Sulfonium salt type monomer, polymer, chemically amplified positive resist composition, and resist pattern forming method

Abstract

The invention relates to a sulfonium salt type monomer, a polymer, a chemically amplified positive resist composition and a resist pattern forming method. The present invention addresses the problem of providing: a sulfonium salt-type monomer which has excellent etching resistance, solubility in organic solvents, and appropriate acid strength, and which is capable of generating an acid having small diffusion; a polymer which contains a repeating unit derived from the onium salt-type monomer; a chemically amplified resist composition which contains the polymer; and a pattern forming method using the chemically amplified resist composition. [Solution] A sulfonium salt-type monomer represented by formula (A1). # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a sulfonium salt type monomer, a polymer, a chemically amplified positive resist composition and a resist pattern forming method. Background Art

[0002] In recent years, with the increasing integration and speed of LSIs, the miniaturization of pattern patterns has also progressed rapidly. For processing patterns smaller than 0.2μm, chemically amplified resist compositions, primarily using acid as a catalyst, are used. Furthermore, high-energy radiation such as ultraviolet (UV), extreme UV, and electron beam (EB) is used as an exposure source. EB lithography, an ultra-fine processing technology, has become indispensable for processing photomask blanks used in semiconductor manufacturing.

[0003] Polymers containing a large number of aromatic backbones with acidic side chains, such as polyhydroxystyrene, are useful as materials for resist compositions for KrF lithography using KrF excimer lasers. However, due to their significant absorption of light with a wavelength near 200 nm, they have not been used as materials for ArF lithography using ArF excimer lasers. However, they have become important materials for resist compositions for EB lithography and extreme ultraviolet (EUV) lithography, which are powerful technologies for forming patterns with processing limits even lower than those achieved with ArF excimer lasers, due to their ability to achieve high etching resistance.

[0004] Generally, for base polymers of positive-type EB lithography resist compositions and EUV lithography resist compositions, materials that are soluble in alkaline developer are mainly used, which use an acid generated from a photoacid generator by irradiation with high-energy radiation as a catalyst to deprotect the acid-degradable protecting groups (acid-labile groups) that mask the acidic functional groups of the phenol side chains of the base polymer.

[0005] The acid-degradable protecting groups mentioned above primarily include tertiary alkyl groups, tert-butoxycarbonyl groups, and acetal groups. While using a protecting group like an acetal group, which requires a low activation energy for deprotection, offers the advantage of producing a highly sensitive resist film, insufficient suppression of the diffusion of the generated acid can lead to deprotection reactions in unexposed portions of the resist film, resulting in degradation of line edge roughness (LER) and reduced dimensional uniformity (CDU) of the pattern width. Furthermore, in the processing of photomask blanks, a particularly important application, chromium compound films, such as chromium oxide films formed on photomask substrates, have surface materials that can easily affect the pattern shape of the chemically amplified resist film. Therefore, maintaining a rectangular pattern profile in the resist film, regardless of the substrate type, is crucial for maintaining high resolution and a high post-etching shape. In addition, in recent years, in order to achieve miniaturization, MBMW (Multi-Beam Mask Writing) drawing processing has been used in the processing of blank masks. At this time, the resist composition uses a low-sensitivity resist composition (high-dose area) that is beneficial to roughness, and the optimization of the resist composition in the high-dose area has also received attention.

[0006] To control sensitivity and pattern profiles, various improvements have been made through the selection and combination of materials used in resist compositions, as well as processing conditions. One such improvement addresses the issue of acid diffusion. This acid diffusion has been extensively studied because it significantly affects the sensitivity and resolution of chemically amplified resist compositions.

[0007] Patent Documents 1 and 2 describe methods for reducing roughness by increasing the volume of benzenesulfonic acid generated from a photoacid generator during exposure. However, the suppression of acid diffusion by these acid generators remains insufficient, leading to a desire for the development of acid generators with even smaller diffusion rates.

[0008] Furthermore, when using sulfonium salts described in Patent Document 3 that generate acids with high acid strength, such as fluorinated alkanesulfonic acid, with polymers containing repeating units having acetal groups, there is a problem of forming patterns with large LER. When deprotecting acetal groups, which have a relatively low activation energy for deprotection, the acid strength of fluorinated alkanesulfonic acid is too high. Therefore, even if the diffusion of the acid is suppressed, the deprotection reaction will still proceed due to the trace amount of acid that diffuses into the unexposed area. This situation is also the case with the sulfonium salts described in Patent Documents 1 and 2 that generate benzenesulfonic acid. Therefore, it is desirable to develop an acid generator that can generate an acid with a more ideal strength for deprotecting acetal groups.

[0009] In order to suppress acid diffusion, some people have proposed resist compounds containing repeating units of onium salts of sulfonic acids with polymerizable unsaturated bonds (Patent Documents 4 to 6). Such so-called polymer-bonded acid generators have the characteristic of very short acid diffusion due to the generation of polymer-type sulfonic acid upon exposure. In addition, by increasing the ratio of the acid generator, the sensitivity can be improved. In the case of additive acid generators, increasing the amount of addition will also increase the sensitivity, but in this case the acid diffusion distance will also increase. Since the acid diffuses unevenly, if the acid diffusion increases, the LER and CDU will deteriorate. In the balance between sensitivity, LER and CDU, polymer-bonded acid generators have higher capabilities, and it is hoped that acid generators that can generate acids with more ideal strength will be developed.

[0010] Patent Document 7 describes an example of controlling acid diffusion by binding sulfonic acid generated by exposure to a polymer used in a resist composition, thereby inhibiting diffusion and controlling acid diffusion. This method of suppressing acid diffusion by incorporating repeating units that generate acid upon exposure into a base polymer is effective for obtaining patterns with low LER. However, depending on the structure and incorporation rate of such repeating units, the base polymer to which repeating units that generate acid upon exposure are bonded may sometimes have problems with solubility in organic solvents.

[0011] With the recent advancement of miniaturization of resist patterns, resist pattern collapse during development and poor resistance during etching have become issues. While the introduction of repeating units derived from onium salts of sulfonic acids having polymerizable unsaturated bonds can somewhat suppress the diffusion of the generated acid, there remains room for improvement in various aspects of lithographic performance, resist pattern collapse, and poor etching resistance. To meet future demands for miniaturization, the development of polymer-based acid generators that combine lithographic performance with resist pattern collapse and etching resistance is crucial.

[0012] Prior art literature

[0013] Patent Literature

[0014] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-53518

[0015] [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-100604

[0016] [Patent Document 3] Japanese Patent No. 5083528

[0017] [Patent Document 4] Japanese Patent No. 4425776

[0018] [Patent Document 5] Japanese Patent No. 5201363

[0019] [Patent Document 6] Japanese Patent No. 5231357

[0020] [Patent Document 7] Japanese Patent Application Laid-Open No. 2011-22564 Summary of the Invention

[0021] [Problems to be Solved by the Invention]

[0022] The present invention is made in view of the above situation, and its purpose is to provide:

[0023] Sulfonium salt monomers have excellent etching resistance, organic solvent solubility, appropriate acid strength, and can produce acid with low diffusion.

[0024] a polymer containing repeating units derived from the onium salt-type monomer,

[0025] A chemically amplified resist composition containing the polymer, and

[0026] A resist pattern forming method using the chemically amplified resist composition.

[0027] [Methods for solving the problem]

[0028] The present inventors have conducted extensive research to achieve the aforementioned objectives and have discovered that by using a polymer containing repeating units derived from a sulfonium salt containing an aromatic sulfonic acid anion having an aromatic ring substituted with a vinyl group as a polymer-bound acid generator, a chemically amplified resist composition with improved LER, high contrast and resolution, and excellent etching resistance can be obtained, thereby completing the present invention.

[0029] That is, the present invention provides the following sulfonium salt-type monomers, polymers, chemically amplified positive resist compositions, and resist pattern forming methods.

[0030] 1. A sulfonium salt-type monomer represented by the following formula (A1).

[0031] [Chemistry 1]

[0032]

[0033] In the formula, n1 is an integer from 0 to 2. n2 is an integer satisfying 0≤n2≤5+2(n1)-1. p is an integer from 1 to 5. q is an integer from 1 to 3.

[0034] R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0035] R 1It is a halogen atom, a nitro group, a cyano group, a saturated hydrocarbon group having 1 to 10 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 10 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon carbonyloxy group having 2 to 10 carbon atoms which may be substituted by a halogen atom, or a fluorinated saturated hydrocarbon thio group having 1 to 10 carbon atoms.

[0036] R 2 It is a hydrocarbon group having 1 to 30 carbon atoms which may contain a heteroatom.

[0037] R 3 It is a (p+1)-valent hydrocarbon group having 1 to 30 carbon atoms which may contain a heteroatom.

[0038] R 4 It is a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 5 carbon atoms, a fluorinated saturated hydrocarbon oxy group having 1 to 5 carbon atoms, a fluorinated saturated hydrocarbon carbonyloxy group having 2 to 5 carbon atoms, a fluorinated saturated hydrocarbon oxycarbonyl group having 2 to 5 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 5 carbon atoms, and a portion of the hydrogen atoms of these groups may be substituted by at least one selected from a hydroxyl group, a chlorine atom, a bromine atom, an iodine atom, a nitro group, and a cyano group, and at least one selected from an ester bond, an ether bond, a sulfonate bond, a carbonate bond, and a carbamate bond may be inserted between the carbon-carbon bonds of these groups.

[0039] When q is 1, 2 R 2 and R 3 Any two of them can also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. 3 and R 2 Any two of them can also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. 3 Any two of them may be bonded to each other and form a ring together with the sulfur atom to which they are bonded.

[0040] 2. The sulfonium salt-type monomer according to 1., which is represented by the following formula (A1-1).

[0041] [Chemistry 2]

[0042]

[0043] Where n1, n2, p, q, R A 、R 1 and R 4 Same as above.

[0044] R 5 and R 6 Each independently represents a halogen atom other than a fluorine atom, a nitro group, a cyano group, or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom.

[0045] r1 and r2 are each independently an integer of 0 to 2. s1 is an integer satisfying 0≤s1≤(2r1+4). s2 is an integer satisfying 0≤s2≤(2r2+4).

[0046] 3. The sulfonium salt monomer of 2., wherein R 4 is a fluorine atom, a trifluoromethyl group, a trifluoromethoxy group or a trifluoromethylthio group.

[0047] 4. A polymer comprising a repeating unit derived from the sulfonium salt-type monomer according to any one of 1. to 3., wherein the solubility of the polymer in an aqueous alkaline solution is increased by the action of an acid.

[0048] 5. The polymer according to 4., further comprising a repeating unit represented by the following formula (A2).

[0049] [Chemistry 3]

[0050]

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

[0052] R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0053] R 11 It is a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom.

[0054] A 1 It is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a part of the -CH2- in the saturated alkylene group may be substituted by -O-.

[0055] 6. The polymer according to 4. or 5., further comprising at least one selected from the group consisting of a repeating unit represented by the following formula (A3-1) and a repeating unit represented by the following formula (A3-2).

[0056] [Chemistry 4]

[0057]

[0058] In the formula, b1 is 0 or 1. b2 is an integer from 0 to 2. b3 is an integer satisfying 0≤b3≤5+2(b2)-b4. b4 is an integer from 1 to 3. b5 is 0 or 1.

[0059] c1 is an integer from 0 to 2. c2 is an integer from 0 to 2. c3 is an integer from 0 to 5. c4 is an integer from 0 to 2.

[0060] R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0061] R 12 It is a nitro group, a cyano group, a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon thio group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon carbonyl group having 2 to 8 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom.

[0062] R 13 and R 14 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may contain a heteroatom, and R 13 With R 14 They may also bond to each other and to the carbon atoms to which they are bonded to form a ring.

[0063] R 15 Each independently represents a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkoxy group having 1 to 5 carbon atoms.

[0064] R 16 Each independently represents a hydrocarbon group having 1 to 10 carbon atoms which may contain a heteroatom.

[0065] A 2 It is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a part of the -CH2- in the saturated alkylene group may be substituted by -O-.

[0066] When b4 is 1, X is an acid-labile group. When b4 is 2 or 3, X is independently a hydrogen atom or an acid-labile group, but at least one of them is an acid-labile group.

[0067] A 3 is a single bond, phenylene, naphthylene or *-C(=O)-OA 31 -.A 31 It is an aliphatic hydrocarbylene group having 1 to 20 carbon atoms, a phenylene group, or a naphthylene group, and the aliphatic hydrocarbylene group may contain at least one selected from a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * is an atomic bond to a carbon atom of the main chain.

[0068] 7. The polymer according to any one of 4. to 6., further comprising at least one selected from the group consisting of a repeating unit represented by the following formula (A4), a repeating unit represented by the following formula (A5), and a repeating unit represented by the following formula (A6).

[0069] [Chemistry 5]

[0070]

[0071] In the formula, d and e are each independently an integer of 0 to 4. f1 is 0 or 1. f2 is an integer of 0 to 2. f3 is an integer of 0 to 5.

[0072] R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0073] R 21 and R 22 Each of them is independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom.

[0074] R 23 is a halogen atom, a trifluoromethyl group, a trifluoromethoxy group, a nitro group, a cyano group, a saturated hydrocarbon group having 1 to 20 carbon atoms, a saturated hydrocarbon oxy group having 1 to 20 carbon atoms, a saturated hydrocarbon carbonyloxy group having 2 to 20 carbon atoms, a saturated hydrocarbon oxyhydrocarbyl group having 2 to 20 carbon atoms, a saturated hydrocarbon thiohydrocarbyl group having 2 to 20 carbon atoms, a saturated hydrocarbon sulfinyl group having 1 to 20 carbon atoms, or a saturated hydrocarbon sulfonyl group having 1 to 20 carbon atoms.

[0075] A 4 It is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a part of the -CH2- in the saturated alkylene group may be substituted by -O-.

[0076] 8. A chemically amplified positive resist composition comprising:

[0077] (A) The base polymer comprises the polymer according to any one of 4. to 7.

[0078] 9. The chemically amplified positive resist composition according to 8., wherein the content of repeating units having an aromatic ring skeleton in all repeating units of the polymer contained in the base polymer is 60 mol% or more.

[0079] 10. The chemically amplified positive resist composition according to 8. or 9., further comprising (B) a quencher.

[0080] 11. The chemically amplified positive resist composition according to any one of 8. to 10., further comprising (C) a photoacid generator.

[0081] 12. The chemically amplified positive resist composition according to any one of 8. to 11., wherein the content ratio of the (C) photoacid generator to the (B) quencher is less than 6 in terms of mass ratio.

[0082] 13. The chemically amplified positive resist composition according to any one of 8. to 12., further comprising:

[0083] (D) A fluorine-containing polymer containing at least one selected from the group consisting of a repeating unit represented by the following formula (D1), a repeating unit represented by the following formula (D2), a repeating unit represented by the following formula (D3), and a repeating unit represented by the following formula (D4), and may further contain at least one selected from the group consisting of a repeating unit represented by the following formula (D5) and a repeating unit represented by the following formula (D6).

[0084] [Chemistry 6]

[0085]

[0086] In the formula, x is an integer from 1 to 3. y is an integer satisfying 0≤y≤5+2z-x. z is 0 or 1. h is an integer from 1 to 3.

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

[0088] R C are each independently a hydrogen atom or a methyl group.

[0089] R 301 、R 302 、R 304 and R 305 Each independently represents a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms.

[0090] R 303 、R 306 、R 307 and R 308 are independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, a fluorinated hydrocarbon group having 1 to 15 carbon atoms, or an acid-labile group, and R 303 、R 306 、R 307 and R 308 In the case of a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond or a carbonyl group may be inserted between carbon-carbon bonds.

[0091] R 309 It is a hydrogen atom or a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may have a heteroatom-containing group inserted between carbon-carbon bonds.

[0092] R 310 It is a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may have a heteroatom-containing group inserted between carbon-carbon bonds.

[0093] R 311 It is a saturated hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted by a fluorine atom, and a portion of the -CH2- groups in the saturated hydrocarbon group may be substituted by an ester bond or an ether bond.

