0112] R C Each can be a hydrogen atom or a methyl group, independently.

[0113] R 101 R 102 R 104 and R 105 Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms.

[0114] R 103 R 106 R 107 and R 108Each of the following 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-unstable group, and R 103 R 106 R 107 and R 108 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.

[0115] R 109 A straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, which may be hydrogen atoms or may have heteroatom-containing groups inserted between carbon-carbon bonds.

[0116] R 110 It can also be a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, in which heteroatoms are inserted between carbon-carbon bonds.

[0117] R 111 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.

[0118] X 1 It is a (k+1) valence hydrocarbon group with 1 to 20 carbon atoms or a (k+1) valence fluorinated hydrocarbon group with 1 to 20 carbon atoms.

[0119] X 2 It is a single bond, *-C(=O)-O- or *-C(=O)-NH-. * represents an atomic bond with a carbon atom in the main chain.

[0120] X 3 For single bonds, -O-, *-C(=O)-OX 31 -X 32 -or *-C(=O)-NH-X 31 -X 32 -. X 31 It is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms. X 32 These are single bonds, ester bonds, ether bonds, or sulfonamide bonds. * indicates an atomic bond with a carbon atom in the main chain.

[0121] 10. A chemically amplified positive resist composition as described in any of 1. to 9, further comprising a quencher other than the quencher described in 1.

[0122] 11. A method for forming a resist pattern, comprising the following steps:

[0123] A resist film is formed on a substrate using a chemically amplified positive resist composition as described in any of 1. to 10.

[0124] The pattern was irradiated with high-energy rays onto the aforementioned resist film, and

[0125] The resist film with the aforementioned irradiated pattern was developed using an alkaline developer.

[0126] 12. The resist patterning method of 11, wherein the aforementioned high-energy rays are EUV or EB with wavelengths of 3 to 15 nm.

[0127] 13. A method for forming a resist pattern as described in 11 or 12, wherein the outermost surface of the aforementioned substrate is made of a chromium-containing material.

[0128] 14. A method for forming a resist pattern as described in any one of 11 to 13, wherein the aforementioned substrate is a blank photomask.

[0129] [The effects of the invention]

[0130] The chemically amplified positive resist composition of the present invention utilizes the effect of the onium salt represented by formula (A) to effectively control acid diffusion caused by exposure during pattern formation. When using this composition to form a resist film and form a pattern, patterns with extremely high resolution, high pattern fidelity, and improved LER and dose tolerance can be obtained. Furthermore, the repeating unit represented by formula (B1) exhibits good solubility in alkaline developer and also improves the adhesion of the resist film to the substrate during formation.

[0131] The resist patterning method using the chemically amplified positive resist composition of the present invention can form patterns with high resolution, pattern fidelity, and improved LER and dose tolerance, thus making it ideal for use in microfabrication technologies, especially in EUV lithography and EB lithography. Detailed Implementation

[0132] The present invention will now be described in detail. Furthermore, in the following description, asymmetric carbon may be present depending on the structure represented by the chemical formula, and sometimes mirror-image isomers and non-mirror-image isomers may exist; in these cases, a general formula is used to represent these isomers. These isomers may be used individually or in mixtures.

[0133] [Chemical amplification positive resist composition]

[0134] The chemically amplified positive resist composition of the present invention is characterized by containing: (A) a quencher composed of an onium salt containing a conjugate acid (XqH) with a boiling point of less than 165°C and a molecular weight of less than 150; (B) a base polymer containing a predetermined polymer that decomposes due to the action of acid and increases the solubility in alkaline developer; and (C) a photoacid generator.

[0135] [(A) Quenching agent]

[0136] The onium salt that serves as the quenching agent in component (A) is represented by the following formula (A).

[0137] [Chemistry 10]

[0138] z + xq - In equation (A), Xq - It is an anion. However, with Xq - An acid (XqH) that acts as a conjugate base has a boiling point below 165°C and a molecular weight below 150. Examples of XqH include formic acid, acetic acid, propionic acid, butyric acid, trifluoroacetic acid, 3,3,3-trifluoropropionic acid, trimethylacetic acid, and nitric acid. Ideally, XqH should have a boiling point below 150°C and a molecular weight below 120.

[0139] In formula (A), Z + The aforementioned onium cation is preferably a sulfonium cation represented by formula (Z-1), a monium cation represented by formula (Z-2), or an ammonium cation represented by formula (Z-3).

[0140] [Chemistry 11]

[0141]

[0142] In equations (Z-1) to (Z-3), R 1 ~R 9 Each is a hydrocarbon group with 1 to 30 carbon atoms, which may be independently composed of halogen atoms or may contain heteroatoms.

[0143] R 1 ~R 9 Examples of halogen atoms that can be represented include: fluorine, chlorine, bromine, and iodine atoms.

[0144] R 1 ~R 9The hydrocarbon group represented can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 30 carbon atoms such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclohexenyl; aryl groups with 6 to 30 carbon atoms such as phenyl, naphthyl, and thiophene; aralkyl groups with 7 to 30 carbon atoms such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining them, but preferably aryl. 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, and a portion of the -CH2- group of the hydrocarbon group can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0145] Also, R 1 and R 2 They can also bond to each other and form a ring together with the sulfur atoms they are bonded to. In this case, the sulfonium cation represented by formula (Z-1) can be represented by the following formulas, etc.

[0146] [Chemistry 12]

[0147]

[0148] In the formula, the dashed line represents R. 3 Atomic bonds.

[0149] In addition, R 6 ~R 9 Any two atoms in the atom can also bond to each other and form a ring together with the nitrogen atoms they are bonded to.

[0150] Specific examples of sulfonium cations represented by formula (Z-1) include those described in paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-003744, and those described in paragraphs

[0070] to

[0085] of Japanese Patent Application Publication No. 2023-169812, but are not limited thereto. Specific examples of monium cations represented by formula (Z-2) include those described in paragraph

[0181] of Japanese Patent Application Publication No. 2024-000259, but are not limited thereto. Ammonium cations represented by formula (Z-3) include those described in paragraph

[0221] of Japanese Patent Application Publication No. 2024-000259, but are not limited thereto.

[0151] The aforementioned onium cation should also be a sulfonium cation represented by the following formula (Z-4).

[0152] [Chemistry 13]

[0153]

[0154] In formula (Z-4), 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, it is preferable to have a benzene ring with m1 = 0. 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, it is preferable to have a benzene ring with m2 = 0. 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, it is preferable to have a benzene ring with m3 = 0.

[0155] In formula (Z-4), m4 is 0, 1, 2, 3, or 4. The more iodine atoms in the cationic structure, the higher the absorption of EUV, but there is a concern that it will become less solvent-soluble and precipitate in the resist composition. Therefore, m4 should preferably be 0, 1, 2, or 3, with 0, 1, or 2 being better.

[0156] In formula (Z-4), m5 can be 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 more preferred. m6 can be 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 more preferred. m7 can be 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 more preferred.

[0157] In equation (Z-4), m8 is 0, 1, or 2. Considering the availability of raw materials, m8 should preferably be 0 or 1. m9 is 0, 1, or 2. Considering the availability of raw materials, m9 should preferably be 0 or 1. m10 is 0, 1, or 2. Considering the availability of raw materials, m10 should preferably be 0 or 1.

[0158] In formula (Z-4), 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, it is preferable to have a benzene ring with m11 of 0.

[0159] In formula (Z-4), m12 is 0, 1, 2, 3, or 4. The more iodine atoms in the cationic structure, the higher the absorption of EUV, but there is a concern that it will become less solvent-soluble and precipitate in the resist composition. Therefore, m12 should preferably be 0, 1, 2, or 3, with 0, 1, or 2 being more preferred.

[0160] In equation (Z-4), m13 is 0, 1, or 2. From the perspective of raw material availability, m13 should preferably be 0 or 1. m14 is 0, 1, or 2. From a synthetic perspective, m14 should preferably be 0 or 1.

[0161] However, when m1 is 0, the condition is 0 ≤ m6 + m9 ≤ 4; when m1 is 1, the condition is 0 ≤ m6 + m9 ≤ 6. When m2 is 0, the condition is 0 ≤ m7 + m10 ≤ 4; when m2 is 1, the condition is 0 ≤ m7 + m10 ≤ 6. When m3 is 0, the condition is 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, the condition is 1 ≤ m4 + m5 + m8 + m14 ≤ 6. When m11 is 0, the condition is 0 ≤ m12 + m13 ≤ 4; when m11 is 1, the condition is 0 ≤ m12 + m13 ≤ 6. Also, m4 + m12 ≥ 1.

[0162] In equation (Z-4), 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 group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon 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.

[0163] In equation (Z-4), R 10 ~R 13 The hydroxyl group can be a halogen atom other than iodine or fluorine, a nitro group, a cyano group, a hydrocarbon group with 1 to 20 carbon atoms (which may also contain heteroatoms), a hydrocarbon oxygen group with 1 to 20 carbon atoms (which may also contain heteroatoms), or a hydrocarbon thio group with 1 to 20 carbon atoms (which may also contain heteroatoms). The hydrocarbon group, hydrocarbon oxygen group, and hydrocarbon thio group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given in the description of formula (Z-1) as R. 1 ~R 9 The same example applies to the hydrocarbon group. Furthermore, some or all of the hydrogen atoms in the hydrocarbon group, hydrocarbon oxygen group, and hydrocarbon sulfide group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Also, a portion of the -CH2- group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, the hydrocarbon group may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0164] Also, when m8 is 2, there are 2 Rs. 10 They can be the same or different, and there are 2 Rs. 10 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. 11They can be the same or different, and there are 2 Rs. 11 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... 12 They can be the same or different, and there are 2 Rs. 12 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. 13 They can be the same or different, and there are 2 Rs. 13 They can also bond with 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, and halogen atoms, and some of the -CH2- in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, they may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0165] Furthermore, S is directly bonded to the sulfonium cation represented by formula (Z-4). + 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.

[0166] [Chemistry 14]

[0167]

[0168] In the formula, the dashed lines represent atomic bonds.

[0169] In equation (Z-4), L A and L B These can be independently identified as single bonds, ether bonds, ester bonds, amide bonds, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Among them, L... A The bonds should ideally be single bonds, ether bonds, ester bonds, or sulfonate bonds, with ester bonds or sulfonate bonds being preferred. B It is preferable to have a single bond, ether bond, or ester bond, with a single bond being better.

[0170] In equation (Z-4), X L It is a single bond, or may contain heteroatoms, of carbon atoms ranging from 1 to 40. The aforementioned hydrocarbon group can be linear, branched, or cyclic; specific examples include alkyldiyl groups and cyclic saturated hydrocarbon groups. Specific examples of the aforementioned heteroatoms include oxygen atoms, nitrogen atoms, and sulfur atoms.

[0171] X LExamples of hydrocarbon groups containing 1 to 40 carbon atoms that may also contain heteroatoms are shown below, but are not limited to these. Additionally, in the following formula, * indicates that they are related to L... A and L B Atomic bonds.

[0172] [Chemistry 15]

[0173]

[0174] [Chemistry 16]

[0175]

[0176] [Chemistry 17]

[0177]

[0178] [Chemistry 18]

[0179]

[0180] Among them, X is the most suitable. L -0~X L -22 and X L -47~X L -58. The sulfonium cation represented by formula (Z-4) should preferably be represented by formula (Z-4-1).

[0181] [Chemistry 19]

[0182]

[0183] In the formula, m4~m10, m12~m14, R F1 ~R F3 R 10 ~R 13 L A L B and X L Same as above.

[0184] The cation represented by formula (Z-4-1) should preferably be represented by formula (Z-4-2).

[0185] [Chemistry 20]

[0186]

[0187] In the formula, m4~m10, R F1 ~R F3 and R 10 ~R 12 Same as above.

[0188] Specific examples of sulfonium cations represented by formula (Z-4) are shown below, but are not limited thereto. Additionally, in the following formula, Me is a methyl group.

[0189] [Chemistry 21]

[0190]

[0191] [Chemistry 22]

[0192]

[0193] [Chemistry 23]

[0194]

[0195] [Chemistry 24]

[0196]

[0197] [Chemistry 25]

[0198]

[0199] [Chemistry 26]

[0200]

[0201] [Chemistry 27]

[0202]

[0203] [Chemistry 28]

[0204]

[0205] [Chemistry 29]

[0206]

[0207] [Chemistry 30]

[0208]

[0209] [Chemistry 31]

[0210]

[0211] [Chemistry 32]

[0212]

[0213] [Chemistry 33]

[0214]

[0215] [Chemistry 34]

[0216]

[0217] [Chemistry 35]

[0218]

[0219] [Chemistry 36]

[0220]

[0221] [Chemistry 37]

[0222]

[0223] [Chemistry 38]

[0224]

[0225] [Chemistry 39]

[0226]

[0227] [Chemistry 40]

[0228]

[0229] [Chemistry 41]

[0230]

[0231] [Chemistry 42]

[0232]

[0233] [Chemistry 43]

[0234]

[0235] [Chemistry 44]

[0236]

[0237] [Chemistry 45]

[0238]

[0239] [Chemistry 46]

[0240]

[0241] [Chemistry 47]

[0242]

[0243] [Chemistry 48]

[0244]

[0245] Specific examples of the aforementioned onium salts can be listed as any combination of the aforementioned anions and cations.

