Positive resist materials and pattern formation methods

Abstract

This invention relates to positive resist materials and a method for forming patterns. The objective of this invention is to provide a positive resist material and a method for forming patterns that exhibit controlled acid diffusion, superior resolution compared to known positive resist materials, smaller edge roughness and dimensional deviations, and better pattern shape after exposure. The solution to this objective is a positive resist material comprising a base polymer capped with a sulfonate salt containing a carboxylic acid anion attached to a thioether group.

Description

Technical Field

[0001] This invention relates to positive resist materials and a method for forming patterns. Existing technology

[0002] With the increasing integration and speed of LSI (Lithium-ion Sensors), the miniaturization of patterning is also progressing rapidly. This is due to the widespread adoption of high-speed 5G communication and artificial intelligence (AI), making high-performance devices to process them essential. Regarding the most advanced miniaturization technology, mass production of 5nm node devices using 13.5nm extreme ultraviolet (EUV) lithography is already underway. Furthermore, discussions are underway regarding the use of EUV lithography in next-generation 3nm node devices and the next-next-generation 2nm node devices.

[0003] As miniaturization progresses, image blurring due to acid diffusion becomes a problem. To ensure resolution of fine patterns smaller than 45 nm, it has been proposed that not only improvements in dissolution contrast, as already known, are important, but also the control of acid diffusion (Non-Patent Literature 1). However, chemically amplified resist materials utilize acid diffusion to improve sensitivity and contrast; therefore, if the post-exposure baking (PEB) temperature is lowered or the baking time is shortened to suppress acid diffusion to its limit, sensitivity and contrast will be significantly reduced.

[0004] Adding acid-generating agents that produce bulky acids is effective in suppressing acid diffusion. Therefore, it has been proposed to include repeating units from onium salts with polymerizable unsaturated bonds in the polymer. In this case, the polymer also functions as an acid-generating agent (polymer-bonded acid-generating agent). Patent Document 1 proposes sulfonium salts and sulfonium salts with polymerizable unsaturated bonds that produce specific sulfonic acids. Patent Document 2 proposes sulfonium salts where the sulfonic acid is directly bonded to the main chain.

[0005] Resist materials modified at the ends of polymers have been proposed. Examples include: a resist material formed by adding acid-unstable groups to the ends of anionic polymers using alkyllithium as an initiator (Patent Document 3); a resist material formed by adding a sulfonium salt, an acid-generating agent of fluorosulfonic acid, to the polymer ends during living radical polymerization (RAFT) (Patent Document 4); and a resist material formed by using an azo-based polymerization initiator with sulfonium salts containing fluorosulfonic acid acid-generating agents on both sides, followed by adding acid-generating agents to both ends of the polymer (Patent Document 5). However, polymers formed by adding acid-generating agents to the ends, in particular, have the disadvantage of increased acid diffusion due to the tendency for the ends to migrate.

[0006] Existing technical documents

[0007] Patent documents

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2006-45311

[0009] [Patent Document 2] Japanese Patent Application Publication No. 2006-178317

[0010] [Patent Document 3] Japanese Patent No. 4132783

[0011] [Patent Document 4] Japanese Patent Application Publication No. 2014-65896

[0012] [Patent Document 5] Japanese Patent Application Publication No. 2013-1850

[0013] Non-patent literature

[0014] [Non-Patent Literature 1] SPIE Vol.3331p531(1998) Summary of the Invention

[0015] [The problem that the invention aims to solve]

[0016] The present invention is made in view of the foregoing circumstances, and aims to provide a positive resist material with controlled acid diffusion, superior resolution compared to known positive resist materials, small edge roughness and dimensional variation, and good pattern shape after exposure, as well as a method for pattern formation.

[0017] [Methods for solving the problem]

[0018] The inventors of this application, after repeated and in-depth research in order to obtain the high-resolution positive resist material with minimal edge roughness and dimensional variation required in recent years, have obtained the following insights: where it is necessary to shorten the acid diffusion distance to the limit and suppress swelling in alkaline developer, acid diffusion is reduced to the limit and swelling is reduced by adding a sulfonium salt containing a carboxylic acid anion as a quencher to the end of the polymer, and the following insights are obtained: especially if a base polymer is used as a chemically amplified positive resist material, it is extremely effective.