[0094] Z 1It is a (h+1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (h+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms.

[0095] Z 2 It is a single bond, *-C(=O)-O- or *-C(=O)-NH-. * is an atomic bond to a carbon atom of the main chain.

[0096] Z 3 is a single bond, -O-, *-C(=O)-OZ 31 -Z 32 - or *-C(=O)-NH-Z 31 -Z 32 -.Z 31 Z is a single bond or a saturated alkylene group having 1 to 10 carbon atoms. 32 is a single bond, ester bond, ether bond or sulfonamide bond. * is an atomic bond to a carbon atom of the main chain.

[0097] 14. The chemically amplified positive resist composition according to any one of 8. to 13., further comprising (E) an organic solvent.

[0098] 15. A method for forming a resist pattern, comprising the following steps:

[0099] Forming a resist film on a substrate using the chemically amplified positive resist composition according to any one of 8. to 14.

[0100] irradiating the resist film with a pattern of high-energy rays, and

[0101] The resist film having the irradiated pattern is developed using an alkaline developer.

[0102] 16. The resist pattern forming method according to 15., wherein the high-energy ray is extreme ultraviolet ray or electron beam.

[0103] 17. The resist pattern forming method according to 15. or 16., wherein the outermost surface of the substrate is made of a material containing at least one selected from the group consisting of chromium, silicon, tantalum, molybdenum, cobalt, nickel, tungsten, and tin.

[0104] 18. The resist pattern forming method according to any one of 15. to 17., wherein the substrate is a transmissive or reflective mask blank.

[0105] 19. A transmissive or reflective blank mask coated with the chemically amplified positive resist composition according to any one of 8. to 14.

[0106] [Effects of the Invention]

[0107] Polymers containing repeating units derived from an onium salt-type monomer represented by formula (A1) exhibit good solvent solubility and, due to the rigidity of the aromatic sulfonic acid structure, exhibit minimal acid diffusion. Therefore, positive-type resist compositions containing such polymers can prevent the loss of resolution caused by blurring due to acid diffusion, thereby improving resolution and LER. Furthermore, the aromatic rings function as excellent etching-resistant groups, making them ideal for fine pattern formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0108] [ Figure 1 ]NMR spectrum of the monomer PM-1 synthesized in Example 1-1 ( 1 H-NMR / DMSO-d6). DETAILED DESCRIPTION

[0109] The present invention will be described in detail below. In the following description, depending on the structure represented by the chemical formula, asymmetric carbon atoms may exist, and mirror isomers and diastereomers may exist. In such cases, these isomers are represented by a single general formula. These isomers may be used alone or as a mixture.

[0110] [Sulfonium salt type monomer]

[0111] The sulfonium salt-type monomer of the present invention is represented by the following formula (A1).

[0112] [Chemistry 7]

[0113]

[0114] In formula (A1), n1 is an integer of 0 to 2 and is a condensed polycyclic aromatic group consisting of a benzene ring or three or less aromatic rings selected from benzene rings such as a benzene ring, a naphthalene ring, anthracene ring, and a phenanthrene ring. From the perspective of solvent solubility, n1 is preferably a benzene ring of 0.

[0115] In formula (A1), n2 is an integer satisfying 0≤n2≤5+2(n1)-1. When n1 is 0, n2 is preferably 0, 1, 2 or 3, more preferably 0. When n1 is 1 or 2, n2 is preferably 0, 1, 2, 3 or 4.

[0116] In formula (A1), p is an integer of 1 to 5, preferably 1, 2 or 3, more preferably 1 or 2, in view of raw material availability. q is an integer of 1 to 3, preferably 1 or 2, more preferably 1.

[0117] In formula (A1), R A It is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Among them, it is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

[0118] In formula (A1), R 1It is a halogen atom, a nitro group, a cyano group, a saturated hydrocarbon group having 1 to 10 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 10 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon carbonyl oxy group having 2 to 10 carbon atoms which may be substituted by a halogen atom, or a fluorinated saturated hydrocarbon thio group having 1 to 10 carbon atoms. The saturated hydrocarbon group and the saturated hydrocarbon group portion of the saturated hydrocarbon oxy group, saturated hydrocarbon carbonyl oxy group and saturated hydrocarbon thio group may be straight chain, branched or cyclic. Specific examples thereof include: alkyl groups having 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, butyl, pentyl and hexyl; cycloalkyl groups having 3 to 10 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl; and groups obtained by combining these. If the number of carbon atoms is below the upper limit, the solubility in the alkaline developer is good. When n2 is 2 or more, each R 1 They can be the same or different from each other.

[0119] In formula (A1), R 2 It is a hydrocarbon group having 1 to 30 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include: alkyl groups having 1 to 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and tert-butyl; cyclic saturated hydrocarbon groups having 3 to 30 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 30 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups having 3 to 30 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 30 carbon atoms, such as phenyl and naphthyl; aralkyl groups having 7 to 30 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and combinations thereof. Among these, aryl groups are preferred. Furthermore, a part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and a part of the -CH2- constituting the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, the group may contain a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like.

[0120] In formula (A1), R 3It is a (p+1)-valent hydrocarbon group having 1 to 30 carbon atoms, which may contain a heteroatom. The (p+1)-valent hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include a hydrocarbonyl group having 1 to 30 carbon atoms and a group obtained by removing (p-1) hydrogen atoms from the above hydrocarbonyl group. Examples of the aforementioned alkylene groups include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, heptadecane-1,17-diyl, and heptadecane-1,18-diyl. Alkanediyl groups having 1 to 30 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norbornanediyl, and adamantanediyl; cyclic saturated alkylene groups having 3 to 30 carbon atoms, such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, sec-butylnaphthylene, and tert-butylnaphthylene; and groups derived from combinations thereof.

[0121] Furthermore, a part or all of the hydrogen atoms of the aforementioned (p+1)-valent hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and a part of the -CH2- constituting the aforementioned (p+1)-valent hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, the group may contain a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like.

[0122] In formula (A1), R 4 is a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 5 carbon atoms, a fluorinated saturated hydrocarbon oxy group having 1 to 5 carbon atoms, a fluorinated saturated hydrocarbon carbonyloxy group having 2 to 5 carbon atoms, a fluorinated saturated hydrocarbon oxycarbonyl group having 2 to 5 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 5 carbon atoms, and a portion of the hydrogen atoms of these groups may be substituted with at least one selected from a hydroxyl group, a chlorine atom, a bromine atom, an iodine atom, a nitro group, and a cyano group, and at least one selected from an ester bond, an ether bond, a sulfonate bond, a carbonate bond, and a carbamate bond may be inserted between the carbon-carbon bonds of these groups. Among them, R 4Preferred groups include fluorine atoms, trifluoromethyl groups, difluoromethyl groups, trifluoromethoxy groups, difluoromethoxy groups, trifluoromethylthio groups, or difluoromethylthio groups. Fluorine atoms, trifluoromethyl groups, or trifluoromethoxy groups are more preferred, and trifluoromethoxy groups are even more preferred. The use of a trifluoromethoxy group, in particular, significantly improves solvent solubility and alleviates restrictions on the incorporation rate of repeating unit A1. Furthermore, the sulfonium salt dissolves uniformly in the solvent without agglomerating, allowing for uniform dispersion in the resist film. High-energy irradiation generates acid from the uniformly dispersed sulfonium salt, resulting in high resolution and improved LER. Furthermore, the inclusion of fluorine atoms in the sulfonium cations controls the solubility of the unexposed area in alkaline developer solutions, thereby improving pattern contrast and contributing to improved resolution.

[0123] When q is 1, 2 R 2 and R 3 Any two of them can also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. 3 and R 2 Any two of them can also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. 3 Any two of them may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, specific examples of the ring include those represented by the following formula.

[0124] [Chemistry 8]

[0125]

[0126] In the formula, the dotted lines are atomic bonds.

[0127] The sulfonium salt represented by the formula (A1) is preferably represented by the following formula (A1-1).

[0128] [Chemistry 9]

[0129]

[0130] Where n1, n2, p, q, R A 、R 1 and R 4 Same as above.

[0131] In formula (A1-1), R 5 and R 6Each independently represents a halogen atom other than a fluorine atom, a nitro group, a cyano group, or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, or cyclic. Specific examples thereof include: alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6

[0015] Cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; aryl groups having 6 to 20 carbon atoms, such as phenyl, naphthyl, and anthracenyl; and groups obtained by combining these. Furthermore, some or all of the hydrogen atoms of the aforementioned hydrocarbon groups may be substituted with groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- groups constituting the aforementioned hydrocarbon groups may be substituted with groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. Consequently, the hydrocarbon groups may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, carbamate bonds, amide bonds, imide bonds, lactone rings, sultone rings, thiolactone rings, lactam rings, intrasulfonamide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), and haloalkyl groups.

[0132] In formula (A1-1), r1 and r2 are each independently an integer of 0 to 2, and represent a benzene ring when 0, a naphthalene ring when 1, and an anthracene ring when 2. Among these, a benzene ring in which r1 and r2 are 0 is preferred from the viewpoint of solvent solubility.

[0133] In formula (A1-1), s1 is an integer satisfying 0≤s1≤(2r1+4), preferably 0. s2 is an integer satisfying 0≤s2≤(2r2+4), preferably 0. When s1≥2, two or more R 5 They can be the same or different, and there are more than two R 5 They can also bond to each other and form a ring. When s2≥2, two or more R 6 They can be the same or different, and there are more than two R 6 They may be bonded to each other to form a ring. Examples of the ring include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a norbornane ring, and an adamantane ring.

[0134] The sulfonate anion of the sulfonium salt represented by formula (A1) may be exemplified by the following, but is not limited thereto. A Same as above.

[0135] [Chemistry 10]

[0136]

[0137] [Chemistry 11]

[0138]

[0139] [Chemistry 12]

[0140]

[0141] Examples of the sulfonium cation of the sulfonium salt-type monomer represented by formula (A1) include, but are not limited to, the following.

[0142] [Chemistry 13]

[0143]

[0144] [Chemistry 14]

[0145]

[0146] [Chemistry 15]

[0147]

[0148] [Chemistry 16]

[0149]

[0150] [Chemistry 17]

[0151]

[0152] [Chemistry 18]

[0153]

[0154] [Chemistry 19]

[0155]

[0156] [Chemistry 20]

[0157]

[0158] [Chemistry 21]

[0159]

[0160] [Chemistry 22]

[0161]

[0162] [Chemistry 23]

[0163]

[0164] [Chemistry 24]

[0165]

[0166] [Chemistry 25]

[0167]

[0168] [Chemistry 26]

[0169]

[0170] [Chemistry 27]

[0171]

[0172] [Chemistry 28]

[0173]

[0174] [Chemistry 29]

[0175]

[0176] [Chemistry 30]

[0177]

[0178] [Chemistry 31]

[0179]

[0180] [Chemistry 32]

[0181]

[0182] [Chemistry 33]

[0183]

[0184] [Chemistry 34]

[0185]

[0186] [Chemistry 35]

[0187]

[0188] [Chemistry 36]

[0189]

[0190] [Chemistry 37]

[0191]

[0192] [Chemistry 38]

[0193]

[0194] [Chemistry 39]

[0195]

[0196] [Chemistry 40]

[0197]

[0198] [Chemistry 41]

[0199]

[0200] The onium salt-type monomer represented by formula (A1) can be synthesized, for example, by the same method as that for the sulfonium salt having a polymerizable anion described in Japanese Patent No. 5201363, but the method is not limited thereto.

[0201] [polymer]

[0202] The polymer of the present invention contains a repeating unit derived from a sulfonium salt-type monomer represented by formula (A1) (hereinafter also referred to as repeating unit A1), and its solubility in an aqueous alkaline solution is increased by the action of an acid.

[0203] The polymer of the present invention is a polymer-bonded photoacid generator that functions both as a photoacid generator and as a base polymer in a chemically amplified resist composition. The structural features of the onium salt-type monomer of the present invention include an aromatic vinyl structure as a polymerizable group and an aromatic sulfonic acid anion. The presence of an aromatic ring directly bonded to the main chain rigidifies the main chain of the base polymer, thereby improving the glass transition temperature (Tg) of the base polymer. It is believed that the aromatic rings within and between base polymers interact (π-π stacking effect), resulting in a regular arrangement of the base polymer and resistance to pattern collapse in developer during fine pattern formation. Furthermore, the presence of an aromatic ring directly bonded to the main chain also demonstrates excellent etching resistance during the etching step after fine pattern formation. The aromatic sulfonic acid moiety of the generated acid has a more rigid structure than that of known partially fluorinated alkanesulfonic acid anions, thereby suppressing excessive acid diffusion. Furthermore, by incorporating fluorine atoms into the sulfonium cation structure, solubility in organic solvents is also ensured. Leveraging these synergistic effects, the polymer of the present invention combines pattern formation with strong pattern collapse resistance, excellent LER, and etch resistance, making it particularly suitable as a material for chemically amplified positive resist compositions.

[0204] The content of the repeating unit A1 is preferably 1 to 30 mol%, more preferably 2 to 15%, and even more preferably 3 to 10 mol%, based on the total repeating units constituting the polymer. If it exceeds 30 mol%, organic solvent solubility may deteriorate, potentially preventing synthesis of the desired polymer. Even if synthesis is possible, precipitation, coating defects, and development defects may occur when the polymer is prepared as a resist composition. The repeating unit A1 may be used alone or in combination of two or more.

[0205] The aforementioned polymer may further contain a repeating unit represented by the following formula (A2) (hereinafter also referred to as repeating unit A2).

[0206] [Chemistry 42]

[0207]

[0208] In formula (A2), a1 is 0 or 1. a2 is an integer from 0 to 2, and when 0, it represents a benzene skeleton, when 1, it represents a naphthalene skeleton, and when 2, it represents an anthracene skeleton. a3 is an integer satisfying 0 ≤ a3 ≤ 5 + 2(a2) - a4. a4 is an integer from 1 to 3. When a2 is 0, a3 is preferably 0, 1, 2, or 3, and a4 is preferably 1, 2, or 3. When a2 is 1 or 2, a3 is preferably 0, 1, 2, 3, or 4, and a4 is preferably 1, 2, or 3.

[0209] In formula (A2), R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0210] In formula (A2), R 11 It is a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom. The saturated hydrocarbon group, the saturated hydrocarbon group portion of the saturated hydrocarbon oxy group and the saturated hydrocarbon carbonyloxy group may be any of linear, branched, or cyclic. Specific examples thereof include: alkyl groups such as methyl, ethyl, n-propyl, isopropyl, butyl, pentyl, hexyl, and their structural isomers; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; and groups obtained by combining these groups. If the number of carbon atoms is below the upper limit, the solubility in alkaline developer is good. When a3 is 2 or more, each R 11 They can be the same or different from each other.

[0211] In formula (A2), A 1represents a single bond or a saturated alkylene group having 1 to 10 carbon atoms, wherein a portion of the -CH2- residues in the saturated alkylene group may be substituted with -O-. The saturated alkylene group may be linear, branched, or cyclic. Specific examples include alkanediyl groups having 1 to 10 carbon atoms, such as methylene, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, and their structural isomers; cyclic saturated alkylene groups having 3 to 10 carbon atoms, such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and combinations thereof. When the saturated alkylene group contains an ether bond, when a1 in formula (A2) is 1, the group may be inserted at any position other than between the carbon atom at the alpha position and the carbon atom at the beta position relative to the ester oxygen atom. When a1 is 0, the atom bonded to the main chain becomes an etheric oxygen atom, and a second ether bond may be inserted at any position other than between the carbon atom at the α-position and the carbon atom at the β-position relative to the etheric oxygen atom. Furthermore, it is preferred that the carbon number of the saturated alkylene group is 10 or less, since sufficient solubility in an alkaline developer can be achieved.

[0212] a1 is 0 and A 1 When it is a single bond, that is, the aromatic ring is directly bonded to the main chain of the polymer (that is, there is no connecting group (-C(=O)-OA 1 -)), preferable examples of the repeating unit A2 include units derived from 3-hydroxystyrene, 4-hydroxystyrene, 5-hydroxy-2-vinylnaphthalene, 6-hydroxy-2-vinylnaphthalene, etc. In particular, the repeating unit represented by the following formula (A2-1) is preferable.