[0246] The aforementioned onium salts can be synthesized, for example, using the same method as that described in Japanese Patent Application Publication No. 2020-91312, but are not limited thereto.

[0247] The aforementioned onium salts can ideally be used as quenchers. Furthermore, in this invention, a quencher refers to a material that prevents the diffusion of strong acids generated from photoacid generators into unexposed areas by capturing them, thereby forming a desired pattern. A photoacid generator is a compound that generates strong acids due to high-energy radiation; a strong acid is a compound with sufficient acidity to induce a deprotection reaction of the unstable acid groups. The acids such as acetic acid, nitric acid, and trifluoroacetic acid generated by the onium salts of this invention do not have sufficient acidity to induce a deprotection reaction when the unstable acid groups are tertiary esters or tertiary ethers. Therefore, as described later, it is effective to add a photoacid generator that generates α-fluorinated sulfonic acid, imide acid, or methylated acid, which produces a strong acid, in order to induce a deprotection reaction of the unstable acid groups. Furthermore, the photoacid generator that generates α-fluorinated sulfonic acid, imide acid, or methylated acid can be additive or polymerically bonded to a base polymer.

[0248] When an onium salt that produces acids such as acetic acid, nitric acid, and trifluoroacetic acid is mixed with a photoacid generator that produces strong acids such as sulfonic acid and acetic acid, and then subjected to light, acids such as acetic acid, nitric acid, and trifluoroacetic acid, as well as sulfonic acid, will be produced. The photoacid generator will not completely decompose, so undecomposed photoacid generator will remain nearby. In this situation, if the onium salt that produces acids such as acetic acid, nitric acid, and trifluoroacetic acid coexists with the sulfonic acid, initially the sulfonic acid will undergo ion exchange with the onium salt that produces carboxylic acids and nitric acid, producing onium sulfonate salts and releasing acids such as acetic acid, nitric acid, and trifluoroacetic acid. This is because sulfonates, which are strong acids, are more stable. On the other hand, even if onium sulfonate salts are present with acids such as acetic acid, nitric acid, and trifluoroacetic acid, ion exchange will not occur.

[0249] The structural features of the onium salt of the present invention can be exemplified by anions having a conjugate acid (XqH) with a boiling point below 165°C and a molecular weight below 150. It is speculated that the weak acid generated from the onium salt of the present invention has a low boiling point, and therefore a portion of the generated acid will volatilize. The generated weak acid migrates to the developer and causes swelling of the resist film, resulting in pattern collapse. In contrast, as with the aforementioned onium salt, the volatilization of the weak acid reduces swelling. That is, the limiting resolution can be improved. Furthermore, the aforementioned anions have small molecular weights, making them easily flowable with the developer. Therefore, trace amounts of dissolved residue are less likely to remain at the interface between the exposed and unexposed areas after development, resulting in improved LWR. The aforementioned onium salt-type quencher generates a non-sulfonic acid weak acid, thus exhibiting low acid diffusion and, as mentioned above, low swelling. If the acid generator is formulated as a polymer bond type incorporating the photoacid generating unit into the base polymer used, acid diffusion can be further controlled, and the desired effect can be achieved.

[0250] In the chemically amplified positive resist composition of the present invention, the content of (A) quencher relative to 80 parts by weight of the base polymer described later is preferably 0.1 to 40 parts by weight, and more preferably 0.5 to 30 parts by weight. If the content of (A) quencher is within the aforementioned range, the sensitivity and resolution are good, and there is no concern about foreign matter forming in the resist film after development or during peeling, which is therefore ideal. (A) Quencher can be used alone or in combination of two or more types.

[0251] [(B) Basic Polymer]

[0252] (B) The base polymer of the component contains repeating units represented by the following formula (B1) (hereinafter also referred to as repeating unit B1), and is a polymer that decomposes due to the action of acid and increases its solubility in alkaline developing solution.

[0253] [Chemistry 49]

[0254]

[0255] In formula (B1), 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 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 1, 2, or 3.

[0256] In equation (B1), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0257] In equation (B1), R 21The saturated hydrocarbon group can be a halogen atom, nitro group, carboxyl group, or a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted by a halogen atom; a saturated hydrocarbon oxy group with 1 to 6 carbon atoms that can be substituted by a halogen atom; or a saturated hydrocarbon carbonyl oxy group with 2 to 8 carbon atoms that can be substituted by a halogen atom. The saturated hydrocarbon group, saturated hydrocarbon oxy group, and saturated hydrocarbon carbonyl oxy group can be any of the following: 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 them. If the number of carbon atoms is below the upper limit, the solubility in alkaline developing solutions is good. When a3 is 2 or higher, each R... 21 They can be the same or different.

[0258] In equation (B1), 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 may also be replaced by -O-. The aforementioned saturated alkylene group can be any of the following: linear, branched, or cyclic. Specific examples include: 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, etc., which are alkyl diyl groups with 1 to 10 carbon atoms; cyclopropane diyl, cyclobutane diyl, cyclopentane diyl, cyclohexane diyl, etc., which are cyclic saturated alkylene groups with 3 to 10 carbon atoms; and groups obtained by combining them. When the aforementioned saturated alkylene group contains an ether bond, if a1 in formula (B1) is 1, it can also be inserted at any position other than between the α- and β-carbon atoms relative to 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 other than between the α-position carbon atom and the β-position carbon atom relative to this ether oxygen atom. In addition, if the number of carbon atoms in the aforementioned saturated hydrocarbon group is 10 or less, sufficient solubility in alkaline developing solutions can be obtained, which is ideal.

[0259] 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 B1, ideal examples can be listed from units such as 3-hydroxystyrene, 4-hydroxystyrene, 5-hydroxy-2-vinylnaphthalene, 6-hydroxy-2-vinylnaphthalene, etc. Specifically, those shown below can be listed, but are not limited to. Additionally, in the following formula, R... A Same as above.

[0260] [Transformation 50]

[0261]

[0262] [Chemistry 51]

[0263]

[0264] [Chemistry 52]

[0265]

[0266] a1 is 1 (that is, it has -C(=O)-OA) 1 When R is used as a linking group, ideal examples of repeating unit B1 can be listed below, but are not limited to these. Additionally, in the following formula, R... A Same as above.

[0267] [Chemistry 53]

[0268]

[0269] [Chemistry 54]

[0270]

[0271] [Chemistry 55]

[0272]

[0273] [Chemistry 56]

[0274]

[0275] [Chemistry 57]

[0276]

[0277] The content of repeating unit B1 in all repeating units constituting the aforementioned polymer is preferably 15-90 mol%, and more preferably 15-80 mol%. However, it is ideal to include at least one of the repeating units represented by formula (B3) and formula (B4) that impart higher etch resistance to the polymer described later, and the unit has a phenolic hydroxyl group as a substituent, and the ratio falls within the aforementioned range. Repeating unit B1 may be used alone or in combination of two or more.

[0278] In order to form a positive resist composition, the aforementioned polymer should contain repeating units with acidic functional groups protected by acid-instable groups, that is, repeating units that are protected by acid-instable groups and become alkali-soluble due to the action of acid (hereinafter also referred to as repeating unit B2).

[0279] The best example of repeating unit B2 can be listed as follows: (B2-1) (hereinafter also referred to as repeating unit B2-1).

[0280] [Chem.58]

[0281]

[0282] In formula (B2-1), b1 is 0 or 1. b2 is 0, 1, or 2; 0 indicates a benzene skeleton, 1 indicates naphthalene, and 2 indicates anthracene. 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, it is preferable that b3 is 0, 1, 2, or 3, and b4 is 1, 2, or 3. When b2 is 1 or 2, it is preferable that b3 is 0, 1, 2, 3, or 4, and b4 is 1, 2, or 3.

[0283] In equation (B2-1), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0284] In equation (B2-1), R 31 The carbonyl group is a 2-8 carbon-numbered saturated hydrocarbon group that can be substituted with a halogen atom, or a 1-6 carbon-numbered saturated hydrocarbon group that can be substituted with a halogen atom, or a 1-6 carbon-numbered saturated hydrocarbon group that can be substituted with a halogen atom. The aforementioned saturated hydrocarbon group, as well as the saturated hydrocarbon group carbonyl group and the saturated hydrocarbon 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 them. If the number of carbon atoms is below the upper limit, the solubility in alkaline developing solutions is good. When b3 is 2 or more, each R... 31 They can be the same or different.

[0285] In equation (B2-1), A 2It 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 any of the following: linear, branched, or cyclic. Specific examples include: 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, etc., which are alkyl diyl groups with 1 to 10 carbon atoms; cyclopropane diyl, cyclobutane diyl, cyclopentane diyl, cyclohexane diyl, etc., which are cyclic saturated alkylene groups with 3 to 10 carbon atoms; and groups obtained by combining them. When the aforementioned saturated alkylene group contains an ether bond, if b1 in formula (B2-1) is 1, it can also be inserted at any position other than between the α- and β-carbon atoms relative to 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 other than between the α- and β-position carbon atoms relative to this ether oxygen atom. In addition, if the number of carbon atoms in the aforementioned saturated hydrocarbon group is 10 or less, sufficient solubility in alkaline developing solutions can be obtained, which is ideal.

[0286] In formula (B2-1), 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 independently, but at least one is an acid-labile group. That is, the repeating unit B2-1 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 group is not particularly limited to those known to be used in many chemically amplified positive resist compositions that have been deactivated by acid to provide an acidic group; all such groups may be used.

[0287] Examples of the aforementioned acid-labile groups include tertiary saturated hydrocarbon groups. To obtain the monomer for polymerization by distillation, the aforementioned tertiary saturated hydrocarbon groups should preferably have 4 to 18 carbon atoms.

[0288] The saturated hydrocarbon groups bonded to the aforementioned tertiary carbon atoms preferably have 1 to 15 carbon atoms. These saturated hydrocarbon groups with 1 to 15 carbon atoms can be linear, branched, or cyclic, and their carbon-carbon bonds may contain oxygen-containing functional groups such as ether bonds or carbonyl groups. 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 they are bonded to.

[0289] Examples of the aforementioned alkyl substituents include: 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 .17,10 Dodecyl, tetracyclo[4.4.0.1] 2,5 .1 7,10 Dodecyl, 3-oxo-1-cyclohexyl, etc.

[0290] The aforementioned tertiary saturated hydrocarbon groups can be listed as follows: tert-butyl, tert-pentyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1,2-trimethylpropyl, 1-adamantyl-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 Dodecyl, 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 thereto.

[0291] Furthermore, the aforementioned acid-indestructible groups can be exemplified by groups represented by formula (B2-1-1). Groups represented by formula (B2-1-1) are often used as acid-indestructible groups, and are a useful option as acid-indestructible groups that can stably provide a more rectangular pattern at the interface between the pattern and the substrate. When X is a group represented by formula (B2-1-1), an acetal structure is formed.

[0292] [Chemistry 59]

[0293]

[0294] In the formula, the dashed lines represent atomic bonds.

[0295] In equation (B2-1-1), R L1 It consists of a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. The aforementioned saturated hydrocarbon group can be any of the following: straight-chain, branched, or cyclic.

[0296] R L1 The appropriate group should be selected based on the design considerations regarding its sensitivity to acids. For example, if the design aims to ensure high stability before decomposition by strong acids, a group with a hydrogen atom or a tertiary carbon atom bonded to the acetal carbon is preferable. A group with a tertiary carbon atom bonded to the acetal carbon is suitable. L1 Examples include tert-butyl, tert-pentyl, and 1-adamantyl, but are not limited to these. For designs that utilize high reactivity and sensitivity to pH changes, straight-chain alkyl groups are preferable. While the combination of acid-generating agents and quenchers incorporated into the resist composition also depends on the design success of R... L2 In particular, when the terminal alkyl group is larger and the solubility change due to decomposition is large, R L1 It is preferable for the carbon atom bonded to the acetal carbon to be a secondary carbon atom. The R-type bonded to the acetal carbon by a secondary carbon atom... L1 Examples include isopropyl, sec-butyl, cyclopentyl, cyclohexyl, etc., but are not limited to these.

[0297] In equation (B2-1-1), R L2 The hydrocarbon group has 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 is replaced by heteroatoms such as oxygen or sulfur atoms, resulting in the presence of ether bonds or thioether bonds. 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, to obtain higher resolution, R... L2 It should preferably be 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 positive pattern formation is carried out using alkaline developer, it will dissolve in the developer, thus suppressing residue defects in the exposed area.

[0298] Ideal examples of the groups represented by formula (B2-1-1) can be listed below, but are not limited to these. Additionally, in the following formula, R... L1 As mentioned above, dashed lines represent atomic bonds.

[0299] [Transformation 60]

[0300]

[0301] [Chemistry 61]

[0302]

[0303] Other acid-labile groups can also be those where the hydrogen atom of the phenolic hydroxyl group is 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 for the protection of the aforementioned phenolic hydroxyl group.