[0019] Furthermore, the following insights were gained: In order to improve the dissolution contrast, by introducing repeating units formed by replacing the hydrogen atoms of carboxyl or phenolic hydroxyl groups with acid-instable groups into the aforementioned base polymer, a positive resist material that is particularly suitable as a fine pattern forming material for ultra-large integrated circuit manufacturing or photomasks can be obtained, which has a significantly improved contrast between alkali dissolution rates before and after exposure, a high effect on suppressing acid diffusion, high resolution, and good pattern shape, edge roughness, and dimensional uniformity (CDU) after exposure. This leads to the completion of the present invention.

[0020] That is, the present invention provides the following positive resist material and pattern forming method.

[0021] 1. A positive resist material comprising: a base polymer whose ends are capped by a sulfonate salt containing a carboxylic acid anion attached to a thioether group.

[0022] 2. The positive resist material as in 1, wherein the structure of the aforementioned end is represented by the following formula (a).

[0023] [Chemistry 1]

[0024]

[0025] In the formula, X 1 It is a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may also contain at least one of the following: hydroxyl group, ether bond, thioether group, ester bond, carbonate bond, carbamate bond, lactone ring, sulfonyl lactone ring and halogen atom.

[0026] R 1 ~R 3 Each group is independently a hydrocarbon group having 1 to 20 carbon atoms, and may also contain at least one selected from oxygen, sulfur, nitrogen, and halogen atoms. Furthermore, R... 1 With R 2 They can also bond to each other and form rings together with the sulfur atoms they bond to.

[0027] The dashed lines represent atomic bonds.

[0028] 3. A positive resist material as described in 1 or 2, wherein the aforementioned base polymer comprises a repeating unit b1 formed by replacing hydrogen atoms of a carboxyl group with acid-indestabilized groups, or a repeating unit b2 formed by replacing hydrogen atoms of a phenolic hydroxyl group with acid-indestabilized groups.

[0029] 4. The positive resist material as in 3, wherein the repeating unit b1 is represented by the following formula (b1), and the repeating unit b2 is represented by the following formula (b2).

[0030] [Chemistry 2]

[0031]

[0032] In the formula, R A Each can be a hydrogen atom or a methyl group, independently.

[0033] Y 1 It is a single bond, a phenylene or naphthylene group, or contains a linking group with 1 to 12 carbon atoms selected from at least one of ester bonds, ether bonds and lactone rings.

[0034] Y 2 It can be a single bond, ester bond, or amide bond.

[0035] Y 3 It can be a single bond, an ether bond, or an ester bond.

[0036] R 11 and R 12 Each is an acid-labile group.

[0037] R 13 It is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbon group having 1 to 6 carbon atoms.

[0038] R 14 It is a single bond or an alkyl dienyllium with 1 to 6 carbon atoms, and the alkyl dienyllium may also contain ether bonds or ester bonds.

[0039] a is 1 or 2. b is an integer from 0 to 4. However, 1 ≤ a + b ≤ 5.

[0040] 5. A positive resist material as described in any one of 1. to 4., wherein the aforementioned base polymer further comprises a repeating unit c containing a close-knit group selected from hydroxyl, carboxyl, lactone ring, carbonate bond, thiocarbonate bond, carbonyl, cyclic acetal, ether bond, ester bond, sulfonate bond, cyano, amide bond, -OC(=O)-S- and -OC(=O)-NH-.

[0041] 6. A positive resist material as described in any one of 1 to 5, wherein the aforementioned base polymer further comprises a repeating unit represented by any one of the following formulas (d1) to (d3).

[0042] [Chemistry 3]

[0043]

[0044] In the formula, R A Each can be a hydrogen atom or a methyl group, independently.

[0045] Z 1 It is a single bond, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining them, or -OZ. 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -. Z 11 It is an aliphatic alkylene group, phenylene group, naphthylene group or a combination thereof with 7 to 18 carbon atoms, and may also contain carbonyl groups, ester bonds, ether bonds or hydroxyl groups.

[0046] Z 2 It is a single bond or an ester bond.

[0047] Z 3 For single key, -Z 31 -C(=O)-O-、-Z 31 -O- or -Z 31 -OC(=O)-。 Z 31It is an aliphatic hydrocarbon group with 1 to 12 carbon atoms, a phenylene group, or a group with 7 to 18 carbon atoms obtained by combining them, and may also contain a carbonyl group, an ester bond, an ether bond, a bromine atom, or an iodine atom.

[0048] Z 4 It can be methylene, 2,2,2-trifluoro-1,1-ethanediyl, or carbonyl.

[0049] Z 5 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -. Z 51 It is an aliphatic alkylene group, phenylene, fluorinated phenylene, or phenylene substituted with trifluoromethyl, having 1 to 6 carbon atoms, and may also contain carbonyl groups, ester bonds, ether bonds, halogen atoms, or hydroxyl groups.