[0213] [Chemistry 43]

[0214]

[0215] Where R A 、R 11 , a3 and a4 are the same as above.

[0216] a1 is 0 and A 1 is a single bond (i.e., does not have a linking group (-C(=O)-OA 1 -)), the specific examples of repeating unit A2 include those shown below, but are not limited thereto. A Same as above.

[0217] [Chemistry 44]

[0218]

[0219] [Chemistry 45]

[0220]

[0221] Moreover, a1 is 1 (ie, having -C(=O)-OA 1 - as a linking group), the following are examples of desirable repeating units A2, but are not limited thereto. A Same as above.

[0222] [Chemistry 46]

[0223]

[0224] [Chemistry 47]

[0225]

[0226] [Chemistry 48]

[0227]

[0228] The content of repeating unit A2 is preferably 10 to 95 mol%, more preferably 50 to 90 mol%, even more preferably 55 to 85 mol%, and most preferably 60 to 80 mol% of all repeating units constituting the aforementioned polymer. However, when at least one of a repeating unit represented by formula (A4) and a repeating unit represented by formula (A5), which impart higher etching resistance to the polymer, is contained, and such unit has a phenolic hydroxyl group as a substituent, it is also preferable to adjust the ratio within the aforementioned range in addition. Repeating unit A2 may be used alone or in combination of two or more.

[0229] Since the polymer, as a positive resist composition, imparts the property of dissolving the exposed portion in an alkaline developer, it preferably contains a repeating unit having an acidic functional group protected by an acid-labile group, that is, a repeating unit protected by an acid-labile group and rendered alkali-soluble by the action of an acid (hereinafter also referred to as repeating unit A3). In this case, the acid-labile group (protecting group) in the repeating unit undergoes a deprotection reaction by the action of the acid, thereby exhibiting better solubility in an alkaline developer.

[0230] Specific examples of the repeating unit A3 include those represented by the following formula (A3-1) (hereinafter also referred to as repeating unit A3-1).

[0231] [Chemistry 49]

[0232]

[0233] In formula (A3-1), b1 is 0 or 1. b2 is an integer from 0 to 2, and when 0, it represents a benzene skeleton, when 1, it represents a naphthalene skeleton, and when 2, it represents an anthracene skeleton. b3 is an integer satisfying 0≤b3≤5+2(b2)-b4. b4 is an integer from 1 to 3. b5 is 0 or 1. When b2 is 0, b3 is preferably 0, 1, 2, or 3, and b4 is preferably 1, 2, or 3. When b2 is 1 or 2, b3 is preferably 0, 1, 2, 3, or 4, and b4 is preferably 1, 2, or 3.

[0234] In formula (A3-1), R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0235] In formula (A3-1), R 12 The saturated hydrocarbon group may be a nitro group, a cyano group, a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbon thio group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbon carbonyl group having 2 to 8 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted with a halogen atom. Specific examples of the halogen atom include fluorine, chlorine, bromine, and iodine. The saturated hydrocarbon group portion of the saturated hydrocarbon group, saturated hydrocarbon oxy group, and saturated hydrocarbon carbonyloxy group may 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 combinations thereof. Examples of saturated hydrocarbon groups having 1 to 6 carbon atoms substituted by halogen atoms include trifluoromethyl and difluoromethyl. Specific examples of saturated hydrocarbon oxy groups having 1 to 6 carbon atoms substituted by halogen atoms include trifluoromethoxy and difluoromethoxy. Specific examples of saturated hydrocarbon thio groups having 1 to 6 carbon atoms substituted by halogen atoms include trifluoromethylthio and difluoromethylthio. When the number of carbon atoms is below the upper limit, the solubility in alkaline developer is good. When b3 is 2 or more, each R 12 They can be the same or different from each other.

[0236] In formula (A3-1), A 2represents a single bond or a saturated alkylene group having 1 to 10 carbon atoms, wherein a portion of the -CH2- residues of the saturated alkylene group may be substituted with -O-. The saturated alkylene group may be linear, branched, or cyclic. Specific examples include: alkylene groups having 1 to 10 carbon atoms, such as methylene, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, and their structural isomers; cyclic saturated alkylene groups having 3 to 10 carbon atoms, such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and combinations thereof. When the saturated alkylene group contains an ether bond, when b1 in formula (A3-1) is 1, it may be inserted at any position other than between the carbon atom at the alpha position and the carbon atom at the beta position relative to the ester oxygen atom. When b1 is 0, the atom bonded to the main chain becomes an etheric oxygen atom, and a second ether bond may be inserted at any position other than between the carbon atom at the α-position and the carbon atom at the β-position relative to the etheric oxygen atom. Furthermore, it is preferred that the carbon number of the saturated alkylene group is 10 or less, since sufficient solubility in an alkaline developer can be achieved.

[0237] In formula (A3-1), 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, provided that at least one of the groups is an acid-labile group. That is, in repeating unit A3-1, at least one of the phenolic hydroxyl groups bonded to the aromatic ring is protected by an acid-labile group, or at least one of the carboxyl groups bonded to the aromatic ring is protected by an acid-labile group. The acid-labile groups used in many known chemically amplified positive resist compositions, which dissociate in response to acid to provide an acidic group, can be used without particular limitation.

[0238] Preferred examples of the acid-labile group represented by X include groups represented by the following formula (X-1).

[0239] [Chemistry 50]

[0240]

[0241] In the formula, * represents the atomic bond with the adjacent -O-.

[0242] In formula (X-1), R L1 、R L2 and R L3 are each independently a hydrocarbon group having 1 to 10 carbon atoms. L1 、R L2 and R L3 Any two of them may also be bonded to each other and form a ring together with the carbon atoms to which they are bonded. Examples of the ring formed in this case include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a norbornane ring, and an adamantane ring. b6 is 0 or 1, preferably 0.

[0243] Specific examples of the group represented by formula (X-1) include the following, but are not limited thereto: In the following formula, * represents an atomic bond with the adjacent -O-.

[0244] [Chemistry 51]

[0245]

[0246] [Chemistry 52]

[0247]

[0248] [Chemistry 53]

[0249]

[0250] [Chemistry 54]

[0251]

[0252] [Chemistry 55]

[0253]

[0254] [Chemistry 56]

[0255]

[0256] [Chemistry 57]

[0257]

[0258] [Chemistry 58]

[0259]

[0260] [Chemistry 59]

[0261]

[0262] [Chemistry 60]

[0263]

[0264] [Chemistry 61]

[0265]

[0266] Selecting a tertiary saturated hydrocarbon group as the acid-labile group is preferred because it provides a pattern with a low LER even when forming a resist film with a thickness of, for example, 10 to 100 nm and forming a fine pattern with a line width of 45 nm or less. The tertiary alkyl group preferably has 4 to 18 carbon atoms so that the resulting monomer for polymerization can be obtained by distillation. Examples of groups bonded to the tertiary carbon atom of the tertiary saturated hydrocarbon group include saturated hydrocarbon groups having 1 to 15 carbon atoms, which may also contain oxygen-containing functional groups such as ether bonds and carbonyl groups. Groups bonded to the tertiary carbon atoms may also bond to form a ring.

[0267] The acid-labile group may be a group represented by the following formula (X-2). The group represented by formula (X-2) is often used as an acid-labile group and is a useful option for stabilizing a pattern that provides a relatively rectangular interface between the pattern and the substrate. When X is a group represented by formula (X-2), an acetal structure is formed.

[0268] [Chemistry 62]

[0269]

[0270] In formula (X-2), R L4 is a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. L5 It is a saturated hydrocarbon group having 1 to 30 carbon atoms. The saturated hydrocarbon group may be linear, branched, or cyclic. * represents an atomic bond to an adjacent -O-.

[0271] R L4 The degradable group should be appropriately selected according to the design of the acid sensitivity. For example, if the design is to ensure high stability and then decompose with a strong acid, a hydrogen atom is selected. If the design is to use high reactivity and high sensitivity to pH changes, a straight-chain alkyl group is selected. Although it also depends on the combination of the acid generator and the basic compound added to the resist composition, it is generally recommended to select a large terminal alkyl group as R. L5 , and when the solubility change caused by decomposition is large, R L4 Preferably, the carbon atom bonded to the acetal carbon is a secondary carbon atom. L4 Preferred examples include methyl, ethyl, isopropyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl, phenyl, 2,6-difluorophenyl, 4-fluorophenyl, 4-chlorophenyl, 4-bromophenyl, 4-iodophenyl, 4-trifluoromethylphenyl, 4-trifluoromethoxyphenyl, 4-methylphenyl, 4-methoxyphenyl, adamantyl, and tricyclodecyl.

[0272] R L5 Specific examples of the group represented by include the following, but are not limited thereto. In the following formula, * represents an atomic bond with the adjacent -O-.

[0273] [Chemistry 63]

[0274]

[0275] [Chemistry 64]

[0276]

[0277] The repeating unit A3-1 is preferably represented by the following formula (A3-1-1).

[0278] [Chemistry 65]

[0279]

[0280] Where R A 、R 12 , b3, b4, b5 and X are the same as above.

[0281] Specific examples of the repeating unit A3 include repeating units represented by the following formula (A3-2) (hereinafter also referred to as repeating unit A3-2). Repeating unit A3-2 is a useful option for units containing an acid-labile group, as it increases the dissolution rate of the exposed portion and thus provides good performance against line width fluctuations during development.

[0282] [Chemistry 66]

[0283]

[0284] In formula (A3-2), c1 is an integer of 0 to 2. c2 is an integer of 0 to 2. c3 is an integer of 0 to 5. c4 is an integer of 0 to 2.

[0285] In formula (A3-2), R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0286] In formula (A3-2), R 13 and R 14 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may contain a heteroatom, and R 13 With R 14 They may also bond to each other and to the carbon atoms to which they are bonded to form a ring.

[0287] In formula (A3-2), R 15 Each independently represents a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkoxy group having 1 to 5 carbon atoms.

[0288] In formula (A3-2), R 16 Each independently represents a hydrocarbon group having 1 to 10 carbon atoms which may contain a heteroatom.

[0289] In formula (A3-2), A3 is a single bond, phenylene, naphthylene or *-C(=O)-OA 31 -.A 31 It is an aliphatic hydrocarbylene group having 1 to 20 carbon atoms, a phenylene group, or a naphthylene group, and the aliphatic hydrocarbylene group may contain at least one selected from a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * is an atomic bond to a carbon atom of the main chain.

[0290] Preferred examples of repeating unit A3-2 include, but are not limited to, the following. A Same as above.

[0291] [Chemistry 67]

[0292]

[0293] Other acid-labile groups may also be groups in which the hydrogen atom of the phenolic hydroxyl group is replaced by -CH2COO- (tertiary saturated hydrocarbon group). In this case, the tertiary saturated hydrocarbon group may be the same as that used for the protection of the phenolic hydroxyl group.

[0294] The content of the repeating unit A3 is preferably 5 to 50 mol%, more preferably 10 to 30 mol%, of all the repeating units constituting the polymer. The repeating unit A3 may be used alone or in combination of two or more.

[0295] The aforementioned polymer may further contain at least one selected from the group consisting of a repeating unit represented by the following formula (A4) (hereinafter also referred to as repeating unit A4), a repeating unit represented by the following formula (A5) (hereinafter also referred to as repeating unit A5), and a repeating unit represented by the following formula (A6) (hereinafter also referred to as repeating unit A6).

[0296] [Chemistry 68]

[0297]

[0298] In formulae (A4) and (A5), d and e are each independently an integer of 0 to 4.

[0299] In formulas (A4) and (A5), R 21 and R 22 Each of the following is independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxy group, and saturated hydrocarbon carbonyloxy group may be linear, branched, or cyclic. When d is 2 or more, each R 21 They may be the same or different from each other. When e is 2 or more, each R 22 They can be the same or different from each other.

[0300] In formula (A6), f1 is 0 or 1. f2 is an integer from 0 to 2, and when 0, it represents a benzene skeleton, when 1, it represents a naphthalene skeleton, and when 2, it represents an anthracene skeleton. f3 is an integer from 0 to 5. When f2 is 0, f3 is preferably 0, 1, 2, or 3. When f2 is 1 or 2, f3 is preferably 0, 1, 2, 3, or 4.

[0301] In formula (A6), R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. 23 is a halogen atom, a trifluoromethyl group, a trifluoromethoxy group, a nitro group, a cyano group, a saturated hydrocarbon group having 1 to 20 carbon atoms, a saturated hydrocarbon oxy group having 1 to 20 carbon atoms, a saturated hydrocarbon carbonyl oxy group having 2 to 20 carbon atoms, a saturated hydrocarbon oxyhydrocarbon group having 2 to 20 carbon atoms, a saturated hydrocarbon thiohydrocarbon group having 2 to 20 carbon atoms, a saturated hydrocarbon sulfinyl group having 1 to 20 carbon atoms, or a saturated hydrocarbon sulfonyl group having 1 to 20 carbon atoms. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyl oxy group, saturated hydrocarbon oxyhydrocarbon group, saturated hydrocarbon thiohydrocarbon group, saturated hydrocarbon sulfinyl group, and saturated hydrocarbon sulfonyl group may be straight-chain, branched, or cyclic. When f3 is 2 or more, each R 23 They can be the same or different from each other.

[0302] R 23 Preferred are halogen atoms such as fluorine, chlorine, bromine, and iodine; trifluoromethyl, trifluoromethoxy, nitro, and cyano; saturated hydrocarbon groups such as methyl, ethyl, propyl, butyl, tert-butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, and structural isomers thereof; and saturated hydrocarbon oxy groups such as methoxy, ethoxy, propoxy, butoxy, tert-butoxy, pentyloxy, hexyloxy, cyclopentyloxy, and cyclohexyloxy, and structural isomers of the hydrocarbon portions thereof.

[0303] Furthermore, saturated hydrocarbon carbonyloxy groups can be easily introduced by chemical modification after polymer polymerization, allowing for fine-tuning of the base polymer's solubility in alkaline developer solutions. Examples of such saturated hydrocarbon carbonyloxy groups include methylcarbonyloxy, ethylcarbonyloxy, propylcarbonyloxy, butylcarbonyloxy, pentylcarbonyloxy, hexylcarbonyloxy, cyclopentylcarbonyloxy, cyclohexylcarbonyloxy, benzoyloxy, and structural isomers of their hydrocarbon moieties. A carbon number of 20 or less allows for an appropriate control and adjustment of the base polymer's solubility in alkaline developer solutions (primarily a reduction effect), and can suppress the generation of residues (development defects).

[0304] Among the above-mentioned preferred substituents, particularly useful substituents that are easily prepared as monomers include fluorine atom, chlorine atom, bromine atom, iodine atom, methyl group, ethyl group, methoxy group, trifluoromethyl group, trifluoromethoxy group, nitro group, and cyano group.

[0305] In formula (A6), A4 represents a single bond or a saturated alkylene group having 1 to 10 carbon atoms, wherein a portion of the -CH2- residues of the saturated alkylene group may be substituted with -O-. The saturated alkylene group may be linear, branched, or cyclic. Specific examples include alkanediyl groups having 1 to 10 carbon atoms, such as methylene, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, and their structural isomers; cyclic saturated alkylene groups having 3 to 10 carbon atoms, such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and combinations thereof. When the saturated alkylene group contains an ether bond, when f1 in formula (A6) is 1, it may be inserted at any position other than between the carbon atom at the alpha position and the carbon atom at the beta position relative to the ester oxygen atom. When f1 is 0, the atom bonded to the main chain becomes an etheric oxygen atom, and a second ether bond may be inserted at any position other than between the carbon atom at the α-position and the carbon atom at the β-position relative to the etheric oxygen atom. Furthermore, it is preferred that the carbon number of the saturated alkylene group is 10 or less, since sufficient solubility in an alkaline developer can be achieved.