[0304] Furthermore, repeating unit B2 can be represented by the following formula (B2-2) (hereinafter also referred to as repeating unit B2-2). Since repeating unit B2-2 increases the dissolution rate of the exposure section, it is a useful option as a unit containing an acid-inhibitory group that provides good performance for linewidth variations in the developing load.

[0305] [Chemistry 62]

[0306]

[0307] In equation (B2-2), 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.

[0308] In equation (B2-2), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0309] In equation (B2-2), R 32 and R 33 Each can be independently a hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms, and R 32 With R 33 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0310] In equation (B2-2), R 34 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.

[0311] In equation (B2-2), R 35 Each can be an independent hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms.

[0312] In equation (B2-2), A 3 It is a single bond, phenylene, naphthylene, or *-C(=O)-OA 31 -. A 31 It may also contain an aliphatic alkylene group, or a phenylene or naphthylene group, with 1 to 20 carbon atoms, and may also contain a hydroxyl group, ether bond, ester bond, or lactone ring. * indicates an atomic bond with the carbon atom of the main chain.

[0313] Ideal examples of repeating unit B2-2 can be listed below, but are not limited to these. Additionally, in the following formula, R... A Same as above.

[0314] [Chemistry 63]

[0315]

[0316] [Chemistry 64]

[0317]

[0318] The content of repeating unit B2 in all repeating units constituting the aforementioned polymer is preferably 5-95 mol%, and more preferably 20-80 mol%. Repeating unit B2 can be used alone or in combination of two or more types.

[0319] The aforementioned polymer may also contain at least one of the repeating units represented by the following formula (B3) (hereinafter also referred to as repeating unit B3), the repeating unit represented by the following formula (B4) (hereinafter also referred to as repeating unit B4), and the repeating unit represented by the following formula (B5) (hereinafter also referred to as repeating unit B5).

[0320] [Chemistry 65]

[0321]

[0322] In equations (B3) and (B4), d is 0, 1, 2, 3, 4, 5, or 6. e is 0, 1, 2, 3, or 4.

[0323] In equations (B3) and (B4), R 41 and R 42 Each R can be independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted by a halogen atom, a saturated hydrocarbon carbonyloxy group with 1 to 6 carbon atoms that can be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group with 2 to 8 carbon atoms that can be substituted by a halogen atom. The aforementioned saturated hydrocarbon group, saturated hydrocarbon carbonyloxy group, and saturated hydrocarbon carbonyloxy group can be any of the following: linear, branched, or cyclic. When d is 2 or more, each R... 41 They can be the same or different. When e is 2 or higher, each R... 42 They can be the same or different.

[0324] In formula (B5), f1 is 0 or 1. f2 is 0, 1, or 2. When f2 is 0, it is a benzene skeleton; when it is 1, it is a naphthalene skeleton; and when it is 2, it is an 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.

[0325] In equation (B5), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0326] In equation (B5), R 43The group can be a saturated hydrocarbon group (1-20 carbon atoms), a saturated hydrocarbon oxy group (1-20 carbon atoms), a saturated hydrocarbon carbonyl oxy group (2-20 carbon atoms), a saturated hydrocarbon oxyalkyl group (2-20 carbon atoms), a saturated hydrocarbon thioalkyl group (2-20 carbon atoms), a halogen atom, a nitro group, or a cyano group, and when f2 is 1 or 2, it can also be a hydroxyl group. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxyalkyl group, saturated hydrocarbon carbonyl oxyalkyl group, saturated hydrocarbon oxyalkyl group, and saturated hydrocarbon thioalkyl group can be any of the following: linear, branched, or cyclic. When f3 is 2 or more, each R... 43 They can be the same or different.

[0327] In equation (B5), A 4 It is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated hydrocarbon group may also be replaced by -O-. The aforementioned saturated hydrocarbon group can be linear, branched, or cyclic, and specific examples can be listed in A of formula (B1). 1 The same examples are illustrated in the description.

[0328] When at least one of repeating units B3 to B5 is used as a constituent unit of the aforementioned polymer, the etching resistance of the aromatic ring and the etching resistance and EB irradiation resistance during pattern inspection can be improved by adding a ring structure to the main chain.

[0329] To improve etching resistance, the content of repeating units B3 to B5 should preferably be 5 mol% or more in all repeating units constituting the aforementioned polymer. Furthermore, the content of repeating units B3 to B5 in all repeating units constituting the aforementioned polymer should preferably be 25 mol% or less, and more preferably 20 mol% or less. Ideally, if the amount of units without functional groups, or with functional groups other than hydroxyl groups, is 25 mol% or less, there is no concern about developing defects. Repeating units B3 to B5 can be used alone or in combination of two or more.

[0330] If the aforementioned polymer contains repeating unit B1, repeating unit B2, and at least one of repeating units selected from B3 to B5, it is ideal to have both high etch resistance and excellent resolution. In this case, these repeating units should preferably contain 60 mol% or more, more preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more in all the repeating units of the aforementioned polymer.

[0331] The aforementioned polymer may also contain at least one of the following: repeating unit represented by formula (B6) (hereinafter also referred to as repeating unit B6), repeating unit represented by formula (B7) (hereinafter also referred to as repeating unit B7), repeating unit represented by formula (B8) (hereinafter also referred to as repeating unit B8), repeating unit represented by formula (B9) (hereinafter also referred to as repeating unit B9), and repeating unit represented by formula (B10) (hereinafter also referred to as repeating unit B10).

[0332] [Chemistry 66]

[0333]

[0334] In equations (B6) to (B10), R A Each can be independently composed of a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 It is a single bond or may have substituents. Z 2 For single bonds, **-C(=O)-OZ 21 -、**-C(=O)-NH-Z 21 -or**-OZ 21 -. Z 21 It is a divalent group consisting of an aliphatic hydrocarbon group, a phenylene group, or a combination thereof, having 1 to 6 carbon atoms, and may also contain a halogen atom, a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 3 It can be a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. 4 It is a single bond, or an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, or a divalent group obtained by combining them, and may also contain a halogen atom, a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 5 Each can be a single bond, or may have substituents such as phenylene, naphthylene, or *-C(=O)-OZ. 51 -. Z 51 It is an aliphatic hydrocarbon group, phenylene group, or naphthylene group having 1 to 10 carbon atoms, and the aliphatic hydrocarbon group may also contain a halogen atom, a hydroxyl group, an ether bond, an ester bond, or an lactone ring. 6 It can be a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. 7 Each is independently a single bond, ***-Z 71 -C(=O)-O-、***-C(=O)-NH-Z 71 -or ***-OZ 71 -. Z 71 It can also contain alkylene groups with 1 to 20 carbon atoms, which may also contain heteroatoms. Z 8 Each is independently a single bond, ****-Z 81 -C(=O)-O-、****-C(=O)-NH-Z81 -or ****-OZ 81 -. Z 81 It can also contain alkylene groups with 1 to 20 carbon atoms, which may also contain heteroatoms. Z 9 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, *-C(=O)-OZ 91 -、*-C(=O)-N(H)-Z 91 -or *-OZ 91 -. Z 91 It is an aliphatic alkylene group, phenylene, fluorinated phenylene, or phenylene substituted with trifluoromethyl, having 1 to 6 carbon atoms, and may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group. * indicates an atomic bond with the carbon atom of the main chain. ** indicates a bond with Z. 1 The atomic bonds. *** indicates the relationship between Z and 6 Atomic bonds. **** represents the bond between Z and Z. 7 Atomic bonds.

[0335] Z 21 Z 51 and Z 91 The aliphatic alkyl sub-group can be any of the following: 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, 1,1-dimethylethane-1,2-diyl, pentane-1,5-diyl, 2-methylbutane-1,2-diyl, hexane-1,6-diyl, etc.; cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, cyclohexanediyl, etc.; and groups obtained by combining them.

[0336] Z 71 and Z 81 The sub-hydrocarbon group represented may contain heteroatoms and can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples are listed below, but are not limited to these.

[0337] [Chemistry 67]

[0338]

[0339] In the formula, the dashed lines represent atomic bonds.

[0340] In equation (B6), R 51 and R 52Each of the above-mentioned hydrocarbon groups can be independently a hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms such as vinyl, 1-propenyl, 2-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, naphthyl, and thiophene; aralkyl groups with 7 to 20 carbon atoms such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining them, but preferably aryl. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and a portion of the -CH2- group of the hydrocarbon group may also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0341] Also, R 51 and R 52 They can also bond to each other and form rings together with the sulfur atoms they are bonded to. Specific examples of the aforementioned rings can be shown in the following formulas, etc.

[0342] [Chemistry 68]

[0343]

[0344] In the formula, the dashed line represents Z. 4 Atomic bonds.

[0345] Specific examples of the cation in repeating unit B6 can be listed below, but are not limited to these. Additionally, in the following formula, R... A Same as above.

[0346] [Chemistry 69]

[0347]

[0348] [Chemistry 70]

[0349]

[0350] [Chemistry 71]

[0351]

[0352] [Chemistry 72]

[0353]

[0354] [Chemistry 73]

[0355]

[0356] [Chemistry 74]

[0357]

[0358] [Chemistry 75]

[0359]

[0360] [Chemistry 76]

[0361]

[0362] [Chemistry 77]

[0363]

[0364] [Chemistry 78]

[0365]

[0366] In equation (B6), M - These are non-nucleophilic relative ions. The aforementioned non-nucleophilic relative ions are preferably halide ions, sulfonic acid anions, imide acid anions, and methylated acid anions. Specific examples of the aforementioned halide ions include chloride ions and bromide ions. Specific examples of the aforementioned sulfonic acid anions (sulfonate ions) include trifluoromethanesulfonate ions, 1,1,1-trifluoroethanesulfonate ions, nonafluorobutanesulfonate ions, and other fluoroalkyl sulfonate ions; toluenesulfonate ions, benzenesulfonate ions, 4-fluorobenzenesulfonate ions, 1,2,3,4,5-pentafluorobenzenesulfonate ions, and other aryl sulfonate ions; methanesulfonate ions, butanesulfonate ions, and other alkyl sulfonate ions, etc. Specific examples of the aforementioned imide acid anions (imide ions) include bis(trifluoromethylsulfonyl)imide ions, bis(perfluoroethylsulfonyl)imide ions, bis(perfluorobutylsulfonyl)imide ions, etc. Specific examples of the aforementioned methylated acid anions (methylated ions) include: tris(trifluoromethylsulfonyl) methylated ion, tris(perfluoroethylsulfonyl) methylated ion, etc.

[0367] Other examples of the aforementioned non-nucleophilic relative ions can be listed as anions represented by any of the formulas (B6-1) to (B6-4).

[0368] [Chemistry 79]

[0369]

[0370] In equation (B6-1), R fa The hydrocarbon group consists of fluorine atoms, or may contain heteroatoms, and has 1 to 40 carbon atoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated as R in the following formula (B6-1-1). fa1 The same example represents hydrocarbon groups.

[0371] The anion represented by formula (B6-1) should preferably be represented by the following formula (B6-1-1).

[0372] [Chemistry 80]

[0373]

[0374] In equation (B6-1-1), Q 1 and Q 2 Each atom is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; to improve solvent solubility, at least one of them is preferably trifluoromethyl. m can be 0, 1, 2, 3, or 4, with 1 being particularly preferred. R fa1 The hydrocarbon group may contain heteroatoms and has 1 to 35 carbon atoms. The aforementioned heteroatoms are preferably oxygen, nitrogen, sulfur, or halogen atoms, with oxygen atoms being more preferred. Considering the high resolution achieved during the formation of fine patterns, hydrocarbon groups with 6 to 30 carbon atoms are particularly preferred.

[0375] In equation (B6-1-1), R fa1 The hydrocarbon group represented by carbon number 1 to 35 can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 35 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and eicosyl; cyclic saturated hydrocarbon groups with 3 to 35 carbon atoms, such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norcamphenyl, norcamphenylmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups with 2 to 35 carbon atoms, such as 2-propenyl and 3-cyclohexenyl; aryl groups with 6 to 35 carbon atoms, such as phenyl, 1-naphthyl, 2-naphthyl, and 9-fluorenyl; aralkyl groups with 7 to 35 carbon atoms, such as benzyl and diphenylmethyl; and groups obtained by combining them.

[0376] 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 hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. This can result in the presence of hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulopentalide ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. Specific examples of hydrocarbon groups containing heteroatoms include: tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidemethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, 3-oxocyclohexyl, etc.

[0377] In formula (B6-1-1), L a1 The bonds can be single bonds, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, or carbamate bonds. From a synthetic point of view, ether bonds or ester bonds are preferred, with ester bonds being even better.

[0378] Specific examples of anions represented by formula (B6-1) are shown below, but are not limited to these. Additionally, in the following formula, Q... 1 As mentioned above, Ac is an acetyl group.