[0050] R 21 ~R 28 Each group consists independently of a halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 20 carbon atoms. Also, R 23 and R 24 or R 26 and R 27 They can also bond to each other and form rings together with the sulfur atoms they bond to.

[0051] M - It is a non-nucleophilic relative ion.

[0052] 7. Positive resist materials such as any one of 1. to 6, wherein the resist further contains an acid generating agent.

[0053] 8. A positive resist material as described in any of 1 to 7, wherein it further contains an organic solvent.

[0054] 9. A positive resist material as described in any of 1 to 8, wherein it further contains a quenching agent.

[0055] 10. A positive resist material as described in any of 1. to 9, wherein it further contains a surfactant.

[0056] 11. A method for forming a pattern, comprising the following steps:

[0057] A resist film is formed on the substrate using a positive resist material as described in any one of 1. to 10.

[0058] The aforementioned resist film was exposed to high-energy radiation, and

[0059] The previously exposed resist film was developed using a developer.

[0060] 12. The pattern forming method of 11, wherein the aforementioned high-energy rays are i-rays, KrF excimer lasers, ArF excimer lasers, electron beams (EB), or EUV with a wavelength of 3 to 15 nm.

[0061] [The effects of the invention]

[0062] The positive resist material of this invention exhibits high acid diffusion inhibition, high contrast between alkali dissolution rates before and after exposure when forming the resist film, high resolution, and good pattern shape, edge roughness, and CDU after exposure. Therefore, due to these excellent properties, it is highly practical, especially as a micro-patterning material for ultra-large-scale integrated circuit manufacturing or for photomasks drawn using EB, and as a patterning material for EB or EUV exposure. The positive resist material of this invention can be applied not only to photolithography in semiconductor circuit formation, but also to mask circuit pattern formation, micromechanics, and thin-film magnetic head circuit formation. Detailed Implementation

[0063] [Basic Polymers]

[0064] The positive resist material of the present invention is characterized by containing a base polymer whose ends are capped by a sulfonate salt containing a carboxylic acid anion connected to a thioether group.

[0065] The aforementioned end structure (hereinafter also referred to as end structure a) should preferably be the structure represented by the following formula (a).

[0066] [Chemistry 4]

[0067]

[0068] In the formula, the dashed lines represent atomic bonds.

[0069] In equation (a), X 1It is an alkylene group having 1 to 20 carbon atoms, and this alkylene group may also contain at least one selected from hydroxyl, ether bond, thioether group, ester bond, carbonate bond, carbamate bond, lactone ring, sulfonyl ring, and halogen atom. The aforementioned alkylene group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include: methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, etc., having alkyl diyl groups having 1 to 20 carbon atoms; cyclopentanediyl... Cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclohexanediyl, norcamphenediyl, and adamantanediyl; unsaturated aliphatic hydrocarbon groups with 2 to 20 carbon atoms, such as vinylene, propylene-1,3-diyl, acetylene-1,2-diyl, and propyne-1,3-diyl; aryl groups with 6 to 20 carbon atoms, such as phenylene, naphthylene, and biphenylene; groups formed by replacing some or all of the hydrogen atoms of these groups with hydrocarbon groups with 1 to 12 carbon atoms; and groups obtained by combining these groups. Furthermore, the aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given in the descriptions of formulas (1-1) and (1-2) below, exemplified as R. 101 ~R 105 The hydrocarbon group representing 1 to 20 carbon atoms, specifically those with 1 to 12 carbon atoms.

[0070] In equation (a), R 1 ~R 3 Each group is independently a hydrocarbon group having 1 to 20 carbon atoms, and may also contain at least one of oxygen, sulfur, nitrogen, and halogen atoms. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed and illustrated in the descriptions of formulas (1-1) and (1-2) below as R. 101 ~R 105 The same applies to hydrocarbon groups representing 1 to 20 carbon atoms. Also, R... 1 With R 2 They can also bond to each other and form rings together with the sulfur atoms they bond to. In this case, the aforementioned rings can be enumerated and illustrated in the description of formula (1-1) below as R. 101 With R 102 The same applies to rings that can be formed by mutual bonding and the sulfur atoms bonded to them.

[0071] To add a sulfonium salt containing a carboxylic acid anion attached to a thioether group to the polymer terminus, a compound represented by formula (a1) is used as a chain transfer agent, and the polymerization reaction is carried out by adding it to the polymerization bath before or during polymerization. Free radicals are generated by the decomposition of the polymerization initiator, and polymerization begins through chain transfer of the free radicals to the thiol, resulting in a polymer with the terminus capped by the sulfonium salt.