[0306] f1 is 0 and A 4 When it is a single bond, that is, the aromatic ring is directly bonded to the main chain of the polymer (that is, there is no connecting group (-C(=O)-OA 4 -)), preferable examples of the repeating unit A6 include units derived from styrene, 4-chlorostyrene, 4-methylstyrene, 4-methoxystyrene, 4-bromostyrene, 4-acetoxystyrene, 2-hydroxypropylstyrene, 2-vinylnaphthalene, 3-vinylnaphthalene and the like.

[0307] Moreover, when f1 is 1 (ie, having -C(=O)-OA 4 - as a linking group), the following are examples of desirable repeating units A6, but are not limited thereto. A Same as above.

[0308] [Chemistry 69]

[0309]

[0310] [Chemistry 70]

[0311]

[0312] When at least one of the repeating units A4 to A6 is used as a constituent unit of the polymer, the etching resistance of the aromatic ring can be improved. In addition, the etching resistance due to the addition of a ring structure to the main chain and the EB irradiation resistance during pattern inspection can be improved.

[0313] To achieve improved etching resistance, the content of repeating units A4 to A6 is preferably 5 mol% or greater based on the total repeating units comprising the polymer. Furthermore, the content of repeating units A4 to A6 is preferably 35 mol% or less, and more preferably 30 mol% or less, based on the total repeating units comprising the polymer. When the polymer has no functional groups or when the functional groups are other than hydroxyl groups, an amount of 35 mol% or less is preferably introduced to avoid developing defects. Repeating units A4 to A6 may be used alone or in combination of two or more.

[0314] The polymer preferably contains repeating units A1, A2, A3-1 and / or A3-2, and at least one selected from repeating units A4 to A6, from the perspective of achieving both high etching resistance and high resolution. In this case, the content of these repeating units is preferably 60 mol% or more, more preferably 80 mol% or more, and even more preferably 100 mol% of all the repeating units constituting the polymer.

[0315] In view of etching resistance, the content of repeating units having an aromatic ring skeleton in all repeating units constituting the polymer is preferably 60 mol % or more, more preferably 80 mol % or more, and even more preferably all repeating units have an aromatic ring skeleton.

[0316] The polymer may also contain a conventional (meth)acrylate unit protected by an acid-labile group, or a (meth)acrylate unit having a lactone structure or an adhesive group such as a hydroxyl group other than a phenolic hydroxyl group. These repeating units can be used to fine-tune the properties of the resist film, but these units do not have to be present.

[0317] Examples of the (meth)acrylate unit having an adhesive group include a repeating unit represented by the following formula (A7) (hereinafter also referred to as repeating unit A7), a repeating unit represented by the following formula (A8) (hereinafter also referred to as repeating unit A8), and a repeating unit represented by the following formula (A9) (hereinafter also referred to as repeating unit A9). These units do not exhibit acidity but can be used auxiliaryly as units that provide adhesion to the substrate or units that adjust solubility.

[0318] [Chemistry 71]

[0319]

[0320] In formulas (A7) to (A9), R A R are independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. 31 is -O- or methylene. 32 is a hydrogen atom or a hydroxyl group. 33 is a saturated hydrocarbon group having 1 to 4 carbon atoms. g is an integer of 0 to 3.

[0321] When repeating units A7 to A9 are present, their content is preferably 0 to 30 mol%, more preferably 0 to 20 mol%, of all repeating units constituting the polymer. Repeating units A7 to A9 may be used alone or in combination of two or more.

[0322] The weight average molecular weight (Mw) of the aforementioned polymer is preferably 1,000 to 50,000, and more preferably 2,000 to 20,000. If Mw is 1,000 or more, there is no concern that the head of the pattern becomes rounded, the resolution is reduced, and the LER and CDU are deteriorated, as is known. On the other hand, if Mw is 50,000 or less, there is no concern that the LER and CDU are deteriorated, especially when forming a pattern with a line width of 100 nm or less. In addition, Mw in the present invention is a polystyrene-converted measurement value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or dimethylformamide (DMF) as a solvent.

[0323] The molecular weight distribution (Mw / Mn) of the polymer is preferably 1.0 to 2.2, and a narrow dispersion of 1.0 to 2.0 is particularly preferred. With such a narrow dispersion, there is no risk of foreign matter forming on the pattern after development, nor of deterioration in the pattern shape.

[0324] The method for synthesizing the aforementioned polymer includes, for example, a method in which a monomer providing the aforementioned repeating unit is placed in an organic solvent, a radical polymerization initiator is added, and the mixture is heated to polymerize.

[0325] Examples of organic solvents used in the polymerization include toluene, benzene, THF, diethyl ether, dioxane, cyclohexane, cyclopentane, methyl ethyl ketone (MEK), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), and γ-butyrolactone (GBL). Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2-azobis(2-methylpropionate), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, and lauroyl peroxide. The amount of these initiators added is preferably 0.01 to 25 mol% relative to the total amount of the monomers to be polymerized. The reaction temperature is preferably 50 to 150°C, more preferably 60 to 100°C. The reaction time is preferably 2 to 24 hours, and more preferably 2 to 12 hours from the perspective of production efficiency.

[0326] The polymerization initiator can be added to the monomer solution and supplied to the reactor, or an initiator solution different from the monomer solution can be prepared and supplied to the reactor separately. Since there is a possibility that the polymerization reaction will proceed and form an ultra-high molecular weight polymer due to free radicals generated from the initiator during the standby time, the monomer solution and the initiator solution should be prepared separately and added dropwise from the perspective of quality control. The acid-labile group can be directly introduced into the monomer, or it can be protected or partially protected after polymerization. In addition, in order to adjust the molecular weight, a well-known chain transfer agent such as dodecyl mercaptan or 2-mercaptoethanol can be used in combination. The amount of the chain transfer agent added is preferably 0.01 to 20 mol% relative to the total amount of the monomers to be polymerized.

[0327] In the case of monomers containing hydroxyl groups, the hydroxyl groups can be replaced with acetal groups such as ethoxyethoxy groups that are easily deprotected by acid during polymerization, and then deprotected using weak acid and water after polymerization. Alternatively, the hydroxyl groups can be replaced with acetyl groups, formyl groups, pivaloyl groups, etc., and then alkaline hydrolysis can be performed after polymerization.

[0328] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, hydroxystyrene or hydroxyvinylnaphthalene and other monomers can be added with a free radical polymerization initiator in an organic solvent and heated for polymerization. Alternatively, acetoxystyrene or acetoxyvinylnaphthalene can be used, and after polymerization, the acetoxy group can be deprotected by alkaline hydrolysis to obtain polyhydroxystyrene or hydroxyvinylnaphthalene.

[0329] Specific examples of the base used in alkaline hydrolysis include aqueous ammonia, triethylamine, etc. The reaction temperature is preferably -20 to 100°C, more preferably 0 to 60°C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0330] The amount of each monomer in the monomer solution may be appropriately set, for example, so as to achieve an ideal content ratio of the repeating unit.

[0331] The polymer obtained by the above-mentioned production method can be a reaction solution obtained by the polymerization reaction as the final product, or a powder obtained by a purification step such as a reprecipitation method in which the polymerization solution is added to a poor solvent to obtain a powder can be used as the final product. From the perspective of operating efficiency and quality stabilization, it is preferable to use a polymer solution obtained by dissolving the powder obtained by the purification step in a solvent as the final product.

[0332] Specific examples of the solvent used at this time include ketones such as cyclohexanone and methyl-2-n-pentyl ketone described in paragraphs

[0144] to

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

[0333] The concentration of the polymer in the polymer solution is preferably 0.01 to 30% by mass, more preferably 0.1 to 20% by mass.

[0334] The reaction solution and polymer solution are preferably filtered. Filtering can remove foreign matter and gel that may cause defects, which is effective in stabilizing quality.

[0335] The materials of the filter used in the aforementioned filtration include fluorocarbons, celluloses, nylons, polyesters, hydrocarbons, and the like. In the filtration step of the chemically amplified resist composition, a filter made of a fluorocarbon called Teflon (registered trademark), a hydrocarbon such as polyethylene or polypropylene, or nylon is preferred. The pore size of the filter can be appropriately selected according to the desired cleanliness level, preferably being 100 nm or less, and more preferably 20 nm or less. Furthermore, one of these filters may be used alone, or a combination of multiple filters may be used. The filtration method may be to pass the solution only once, but it is more preferred to circulate the solution and perform multiple filtrations. The filtration step may be performed in any order and at any number of times during the polymer production step, and it is preferred to filter the reaction solution after the polymerization reaction, the polymer solution, or both.

[0336] [Chemically amplified resist composition]

[0337] [(A) Base polymer]

[0338] The chemically amplified resist composition of the present invention contains a base polymer composed of the above-mentioned polymer as component (A).

[0339] The aforementioned base polymer may be used alone or in combination of two or more having different composition ratios, Mw, and / or Mw / Mn. When combining two or more base polymers, a polymer containing the aforementioned repeating unit A1 and a polymer containing none of the aforementioned repeating units A2, A3-1, A3-2, A4, A5, and A6 may be used. In this case, the content of the polymer containing none of the repeating units A1 is preferably 2 to 5000 parts by mass, more preferably 10 to 1000 parts by mass, relative to 100 parts by mass of the polymer containing the repeating unit A1.

[0340] In view of etching resistance, the content of repeating units having an aromatic ring skeleton in all repeating units of the base polymer is preferably 60 mol % or more, more preferably 80 mol % or more, and even more preferably all repeating units have an aromatic ring skeleton.

[0341] [(B) Quencher]

[0342] The chemically amplified positive resist composition of the present invention preferably contains a quencher (acid diffusion inhibitor) as component (B). The quencher herein refers to a material that traps the acid generated by the photoacid generator in the chemically amplified resist composition, preventing it from diffusing toward unexposed areas and thereby forming a desired pattern.

[0343] Examples of the quencher include known basic compounds. Examples of known basic compounds include primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having carboxyl groups, nitrogen-containing compounds having sulfonyl groups, nitrogen-containing compounds having hydroxyl groups, nitrogen-containing compounds having hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amides, imides, and carbamates. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Laid-Open No. 2008-111103, particularly amine compounds having a hydroxyl group, an ether bond, an ester bond, a lactone ring, a cyano group, or a sulfonate bond, and compounds having a carbamate group as described in Japanese Patent No. 3790649 are particularly preferred. Preferred examples include tris[2-(methoxymethoxy)ethyl]amine, tris[2-(methoxymethoxy)ethyl]amine-N-oxide, dibutylaminobenzoic acid, morpholine derivatives, and imidazole derivatives. By adding such a basic compound, for example, the diffusion rate of acid in the resist film can be further suppressed or the shape can be corrected.

[0344] The quencher is preferably represented by the following formula (B1).

[0345] [Chemistry 72]

[0346]

[0347] In formula (B1), R 101 、R 102 and R 103 Each is independently a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. The aforementioned hydrocarbon group may be saturated or unsaturated and may be linear, branched or cyclic. Specific examples thereof include: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl; alkyl groups having 1 to 20 carbon atoms, such as cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6 ] cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; and aryl groups having 6 to 20 carbon atoms, such as phenyl, naphthyl, and anthracenyl. Furthermore, a portion of the hydrogen atoms of the aforementioned hydrocarbon groups may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and a portion of the -CH2- of the hydrocarbon groups may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, the hydrocarbon groups may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonate bonds, carbonate bonds, carbamate bonds, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), and haloalkyl groups.

[0348] In formula (B1), k1 and k2 are each independently an integer of 0 to 5. k3 is an integer of 0 to 4. From the viewpoint of ease of synthesis and availability of raw materials, k1, k2 and k3 are each preferably 0, 1 or 2.

[0349] When k1 is 2 to 5, the two adjacent R 101 They can also bond to each other and form a ring together with the carbon atoms to which they are bonded. When k2 is 2 to 5, the two adjacent R 102 They can also bond to each other and form a ring together with the carbon atoms to which they are bonded. 103 They may also bond to each other and to the carbon atoms to which they are bonded to form a ring.

[0350] Examples of the betaine-type compound represented by formula (B1) include, but are not limited to, the following.

[0351] [Chemistry 73]

[0352]

[0353] Since the betaine-type compound is a phenoxide with a strong alkalinity relative to the anion, it exhibits excellent acid diffusion control capabilities, resulting in improved contrast. Furthermore, in the resist composition, salt exchange occurs with the sulfonium salt contained in the repeating unit A1, maintaining the solvent solubility of the base polymer containing the repeating unit A1 while preventing the formation of aggregates. Furthermore, it effectively prevents post-development defects and post-etching defects after resist patterning, and is less likely to produce aggregate defects in fine patterns, thereby providing a next-generation resist composition that combines high resolution with excellent defect suppression.

[0354] Furthermore, the aforementioned quencher may also be a weak acid betaine type compound. Specific examples thereof include, but are not limited to, the following.

[0355] [Chemistry 74]

[0356]

[0357] Examples of the quencher include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of α-unfluorinated carboxylic acids described in Japanese Patent Application Laid-Open No. 2008-158339. Sulfonic acids, imidic acids, or methylated acids fluorinated at the α-position are necessary for deprotecting acid-labile groups. Salt exchange with the α-unfluorinated onium salt releases the α-unfluorinated carboxylic acid. Since the α-unfluorinated carboxylic acid hardly undergoes a deprotection reaction, it functions as a quencher.

[0358] Examples of the onium salt of a carboxylic acid whose α-position is not fluorinated include those represented by the following formula (B2).

[0359] [Chemistry 75]

[0360]

[0361] In formula (B2), R 111 It is a hydrogen atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a heteroatom, but excludes those in which the hydrogen atom bonded to the carbon atom at the α-position of the carboxyl group is substituted by a fluorine atom or a fluoroalkyl group.

[0362] R 111 The hydrocarbon group represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples include: alkyl groups having 1 to 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6] Cyclic saturated hydrocarbon groups having 3 to 40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; alkenyl groups having 2 to 40 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 40 carbon atoms, such as cyclohexenyl; aryl groups having 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.), dialkylnaphthyl (dimethylnaphthyl, diethylnaphthyl, etc.); aralkyl groups having 7 to 40 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl, etc.

[0363] Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of the -CH2- of the hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom. As a result, the hydrocarbon group may contain a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like. Examples of the hydrocarbon group containing a heteroatom include heteroaryl groups such as thienyl; 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 pendant oxyalkyl groups such as 2-aryl-2-oxoethyl groups such as 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl; and the like.

[0364] In formula (B2), Mq A + It is an onium cation. The onium cation is preferably a sulfonium cation, an iodonium cation or an ammonium cation, and is more preferably a sulfonium cation or an iodonium cation. As an ideal example, specific examples of the compound include those described in paragraphs

[0154] to

[0182] of Japanese Patent Application Laid-Open No. 2023-091749, and it is more preferably a cation of a sulfonium salt represented by formula (A1).

[0365] Examples of the anion of the onium salt represented by formula (B2) include, but are not limited to, the following.

[0366] [Chemistry 76]

[0367]

[0368] [Chemistry 77]

[0369]

[0370] [Chemistry 78]

[0371]

[0372] As the quencher, a sulfonium salt of a carboxylic acid containing an iodinated benzene ring represented by the following formula (B3) can also be preferably used.

[0373] [Chemistry 79]

[0374]

[0375] In formula (B3), k11 is an integer of 1 to 5. k12 is an integer of 0 to 3. k13 is an integer of 1 to 3.

[0376] In formula (B3), R 121 is a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano group, a saturated hydrocarbon group having 1 to 6 carbon atoms which may contain a halogen atom, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms which may contain a halogen atom, a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms which may contain a halogen atom, a saturated hydrocarbon sulfonyloxy group having 1 to 4 carbon atoms which may contain a halogen atom, or -N(R 121A )-C(=O)-R 121B or -N(R 121A )-C(=O)-OR 121B . R 121A R is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. 121B is a saturated hydrocarbon group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbon group having 2 to 8 carbon atoms. 121 They can be the same or different.

[0377] In formula (B3), L 1 The alkyl group is a single bond or a (k13+1)-valent linking group having 1 to 20 carbon atoms, and may contain at least one selected from an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxyl group, and a carboxyl group. The saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyl oxy group, and saturated hydrocarbon sulfonyl oxy group may be linear, branched, or cyclic.