[0379] [Chemistry 81]

[0380]

[0381] [Chemistry 82]

[0382]

[0383] [Chemistry 83]

[0384]

[0385] [Chemistry 84]

[0386]

[0387] [Chemistry 85]

[0388]

[0389] [Chemistry 86]

[0390]

[0391] [Chemistry 87]

[0392]

[0393] [Chemistry 88]

[0394]

[0395] [Chemistry 89]

[0396]

[0397] [Chemistry 90]

[0398]

[0399] In equation (B6-2), R fb1 and R fb2 Each hydrocarbon group consists independently of a fluorine atom or may contain heteroatoms and has 1 to 40 carbon atoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated as R in formula (B6-1-1). fa1 The same example represents a hydrocarbon group. R fb1 and R fb2 It should preferably be a fluorine atom or a straight-chain fluorinated alkyl group having 1 to 4 carbon atoms. Also, R fb1 and R fb2 They can also bond to each other and to the groups they are bonded to (-CF2-SO2-N). - -SO2-CF2-) together form a ring, at which point R fb1 and R fb2 The groups formed by mutual bonding should preferably be fluorinated ethylidene or fluorinated propyleneide.

[0400] In equation (B6-3), R fc1 R fc2 and R fc3 Each hydrocarbon group consists independently of a fluorine atom or may contain heteroatoms and has 1 to 40 carbon atoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated as R in formula (B6-1-1). fa1 The same example represents a hydrocarbon group. R fc1 R fc2 and R fc3 It should preferably be a fluorine atom or a straight-chain fluorinated alkyl group having 1 to 4 carbon atoms. Also, R fc1 and R fc2 They can also bond to each other and to the bases they are bonded to (-CF2-SO2-C). - -SO2-CF2-) together form a ring, at which point R fc1 and R fc2 The groups formed by mutual bonding should preferably be fluorinated ethylidene or fluorinated propyleneide.

[0401] In equation (B6-4), R fdIt can be a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated as R in formula (B6-1-1). fa1 The same example represents hydrocarbon groups.

[0402] Specific examples of anions represented by formula (B6-4) are listed below, but are not limited thereto.

[0403] [Chemistry 91]

[0404]

[0405] [Chemistry 92]

[0406]

[0407] The examples of the aforementioned non-nucleophilic relative ions can be further illustrated by anions having aromatic rings substituted with iodine or bromine atoms. Specific examples of such anions can be represented by the following formula (B6-5).

[0408] [Chemistry 93]

[0409]

[0410] In equation (B6-5), x is 1, 2, or 3. y is 1, 2, 3, 4, or 5. z is 0, 1, 2, or 3. However, 1 ≤ y + z ≤ 5. y should preferably be 1, 2, or 3, with 2 or 3 being even better. z should preferably be 0, 1, or 2.

[0411] In equation (B6-5), X BI When x and / or y are 2 or more, they can be the same or different.

[0412] In formula (B6-5), L 11 It is a saturated hydrocarbon group with 1 to 6 carbon atoms, consisting of a single bond, ether bond, or ester bond, or may also contain ether or ester bonds. The aforementioned saturated hydrocarbon group may be linear, branched, or cyclic.

[0413] In formula (B6-5), L 12 When x is 1, it is a single bond or a divalent linker with 1 to 20 carbon atoms; when x is 2 or 3, it is a (x+1) valent linker with 1 to 20 carbon atoms, and the linker may also contain oxygen, sulfur or nitrogen atoms.

[0414] In equation (B6-5), R feThe carbon group may be a hydroxyl, carboxyl, fluorine, chlorine, bromine, or amino group, or may contain a fluorine, chlorine, bromine, hydroxyl, amino, or ether bond, and may be a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon oxy group having 1 to 20 carbon atoms, a hydrocarbon carbonyl group having 2 to 20 carbon atoms, a hydrocarbon oxycarbonyl group having 2 to 20 carbon atoms, or a hydrocarbon sulfonyl oxy group having 1 to 20 carbon atoms, or -N(R) feA (R) feB ), -N(R feC )-C(=O)-R feD or -N(R) feC )-C(=O)-OR feD R feA and R feB Each can be independently a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R feC It is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms. R feD It is an aliphatic hydrocarbon group with 1 to 16 carbon atoms, an aryl group with 6 to 12 carbon atoms, or an aralkyl group with 7 to 15 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group with 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group with 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyl oxy group with 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. The aforementioned hydrocarbon group, hydrocarbon oxy group, hydrocarbon carbonyl group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyl oxy group, and hydrocarbon sulfonyl oxy group can be straight-chain, branched, or cyclic. When x and / or z are 2 or more, each R fe They can be the same or different.

[0415] Among them, R fe It is advisable to use hydroxyl groups, -N(R) feC )-C(=O)-R feD -N(R) feC )-C(=O)-OR feD Fluorine atoms, chlorine atoms, bromine atoms, methyl groups, methoxy groups, etc.

[0416] In equation (B6-5), Rf 11 ~Rf 14 Each of these atoms can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them must be a fluorine atom or a trifluoromethyl group. Also, Rf 11 With Rf 12 They can also combine to form carbonyl groups. Rf 13 and Rf 14 All of them are fluorine atoms, which is of excellent quality.

[0417] Specific examples of anions represented by equation (B6-5) are shown below, but are not limited to these. Additionally, in the following equation, X... BI Same as above.

[0418] [Chemistry 94]

[0419]

[0420] [Chem. 95]

[0421]

[0422] [Chemistry 96]

[0423]

[0424] [Chemistry 97]

[0425]

[0426] [Chem. 98]

[0427]

[0428] [Chemistry 99]

[0429]

[0430] [Chemistry 100]

[0431]

[0432] [Chemistry 101]

[0433]

[0434] [Chemistry 102]

[0435]

[0436] [Chemistry 103]

[0437]

[0438] [Chemistry 104]

[0439]

[0440] [Chemistry 105]

[0441]

[0442] [Chemistry 106]

[0443]

[0444] [Chemistry 107]

[0445]

[0446] [Chemistry 108]

[0447]

[0448] [Chemistry 109]

[0449]

[0450] [Chemical 110]

[0451]

[0452] [Chemistry 111]

[0453]

[0454] [Chemistry 112]

[0455]

[0456] [Chemistry 113]

[0457]

[0458] [Chemistry 114]

[0459]

[0460] [Chemistry 115]

[0461]

[0462] [Chemistry 116]

[0463]

[0464] The aforementioned non-nucleophilic relative ions may also be used: the fluorobenzenesulfonate anion bonded to an aromatic group containing an iodine atom as described in Japanese Patent No. 6648726; the anion with a mechanism of decomposition due to acid as described in International Publication No. 2021 / 200056 and Japanese Patent Application Publication No. 2021-70692; the anion with a cyclic ether group as described in Japanese Patent Application Publication No. 2018-180525 and Japanese Patent Application Publication No. 2021-35935; and the anion as described in Japanese Patent Application Publication No. 2018-92159.

[0465] The aforementioned non-nucleophilic relative ions may also be used as follows: the bulky benzenesulfonic acid derivative anions without fluorine atoms described in Japanese Patent Application Publication No. 2006-276759, Japanese Patent Application Publication No. 2015-117200, Japanese Patent Application Publication No. 2016-65016 and Japanese Patent Application Publication No. 2019-202974; the benzenesulfonic acid anions without fluorine atoms bonded to aromatic groups containing iodine atoms and the alkylsulfonic acid anions described in Japanese Patent No. 6645464.

[0466] The aforementioned non-nucleophilic relative ions may also be used as follows: the anion of disulfonic acid as described in Japanese Patent Application Publication No. 2015-206932, the anion of sulfonamide or sulfonylimide with one side being sulfonic acid and the other side being different as described in International Patent Application Publication No. 2020 / 158366, and the anion of carboxylic acid with one side being sulfonic acid and the other side being described in Japanese Patent Application Publication No. 2015-24989.

[0467] In equations (B7) and (B8), g1 and g2 are independently 0, 1, 2 or 3, and it is preferable to be 1.

[0468] In equation (B9), h1 is 0 or 1. h2 is 0, 1, 2, 3 or 4. h3 is 0, 1, 2, 3 or 4. However, when h1 is 0, 0 ≤ h2 + h3 ≤ 4, and when h1 is 1, 0 ≤ h2 + h3 ≤ 6.

[0469] In equations (B7), (B8) and (B9), L 1 The bonds can be single bonds, ether bonds, ester bonds, carbonyl bonds, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. From a synthetic point of view, ether bonds, ester bonds, and carbonyl bonds are preferred, with ester bonds and carbonyl bonds being even more desirable.

[0470] In equation (B7), Rf 1 and Rf 2 Each is independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Among them, Rf 1 and Rf 2 To increase the acid strength of the produced acid, it is preferable that all atoms be fluorine atoms. Rf 3 and Rf 4 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Among them, Rf is used to improve solvent solubility. 3 and Rf 4 At least one of them should preferably be trifluoromethyl.

[0471] In equation (B8), Rf 5 and Rf 6 Each can be independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. However, all Rf 5 and Rf6 They cannot all be hydrogen atoms simultaneously. Among them, Rf is used to improve solvent solubility. 5 and Rf 6 At least one of them should preferably be trifluoromethyl.

[0472] In equation (B9), Rf 7 It is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkyl thiogroup having 1 to 6 carbon atoms. Rf 7 It is preferable to have a fluorine atom, trifluoromethyl, difluoromethyl, trifluoromethoxy, difluoromethoxy, trifluoromethylthio, or difluoromethylthio, with fluorine, trifluoromethyl, or trifluoromethoxy being more preferred. When h2 is 2, 3, or 4, each Rf 7 They can be the same or different.

[0473] In equation (B9), R 53 It is a hydrocarbon group with 1 to 20 carbon atoms other than fluorine atoms, or it may contain heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated in the description of formula (Z-1) as R. 1 ~R 9 Examples of hydrocarbon groups are similar, but not limited to these. Also, when h3 is 2, 3, or 4, each R... 53 They can be the same or different.

[0474] Furthermore, when h3 is 2, 3, or 4, multiple R 53 They can also bond with 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, and halogen atoms, and some of the -CH2- in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, they may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0475] Specific examples of the anion of repeating unit B7 can be listed below, but are not limited to these. Additionally, in the following formula, R... A As mentioned above, Me is a methyl group.

[0476] [Chemistry 117]

[0477]

[0478] [Chemistry 118]

[0479]

[0480] [Chemistry 119]

[0481]

[0482] [Chemistry 120]

[0483]

[0484] [Chemistry 121]

[0485]

[0486] [Chemistry 122]

[0487]

[0488] [Chemistry 123]

[0489]

[0490] [Chemistry 124]

[0491]

[0492] [Chemistry 125]

[0493]

[0494] [Chemistry 126]

[0495]

[0496] [Chemistry 127]

[0497]

[0498] [Chemistry 128]

[0499]

[0500] [Chemistry 129]

[0501]

[0502] Specific examples of the anion of repeating unit B8 can be listed below, but are not limited to these. Additionally, in the following formula, R... A Same as above.

[0503] [Chemistry 130]

[0504]

[0505] [Chemistry 131]

[0506]

[0507] [Chemistry 132]

[0508]

[0509] [Chemistry 133]

[0510]

[0511] [Chemistry 134]

[0512]

[0513] [Chemistry 135]

[0514]

[0515] [Chemistry 136]

[0516]

[0517] [Chemistry 137]

[0518]

[0519] [Chemistry 138]

[0520]

[0521] [Chemistry 139]

[0522]

[0523] [Chemistry 140]

[0524]

[0525] Specific examples of the anion of repeating unit B9 can be listed below, but are not limited to these. Additionally, in the following formula, R... A Same as above.

[0526] [Chemistry 141]

[0527]

[0528] [Chemistry 142]

[0529]

[0530] [Chemistry 143]

[0531]

[0532] [Chemistry 144]

[0533]

[0534] [Chemistry 145]

[0535]

[0536] [Chemistry 146]

[0537]

[0538] [Chemistry 147]

[0539]

[0540] [Chemistry 148]

[0541]

[0542] [Chemistry 149]

[0543]

[0544] [Chemistry 150]

[0545]

[0546] [Chemistry 151]

[0547]

[0548] [Chemistry 152]

[0549]

[0550] [Chemistry 153]

[0551]

[0552] [Chemistry 154]

[0553]

[0554] [Chemistry 155]

[0555]

[0556] [Chemistry 156]

[0557]

[0558] [Chemistry 157]

[0559]

[0560] Specific examples of the anion of repeating unit B10 can be listed below, but are not limited to these. Additionally, in the following formula, R... A Same as above.

[0561] [Chemistry 158]

[0562]

[0563] In equations (B7) to (B10), A + The cation is a monium cation. The aforementioned monium cation is preferably a sulfonium cation or a monium cation. Specific examples of the aforementioned sulfonium cation may be listed and illustrated as examples of sulfonium cations represented by formula (Z-1), or as examples of sulfonium cations represented by formula (Z-4), but are not limited thereto. Specific examples of the aforementioned monium cation may be listed and illustrated as examples of monium cations represented by formula (Z-2), but are not limited thereto.

[0564] The specific structures of repeating units B6 to B10 can be listed as any combination of the aforementioned anions and cations.

[0565] Repeating units B6 to B10 are units that generate acid using high-energy radiation. It is believed that by incorporating these units into the polymer, a pattern with moderately suppressed acid diffusion and reduced LER (Leakage Rate) can be obtained. Furthermore, it is believed that by incorporating these units into the polymer, during vacuum baking, the phenomenon of acid evaporation from the exposed areas and re-adhesion to the unexposed areas is suppressed, and this is effective in reducing LER and minimizing shape degradation caused by undesirable film loss in the unexposed areas.

[0566] Among the repeating units B6 to B10, the units that are most ideal for processing blank photomasks, considering the design to suppress acid diffusion and the optimal acid strength for the acid-instable groups of the polymer, are repeating units B7 to B10, with repeating units B8, B9, and B10 being even better.

[0567] The repeating units B6 to B10 are preferably introduced in the range of 0.1 to 30 mol%, and more preferably in the range of 0.5 to 20 mol%, among all the repeating units in the aforementioned polymer. Repeating units B6 to B10 may be used alone or in combination of two or more.

[0568] Of all the repeating units 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. When repeating units B6 to B10 are not present, all units should preferably have an aromatic ring skeleton.

[0569] The aforementioned polymers 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, and other tightly bound groups. These repeating units can be used to fine-tune the properties of the resist film, but they may also be omitted.

[0570] Examples of (meth)acrylate units having the aforementioned binding groups include: repeating units represented by formula (B11) (hereinafter also referred to as repeating unit B11), repeating units represented by formula (B12) (hereinafter also referred to as repeating unit B12), and repeating units represented by formula (B13) (hereinafter also referred to as repeating unit B13). These units do not exhibit acidity but can be used as auxiliary units to provide adhesion to the substrate and to adjust solubility.

[0571] [Chemistry 159]

[0572]

[0573] In equations (B11) to (B13), R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 61 It is -O- or methylene. R 62 It can be a hydrogen atom or a hydroxyl group. R 63 It is a saturated hydrocarbon group with 1 to 4 carbon atoms. i is 0, 1, 2 or 3.

[0574] When the polymer contains repeating units B11 to B13, their content in the total number of repeating units in the aforementioned polymer should preferably be 0 to 20 mol%, and 0 to 10 mol% is more preferred. Repeating units B11 to B13 can be used alone or in combination of two or more.

[0575] The aforementioned polymers can be synthesized by copolymerizing monomers that require protection groups using known methods, followed by a deprotection reaction as needed. There are no particular limitations on the copolymerization reaction; free radical polymerization and anionic polymerization are preferred. These methods can be referenced in Japanese Patent Application Publication No. 2004-115630.

[0576] The weight-average molecular weight (Mw) of the aforementioned polymer is preferably between 1,000 and 50,000, and more preferably between 2,000 and 20,000. If Mw is above 1,000, there is no concern about the phenomenon of rounding at the top of the pattern, resulting in reduced resolution, and LER degradation, as is known. On the other hand, if Mw is below 50,000, there is no concern about LER degradation when forming patterns with a linewidth of 100 nm or less. In addition, in this invention, Mw is a polystyrene equivalent value obtained by gel permeation chromatography (GPC) using THF or DMF as a solvent.

[0577] The molecular weight distribution (Mw / Mn) of the aforementioned polymer is 1.0 to 2.0, preferably 1.0 to 1.9, and even more preferably a narrow dispersion of 1.0 to 1.8. With such a narrow dispersion, there will be no foreign matter generated on the pattern after development, or the pattern shape will deteriorate.

[0578] Furthermore, regarding the aforementioned basic polymer design, the dissolution rate of the alkaline developer should preferably be below 10 nm / min, more preferably below 7 nm / min, and even more preferably below 5 nm / min. In advanced generations, when the coating film applied to the substrate is in the thin film field (below 100 nm), the impact on pattern loss during alkaline development becomes greater. When the alkaline dissolution rate of the polymer exceeds 10 nm / min, the pattern will break down, and it will become impossible to form fine patterns. This is particularly noticeable in the fabrication of photomasks requiring defect-free results, where there is a tendency for stronger development processes. In addition, in this invention, the dissolution rate of the basic polymer to the alkaline developer is determined by the amount of film loss when a polymer solution (polymer concentration: 16.7% by mass, solvent: propylene glycol monomethyl ether acetate (PGMEA)) is spin-coated onto an 8-inch silicon wafer, baked at 100°C for 90 seconds to form a film with a thickness of 1000 nm, and then developed at 23°C for 100 seconds using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.

[0579] (B) The base polymer of the component may also contain other polymers besides those mentioned above. Other polymers may be base polymers known as components of resists. The content of other polymers is not particularly limited as long as it does not impair the effects of the invention.

[0580] [(C) Photoacid Generator]

[0581] The chemically amplified positive resist composition of the present invention may also contain a photoacid generator as component (C). There are no particular limitations on the aforementioned photoacid generator, which is a compound that generates acid upon irradiation by high-energy rays. Ideal photoacid generators include sulfonium salts, sulfonyl diazomethanes, N-sulfonyloxyimides, and oxime-O-sulfonate type acid generators.

[0582] Specific examples of the aforementioned photoacid generating agents include: nonafluorobutane sulfonate, partially fluorinated sulfonates described in paragraphs

[0247] to

[0251] of Japanese Patent No. 5706778, partially fluorinated sulfonates described in paragraphs

[0261] to

[0265] of Japanese Patent No. 5852851, and those described in paragraphs

[0122] to

[0142] of Japanese Patent No. 4858714 and paragraphs

[0080] to

[0081] of Japanese Patent No. 5368270. Furthermore, the anion of the photoacid generating agent can also be exemplified as M in formula (B6). -The anions are represented. Among them, aryl sulfonate or alkyl sulfonate type photoacid generators are more desirable because they can produce acids of appropriate strength that deprotect the acid-unstable groups of repeating unit B2.

[0583] Furthermore, in order to improve the effects of LER and CDU by combining the aforementioned photoacid generator with the quencher of component (A), the pKa of the acid generated from the photoacid generator is -3.0 or higher, preferably in the range of -3.0 to 2.0, and more preferably in the range of -2.0 to 1.5.

[0584] The aforementioned photoacid generator is preferably a salt compound having anion as shown below.

[0585] [Chemistry 160]

[0586]

[0587] The anion of the aforementioned photoacid generator should also be one described in

[0220] to

[0225] of Japanese Patent No. 7032549,

[0027] to

[0029] of Japanese Patent No. 6248882,

[0028] to

[0029] of Japanese Patent No. 7067271,

[0039] to

[0066] of Japanese Patent Application Publication No. 2023-177038, and

[0229] to

[0231] of Japanese Patent Application Publication No. 2024-077330.

[0588] The anion of the aforementioned photoacid generator should also preferably be a salt compound having the anion shown below.

[0589] [Chemistry 161]

[0590]

[0591] [Chemistry 162]

[0592]

[0593] [Chemistry 163]

[0594]

[0595] [Chemistry 164]

[0596]

[0597] [Chemistry 165]

[0598]

[0599] [Chemistry 166]

[0600]

[0601] [Chemistry 167]

[0602]

[0603] [Chemistry 168]

[0604]

[0605] [Chemistry 169]

[0606]

[0607] [Chemistry 170]

[0608]

[0609] [Chemistry 171]

[0610]

[0611] [Chemistry 172]

[0612]

[0613] [Chemistry 173]

[0614]

[0615] [Chemistry 174]

[0616]

[0617] [Chemistry 175]

[0618]

[0619] [Chemistry 176]

[0620]

[0621] [Chemistry 177]

[0622]

[0623] [Chemistry 178]

[0624]

[0625] [Chemistry 179]

[0626]

[0627] [Chemistry 180]

[0628]

[0629] [Chemistry 181]

[0630]

[0631] [Chemistry 182]

[0632]

[0633] [Chemistry 183]

[0634]

[0635] [Chemistry 184]

[0636]

[0637] [Chemistry 185]

[0638]

[0639] [Chemistry 186]

[0640]

[0641] Cations that pair with the aforementioned anions can be exemplified as sulfonium cations represented by formula (Z-1) and sulfonium cations represented by formula (Z-4), or as monium cations represented by formula (Z-2).

[0642] When the chemically amplified positive resist composition of the present invention contains (C) a photoacid generator, its content relative to 80 parts by mass of (B) the base polymer is preferably 1 to 30 parts by mass, and more preferably 2 to 20 parts by mass. Furthermore, when the base polymer contains repeating units B6 to B13 (i.e., a polymer-bonded acid generator), the addition of (C) the acid generator can be omitted. (C) The acid generator can be used alone or in combination of two or more types.

[0643] In the chemically amplified positive resist composition of the present invention, regarding the quencher in component (A) and the photoacid generator in component (C), the content ratio of the photoacid generator to the quencher ((C) / (A)) is preferably less than 6 by mass, more preferably less than 5, and even more preferably less than 4. 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.

[0644] [(D) Organic solvent]

[0645] The chemically amplified positive resist composition of the present invention may also contain an organic solvent as component (D). There are no particular limitations on the organic solvent being capable of dissolving each component. Examples of such organic solvents include, for instance, ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone as described in paragraphs

[0144] to

[0145] of Japanese Patent Application Publication No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; and propylene glycol monomethyl ether (PGME), ethylene glycol monomethyl ether, and propylene glycol monomethyl ether. Ethers such as propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate (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-unstable 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 can also be added.

[0646] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, and their mixed solvents are preferred.

[0647] When the chemically amplified positive resist composition of the present invention contains (D) organic solvent, its content relative to 80 parts by mass of (B) base polymer is preferably 200 to 10,000 parts by mass, and more preferably 400 to 5,000 parts by mass. (D) organic solvent can be used alone or in combination with two or more types.

[0648] [(E) Polymers containing fluorine atoms]

[0649] In the chemically amplified positive resist composition of the present invention, in order to achieve high contrast, suppress chemical flare of acid during high-energy ray irradiation, shield the mixing of acid from the antistatic film during the process of coating the antistatic film material onto the resist film, and suppress unintended and unnecessary pattern degradation, it may also contain at least one of the repeating units represented by formula (E1) (hereinafter also referred to as repeating unit E1), repeating units represented by formula (E2) (hereinafter also referred to as repeating unit E2), repeating units represented by formula (E3) (hereinafter also referred to as repeating unit E3), and repeating units represented by formula (E4) (hereinafter also referred to as repeating unit E4), and may further contain a polymer containing fluorine atoms as component (E) selected from at least one of the repeating units represented by formula (E5) (hereinafter also referred to as repeating unit E5) and repeating units represented by formula (E6) (hereinafter also referred to as repeating unit E6). The aforementioned fluorine-containing polymers also function as surfactants, preventing insoluble substances that may be generated during the development process from re-attaching to the substrate, thus also playing a role in addressing development defects.

[0650] [Chemistry 187]

[0651]

[0652] In equations (E1) to (E6), j1 is 1, 2, or 3. j2 is an integer satisfying 0 ≤ j2 ≤ 5 + 2(j3) - j1. j3 is 0 or 1. k 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 C Each can be independently a hydrogen atom or a methyl group. R 101 R 102 R 104 and R 105 Each can be independently a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. R 103 R 106 R 107 and R 108 Each of the following 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-unstable group, and R 103 R 106 R 107 and R 108 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. R 109 A linear or branched hydrocarbon group with 1 to 5 carbon atoms, consisting of hydrogen atoms or groups containing heteroatoms inserted between carbon-carbon bonds. R 110 It can also be a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, in which heteroatoms are inserted between carbon-carbon bonds. R 111It 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 a portion of the -CH2- of the aforementioned saturated hydrocarbon group may also be replaced by an ester bond or an ether bond. X 1 It is a (k+1) valence hydrocarbon group with 1 to 20 carbon atoms or a (k+1) valence fluorinated hydrocarbon group with 1 to 20 carbon atoms. X 2 It is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * represents an atomic bond with a carbon atom in the main chain. X 3 For single bonds, -O-, *-C(=O)-OX 31 -X 32 -or *-C(=O)-NH-X 31 -X 32 -. X 31 It is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms. X 32 These are single bonds, ester bonds, ether bonds, or sulfonamide bonds. * indicates an atomic bond with a carbon atom in the main chain.

[0653] In equations (E1) and (E2), R 101 R 102 R 104 and R 105 The saturated hydrocarbon groups 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.

[0654] In equations (E1) to (E4), R 103 R 106 R 107 and R 108 The 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 having 1 to 15 carbon atoms being preferable. The aforementioned alkyl groups can include those listed above, as well as: 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, n-pentadecanyl, etc. 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.

[0655] In equation (E4), X 1The (k+1) valence hydrocarbon groups representing 1 to 20 carbon atoms can be categorized as groups obtained by further removing k hydrogen atoms from alkyl groups having 1 to 20 carbon atoms or cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms. Also, X 1 The (k+1) valence fluorinated hydrocarbon groups representing carbon numbers from 1 to 20 can be categorized as groups in which at least one hydrogen atom of the aforementioned (k+1) valence hydrocarbon groups is replaced by a fluorine atom.

[0656] Specific examples of repeating units E1 to E4 can be listed below, but are not limited to these. Additionally, in the following formula, R... B Same as above.