[0378] In formula (B3), R 122 、R 123 and R 124Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. Specific examples thereof include: alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, arylalkyl groups having 7 to 20 carbon atoms, etc. A part or all of the hydrogen atoms of the aforementioned hydrocarbon group may also be substituted by a hydroxyl group, a carboxyl group, a halogen atom, an oxo group, a cyano group, a nitro group, a sultone ring, a sulfo group, or a group containing a sulfonium salt, and a part of the -CH2- of the hydrocarbon group may also be substituted by an ether bond, an ester bond, a carbonyl group, an amide bond, a carbonate bond, or a sulfonate bond. In addition, R 122 and R 123 They may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. The specific structure of the sulfonium cation of the sulfonium salt represented by formula (B3) can be exemplified by those described in paragraphs

[0154] to

[0180] of JP-A-2023-91749, preferably the cation of the sulfonium salt represented by formula (A1).

[0379] Specific examples of the compound represented by formula (B3) include those described in Japanese Patent Application Laid-Open No. 2017-219836. The compound represented by formula (B3) has a high sensitization effect due to its high absorption and also has a high acid diffusion inhibitory effect.

[0380] As the quencher, a carboxylate-type compound containing a nitrogen atom represented by the following formula (B4) may be used.

[0381] [Chemistry 80]

[0382]

[0383] In formula (B4), R 131 ~R 134 are independently a hydrogen atom, -L 2 -CO2 - , or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. 131 With R 132 、R 132 With R 133 , or R 133 With R 134 They can also bond to each other and to the carbon atoms to which they are bonded to form a ring. 2 R is a single bond or a alkylene group having 1 to 20 carbon atoms which may contain a hetero atom. 135 It is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

[0384] In formula (B4), ring R r It is a ring having 2 to 6 carbon atoms and a nitrogen atom in the formula, and part or all of the hydrogen atoms bonded to the carbon atoms in the ring may be replaced by a hydrocarbon group having 1 to 20 carbon atoms, or -L2 -CO2 - The ring may be substituted, and a portion of the carbon atoms of the ring may be substituted by a sulfur atom, an oxygen atom, or a nitrogen atom. The ring may be an alicyclic ring or an aromatic ring, and preferably a 5-membered ring or a 6-membered ring. Specific examples thereof include a pyridine ring, a pyrrole ring, a pyrrolidine ring, a piperidine ring, a pyrazole ring, an imidazoline ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, an imidazoline ring, an oxazole ring, a thiazole ring, a morpholine ring, a thiazine ring, and a triazole ring.

[0385] The carboxylate salt represented by formula (B4) has at least one -L 2 -CO2 - That is, R 131 ~R 134 At least one of them is -L 2 -CO2 - and / or bonded to ring R r At least one of the hydrogen atoms of the carbon atom is replaced by -L 2 -CO2 - Replacer.

[0386] In formula (B4), Mq B + It is a sulfonium cation, an iodonium cation, or an ammonium cation, preferably a sulfonium cation. Specific examples of the sulfonium cation include those described in paragraphs

[0154] to

[0180] of JP-A-2023-91749, preferably a cation of a sulfonium salt represented by formula (A1).

[0387] Examples of the anion of the compound represented by formula (B4) include, but are not limited to, the following.

[0388] [Chemistry 81]

[0389]

[0390] [Chemistry 82]

[0391]

[0392] [Chemistry 83]

[0393]

[0394] [Chemistry 84]

[0395]

[0396] [Chemistry 85]

[0397]

[0398] [Chemistry 86]

[0399]

[0400] The aforementioned quencher further includes the polymer-type quenchers described in Japanese Patent Application Laid-Open No. 2008-239918. These quenchers improve the rectangularity of the resist pattern by aligning on the surface of the resist film. Polymer-type quenchers also have the effect of reducing film loss and doming of the pattern when using a protective film for immersion exposure.

[0401] When the chemically amplified positive resist composition of the present invention contains a quencher (B), its content is preferably 0.01 to 50 parts by mass, and more preferably 0.1 to 30 parts by mass, relative to 80 parts by mass of the base polymer (A). To inhibit acid diffusion, a quencher content of 5 parts by mass or greater, preferably 6 parts by mass or greater, and even more preferably 7 parts by mass or greater, relative to 80 parts by mass of the base polymer (A) can be used to form patterns with excellent resolution and LER. Quenchers having a betaine-type or sulfonium salt structure are particularly preferred. Quenchers (B) may be used alone or in combination of two or more.

[0402] [(C) Photoacid generator]

[0403] The chemically amplified positive resist composition of the present invention may also contain a photoacid generator as component (C). The photoacid generator is not particularly limited as long as it is a compound that generates an acid upon exposure to high-energy radiation. Preferred photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, and oxime-O-sulfonate acid generators.

[0404] Specific examples of the photoacid generator include nonafluorobutanesulfonates, partially fluorinated sulfonates described in paragraphs

[0247] to

[0251] of JP-A-2012-189977, partially fluorinated sulfonates described in paragraphs

[0261] to

[0265] of JP-A-2013-101271, those described in paragraphs

[0122] to

[0142] of JP-A-2008-111103, paragraphs

[0080] to

[0081] of JP-A-2010-215608, and fluorobenzenesulfonic acid-type photoacid generators. Among the above specific examples, arylsulfonate-type or alkanesulfonate-type photoacid generators are preferred because they generate an acid of appropriate strength when the acid-labile group of the repeating unit represented by formula (A5) is deprotected.

[0405] Such a photoacid generator is preferably an onium salt compound having an anion having the structure shown below.

[0406] [Chemistry 87]

[0407]

[0408] [Chemistry 88]

[0409]

[0410] [Chemistry 89]

[0411]

[0412] [Chemistry 90]

[0413]

[0414] [Chemistry 91]

[0415]

[0416] [Chemistry 92]

[0417]

[0418] [Chemistry 93]

[0419]

[0420] [Chemistry 94]

[0421]

[0422] [Chemistry 95]

[0423]

[0424] The photoacid generator of the component (C) is preferably an onium salt compound containing an anion represented by the following formula (C-1).

[0425] [Chemistry 96]

[0426]

[0427] In formula (C-1), m1 and m2 are each independently an integer of 0 to 2. When m1 is 0, it represents a benzene ring; when m1 is 1, it represents a naphthalene ring; and when m1 is 2, it represents an anthracene ring. From the perspective of solvent solubility, a benzene ring in which m1 is 0 is preferred. Furthermore, from the perspective of solvent solubility, m2 is preferably 0.

[0428] In formula (C-1), m3 is an integer of 1 to 5 when m1 is 0, an integer of 1 to 7 when m1 is 1, and an integer of 1 to 9 when m1 is 2. m4 is an integer of 0 to 5 when m2 is 0, an integer of 0 to 7 when m2 is 1, and an integer of 0 to 9 when m2 is 2.

[0429] In formula (C-1), L 11 It is a single bond, an ether bond, an ester bond, a sulfonate bond, an amide bond, a carbonate bond or a carbamate bond. Among them, an ether bond, an ester bond or a sulfonate bond is preferred, and a sulfonate bond is more preferred.

[0430] In formula (C-1), R 201 is an iodine atom or a branched or cyclic hydrocarbon group having 3 to 20 carbon atoms which may contain a heteroatom, and at least one R 201 Bonded to L 11 Specific examples of the aforementioned hydrocarbon groups include: isopropyl, sec-butyl, tert-butyl, tert-pentyl, cyclopentyl, cyclohexyl, 2-ethylhexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, oxa-norbornyl, tricyclo[5.2.1.0 2,6 ] aliphatic cyclic hydrocarbon groups having 3 to 20 carbon atoms, such as decyl and adamantyl; aromatic groups such as phenyl, naphthyl, anthracenyl; groups obtained by combining them, etc., but not limited thereto. In addition, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and part of the -CH2- of the hydrocarbon group may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, etc., and as a result, it may also contain hydroxyl groups, cyano groups, halogen atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl groups, etc. The aforementioned halogen atoms include: fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc., preferably fluorine atoms or iodine atoms. When m3 is 2 or more, each R 201 They can be the same or different from each other.

[0431] Moreover, when m3 is 2 or more, multiple R 201 They may also be bonded to each other and to form a ring together with the carbon atom to which they are bonded. The aforementioned ring is preferably a 5- to 8-membered ring.

[0432] In formula (C-1), R 202 It is a hydrocarbon group having 1 to 20 carbon atoms which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof include: alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6] Cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; aromatic groups having 6 to 20 carbon atoms, such as phenyl, naphthyl, and anthracenyl. In addition, part or all of the hydrogen atoms of the aforementioned hydrocarbon groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and part of the -CH2- of the hydrocarbon group may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, may contain hydroxyl groups, cyano groups, halogen atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl groups, and the like. Examples of the aforementioned halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and are preferably fluorine atoms or iodine atoms. When m4 is 2 or more, each R 202 They can be the same or different from each other.

[0433] Moreover, when m4 is 2 or more, multiple R 202 They may also be bonded to each other and to form a ring together with the carbon atom to which they are bonded. The aforementioned ring is preferably a 5- to 8-membered ring.

[0434] In formula (C-1), W 1 and the carbon atom C of the adjacent aromatic ring 1 and C 2 Together they form a ring with 3 to 15 carbon atoms, and part of the carbon atoms forming the ring may be substituted with a group containing a heteroatom. The aforementioned ring may be monocyclic or polycyclic. 2 and the carbon atom C of the adjacent aromatic ring 3 and C 4 The carbon atoms forming the ring may be 3 to 15, and part of the carbon atoms forming the ring may be substituted with a group containing a heteroatom. The ring may be monocyclic or polycyclic.

[0435] and W in formula (C-1) 1 and W 2 The structures formed by the condensation of adjacent aromatic rings are shown below, but are not limited thereto. 11 atomic bonds.

[0436] [Chemistry 97]

[0437]

[0438] R in formula (C-1) 201 The structure formed by bonding with an aromatic ring can be exemplified by the following, but is not limited thereto. 11 atomic bonds.

[0439] [Chemistry 98]

[0440]

[0441] [Chemistry 99]

[0442]

[0443] [Chemistry 100]

[0444]

[0445] [Chemistry 101]

[0446]

[0447] [Chemistry 102]

[0448]

[0449] [Chemistry 103]

[0450]

[0451] The anion represented by the formula (C-1) is preferably represented by the following formula (C-1-1).

[0452] [Chemistry 104]

[0453]

[0454] Where m2, m3, m4, L 11 、R 201 、R 202 、W 1 and W 2 Same as above.

[0455] The anion represented by formula (C-1-1) is preferably represented by the following formula (C-1-2).

[0456] [Chemistry 105]

[0457]

[0458] Where m3, m4, R 201 、R 202 and W 1 Same as above.

[0459] Particularly preferred examples of the anion represented by formula (C-1) include those shown below, but the anion is not limited thereto.

[0460] [Chemistry 106]

[0461]

[0462] [Chemistry 107]

[0463]

[0464] [Chemistry 108]

[0465]

[0466] [Chemistry 109]

[0467]

[0468] [Chemistry 110]

[0469]

[0470] [Chemistry 111]

[0471]

[0472] [Chemistry 112]

[0473]

[0474] [Chemistry 113]

[0475]

[0476] [Chemistry 114]

[0477]

[0478] [Chemistry 115]

[0479]

[0480] [Chemistry 116]

[0481]

[0482] [Chemistry 117]

[0483]

[0484] [Chemistry 118]

[0485]

[0486] [Chemistry 119]

[0487]

[0488] [Chemistry 120]

[0489]

[0490] [Chemistry 121]

[0491]

[0492] [Chemistry 122]

[0493]

[0494] [Chemistry 123]

[0495]

[0496] [Chemistry 124]

[0497]

[0498] [Chemistry 125]

[0499]

[0500] [Chemistry 126]

[0501]

[0502] [Chemistry 127]

[0503]

[0504] [Chemistry 128]

[0505]

[0506] [Chemistry 129]

[0507]

[0508] The onium salt containing the anion represented by formula (C-1) is an onium salt of a sulfonic acid not substituted by a fluorine atom, so it can generate an acid of appropriate strength upon irradiation with high-energy radiation. Furthermore, it has the following structural characteristics: a ring structure formed by further condensation of an aromatic ring bonded to the sulfonic group of the anion, and another aromatic ring structure containing a bulky substituent. Due to the steric hindrance between these two aromatic rings, the rotational freedom of the bond connecting the aromatic rings is suppressed, thereby controlling the appropriate acid diffusion of the generated acid. In addition, the onium salt of the present invention is easy to manufacture and handle because it has sufficient fat solubility. Due to these effects, an acid with controlled acid strength and diffusion can be generated in the resist film, so that a pattern with good resolution and low LER can be obtained even in fine patterns. In addition, in positive resist compositions using alkaline developers, due to the appropriate dissolution barrier properties, a pattern with good rectangularity can be obtained.

[0509] The photoacid generator of the component (C) is preferably an onium salt compound containing an anion represented by the following formula (C-2).

[0510] [Chemistry 130]

[0511]

[0512] In formula (C-2), m11 and m12 are each independently an integer of 0 to 2. m13 is an integer of 1 to 4 when m12 is 0, an integer of 1 to 6 when m12 is 1, and an integer of 1 to 8 when m12 is 2.

[0513] In formula (C-2), m14 is an integer of 0 to 3 when m12 is 0, an integer of 0 to 5 when m12 is 1, and an integer of 0 to 7 when m12 is 2. However, m13+m14 is 1 to 4 when m12 is 0, 1 to 6 when m12 is 1, and 1 to 8 when m12 is 2.

[0514] In formula (C-2), m15 is an integer of 1 to 5 when m11 is 0, an integer of 1 to 7 when m11 is 1, and an integer of 1 to 9 when m11 is 2.

[0515] In formula (C-2), R 211 are each independently an iodine atom, or a branched or cyclic hydrocarbon group having 3 to 20 carbon atoms which may contain a heteroatom, and at least one R 211 Bonded to and later described L 21 Specific examples of the aforementioned hydrocarbon group include: branched alkyl groups such as isopropyl, sec-butyl, tert-butyl, tert-pentyl, and 2-ethylhexyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, oxa-norbornyl, tricyclo[5.2.1.0 2,6 ] Cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as decyl and adamantyl; aromatic groups such as phenyl, naphthyl, anthracenyl; groups obtained by combining them, etc., but not limited thereto. In addition, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and part of the -CH2- of the hydrocarbon group may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, etc., and as a result, it may also contain hydroxyl groups, cyano groups, halogen atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl groups, etc. The aforementioned halogen atoms include: fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc., preferably fluorine atoms or iodine atoms. When m15 is 2 or more, each R 211 They can be the same or different from each other.

[0516] Moreover, when m15 is 2 or more, multiple R 211 They may also be bonded to each other and to form a ring together with the carbon atom to which they are bonded. The aforementioned ring is preferably a 5- to 8-membered ring.

[0517] R in formula (C-2)211 The structure formed by bonding with an aromatic ring can be exemplified by the following, but is not limited thereto. 21 atomic bonds.

[0518] [Chemistry 131]

[0519]

[0520] [Chemistry 132]

[0521]

[0522] [Chemistry 133]

[0523]

[0524] [Chemistry 134]

[0525]

[0526] [Chemistry 135]

[0527]

[0528] [Chemistry 136]

[0529]

[0530] [Chemistry 137]

[0531]

[0532] In formula (C-2), R 202 Each is independently a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. The aforementioned hydrocarbon group may be saturated or unsaturated and may be linear, branched or cyclic. Specific examples thereof include: alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6] Cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; aromatic groups having 6 to 20 carbon atoms, such as phenyl, naphthyl, and anthracenyl. In addition, part or all of the hydrogen atoms of the aforementioned hydrocarbon groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and part of the -CH2- of the hydrocarbon group may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, may contain hydroxyl groups, cyano groups, halogen atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl groups, and the like. Examples of the aforementioned halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and are preferably fluorine atoms or iodine atoms. When m14 is 2 or more, each R 202 They can be the same or different from each other.