[0657] [Chemistry 188]

[0658]

[0659] [Chemistry 189]

[0660]

[0661] [Chemistry 190]

[0662]

[0663] In equation (E5), R 109 and R 110 Examples of hydrocarbon groups representing 1 to 5 carbon atoms include alkyl, alkenyl, and ynyl groups, with alkyl being preferred. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and n-pentyl. Furthermore, heteroatoms such as oxygen, sulfur, and nitrogen atoms can be inserted between the carbon-carbon bonds of the aforementioned hydrocarbon groups.

[0664] In equation (E5), -OR 109 It should preferably be a hydrophilic group. In this case, R... 109 Suitable for hydrogen atoms, alkyl groups with 1 to 5 carbon atoms that have oxygen atoms inserted between carbon-carbon bonds, etc.

[0665] In equation (E5), X 2 It should be *-C(=O)-O- or *-C(=O)-NH-. Additionally, R C It should be methyl. Through X 2 The presence of a carbonyl group improves the ability of the antistatic membrane to capture acids. Also, R C If it is methyl, it will become a rigid polymer with a higher glass transition temperature (Tg), thus inhibiting acid diffusion. This results in a resist film with good stability over time, and the resolution and pattern shape will not deteriorate.

[0666] Repeating unit E5 can be listed as shown below, but is not limited to these. Additionally, in the following formula, R... C Same as above.

[0667] [Chemistry 191]

[0668]

[0669] [Chemistry 192]

[0670]

[0671] In equation (E6), X 3 The saturated alkylene groups representing carbons 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, 1,1-dimethylethane-1,2-diyl, etc.

[0672] In equation (E6), R 111 The saturated hydrocarbon group with 1 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom can be any of the following: linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms or cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom.

[0673] Repeating unit E6 can be listed as shown below, but is not limited to these. Additionally, in the following formula, R... C Same as above.

[0674] [Chemistry 193]

[0675]

[0676] [Chemistry 194]

[0677]

[0678] [Chemistry 195]

[0679]

[0680] [Chemistry 196]

[0681]

[0682] The content of repeating units E1 to E4 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 E5 and / or E6 in the aforementioned polymer containing fluorine atoms is preferably 5 to 85 mol%, and more preferably 15 to 80 mol%. Repeating units E1 to E6 may be used alone or in combination of two or more.

[0683] (E) The polymer containing fluorine atoms may also contain other repeating units besides the aforementioned repeating units. Examples of such repeating units include those described in paragraphs

[0046] to

[0078] of Japanese Patent Application Publication No. 2014-177407. (E) 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.

[0684] (E) Fluorine-containing polymers can be synthesized by copolymerizing monomers with protecting groups as needed using known methods, followed by deprotection reactions as required. There are no particular limitations on the copolymerization reaction; free radical polymerization and anionic polymerization are preferred. For these methods, please refer to Japanese Patent Application Publication No. 2004-115630.

[0685] (E) The Mw of fluorine-containing polymers should preferably be between 2000 and 50000, with 3000 to 20000 being more preferred. If the Mw is above 2000, acid will not diffuse, resolution will not deteriorate, and stability over time will not be compromised. If the Mw is below 50000, the solubility in solvents is sufficient, and coating defects will not occur. Furthermore, the Mw / Mn ratio of (E) fluorine-containing polymers should preferably be between 1.0 and 2.2, with 1.0 to 1.7 being more preferred.

[0686] When the chemically amplified positive resist composition of the present invention contains a (E) fluorine-containing polymer, its content relative to 80 parts by mass of the (B) base polymer is preferably 0.01 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass. The (E) fluorine-containing polymer can be used alone or in combination of two or more.

[0687] [(F) Other quenching agents]

[0688] The chemically amplified positive resist composition of the present invention may also contain other quenching agents besides component (A) as component (F), depending on the need. This suppresses the diffusion rate of acid generated from the acid-generating agent into the resist film, and when using a substrate with an outermost surface made of a chromium-containing material as the substrate, the effect of acid generated within the resist film on the chromium-containing material can still be suppressed.

[0689] Other quenching agents mentioned above include known basic compounds. Known basic compounds 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 hydroxyl phenyl groups, alcoholic nitrogen-containing compounds, amides, imides, carbamates, etc. 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, sulfonate bonds, or compounds with carbamate groups described in Japanese Patent No. 3790649, are particularly preferred. Ideal examples 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, the diffusion rate of acid in the resist film can be further suppressed, or the shape can be modified, for example.

[0690] Furthermore, other quenchers mentioned above include 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, imine acids, or methylated acids require deprotection of unstable acid groups, and release α-unfluorinated carboxylic acids through salt exchange with α-unfluorinated onium salts. Since α-unfluorinated carboxylic acids hardly undergo deprotection reactions, they function as quenchers.

[0691] Onium salts of carboxylic acids that are not fluorinated at the α-position can be listed as, for example, those represented by the following formula (F1).

[0692] [Chemistry 197]

[0693] R 201 -CO2 - Mq A + (F1)

[0694] In equation (F1), R 201 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain hydrogen atoms or heteroatoms, but excludes those in which the hydrogen atom at the α-position of the carboxyl group is replaced by a fluorine atom or a fluoroalkyl group.

[0695] R 201The hydrocarbon group represented can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, and other alkyl groups with 1 to 40 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclic [5.2.1.0] 2,6 Cyclic saturated hydrocarbon groups with 3 to 40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; alkenyl groups with 2 to 40 carbon atoms, such as vinyl, 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.

[0696] Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and a portion of the -CH2- group of the hydrocarbon group may also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, cyano groups, 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. Examples of hydrocarbon groups containing heteroatoms include: heteroaryl groups such as thiophene; alkoxyphenyl groups such as 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-tert-butoxyphenyl, and 3-tert-butoxyphenyl; alkoxynaphthyl groups such as methoxynaphthyl, ethoxynaphthyl, n-propoxynaphthyl, and n-butoxynaphthyl; dialkoxynaphthyl groups such as dimethoxynaphthyl and diethoxynaphthyl; aryl-side alkyl groups such as 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl.

[0697] In equation (F1), Mq A +The cation is an onium cation. The aforementioned onium cation is preferably a sulfonium cation, a monazine cation, or an ammonium cation, with sulfonium or monazine cations being more preferred. Specific examples of the aforementioned sulfonium cation can be listed and illustrated as examples of sulfonium cations represented by formula (Z-1) and formula (Z-4). Specific examples of the aforementioned monazine cation can be listed and illustrated as examples of monazine cations represented by formula (Z-2). Specific examples of the aforementioned ammonium cation can be listed and illustrated as examples of ammonium cations represented by formula (Z-3).

[0698] The anions of onium salts represented by formula (F1) can be listed below, but are not limited to these.

[0699] [Chemistry 198]

[0700]

[0701] [Chemistry 199]

[0702]

[0703] [Chemistry 200]

[0704]

[0705] The aforementioned quenching agent can also ideally be a sulfonium salt of a carboxylic acid containing an iodinated benzene ring, represented by the formula (F2).

[0706] [Chemical Engineering 201]

[0707]

[0708] In equation (F2), 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.

[0709] In equation (F2), R 211 The hydroxyl, fluorine, chlorine, bromine, amino, nitro, cyano, or hydrogen atom may be partially or wholly substituted by a halogen atom, and may be a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl oxy group having 2 to 6 carbon atoms, or a saturated hydrocarbon sulfonyl oxy group having 1 to 4 carbon atoms, or -N(R 211A )-C(=O)-R 211B or -N(R) 211A )-C(=O)-OR 211B R 211A It consists of a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 211B 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 211 They can be the same or different.

[0710] In formula (F2), L 21 It is a single bond or a (u+1) valence linking group having 1 to 20 carbon atoms, and may also contain 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.

[0711] In equation (F2), R 212 R 213 and R 214 Each hydrocarbon group consists independently of a halogen atom or may contain heteroatoms and has 1 to 20 carbon atoms. The aforementioned hydrocarbon group 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 hydrocarbon group may be replaced by hydroxyl, carboxyl, halogen, oxo, cyano, nitro, sulfonyl lactone ring, sulfonyl, or sulfonium salt-containing groups, and part of the -CH2- group in the aforementioned hydrocarbon group may be replaced by ether, ester, carbonyl, amide, carbonate, or sulfonate bonds. Also, R... 212 and R 213 They can also bond to each other and form rings together with the sulfur atoms they are bonded to.

[0712] Specific examples of compounds represented by formula (F2) can be found in Japanese Patent Application Publication No. 2017-219836. Compounds represented by formula (F2) have high sensitization effects due to their high absorption and also have high acid diffusion control effects.

[0713] The aforementioned quenching agent may also be a nitrogen-containing carboxylate compound represented by the following formula (F3).

[0714] [Chemical Engineering 202]

[0715]

[0716] In equation (F3), R 221 ~R 224 Each is independently a hydrogen atom, -L 22 -CO2 - It may also contain hydrocarbon groups with 1 to 20 carbon atoms, or heteroatoms. R 221 With R 222 R 222 With R 223 、or R 223 With R 224 They can also bond to each other and form rings together with the carbon atoms they are bonded to. 22It is a single bond or may contain heteroatoms and is a hydrocarbon group with 1 to 20 carbon atoms. R 225 It consists of a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms.

[0717] In equation (F3), ring R r It is a ring containing carbon atoms and nitrogen atoms of 2 to 6 carbons, and some or all of the hydrogen atoms of the carbon atoms bonded to the ring may be replaced by hydrocarbon groups of 1 to 20 carbons, or -L 22 -CO2 - The ring may be substituted, and a portion of the -CH2- group may be replaced by a sulfur atom, an oxygen atom, or a nitrogen atom. The aforementioned ring can be an alicyclic or aromatic ring, and preferably a 5-membered or 6-membered ring. Specific examples include: pyridine ring, pyrrole ring, pyrrolidine ring, piperidine ring, pyrazole ring, imidazoline ring, pyridazine ring, pyrimidine ring, pyrazine ring, imidazoline ring, oxazole ring, thiazole ring, morpholine ring, thiazine ring, triazole ring, etc.

[0718] The carboxylic acid salt represented by formula (F3) has at least one -L 22 -CO2 - Base. That is, R 221 ~R 224 At least one of them is -L 22 -CO2 - and / or bonded to ring R r At least one of the hydrogen atoms in the carbon atom is -L 22 -CO2 - replace.

[0719] In equation (F3), Mq B + It is a sulfonium cation, a monazine cation, or an ammonium cation, preferably a sulfonium cation. Specific examples of the aforementioned sulfonium cations can be listed and illustrated as specific examples of sulfonium cations represented by formula (Z-1) and formula (Z-4), or similar examples.

[0720] The anions of compounds represented by formula (F3) can be listed below, but are not limited to these.

[0721] [Chemical Engineering 203]

[0722]

[0723] [Chemical 204]

[0724]

[0725] [Chemical Engineering 205]

[0726]

[0727] [Chemical Engineering 206]

[0728]

[0729] [Chemical 207]

[0730]

[0731] [Chemical Engineering 208]

[0732]

[0733] Furthermore, the aforementioned quenching agents can also be betaine-type compounds of weak acids. Specific examples are listed below, but are not limited to these.

[0734] [Chemical Engineering 209]

[0735]

[0736] The aforementioned quenchers may further include polymer-type quenchers as described in Japanese Patent Application Publication No. 2008-239918. These quenchers improve the rectangularity of the resist pattern by aligning to the surface of the resist film. Polymer-type quenchers also reduce film loss and dome-shaped patterns when using protective films for immersion exposure.

[0737] When the chemically amplified positive resist composition of the present invention contains other quenchers (F), their content relative to 80 parts by mass of the aforementioned base polymer (B) is preferably 0 to 50 parts by mass, and more preferably 0.1 to 40 parts by mass. Other quenchers (F) may be used alone or in combination of two or more.

[0738] [(G) surfactant]

[0739] In the chemically amplified positive resist composition of the present invention, a conventional surfactant may also be included to improve the coating properties to the substrate. Many examples of the aforementioned surfactants are known, such as those described in Japanese Patent Application Publication No. 2004-115630, and can be referred to and selected from them. When the chemically amplified positive resist composition of the present invention contains surfactant (G), its content is preferably 0 to 5 parts by mass relative to 80 parts by mass of the base polymer (B). Surfactant (G) may be used alone or in combination of two or more.

[0740] [Resist Pattern Formation Method]

[0741] The resist pattern forming method of the present invention includes the following steps:

[0742] A resist film is formed on a substrate using the aforementioned chemically amplified positive resist composition.

[0743] The pattern is irradiated onto the aforementioned resist film using high-energy rays (i.e., the aforementioned resist film is exposed using high-energy rays), and

[0744] The resist film with the aforementioned irradiated pattern was developed using an alkaline developer.

[0745] The aforementioned substrate can be, for example, substrates used in integrated circuit manufacturing (Si, SiO, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective films, etc.) or substrates used in transmissive or reflective mask circuit manufacturing (Cr, CrO, CrON, MoSi2, Si, SiO, SiO2, SiON, SiONC, CoTa, NiTa, TaBN, SnO2, etc.). The aforementioned chemically amplified positive resist composition is coated onto the substrate using methods such as spin coating to achieve a film thickness of 0.03–2 μm. The substrate is then pre-baked on a hot plate, preferably at 60–150°C for 1–20 minutes, and more preferably at 80–140°C for 1–10 minutes, to form a resist film.