[0533] Moreover, when m14 is 2 or more, multiple R 202 They may also be bonded to each other and to form a ring together with the carbon atom to which they are bonded. The aforementioned ring is preferably a 5- to 8-membered ring.

[0534] In formula (C-2), R F1 R is independently 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 thioalkoxy group having 1 to 6 carbon atoms. F1 It is preferably a fluorine atom, a trifluoromethyl group, a difluoromethyl group, a trifluoromethoxy group, a difluoromethoxy group, a trifluoromethylthio group or a difluoromethylthio group, and is more preferably a fluorine atom, a trifluoromethyl group or a trifluoromethoxy group. By containing a fluorine atom, the acid strength of the generated acid is improved, so the deprotection reaction proceeds smoothly. When m13 is 2 or more, each R F1 They can be the same or different from each other.

[0535] In formula (C-2), L 21 and L 22 Each of the following is independently a single bond, an ether bond, an ester bond, an amide bond, a sulfonate bond, a carbonate bond or a carbamate bond, wherein an ether bond, an ester bond or a sulfonate bond is preferred, and an ether bond or a sulfonate bond is more preferred.

[0536] In formula (C-2), X L A single bond or a C1-40 alkylene group which may contain a heteroatom. The alkylene group may be linear, branched, or cyclic. Specific examples thereof include alkanediyl groups and cyclic saturated alkylene groups. Specific examples of the heteroatom include oxygen atoms, nitrogen atoms, and sulfur atoms.

[0537] X L Specific examples of the alkylene group having 1 to 40 carbon atoms which may contain heteroatoms are shown below, but are not limited thereto. 21 and L 22 atomic bonds.

[0538] [Chemistry 138]

[0539]

[0540] [Chemistry 139]

[0541]

[0542] [Chemistry 140]

[0543]

[0544] [Chemistry 141]

[0545]

[0546] Among them, X L -0~X L -22 and X L -47~X L -58.

[0547] The acid generator represented by formula (C-2) is preferably represented by the following formula (C-2-1).

[0548] [Chemistry 142]

[0549]

[0550] Where, m11~m15, R 211 、R 212 、R F1 、L 21 and X L Same as above.

[0551] Specific examples of the anion represented by formula (C-2) include the following, but are not limited thereto.

[0552] [Chemistry 143]

[0553]

[0554] [Chemistry 144]

[0555]

[0556] [Chemistry 145]

[0557]

[0558] [Chemistry 146]

[0559]

[0560] [Chemistry 147]

[0561]

[0562] [Chemistry 148]

[0563]

[0564] [Chemistry 149]

[0565]

[0566] [Chemistry 150]

[0567]

[0568] [Chemistry 151]

[0569]

[0570] [Chemistry 152]

[0571]

[0572] [Chemistry 153]

[0573]

[0574] [Chemistry 154]

[0575]

[0576] [Chemistry 155]

[0577]

[0578] [Chemistry 156]

[0579]

[0580] [Chemistry 157]

[0581]

[0582] [Chemistry 158]

[0583]

[0584] [Chemistry 159]

[0585]

[0586] [Chemistry 160]

[0587]

[0588] [Chemistry 161]

[0589]

[0590] [Chemistry 162]

[0591]

[0592] [Chemistry 163]

[0593]

[0594] [Chemistry 164]

[0595]

[0596] [Chemistry 165]

[0597]

[0598] [Chemistry 166]

[0599]

[0600] [Chemistry 167]

[0601]

[0602] [Chemistry 168]

[0603]

[0604] [Chemistry 169]

[0605]

[0606] [Chemistry 170]

[0607]

[0608] [Chemistry 171]

[0609]

[0610] [Chemistry 172]

[0611]

[0612] [Chemistry 173]

[0613]

[0614] [Chemistry 174]

[0615]

[0616] Furthermore, the photoacid generator of the component (C) is preferably an onium salt compound containing an anion represented by the following formula (C-3).

[0617] [Chemistry 175]

[0618]

[0619] In formula (C-3), m21 is 1, 2 or 3. m22 is an integer of 1 to 5. m23 is an integer of 0 to 3. m24 is 0 or 1.

[0620] In formula (C-3), L 31 It is a single bond, an ether bond, an ester bond, a sulfonate bond, a carbonate bond or a carbamate bond.

[0621] In formula (C-3), L 32 It is an ether bond, an ester bond, a sulfonate bond, a carbonate bond or a carbamate bond.

[0622] In formula (C-3), L 33 When m21 is 1, it is a single bond or an alkylene group having 1 to 20 carbon atoms; when m21 is 2 or 3, it is an (m21+1)-valent hydrocarbon group having 1 to 20 carbon atoms, and the alkylene group and the (m21+1)-valent hydrocarbon group may also contain at least one selected from an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxyl group and a carboxyl group.

[0623] L 33 The alkylene group having 1 to 20 carbon atoms represented by may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include: alkanediyl groups having 1 to 20 carbon atoms, such as methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; cyclic saturated alkylene groups having 3 to 20 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norbornanediyl, and adamantanediyl; unsaturated aliphatic alkylene groups having 2 to 20 carbon atoms, such as vinylene and propylene-1,3-diyl; arylene groups having 6 to 20 carbon atoms, such as phenylene and naphthylene; and groups obtained by combining these. 33 The (m21+1)-valent hydrocarbon group having 1 to 20 carbon atoms represented by may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof include groups obtained by removing one or two hydrogen atoms from the aforementioned specific examples of the hydrocarbylene group having 1 to 20 carbon atoms.

[0624] In formula (C-3), Rf 1 and Rf 2Each independently represents a hydrogen atom, a fluorine atom or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group.

[0625] In formula (C-3), R 221 is a hydroxyl group, a carboxyl group, a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, -N(R 221A )(R 221B )、-N(R 221C )-C(=O)-R 221D or -N(R 221C )-C(=O)-OR 221D . R 221A and R 221B R is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. 221C R is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. 221D It is a saturated hydrocarbon group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbon group having 2 to 8 carbon atoms.

[0626] R 221 、R 221A 、R 221B and R 221C The saturated hydrocarbon group having 1 to 6 carbon atoms represented by may be any of linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, and n-hexyl; and cyclic saturated hydrocarbon groups having 3 to 6 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Furthermore, R 221 The saturated hydrocarbon group portion of the saturated hydrocarbon group having 1 to 6 carbon atoms represented by the alkyloxy group may be the same as the specific examples of the saturated hydrocarbon group described above, and R 221 The saturated hydrocarbon group portion of the saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms can include those having 1 to 5 carbon atoms among the specific examples of the saturated hydrocarbon groups having 1 to 6 carbon atoms.

[0627] R 221D The unsaturated aliphatic hydrocarbon group having 2 to 8 carbon atoms represented by ] may be any of linear, branched, and cyclic, and specific examples thereof include: alkenyl groups having 2 to 8 carbon atoms, such as ethenyl, propenyl, butenyl, and hexenyl; alkynyl groups having 2 to 8 carbon atoms, such as ethynyl, propynyl, and butynyl; and cyclic unsaturated aliphatic hydrocarbon groups having 3 to 8 carbon atoms, such as cyclohexenyl and norbornyl.

[0628] In formula (C-3), R 222It is a saturated hydrocarbylene group having 1 to 20 carbon atoms or an arylene group having 6 to 20 carbon atoms, and some or all of the hydrogen atoms of the saturated hydrocarbylene group may be substituted by halogen atoms other than fluorine atoms, and some or all of the hydrogen atoms of the arylene group may be substituted by a substituent selected from a saturated hydrocarbylene group having 1 to 20 carbon atoms, a saturated hydrocarbyloxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogen atom and a hydroxyl group.

[0629] R 222 The alkylene group having 1 to 20 carbon atoms represented by may be saturated or unsaturated and may be linear, branched or cyclic. Specific examples thereof include and are exemplified as L 33 The same examples apply to the alkylene groups having 1 to 20 carbon atoms.

[0630] R 222 Specific examples of the arylene group having 6 to 20 carbon atoms include phenylene, naphthylene, phenanthrenediyl, and anthracenediyl. The substituents of the arylene group, i.e., the saturated hydrocarbon group having 1 to 20 carbon atoms and the hydrocarbon group portion of the hydrocarbonoxy group having 1 to 20 carbon atoms, may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl; and cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl. Specific examples of the arylene group having 6 to 14 carbon atoms as a substituent of the arylene group include phenylene, naphthylene, phenanthrenediyl, anthracenediyl, and the like.

[0631] The anion represented by the formula (C-3) is preferably an anion represented by the following formula (C-3-1).

[0632] [Chemistry 176]

[0633]

[0634] In formula (C-3-1), m21, m22, m23, L 31 、L 33 and R 221 Same as above. m25 is an integer from 1 to 4. 223 is a saturated hydrocarbon group having 1 to 20 carbon atoms, a saturated hydrocarbon oxy group having 1 to 20 carbon atoms, an aryl group having 6 to 14 carbon atoms, a halogen atom or a hydroxyl group. 223 They can be the same or different from each other.

[0635] Examples of the anion represented by formula (C-3) include, but are not limited to, the following.

[0636] [Chemistry 177]

[0637]

[0638] [Chemistry 178]

[0639]

[0640] [Chemistry 179]

[0641]

[0642] [Chemistry 180]

[0643]

[0644] [Chemistry 181]

[0645]

[0646] [Chemistry 182]

[0647]

[0648] [Chemistry 183]

[0649]

[0650] [Chemistry 184]

[0651]

[0652] [Chemistry 185]

[0653]

[0654] [Chemistry 186]

[0655]

[0656] [Chemistry 187]

[0657]

[0658] [Chemistry 188]

[0659]

[0660] [Chemistry 189]

[0661]

[0662] [Chemistry 190]

[0663]

[0664] [Chemistry 191]

[0665]

[0666] [Chemistry 192]

[0667]

[0668] [Chemistry 193]

[0669]

[0670] [Chemistry 194]

[0671]

[0672] [Chemistry 195]

[0673]

[0674] [Chemistry 196]

[0675]

[0676] [Chemistry 197]

[0677]

[0678] [Chemistry 198]

[0679]

[0680] [Chemistry 199]

[0681]

[0682] [Chemistry 200]

[0683]

[0684] [Chemistry 201]

[0685]

[0686] [Chemistry 202]

[0687]

[0688] [Chemistry 203]

[0689]

[0690] [Chemistry 204]

[0691]

[0692] The cation forming a pair with the anion of the onium salt is an onium cation. The onium cation is preferably a sulfonium cation, an iodonium cation, or an ammonium cation, and is more preferably a sulfonium cation or an iodonium cation. Preferred examples include those described in paragraphs

[0154] to

[0182] of JP-A-2023-91749, and the cation of the sulfonium salt represented by formula (A1) is particularly preferred.

[0693] When the chemically amplified positive resist composition of the present invention contains both an acid generator (component (C)) and a quencher (component (B), the ratio (C) / (B) of the photoacid generator to the quencher is preferably less than 6, more preferably less than 4, even more preferably less than 2, and even more preferably less than 1, by mass. When the ratio of the acid generator to the quencher in the chemically amplified positive resist composition is within the above range, acid diffusion can be sufficiently suppressed, and excellent resolution and dimensional uniformity can be achieved.

[0694] [(D) Fluorine-containing polymer]

[0695] The chemically amplified positive resist composition of the present invention may contain, as component (D), a fluorine-containing polymer comprising at least one member selected from the group consisting of a repeating unit represented by the following formula (D1) (hereinafter also referred to as repeating unit D1), a repeating unit represented by the following formula (D2) (hereinafter also referred to as repeating unit D2), a repeating unit represented by the following formula (D3) (hereinafter also referred to as repeating unit D3), and a repeating unit represented by the following formula (D4) (hereinafter also referred to as repeating unit D4), and further comprising at least one member selected from the group consisting of a repeating unit represented by the following formula (D5) (hereinafter also referred to as repeating unit D5) and a repeating unit represented by the following formula (D6) (hereinafter also referred to as repeating unit D6), for the purpose of achieving high contrast, suppressing acid chemical flare during high-energy ray irradiation, shielding acid from mixing with the antistatic film during the process of coating the antistatic film material on the resist film, and suppressing unintended unnecessary pattern degradation. Since the fluorine-containing polymer also functions as a surfactant, it can prevent insoluble matter that may be generated during the development process from re-adhering to the substrate, thereby also having an effect on preventing development defects.

[0696] [Chemistry 205]

[0697]

[0698] In formulas (D1) to (D6), x is an integer of 1 to 3. y is an integer satisfying 0≤y≤5+2z-x. z is 0 or 1. h is an integer of 1 to 3. R B R are independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Care independently a hydrogen atom or a methyl group. 301 、R 302 、R 304 and R 305 R are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. 303 、R 306 、R 307 and R 308 are independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, a fluorinated hydrocarbon group having 1 to 15 carbon atoms, or an acid-labile group, and R 303 、R 306 、R 307 and R 308 When it is a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond or a carbonyl group may be inserted between carbon-carbon bonds. 309 R is a hydrogen atom or a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may have a heteroatom-containing group inserted between carbon-carbon bonds. 310 It is a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may have a heteroatom-containing group inserted between carbon-carbon bonds. 311 It is a saturated hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted by a fluorine atom, and a portion of the -CH2- in the saturated hydrocarbon group may be substituted by an ester bond or an ether bond. 1 Z is a (h+1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (h+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms. 2 is a single bond, *-C(=O)-O- or *-C(=O)-NH-. * is an atomic bond to a carbon atom of the main chain. Z 3 is a single bond, -O-, *-C(=O)-OZ 31 -Z 32 - or *-C(=O)-NH-Z 31 -Z 32 -.Z 31 Z is a single bond or a saturated alkylene group having 1 to 10 carbon atoms. 32 is a single bond, ester bond, ether bond or sulfonamide bond. * is an atomic bond to a carbon atom of the main chain.

[0699] In formulas (D1) and (D2), R 301 、R 302 、R 304 and R 305 The saturated hydrocarbon group having 1 to 10 carbon atoms represented by may be linear, branched, or cyclic. Specific examples include alkyl groups having 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 having 3 to 10 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornyl. Among these, saturated hydrocarbon groups having 1 to 6 carbon atoms are preferred.

[0700] In formulas (D1) to (D4), R 303 、R 306 、R 307 and R 308 The hydrocarbon group having 1 to 15 carbon atoms may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 15 carbon atoms, alkenyl groups having 2 to 15 carbon atoms, and alkynyl groups having 2 to 15 carbon atoms. Alkyl groups having 1 to 15 carbon atoms are preferred. Examples of the aforementioned alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, and n-pentadecyl. Fluorinated hydrocarbon groups include those in which some or all of the hydrogen atoms bonded to the carbon atoms of the aforementioned hydrocarbon groups are substituted with fluorine atoms.

[0701] In formula (D4), Z 1 The (h+1)-valent hydrocarbon group having 1 to 20 carbon atoms represented by can be exemplified by removing h hydrogen atoms from an alkyl group having 1 to 20 carbon atoms or a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. 1 Examples of the (h+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by include groups in which at least one hydrogen atom in the aforementioned (h+1)-valent hydrocarbon group is substituted with a fluorine atom.

[0702] Specific examples of repeating units D1 to D4 include the following, but are not limited thereto. B Same as above.

[0703] [Chemistry 206]

[0704]

[0705] [Chemistry 207]

[0706]

[0707] [Chemistry 208]

[0708]

[0709] In formula (D5), R 309 and R 310 Examples of the hydrocarbon group having 1 to 5 carbon atoms represented by include alkyl, alkenyl, and alkynyl groups, preferably alkyl groups. Examples of the aforementioned alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and n-pentyl groups. Furthermore, groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms may be inserted between carbon-carbon bonds of the aforementioned hydrocarbon groups.

[0710] In formula (D5), -OR 309It is preferably a hydrophilic group. 309 Preferred are hydrogen atoms, alkyl groups having 1 to 5 carbon atoms with an oxygen atom inserted between carbon-carbon bonds, and the like.

[0711] In formula (D5), Z 2 It is preferably *-C(=O)-O- or *-C(=O)-NH-. In addition, R C Preferably it is methyl. 2 The presence of carbonyl groups improves the ability of the antistatic film to capture acid. C Methyl groups form a rigid polymer with a higher glass transition temperature (Tg), which inhibits acid diffusion. This results in a resist film with good stability over time, without deteriorating resolution or pattern shape.

[0712] The repeating unit D5 may be exemplified by the following, but is not limited thereto. C Same as above.

[0713] [Chemistry 209]

[0714]

[0715] [Chemistry 210]

[0716]

[0717] In formula (D6), Z 3 The saturated alkylene group having 1 to 10 carbon atoms may be linear, branched, or cyclic. Specific examples thereof include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, propane-2,2-diyl, butane-1,1-diyl, butane-1,2-diyl, butane-1,3-diyl, butane-2,3-diyl, butane-1,4-diyl, and 1,1-dimethylethane-1,2-diyl.

[0718] In formula (D6), R 311 The saturated hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom may be any of linear, branched, and cyclic. Specific examples thereof include an alkyl group having 1 to 20 carbon atoms or a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom.

[0719] The repeating unit D6 may be exemplified by the following, but is not limited thereto. C Same as above.

[0720] [Chemistry 211]

[0721]

[0722] [Chemistry 212]

[0723]

[0724] [Chemistry 213]

[0725]

[0726] [Chemistry 214]

[0727]

[0728] The content of repeating units D1 to D4 is preferably 15 to 95 mol%, more preferably 20 to 85 mol%, of the total repeating units of the fluorine-containing polymer. The content of repeating units D5 and / or D6 is preferably 5 to 85 mol%, more preferably 15 to 80 mol%, of the total repeating units of the fluorine-containing polymer. Repeating units D1 to D6 may be used alone or in combination of two or more.

[0729] The fluorine-containing polymer may contain other repeating units in addition to the aforementioned repeating units. Examples of such repeating units include those described in paragraphs

[0046] to

[0078] of JP-A-2014-177407. When the fluorine-containing polymer contains other repeating units, the content of such other repeating units is preferably 50 mol% or less of the total repeating units of the fluorine-containing polymer.

[0730] The fluorine-containing polymers can be synthesized by copolymerizing monomers protected with protecting groups, as needed, using known methods, followed by deprotection reactions as needed. The copolymerization reaction is not particularly limited, but is preferably free radical polymerization or anionic polymerization. These methods can be found in Japanese Patent Application Laid-Open No. 2004-115630.

[0731] The Mw of the fluorine-containing polymer is preferably 2,000 to 50,000, more preferably 3,000 to 20,000. An Mw of less than 2,000 may promote acid diffusion, degrade resolution, or impair stability over time. Excessively high Mw may reduce solubility in solvents and cause coating defects. Furthermore, the Mw / Mn ratio of the fluorine-containing polymer is preferably 1.0 to 2.2, more preferably 1.0 to 1.7.

[0732] When the chemically amplified positive resist composition of the present invention contains a fluorine-containing polymer (D), its content is preferably 0.01 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 0.5 to 10 parts by mass, relative to 80 parts by mass of the base polymer (A). The fluorine-containing polymer (D) may be used alone or in combination of two or more.

[0733] [(E) Organic solvent]

[0734] The chemically amplified positive resist composition of the present invention may also contain an organic solvent as the (E) component. The aforementioned organic solvent is not particularly limited as long as it can dissolve the various components. Examples of such organic solvents include: ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone as described in paragraphs

[0144] to

[0145] of Japanese Patent Application Laid-Open No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; propylene glycol monomethyl ether (PGME), ethylene glycol monomethyl ether (PGME), and propylene glycol monomethyl ether (PGME). 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 an acetal-based acid-labile group, a high-boiling alcohol solvent may be added to accelerate the deprotection reaction of the acetal. Specifically, diethylene glycol, propylene glycol, glycerol, 1,4-butanediol, 1,3-butanediol, diacetone alcohol, and the like may be added.

[0735] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, diacetone alcohol, and mixed solvents thereof are preferred.

[0736] When the chemically amplified positive resist composition of the present invention contains (E) an organic solvent, its content is preferably 200 to 10,000 parts by mass, more preferably 400 to 5,000 parts by mass, relative to 80 parts by mass of the base polymer (A). The organic solvent (E) may be used alone or as a mixture of two or more.

[0737] [(F) Surfactant]

[0738] The chemically amplified positive resist composition of the present invention may also contain a conventional surfactant to improve coating properties on substrates. Many of these surfactants are known, as described in Japanese Patent Application Laid-Open No. 2004-115630, and can be selected with reference to these examples. When the chemically amplified positive resist composition of the present invention contains a surfactant (F), its content is preferably 0 to 5 parts by mass relative to 80 parts by mass of the base polymer (A). The surfactants (F) may be used alone or in combination of two or more.

[0739] [Resist Pattern Formation Method]

[0740] The resist pattern forming method of the present invention comprises the following steps:

[0741] Using the chemically amplified positive resist composition to form a resist film on a substrate,

[0742] irradiating the resist film with a pattern of high-energy rays (i.e., exposing the resist film with high-energy rays), and

[0743] The resist film having the irradiated pattern is developed using an alkaline developer.

[0744] The substrate may be, for example, a substrate used in integrated circuit manufacturing (e.g., Si, SiO, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective film), or a substrate used in transmissive or reflective mask circuit manufacturing (e.g., Cr, CrO, CrON, MoSi2, Si, SiO, SiO2, SiON, SiONC, CoTa, NiTa, TaBN, SnO2). The chemically amplified positive resist composition is applied to the substrate by spin coating or other methods to a film thickness of 0.03 to 2 μm, and then pre-baked on a hot plate at preferably 60 to 150° C. for 1 to 20 minutes, more preferably 80 to 140° C. for 1 to 10 minutes, to form a resist film.

[0745] The resist film is then exposed to high-energy radiation to create a pattern. Examples of such high-energy radiation include ultraviolet rays, extreme ultraviolet rays, excimer lasers (such as KrF and ArF), EUV radiation, X-rays, gamma rays, synchrotron radiation, and EB radiation. In the present invention, EUV radiation or EB radiation is preferably used for exposure.

[0746] When ultraviolet rays, extreme ultraviolet rays, excimer lasers, EUV rays, X-rays, gamma rays or synchrotron radiation are used as the high energy radiation, a mask for forming a target pattern is used and the exposure dose is preferably 1 to 500 mJ / cm 2 More preferably, it is 10 to 400 mJ / cm 2When using EB, in order to form the target pattern, the exposure dose should be 1 to 500 μC / cm 2 More preferably, it is 10 to 450 μC / cm 2 More preferably, it is 100 to 400 μC / cm 2 The best range is 150 to 400 μC / cm 2 way of irradiation.

[0747] Exposure can be performed by a conventional exposure method or by a wetting method between a wetting mask and a resist film, depending on the situation. In this case, a water-insoluble protective film can also be used.

[0748] Then, a post-exposure bake (PEB) is performed on a hot plate at preferably 60-150° C. for 1-20 minutes, more preferably 80-140° C. for 1-10 minutes.

[0749] Thereafter, a developer containing 0.1 to 5% by mass, preferably 2 to 3% by mass, of an alkaline aqueous solution of tetramethylammonium hydroxide (TMAH) is used, and development is performed using a common method such as a dip method, a puddle method, or a spray method for preferably 0.1 to 3 minutes, and more preferably 0.5 to 2 minutes, thereby forming a desired pattern on the substrate.

[0750] In addition, the chemically amplified positive resist composition of the present invention is particularly useful in forming patterns with good resolution and low LER. Furthermore, the chemically amplified positive resist composition of the present invention is particularly useful in forming patterns on substrates whose surfaces have a material that is difficult to obtain adhesiveness of the resist pattern, which easily causes pattern peeling and pattern collapse. Examples of such substrates include substrates having a film of metallic chromium or a chromium compound containing one or more light elements selected from oxygen, nitrogen, and carbon sputtered on the outermost surface, and substrates containing SiO, SiO x , 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 for patterning using a blank photomask as a substrate. In this case, the blank photomask can be either transmissive or reflective.

[0751] Regarding transmissive mask blanks, those having a light-shielding film made of a chromium-based material can be used for either binary or phase-shift masks. Binary mask blanks can include an antireflection layer and a light-shielding layer made of a chromium-based material as the light-shielding film. Alternatively, the entire surface-side antireflection film may be made of a chromium-based material, or only the outermost layer of the surface-side antireflection film may be made of a chromium-based material, with the remainder being made of, for example, a silicon-based compound material that may also contain a transition metal. Furthermore, phase-shift mask blanks can include those having a chromium-based light-shielding film on a phase-shift film.

[0752] The aforementioned blank photomask having a chromium-based material as the outermost layer is already well known as the known current technology as exemplified in Japanese Patent Publication No. 2008-26500, Japanese Patent Publication No. 2007-302873 or therein, and detailed description thereof is omitted. For example, when a shading film having an anti-reflection layer and a shading layer is formed using a chromium-based material, a film structure as described below can be used.

[0753] When using chromium-based materials to form a light-shielding film having an antireflection layer and a light-shielding layer, the layer structure can be stacked sequentially from the surface side, or it can be stacked sequentially. Furthermore, the antireflection layer and the light-shielding layer can each be multiple layers, and the composition of the layers can vary discontinuously or continuously. Chromium-based materials can include metallic chromium and materials containing light elements such as oxygen, nitrogen, and carbon. Specifically, metallic chromium, chromium oxide, chromium nitride, chromium carbide, chromium nitride oxide, chromium carbide oxide, chromium carbide nitride, and chromium carbide oxide nitride.

[0754] A reflective mask blank comprises a substrate, a multilayer reflective film formed on one main surface (the outer surface) 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. A reflective mask (EUV reflective mask) having an absorber pattern (absorber film pattern) formed by patterning the absorber film is manufactured from the reflective mask blank (EUV reflective mask blank). The EUV light used in EUV lithography has a wavelength of 13 to 14 nm, typically approximately 13.5 nm.

[0755] The multilayer reflective film is typically preferably provided in contact with one of the main surfaces of the substrate. However, a base film may be provided between the substrate and the multilayer reflective film as long as the effects of the present invention are not impaired. The absorber film may be formed in contact with the multilayer reflective film, or a protective film (a protective film for the multilayer reflective film) may be provided between the multilayer reflective film and the absorber film, preferably in contact with the multilayer reflective film. More preferably, the protective film (a protective film for the multilayer reflective film) is provided in contact with both the multilayer reflective film and the absorber film. The protective film can be used to protect the multilayer reflective film during processing such as cleaning and correction. 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 used for electrostatically clamping a reflective mask to an exposure apparatus may be provided on the other main surface (the inner surface) of the substrate, which is the surface opposite to the one main surface, preferably in contact with the other main surface. In addition, here, one main surface of the substrate is defined as the surface on the outer surface side and the upper side, and the other main surface is defined as the surface on the inner surface side and the lower side, but the outer surface, inner surface, and upper and lower sides of the two are defined for convenience of explanation. The one main surface and the other main surface can be either of the two main surfaces (film-forming surfaces) of the substrate, and the outer surface, inner surface, and upper and lower sides can be interchangeable. More specifically, it can be formed using a method as known in the art as exemplified in Japanese Patent Application Laid-Open No. 2021-139970 or the like.

[0756] According to the resist pattern forming method of the present invention, even when using a substrate (such as a transmission or reflection type blank mask) whose outermost surface is made of a material that is easily affected by the shape of the resist pattern, such as a material containing chromium, silicon or tantalum, a pattern with extremely high resolution, small LER, excellent rectangularity and excellent pattern fidelity can still be obtained.

[0757] [Example]

[0758] Hereinafter, the present invention will be specifically described with reference to synthesis examples, embodiments and comparative examples, but the present invention is not limited to the following embodiments. In addition, copolymerization composition ratios are molar ratios, and Mw is a polystyrene conversion measurement value obtained by GPC. In addition, the apparatus used is as follows.

[0759] IR: NICOLET 6700 manufactured by Thermo Fisher Scientific

[0760] · 1 H-NMR: ECA-500 manufactured by JEOL Ltd.

[0761] MALDI TOF-MS: S3000 manufactured by JEOL Ltd.

[0762] [1] Synthesis of onium salt monomers

[0763] [Example 1-1] Synthesis of monomer PM-1

[0764] (1) Synthesis of intermediate In-1

[0765] [Chemistry 215]

[0766]

[0767] Under a nitrogen environment, a Grignard reagent was prepared from magnesium (109.4 g), THF (2250 g) and raw material M-1 (1084.6 g). The reaction system was cooled to below 10°C, and a solution consisting of diphenyl sulfoxide (303.4 g) and dichloromethane (1500 g) was added. After the addition, chlorotrimethylsilane (678.2 g) was added dropwise while maintaining the internal temperature below 20°C. After the addition, the mixture was aged for 2 hours at an internal temperature below 20°C. After the aging, the reaction system was cooled, and an aqueous solution consisting of 36% by mass hydrochloric acid (150 g) and water (2250 g) was added dropwise to stop the reaction. Thereafter, diisopropyl ether (2100 g) and water (4500 g) were added and the aqueous layer was separated and extracted. In addition, the separated and extracted aqueous layer was washed twice with diisopropyl ether (1950 g). The washed aqueous layer was directly used in the next step.

[0768] (2) Synthesis of monomer PM-1

[0769] [Chemistry 216]

[0770]

[0771] Under a nitrogen atmosphere, an aqueous solution of intermediate In-1 (537.0 g), intermediate In-2 (45.3 g), and dichloromethane (300 g) were added and stirred at room temperature for 30 minutes. The organic layer was separated, washed with water, and then concentrated under reduced pressure to obtain PM-1 as an oil (yield 95.2 g, 90%).

[0772] The IR spectrum data and TOF-MS results of the monomer PM-1 are shown below. 1 The results of H-NMR / DMSO-d6) are as follows Figure 1 shown.

[0773] IR(D-ATR): ν=3456,3058,1629,1584,1492,1478,1447,1398,1258,1213,11 21,1107,1070,1033,1010,924,845,809,750,733,674,581,555,530,503cm -1 .

[0774] MALDI TOF-MS:POSITIVE M + 347 (equivalent to C 19 H 14 F3OS + )

[0775] NEGATIVE M - 183 (equivalent to C8H7O3S - )

[0776] [2] Synthesis of polymers

[0777] [Example 1-2] Synthesis of polymer P-1

[0778] Under a nitrogen atmosphere, 52.2 g of 3-acetoxystyrene, 31.4 g of 4-(1-methyl-1-cyclopentyloxy)styrene, 16.5 g of PM-1, 11.4 g of V-601 (Fuji Film Wako Pure Chemical Industries, Ltd.), and 120 g of PGME were weighed into a flask to prepare a monomer-polymerization initiator solution. 60 g of PGME was weighed into another flask, which had been adjusted to a nitrogen atmosphere. After heating to 80°C with stirring, the monomer-polymerization initiator solution was added dropwise over 4 hours. After the addition was completed, the polymerization solution was maintained at 80°C with continuous stirring for 18 hours, then cooled to room temperature. The resulting polymerization solution was added dropwise to 5000 g of a stirred MeOH / H₂O mixed solution, and the precipitated polymer was filtered. The resulting polymer was washed twice with 1000 g of the MeOH / H₂O mixed solution and then vacuum-dried at 40°C for 20 hours to obtain 85.2 g of polymer P-1 as a white powder. Polymer P-1 13 C-NMR, 1 When measured by H-NMR and GPC, the following analysis results were obtained: Mw is a polystyrene-equivalent measurement value obtained by GPC using DMF as a solvent.

[0779] [Chemistry 217]

[0780]

[0781] [Examples 1-2 to 1-75] Synthesis of polymers P-2 to P-75

[0782] Polymers P-2 to P-75 shown in Tables 1 to 3 below were synthesized in the same manner as in Example 1-2, except that the types and blending ratios of the monomers were changed. In Tables 1 to 3, the introduction ratios represent molar ratios. The repeating units represented by PP-1 to PP-16 are represented as polymer units by monomers synthesized in the same manner as in Example 1-1.