[0746] Then, the aforementioned resist film is exposed to high-energy radiation to irradiate the pattern. Examples of such high-energy radiation include: ultraviolet light, far-ultraviolet light, excimer lasers (KrF, ArF, etc.), EUV, X-rays, gamma rays, synchrotron radiation, and EB. In this invention, EUV or EB is preferably used for exposure.

[0747] When using ultraviolet light, far ultraviolet light, excimer lasers, EUV, X-rays, gamma rays, or synchrotron radiation to generate the aforementioned high-energy rays, a mask is used to form the desired pattern, with an exposure dose preferably ranging from 1 to 500 mJ / cm². 2 And preferably, it should be 10–400 mJ / cm 2 Irradiation is performed in this manner. When using EB, in order to form the desired pattern, the exposure dose should be 1–500 μC / cm. 2 And preferably, it should be 10–400 μC / cm 2 Irradiation is performed in this manner.

[0748] In addition to the usual exposure methods, wetting methods can also be used depending on the situation, such as wetting between a mask and a resist film. In this case, a water-insoluble protective film can also be used.

[0749] Then, perform post-exposure baking (PEB) on a heating plate, preferably at 60–150°C for 1–20 minutes and more preferably at 80–140°C for 1–10 minutes.

[0750] Subsequently, a developer solution of 0.1-5% by mass, preferably 2-3% by mass, such as TMAH, is used to develop the substrate using common methods such as dip, immersion, and spray, preferably for 0.1-3 minutes, and more preferably 0.5-2 minutes, thereby forming the desired pattern on the substrate.

[0751] Furthermore, the chemically amplified positive resist composition of the present invention is particularly useful for forming patterns with good resolution and low LER. Also, the chemically amplified positive resist composition of the present invention is particularly useful for pattern formation on substrates with surfaces made of materials where pattern adhesion is difficult to achieve, leading to pattern peeling and pattern breakage. Examples of such substrates include: substrates with a chromium film sputtered on the outermost surface; substrates containing a chromium compound of one or more light elements selected from oxygen, nitrogen, and carbon; and substrates containing SiO2 or SiO2 in the outermost layer. x Substrates containing tantalum compounds, molybdenum compounds, cobalt compounds, nickel compounds, tungsten compounds, tin compounds, etc. The chemically amplified positive resist composition of the present invention is particularly useful in pattern formation using a blank photomask as the substrate. In this case, the blank photomask can be either transmissive or reflective.

[0752] Regarding transmissive blank photomasks, blank photomasks with a light-shielding film made of chromium-based materials can be blank photomasks for binary photomasks or blank photomasks for phase-shifting photomasks. When used as a blank photomask for binary photomasks, it can have an anti-reflection layer and a light-shielding layer made of chromium-based materials as the light-shielding film. Alternatively, the anti-reflection film on the surface side can be entirely made of chromium-based materials, or only the outermost layer of the anti-reflection film on the surface side can be made of chromium-based materials, while the remaining portion is made of, for example, a silicon-based compound material that may also contain transition metals. Furthermore, when used as a blank photomask for phase-shifting photomasks, a blank photomask for phase-shifting photomasks with a chromium-based light-shielding film on the phase-shifting film can be considered.

[0753] The aforementioned blank photomasks with chromium-based materials as the outermost layer, such as those described in Japanese Patent Application Publication No. 2008-26500, Japanese Patent Application Publication No. 2007-302873, or examples thereof, are well known as current technology and will be omitted in detail. For example, when a light-shielding film with an anti-reflective layer and a light-shielding layer is constructed using chromium-based materials, a film structure as described below can be used.

[0754] When forming a light-shielding film with an anti-reflective layer and a light-shielding layer using chromium-based materials, the layer structure can be constructed by sequentially stacking the anti-reflective layer and the light-shielding layer from the surface side, or by sequentially stacking the anti-reflective layer, the light-shielding layer, and the anti-reflective layer. Furthermore, the anti-reflective layer and the light-shielding layer can each be multi-layered, and the composition of the layers with different compositions can vary discontinuously or continuously. The chromium-based materials used can be metallic chromium or materials containing light elements such as oxygen, nitrogen, and carbon. Specifically, materials that can be used include: metallic chromium, chromium oxide, chromium nitride, chromium carbide, chromium nitride oxide, chromium carbide oxide, chromium carbide nitride, and chromium carbide nitride oxide.

[0755] Furthermore, a reflective blank mask comprises: a substrate, and a multilayer reflective film formed on one of the main surfaces (outer surface side) of the substrate, specifically a multilayer reflective film that reflects exposure light such as EUV light, and an absorber film formed on the multilayer reflective film, specifically an absorber film that absorbs exposure light such as EUV light and reduces reflectivity. From the reflective blank mask (EUV reflective blank mask), a reflective mask (EUV reflective mask) with an absorber pattern (pattern of absorber film) formed by patterning the absorber film can be manufactured. The wavelength of EUV light used in EUV lithography is 13-14 nm, typically about 13.5 nm.

[0756] The multilayer reflective film is typically disposed in contact with one of the main surfaces of the substrate. However, without compromising the effectiveness of the invention, a base film may also be disposed between the substrate and the multilayer reflective film. The absorber film may be formed in contact with the multilayer reflective film, or a protective film (protective film of the multilayer reflective film) may be disposed between the multilayer reflective film and the absorber film, preferably in contact with the multilayer reflective film. The protective film can be used to protect the multilayer reflective film during cleaning, correction, and other processing. Furthermore, the protective film preferably has the function of protecting the multilayer reflective film and preventing oxidation of the multilayer reflective film when the absorber film is patterned by etching. Alternatively, a conductive film for electrostatically holding the reflective mask in the exposure apparatus may be disposed on the surface opposite to one of the main surfaces of the substrate, i.e., the other main surface (the inner surface side), preferably in contact with the other main surface. Furthermore, here, one main surface of the substrate is defined as the outer surface side and the upper side, and the other main surface is defined as the inner surface side and the lower side. However, the outer and inner surfaces, as well as the top and bottom, are defined for ease of explanation. One main surface and the other main surface can be either of the two main surfaces (film forming surfaces) in the substrate, and the outer and inner surfaces, as well as the top and bottom, can be interchanged. More specifically, it can be formed using Japanese Patent Application Publication No. 2021-139970 or by a method exemplified therein as a conventional art.

[0757] According to the resist patterning method of the present invention, even when using a substrate (e.g., a blank photomask) whose outermost surface is made of a material that easily affects the shape of the resist pattern, such as a chromium- or silicon-containing material, the chemically amplified positive resist composition of the present invention can still efficiently control acid diffusion at the substrate interface, thereby forming a pattern with high resolution, pattern fidelity, and improved LER and dose tolerance.

[0758] [Example]

[0759] The present invention will be specifically described below with examples of synthesis, embodiments, and comparative examples, but the present invention is not limited to the following embodiments. Furthermore, the apparatus used is described below.

[0760] • MALDITOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[0761] [1] Synthesis of onium salts

[0762] [Synthetic Example 1-1] Synthesis of Onium Salt SQ-1

[0763] [Chemical 210]

[0764]

[0765] Compound SM-1 (8.2 g), sodium nitrate (1.7 g), dichloromethane (40 g), and water (10 g) were added under nitrogen atmosphere. After stirring for 15 minutes, the organic layer was separated and washed with water, followed by vacuum concentration. Methyl isobutyl ketone (50 g) was added to the concentrate and azeotropic dehydration was performed. Diisopropyl ether was further added to wash the residue, thereby obtaining 5.7 g of onium salt SQ-1 as the target (yield 72%) in the form of an oil.

[0766] MALDI TOF-MS: POSITIVE M + 335 (equivalent to C) 18 H 11 F4S + )

[0767] NEGATIVE M - 62 (equivalent to NO3) - )

[0768] [Synthetic Examples 1-2 to 1-10] Synthesis of Onium Salts SQ-2 to SQ-10

[0769] Using the corresponding raw materials and known organic synthesis reactions, onium salts SQ-2 to SQ-10 represented by the following formulas were synthesized.

[0770] [Chemistry 211]

[0771]

[0772] [2] Synthesis of basic polymers

[0773] [Synthetic Examples 2-1 to 2-6] Synthesis of Basic Polymers (P-1 to P-6)

[0774] The monomers were combined using a known formulation and copolymerized in a solvent. The reaction solution was then added to hexane, and the precipitated solid was washed with hexane, separated, and dried to obtain a basic polymer (P-1 to P-6) with the composition shown below. The composition of the obtained basic polymer was then determined using... 1 H-NMR, 13 The results were confirmed by C-NMR, and Mw and Mw / Mn were confirmed using GPC (solvent: THF, standard: polystyrene).

[0775] [Chemistry 212]

[0776]

[0777] [3] Preparation of chemically amplified positive resist composition

[0778] [Examples 1-1 to 1-50, Comparative Examples 1-1 to 1-35]

[0779] The components were dissolved in an organic solvent according to the compositions shown in Tables 1-3 below. The resulting solutions were filtered through a 5 nm nylon filter and a 1 nm UPE filter to prepare a chemically amplified positive resist composition. The aforementioned organic solvent was a mixture of 940 parts by weight of PGMEA, 1870 parts by weight of EL, and 1870 parts by weight of PGME1870.

[0780] [Table 1]

[0781]

[0782] [Table 2]

[0783]

[0784]

[0785] [Table 3]

[0786]

[0787]

[0788] In addition, the photoacid generators PAG-1 to PAG-6, the comparative quenchers SQ-A to SQ-D, and the fluorine-containing polymers FP-1 to FP-5 in Tables 1 to 3 are as follows.

[0789] [Chemistry 213]

[0790]

[0791] [Chemistry 214]

[0792]

[0793] [Chemical 215]

[0794]

[0795] [4] Evaluation of EB lithography

[0796] [Examples 2-1 to 2-50, Comparative Examples 2-1 to 2-35]

[0797] Various chemically amplified positive resist compositions (R-1 to R-50, CR-1 to CR-35) were spin-coated onto a 152 mm square EUV exposure mask with a chromium compound outermost surface using ACT-M (Tokyo Power Technology Co., Ltd.). The mask was then pre-baked at 110°C for 600 seconds on a heated plate to obtain 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 Co., Ltd.). Measurements were taken at 81 in-plane locations on the blank substrate, excluding the outer edge portion extending 10 mm inwards, and the average film thickness and thickness range were calculated.

[0798] Then, exposure was performed using an electron beam exposure apparatus (EBM-5000plus manufactured by NuFlare Technology Co., Ltd., with an accelerating voltage of 50kV), PEB was applied at 110°C for 600 seconds, and development was carried out with a 2.38% by mass TMAH aqueous solution to obtain a positive pattern.

[0799] The obtained resist pattern was evaluated as follows. The patterned blank mask was observed using an overhead SEM (scanning electron microscope). The optimal exposure (μC / cm²) was determined by resolving the 1:1 line-to-space (LS) ratio at 200 nm. 2 The resolution (limit resolution) was determined by setting the smallest size among the exposures of the 200nm LS at a 1:1 ratio, and the LER of the 200nm LS was measured by SEM. The limit resolution of the isolation spacing (IS) was set as the smallest size among the exposures of the 200nm 9:1 line-to-spacing (LS) at a 9:1 ratio. Whether the pattern shape was rectangular was determined visually. The results are shown in Tables 4-6.

[0800] [Table 4]

[0801]

[0802] [Table 5]

[0803]

[0804]

[0805] [Table 6]

[0806]

[0807]

[0808] The chemically amplified positive resist compositions (R-1 to R-50) 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-35) have insufficient optimization for acid diffusion, and deterioration in resolution, LER, and pattern rectangularity was observed.