[0783] [Table 1]

[0784]

[0785]

[0786] [Table 2]

[0787]

[0788] [Table 3]

[0789]

[0790] The structure of the repeating unit introduced into the polymer is shown below.

[0791] [Chemistry 218]

[0792]

[0793] [Chemistry 219]

[0794]

[0795] [Chemistry 220]

[0796]

[0797] [Chemistry 221]

[0798]

[0799] [Chemistry 222]

[0800]

[0801] [Chemistry 223]

[0802]

[0803] [Chemistry 224]

[0804]

[0805] [Chemistry 225]

[0806]

[0807] [Chemistry 226]

[0808]

[0809] [Chemistry 227]

[0810]

[0811] The dissolution rates of the aforementioned polymers in an alkaline developer were determined by spin-coating a polymer solution (polymer concentration: 16.7% by mass, solvent: PGME) onto an 8-inch silicon wafer, baking the solution at 100°C for 90 seconds to form a 1000 nm thick film, then developing the film with a 2.38% by mass TMAH aqueous solution at 23°C for 100 seconds, and measuring the film loss. The results showed that the dissolution rates of polymers P-1 to P-75 were 10 nm / min or less.

[0812] [Synthesis Examples 1-1 to 1-16, Comparative Examples 1-1 to 1-4] Synthesis of Polymers AP-1 to AP-16 and Polymers cP-1 to cP-4

[0813] Except for changing the raw material compounds, the same method as in Example 1-2 was used to synthesize the following polymers AP-1 to AP-16 and comparative polymers cP-1 to cP-4.

[0814] [Chemistry 228]

[0815]

[0816] [Chemistry 229]

[0817]

[0818] [Chemistry 230]

[0819]

[0820] [Chemistry 231]

[0821]

[0822] [Chemistry 232]

[0823]

[0824] The dissolution rates of polymers AP-1 to AP-16 and comparative polymers cP-1 to cP-4 were 10 nm / min or less.

[0825] [2] Preparation of chemically amplified positive resist compositions

[0826] [Examples 2-1 to 2-111, Comparative Examples 2-1 to 2-5]

[0827] Chemically amplified positive resist compositions were prepared by dissolving the components shown in Tables 4-8 below in an organic solvent. The resulting solution was filtered through a 5 nm nylon filter and a sub-1 nm UPE filter. The organic solvent was either 920 parts by mass of PGMEA and 1850 parts by mass of EL, or a mixed solvent of 1850 parts by mass of diacetone alcohol and 1850 parts by mass of PGME.

[0828] [Table 4]

[0829]

[0830]

[0831] [Table 5]

[0832]

[0833] [Table 6]

[0834]

[0835] [Table 7]

[0836]

[0837]

[0838] [Table 8]

[0839]

[0840] In addition, in Tables 4 to 8, the structures of quenchers Q-1 to Q-6, photoacid generators PAG-1 to PAG-6, and polymers D-1 to D-5 are as follows.

[0841] [Chemistry 233]

[0842]

[0843] [Chemistry 234]

[0844]

[0845] [Chemistry 235]

[0846]

[0847] [3]EB lithography evaluation

[0848] [Examples 3-1 to 3-111, Comparative Examples 3-1 to 3-5]

[0849] Each chemically amplified positive resist composition (R-1 to R-111, CR-1 to CR-5) was spin-coated using ACT-M (manufactured by Tokyo Electron Co., Ltd.) onto a 152 mm square reflective blank for EUV exposure, whose outermost surface was a chromium compound. The film was pre-baked on a hot plate at 110°C for 600 seconds to produce a resist film with a thickness of 80 nm. The thickness of the resulting resist film was measured using an optical measuring instrument, NANOSPEC (manufactured by Nanometrics). Measurements were taken at 81 locations within the surface of the blank substrate, excluding the outer edge from the periphery to within 10 mm, and the average film thickness and film thickness range were calculated.

[0850] Then, exposure was performed using an electron beam exposure apparatus (EBM-5000plus manufactured by NuFlare Technology Co., Ltd., accelerating voltage 50 kV), PEB was applied at 110° C. for 600 seconds, and development was performed with a 2.38 mass % TMAH aqueous solution to obtain a positive pattern.

[0851] The obtained resist pattern was evaluated as follows. The blank mask with the pattern was observed with an aerial SEM (scanning electron microscope), and the exposure dose that allowed a 1:1 resolution of 200 nm line and space (LS) was determined as the optimum exposure dose (μC / cm 2 ), and the minimum dimension within the exposure dose that allowed resolution of 200 nm LS at a 1:1 ratio was defined as the resolution (limiting resolution). The LER of the 200 nm LS was measured using an SEM. The limiting resolution of the isolated spacing (IS) was defined as the minimum dimension within the exposure dose that allowed resolution of 200 nm line-space (LS) at a 9:1 ratio. The rectangular shape of the pattern was visually determined. The results are shown in Tables 9 to 13.

[0852] [Table 9]

[0853]

[0854]

[0855] [Table 10]

[0856]

[0857]

[0858] [Table 11]

[0859]

[0860]

[0861] [Table 12]

[0862]

[0863] [Table 13]

[0864]

[0865]

[0866] [4] Etching resistance evaluation

[0867] [Examples 4-1 to 4-3, Comparative Examples 4-1 to 4-2]

[0868] Each chemically amplified positive resist composition (R-8, R-9, CR-4, CR-5) was spin-coated on a 152 mm square reflective blank mask for EUV exposure mask with a chromium compound as the outermost surface using ACT-M (manufactured by Tokyo Electron Co., Ltd.), and pre-baked at 110°C for 600 seconds on a hot plate to obtain a resist film with a thickness of 120 nm. The film thickness of the obtained resist film was measured using an optical measuring instrument NANOSPEC (manufactured by Nanometrics). The measurement was performed at 81 positions within the surface of the blank substrate excluding the outer edge portion from the periphery to the inner side of 10 mm, and the average film thickness and the film thickness range were calculated. The obtained coated substrate was dry-etched using a dry etching device (UNAXIS G4) under the following conditions, and the film loss rate (A / sec) derived from the film remaining after etching was calculated. The results are shown in Table 14.

[0869] RF1(RIE): Pulse 700V

[0870] RF2(ICP): CW 400W

[0871] Pressure: 6mTorr

[0872] Cl2: 185sccm

[0873] O2: 55sccm

[0874] He: 9.25 sccm

[0875] Etching time: 75 seconds

[0876] [Table 14]

[0877]

[0878]

[0879] The chemically amplified positive resist compositions (R-1 to R-111) of the present invention all exhibited good resolution, LER, and pattern rectangularity. On the other hand, among the comparative resist compositions (CR-1 to CR-5), CR-2 and CR-3 had low solubility in the resist solvent, and even the resist itself could not be prepared. CR-1, CR-4, and CR-5 were not sufficiently optimized for acid diffusion, and degradation was observed in resolution, LER, and pattern rectangularity. Furthermore, in dry etching evaluations using R-8, R-63, and R-64, the etching resistance was still better than that of CR-4 and CR-5, suggesting that the presence of the skeleton of formula (A1) of the present invention in the polymer is effective in mask processing.

[0880] The resist pattern forming method using the chemically amplified positive resist composition of the present invention is useful in semiconductor device manufacturing, particularly in optical lithography in the processing of transmissive and reflective photomask blanks.

Claims

1. A sulfonium salt-type monomer represented by the following formula (A1); Wherein, n1 is an integer from 0 to 2; n2 is an integer satisfying 0≤n2≤5+2(n1)-1; p is an integer from 1 to 5; q is an integer from 1 to 3; R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R 1 is a halogen atom, a nitro group, a cyano group, a saturated hydrocarbon group having 1 to 10 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 10 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon carbonyloxy group having 2 to 10 carbon atoms which may be substituted by a halogen atom, or a fluorinated saturated hydrocarbon thio group having 1 to 10 carbon atoms; R 2 is a hydrocarbon group having 1 to 30 carbon atoms which may also contain heteroatoms; R 3 It is a (p+1)-valent hydrocarbon group having 1 to 30 carbon atoms which may also contain a heteroatom; R 4 is a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 5 carbon atoms, a fluorinated saturated hydrocarbon oxy group having 1 to 5 carbon atoms, a fluorinated saturated hydrocarbon carbonyloxy group having 2 to 5 carbon atoms, a fluorinated saturated hydrocarbon oxycarbonyl group having 2 to 5 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 5 carbon atoms, and a portion of the hydrogen atoms in these groups may be substituted with at least one selected from a hydroxyl group, a chlorine atom, a bromine atom, an iodine atom, a nitro group, and a cyano group, and at least one selected from an ester bond, an ether bond, a sulfonate bond, a carbonate bond, and a carbamate bond may be inserted between carbon-carbon bonds in these groups; When q is 1, 2 R 2 and R 3 Any two of them can also bond to each other and form a ring together with the sulfur atom to which they are bonded; when q is 2, the two R 3 and R 2 Any two of them can also bond to each other and form a ring together with the sulfur atom to which they are bonded; when q is 3, the three R 3 Any two of them may be bonded to each other and form a ring together with the sulfur atom to which they are bonded.

2. The sulfonium salt-type monomer according to claim 1, which is represented by the following formula (A1-1); Where n1, n2, p, q, R A 、R 1 and R 4 Same as above; R 5 and R 6 are each independently a halogen atom other than a fluorine atom, a nitro group, a cyano group, or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom; r1 and r2 are each independently an integer from 0 to 2; s1 is an integer satisfying 0≤s1≤(2r1+4); and s2 is an integer satisfying 0≤s2≤(2r2+4).

3. The sulfonium salt-type monomer according to claim 2, wherein R 4 is a fluorine atom, a trifluoromethyl group, a trifluoromethoxy group or a trifluoromethylthio group.

4. A polymer comprising a repeating unit derived from the sulfonium salt-type monomer according to claim 1, wherein the solubility of the polymer in an aqueous alkaline solution is increased by the action of an acid.

5. The polymer according to claim 4, further comprising a repeating unit represented by the following formula (A2); Wherein, a1 is 0 or 1; a2 is an integer from 0 to 2; a3 is an integer satisfying 0≤a3≤5+2(a2)-a4; a4 is an integer from 1 to 3; R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R 11 is a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom; A 1 It is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a part of the -CH2- in the saturated alkylene group may be substituted by -O-.

6. The polymer according to claim 4, further comprising at least one selected from the group consisting of a repeating unit represented by the following formula (A3-1) and a repeating unit represented by the following formula (A3-2); Wherein, b1 is 0 or 1; b2 is an integer from 0 to 2; b3 is an integer satisfying 0≤b3≤5+2(b2)-b4; b4 is an integer from 1 to 3; b5 is 0 or 1; c1 is an integer from 0 to 2; c2 is an integer from 0 to 2; c3 is an integer from 0 to 5; c4 is an integer from 0 to 2; R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R 12 is a nitro group, a cyano group, a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon thio group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon carbonyl group having 2 to 8 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom; R 13 and R 14 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may contain a heteroatom, and R 13 With R 14 They can also bond to each other and to the carbon atoms to which they are bonded to form rings; R 15 are each 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; R 16 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may also contain a heteroatom; A 2 is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, wherein a portion of -CH2- in the saturated alkylene group may be substituted by -O-; When b4 is 1, X is an acid-labile group; when b4 is 2 or 3, X is independently a hydrogen atom or an acid-labile group, but at least one of them is an acid-labile group; A 3 is a single bond, phenylene, naphthylene or *-C(=O)-OA 31 -;A 31 It is an aliphatic alkylene group having 1 to 20 carbon atoms, a phenylene group or a naphthylene group, and the aliphatic alkylene group may contain at least one selected from a hydroxyl group, an ether bond, an ester bond or a lactone ring; * is an atomic bond to a carbon atom of the main chain.

7. The polymer according to claim 4, further comprising at least one selected from the group consisting of a repeating unit represented by the following formula (A4), a repeating unit represented by the following formula (A5), and a repeating unit represented by the following formula (A6); wherein d and e are each independently an integer of 0 to 4; f1 is 0 or 1; f2 is an integer of 0 to 2; f3 is an integer of 0 to 5; R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R 21 and R 22 Each of the groups is independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom; R 23 is a halogen atom, a trifluoromethyl group, a trifluoromethoxy group, a nitro group, a cyano group, a saturated hydrocarbon group having 1 to 20 carbon atoms, a saturated hydrocarbon oxy group having 1 to 20 carbon atoms, a saturated hydrocarbon carbonyloxy group having 2 to 20 carbon atoms, a saturated hydrocarbon oxyhydrocarbyl group having 2 to 20 carbon atoms, a saturated hydrocarbon thiohydrocarbyl group having 2 to 20 carbon atoms, a saturated hydrocarbon sulfinyl group having 1 to 20 carbon atoms, or a saturated hydrocarbon sulfonyl group having 1 to 20 carbon atoms; A 4 It is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a part of the -CH2- in the saturated alkylene group may be substituted by -O-.

8. A chemically amplified positive resist composition comprising: (A) A base polymer comprising the polymer according to claim 4.

9. The chemically amplified positive resist composition according to claim 8, wherein The content of repeating units having an aromatic ring skeleton in all repeating units of the polymer contained in the base polymer is 60 mol% or more. 10 . The chemically amplified positive resist composition according to claim 8 , further comprising (B) a quencher. 11 . The chemically amplified positive resist composition according to claim 8 , further comprising (C) a photoacid generator.

12. The chemically amplified positive resist composition according to claim 8, wherein The content ratio of the (C) photoacid generator to the (B) quencher is less than 6 in terms of mass ratio.

13. The chemically amplified positive resist composition according to claim 8, further comprising: (D) a fluorine-containing polymer comprising at least one member selected from the group consisting of a repeating unit represented by the following formula (D1), a repeating unit represented by the following formula (D2), a repeating unit represented by the following formula (D3), and a repeating unit represented by the following formula (D4), and further comprising at least one member selected from the group consisting of a repeating unit represented by the following formula (D5) and a repeating unit represented by the following formula (D6); In the formula, x is an integer from 1 to 3; y is an integer satisfying 0≤y≤5+2z-x; z is 0 or 1; h is an integer from 1 to 3; R B are 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 301 、R 302 、R 304 and R 305 are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms; R 303 、R 306 、R 307 and R 308 are independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, a fluorinated hydrocarbon group having 1 to 15 carbon atoms, or an acid-labile group, and R 303 、R 306 、R 307 and R 308 When it is a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond or a carbonyl group may be inserted between the carbon-carbon bonds; R 309 A hydrogen atom or a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may have a heteroatom-containing group inserted between carbon-carbon bonds; R 310 It is a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may have a heteroatom-containing group inserted between carbon-carbon bonds; R 311 A saturated hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom, wherein a portion of the -CH2- of the saturated hydrocarbon group may be replaced by an ester bond or an ether bond; Z 1 A (h+1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (h+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms; Z 2 is a single bond, *-C(=O)-O- or *-C(=O)-NH-; * is an atomic bond to a carbon atom of the main chain; Z 3 is a single bond, -O-, *-C(=O)-OZ 31 -Z 32 - or *-C(=O)-NH-Z 31 -Z 32 -;Z 31 is a single bond or a saturated alkylene group having 1 to 10 carbon atoms; Z 32 is a single bond, ester bond, ether bond or sulfonamide bond; * is an atomic bond to a carbon atom in the main chain. 14 . The chemically amplified positive resist composition according to claim 8 , further comprising (E) an organic solvent.

15. A method for forming a resist pattern, comprising the following steps: forming a resist film on a substrate using the chemically amplified positive resist composition according to any one of claims 8 to 14, The resist film is irradiated with a pattern of high-energy radiation, and The resist film having the irradiated pattern is developed using an alkaline developer.

16. The resist pattern forming method according to claim 15, wherein The high-energy rays are extreme ultraviolet rays or electron beams.

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

18. The resist pattern forming method according to claim 15, wherein The substrate is a transmission type or reflection type blank mask.

19. A transmissive or reflective mask blank coated with the chemically amplified positive resist composition according to any one of claims 8 to 14.

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