[0809] 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) a quencher consisting of an onium salt represented by the following formula (A), (B) a base polymer comprising a polymer which contains a repeating unit represented by the following formula (Bl) and which is decomposed and increases in solubility to an alkali developer by the action of an acid, and (C) a photo-acid generator; ###0001### (A) ###0002### (Bl) wherein ml 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; mlO is 0, 1 or 2; ml l is 0 or 1; ml2 is 0, 1, 2, 3 or 4; ml3 is 0, 1 or 2; ml4 is 0, 1 or 2; however, when ml is 0, 0 < m6 + m9 < 4, and when ml is 1, 0 < m6 + m9 < 6; when m2 is 0, 0 < m7 + mlO < 4, and when m2 is 1, 0 < m7 + mlO < 6; when m3 is 0, 1 < m4 + m5 + m8 + ml4 < 4, and when m3 is 1, 1 < m4 + m5 + m8 + ml4 < 6; when ml l is 0, 0 < ml2 + ml3 < 4, and when ml l is 1, 0 < ml2 + ml3 < 6; and, further, m4 + ml2 > 1; ###0003### (B) ###0004### (B2-1) wherein al 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; and the polymer further contains a repeating unit represented by the following formula (B2-1); ###0005### (B2-1) wherein bl 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; and X is an acid labile group when b4 is 1, and is a hydrogen atom or an acid labile group when b4 is 2 or 3, but at least one is an acid labile group. ###0006### (B2-2) wherein cl is 0, 1 or 2; c2 is 0, 1 or 2; c3 is 0, 1, 2, 3, 4 or 5; and c4 is 0, 1 or 2; and the polymer contains at least one selected from 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); ###0007### (B3) ###0008### (B4) ###0009### (B5) wherein d is 0, 1, 2, 3, 4, 5 or 6; e is 0, 1, 2, 3 or 4; fl is 0 or 1; f2 is 0, 1 or 2; and f3 is 0, 1, 2, 3, 4 or 5; and the polymer contains at least one selected from a repeating unit represented by the following formula (B6), a repeating unit represented by the following formula (B7), a repeating unit represented by the following formula (B8), a repeating unit represented by the following formula (B9) and a repeating unit represented by the following formula (B 10); ###0010### (B6) ###0011### (B7) ###0012### (B8) ###0013### (B9) ###0014### (B 10) wherein gl and g2 are each independently 0, 1, 2 or 3; hl is 0 or 1; h2 is 0, 1, 2, 3 or 4; h3 is 0, 1, 2, 3 or 4; however, when hl is 0, 0 < h2 + h3 < 4, and when hl is 1, 0 < h2 + h3 < 6. ​ ​ ​ Z + Xq - (A) wherein Xq - is an anion; but, Xq - an acid (XqH) which is a conjugate base of a base having a boiling point of not more than 165°C and a molecular weight of not more than 150; Z + a sulfonium cation represented by the following formula (Z-1), a sulfonium cation represented by the following formula (Z-2), an ammonium cation represented by the following formula (Z-3), or a sulfonium cation represented by the following formula (Z-4); In the formula, R 1 ~R 9 Each is an independent hydrocarbon group consisting of halogen atoms or may contain heteroatoms, having 1 to 30 carbon atoms; also, R 1 ~R 3 Any two atoms in R can also bond to each other and form a ring together with the sulfur atoms they are bonded to. 6 ~R 9 Any two atoms in the atom can also bond to each other and form a ring together with the nitrogen atoms they are bonded to; ​ R F1 ~R F3 each independently is a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbons, a fluorinated saturated hydrocarbon group oxy group having 1 to 6 carbons, or a fluorinated saturated hydrocarbon group thio group having 1 to 6 carbons; when m5 is 2 or more, each R F1 may be the same or different, and when m6 is 2 or more, each R F2 may be the same or different, and when m7 is 2 or more, each R F3 may be the same or different. R 10 ~R 13 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 have a hetero atom, a hydrocarbon oxy group having a carbon number of 1 to 20 which can have a hetero atom, or a hydrocarbon thio group having a carbon number of 1 to 20 which can have a hetero atom; when m8 is 2, the 2 R 10 may be the same or different from each other, and 2 R 10 may be bonded to each other and form a ring together with the carbon atom to which they are bonded, and when m9 is 2, the 2 R 11 may be the same or different from each other, and 2 R 11 may be bonded to each other and form a ring together with the carbon atom to which they are bonded, and when m10 is 2, the 2 R 12 may be the same or different from each other, and 2 R 12 may be bonded to each other and form a ring together with the carbon atom to which they are bonded, and when m13 is 2, the 2 R 13 may be the same or different from each other, and 2 R 13 may be bonded to each other and form a ring together with the carbon atom to which they are bonded. Further, S directly bonded to the sulfonium cation + may also be bonded to each other and to S + together to form a ring; L A and L B are each independently a single bond, ether linkage, ester linkage, amide linkage, sulfonate ester linkage, sulfonamide linkage, carbonate ester linkage, or carbamate ester linkage; X L hydrocarbylene group having a carbon number of 1 to 40 which is a single bond or can also contain heteroatoms; ​ R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R 21 a halogen atom, a nitro group, a carboxyl group, 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 carbonyl oxy group having 2 to 8 carbons which can be substituted with a halogen atom; A 1 is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon number, and a part of -CH2- of the saturated hydrocarbylene group can also be replaced with -O-.

2. The chemically amplified positive resist composition according to claim 1, wherein, Anion Xq - The conjugate acid XqH of Xqis formic acid, acetic acid, propionic acid, butyric acid, trifluoroacetic acid, 3,3,3-trifluoropropionic acid, trimethylacetic acid or nitric acid.

3. The chemically amplified positive resist composition according to claim 1, wherein, ​ In the formula, R A It consists of hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups; ​ R 31 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 group oxy group having a carbon number of 1 to 6 which can be substituted with a halogen atom, or a saturated hydrocarbon group carbonyl oxy 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, and a part of -CH2- of the saturated hydrocarbylene group can also be replaced with -O-; ​ 4. The chemically amplified positive resist composition according to claim 1, wherein, ​ ​ R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R 32 and R 33 are each independently a hydrocarbon group of 1 to 10 carbon numbers which can also contain hetero atoms, and R 32 and R 33 may also be bonded to each other and form a ring together with the carbon atom to which they are bonded; R 34 each independently is 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 35 each independently is a hydrocarbon group of 1 to 10 carbon numbers 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 can also contain a hydroxyl group, an ether bond, an ester bond or a lactone ring, or a phenylene or naphthylene group; * indicates the atomic bond to the carbon atom of the main chain.

5. The chemical amplification positive resist composition of claim 1, wherein, ​ ​ R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R 41 and R 42 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 group oxy group having 1 to 6 carbons which can be substituted with a halogen atom, or a saturated hydrocarbon group carbonyl oxy group having 2 to 8 carbons which can be substituted with a halogen atom; R 43 a saturated hydrocarbon group having a carbon number of 1 to 20, a saturated hydrocarbon group oxy group having a carbon number of 1 to 20, a saturated hydrocarbon group carbonyl oxy group having a carbon number of 2 to 20, a saturated hydrocarbon group oxy hydrocarbon group having a carbon number of 2 to 20, a saturated hydrocarbon group thiohydrocarbon group having a carbon number of 2 to 20, a halogen atom, a nitro group, or a cyano group, and f2may also be a hydroxyl group when f2is 1 or 2; A 4 is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon number, and a part of -CH2- of the saturated hydrocarbylene group can also be replaced with -O-.

6. The chemically amplified positive resist composition according to claim 1, wherein ​ ​ R A are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; Z 1 is a single bond or also a phenylene group which can have substituents; Z 2 is a single bond, **-C(=O)-O-Z 21 -, **-C(=O)-NH-Z 21 - or **-O-Z 21 -; Z 21 is an aliphatic hydrocarbylene group having 1 to 6 carbons, a phenylene group or a 2-valent group obtained by combining them, and can also contain a halogen atom, a carbonyl group, an ester bond, an ether bond or a hydroxyl group; Z 3 is a single bond, an ether linkage, an ester linkage, an amide linkage, a sulfonate ester linkage, a sulfonamide linkage, a carbonate ester linkage, or a carbamate ester linkage; Z 4 is a single bond, or an aliphatic hydrocarbylene group having a carbon number of 1 to 6, a phenylene group, or a divalent group obtained by combining them, and can also contain a halogen atom, a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; Z 5 are each independently a single bond, a phenylene group which can also have a substituent, a naphthylene group or a *-C(=O)-O-Z 51 -; Z 51 is an aliphatic hydrocarbylene group having a carbon number of 1 to 10, a phenylene group or a naphthylene group, and the aliphatic hydrocarbylene group can also contain a halogen atom, a hydroxyl group, an ether bond, an ester bond or a lactone ring; Z 6 is a single bond, an ether linkage, an ester linkage, an amide linkage, a sulfonate ester linkage, a sulfonamide linkage, a carbonate ester linkage, or a carbamate ester linkage; Z 7 are each independently a single bond, ***-Z 71 -C(=O)-O-, ***-C(=O)-NH-Z 71 - or ***-O-Z 71 -; Z 71 is an alkylene radical of 1 to 20 carbon numbers which can also contain heteroatoms; Z 8 are each independently a single bond, ****-Z 81 -C(=O)-O-, ****-C(=O)-NH-Z 81 - or ****-O-Z 81 -; Z 81 is an alkylene radical of 1 to 20 carbon numbers which can also contain heteroatoms; Z 9 is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted by trifluoromethyl, -C(=O)-O-Z 91 -, -C(=O)-N(H)-Z 91 - or -O-Z 91 -; Z 91 is an aliphatic hydrocarbylene group having 1 to 6 carbons, phenylene, fluorinated phenylene or phenylene substituted by trifluoromethyl, and can also contain a carbonyl group, an ester bond, an ether bond or a hydroxyl group; * denotes an atomic bond to a carbon atom of the main chain; ** denotes an atomic bond to Z 1 *** denotes an atomic bond to Z 6 **** denotes an atomic bond to Z 7 **** denotes an atomic bond to Z L 1 is a single bond, an ether linkage, an ester linkage, a carbonyl group, a sulfonate ester linkage, a sulfonamide linkage, a carbonate ester linkage, or a carbamate ester linkage; Rf 1 and Rf 2 each independently is a fluorine atom or a fluorinated saturated hydrocarbon group having a carbon number of 1 to 6; Rf 3 and Rf 4 each independently is a hydrogen atom, a fluorine atom or a fluorinated saturated hydrocarbon group having a carbon number of 1 to 6; Rf 5 and Rf 6 are each independently a hydrogen atom, a fluorine atom or a fluorinated saturated hydrocarbon group having a carbon number of 1 to 6; however, all of Rf 5 and Rf 6 cannot be hydrogen atoms simultaneously; Rf 7 is a fluorine atom, a fluorinated alkyl group having a carbon number of 1 to 6, a fluorinated alkoxy group having a carbon number of 1 to 6, or a fluorinated alkylthio group having a carbon number of 1 to 6; R 51 and R 52 each independently is a hydrocarbon group of 1 to 20 carbon numbers which can also contain hetero atoms; and R 51 and R 52 may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded; R 53 a halogen atom other than a fluorine atom, or a hydrocarbon group having a carbon number of 1 to 20 which can also contain a hetero atom; when h3 is 2, 3 or 4, a plurality of R 53 may also be bonded to each other and form a ring together with the carbon atom to which they are bonded; M - is a non-nucleophilic counterion; A + is an onium cation.

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

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

9. The chemically amplified positive resist composition according to claim 1, further comprising (E) a polymer containing a fluorine atom, which contains at least one selected from the group consisting of a repeating unit represented by the following formula (El), a repeating unit represented by the following formula (E2), a repeating unit represented by the following formula (E3), and a repeating unit represented by the following formula (E4), and can further contain at least one selected from the group consisting of a repeating unit represented by the following formula (E5) and a repeating unit represented by the following formula (E6); in the formula, j1 is 1, 2 or 3; j2 is an integer satisfying 0 < j2 < 5 + 2(j3) - j1; j3 is 0 or 1; and k is 1, 2 or 3; R B are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R C are each independently a hydrogen atom or a methyl group; R 101 , R 102 , R 104 and R 105 are each independently a hydrogen atom or a saturated hydrocarbon group having a carbon number of 1 to 10; R 103 , R 106 , R 107 and R 108 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, and R 103 , R 106 , R 107 and R 108 may also have an ether bond or a carbonyl group interposed between carbon-carbon bonds when they are a hydrocarbon group or a fluorinated hydrocarbon group; R 109 is a hydrogen atom, or a linear or branched hydrocarbon group having 1 to 5 carbon atoms which can also have a hetero atom-containing group interposed between carbon-carbon bonds; R 110 a linear or branched hydrocarbon group having 1 to 5 carbons in which a hetero atom-containing group can be inserted between carbon-carbon bonds; R 111 a saturated hydrocarbon group having 1 to 20 carbon atoms of which at least one hydrogen atom is replaced with a fluorine atom, and a part of -CH2- of the saturated hydrocarbon group can also be replaced with an ester bond or an ether bond; X 1 (k+1) valent hydrocarbon group having a carbon number of 1 to 20 or a (k+1) valent fluorinated hydrocarbon group having a carbon number of 1 to 20; X 2 is a single bond, *-C(=O)-O- or *-C(=O)-NH-; * is a bond to a carbon atom of the backbone; X 3 is a single bond, -O-, -C(=O)-O-X 31 -X 32 or -C(=O)-NH-X 31 -X 32 -; X 31 is a single bond or a saturated hydrocarbylene group having a carbon number of 1 to 10; X 32 is a single bond, an ester bond, an ether bond or a sulfonamide bond; * is a bond with a carbon atom of the main chain.

10. The chemically amplified positive resist composition according to claim 1, further comprising a quencher other than the quencher according to claim 1.

11. 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 10, irradiating a pattern to the resist film using a high energy ray, and developing the resist film having the irradiated pattern using an alkali developer.

12. The resist pattern forming method according to claim 11, wherein, The high energy ray is an extreme ultraviolet ray having a wavelength of 3 to 15 nm or an electron beam.

13. The resist pattern forming method according to claim 11, wherein The topmost surface of the substrate is composed of a material containing chromium.

14. The resist pattern forming method according to claim 11, wherein The substrate is a blank photomask. The substrate is a blank photomask.

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