[0072] [Chemistry 5]

[0073]

[0074] In the formula, X 1 and R 1 ~R 3 Same as above.

[0075] The anions of the compounds represented by formula (a1) can be listed below, but are not limited to these.

[0076] [Chemistry 6]

[0077]

[0078] [Chemistry 7]

[0079]

[0080] [Chemistry 8]

[0081]

[0082] [Chemistry 9]

[0083]

[0084] [Chemistry 10]

[0085]

[0086] [Chemistry 11]

[0087]

[0088] [Chemistry 12]

[0089]

[0090] [Chemistry 13]

[0091]

[0092] [Chemistry 14]

[0093]

[0094] [Chemistry 15]

[0095]

[0096] [Chemistry 16]

[0097]

[0098] Specific examples of cations with terminal structure a and cations of compounds represented by formula (a1) can be listed and illustrated as specific examples of cations of sulfonium salts represented by formula (1-1) described later.

[0099] Compounds represented by formula (a1) can be synthesized, for example, by ion exchange reactions of carboxylic acids and sulfonium salts linked to thioether groups, and carbonates and hydrochlorides of sulfonium salts.

[0100] The aforementioned basic polymer preferably contains repeating unit b1, which is formed by replacing the hydrogen atom of the carboxyl group with an acid-instable group, or repeating unit b2, which is formed by replacing the hydrogen atom of the phenolic hydroxyl group with an acid-instable group.

[0101] The repeating units b1 and b2 can be represented by the following formulas (b1) and (b2), respectively.

[0102] [Chemistry 17]

[0103]

[0104] In equations (b1) and (b2), R A Each can be independently a hydrogen atom or a methyl group. Y 1 It is a single bond, a phenylene or naphthylene group, or contains a linking group with 1 to 12 carbon atoms selected from at least one of ester bonds, ether bonds and lactone rings.

[0105] Y 2 It is a single bond, ester bond, or amide bond. 3 It can be a single bond, an ether bond, or an ester bond. R 11 and R 12 Each is an acid-labile group, independently. R 13 It is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 14 It is a single bond or an alkyldiyl group having 1 to 6 carbon atoms, and the alkyldiyl group may also contain ether or ester bonds. a is 1 or 2. b is an integer from 0 to 4. However, 1 ≤ a + b ≤ 5.

[0106] The monomers providing the repeating unit b1 can be listed below, but are not limited to. Additionally, in the following formula, R... A and R 11 Same as above.

[0107] [Chemistry 18]

[0108]

[0109] [Chemistry 19]

[0110]

[0111] The monomers providing the repeating unit b2 can be listed below, but are not limited to. Additionally, in the following formula, R... A and R 12 Same as above.

[0112] [Chemistry 20]

[0113]

[0114] R 11 or R 12 The unstable acid group can be represented by various options, such as those represented by formulas (AL-1) to (AL-3).

[0115] [Chemistry 21]

[0116]

[0117] In the formula, the dashed lines represent atomic bonds.

[0118] In equation (AL-1), c is an integer from 0 to 6. R L1 It can be a tertiary hydrocarbon group with 4 to 20 carbon atoms, preferably 4 to 15; a trialkylsilyl group where each hydrocarbon group is a saturated hydrocarbon group with 1 to 6 carbon atoms; a saturated hydrocarbon group with 4 to 20 carbon atoms containing a carbonyl group, an ether bond, or an ester bond; or a group represented by formula (AL-3). In addition, a tertiary hydrocarbon group refers to a group obtained by removing a hydrogen atom from a tertiary carbon atom of a hydrocarbon.

[0119] R L1 The tertiary hydrocarbon group can be saturated or unsaturated, and can be branched or cyclic. Specific examples include: tert-butyl, tert-pentyl, 1,1-diethylpropyl, 1-ethylcyclopentyl, 1-butylcyclopentyl, 1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl, 2-methyl-2-adamantyl, etc. Examples of the aforementioned trialkylsilyl groups include: trimethylsilyl, triethylsilyl, dimethyltert-butylsilyl, etc. The aforementioned saturated hydrocarbon groups containing carbonyl, ether, or ester bonds can be linear, branched, or cyclic, but cyclic is preferred. Specific examples include: 3-oxocyclohexyl, 4-methyl-2-oxooxacyclohexane-4-yl, 5-methyl-2-oxooxacyclopentane-5-yl, 2-tetrahydropyranyl, 2-tetrahydrofuranyl, etc.

[0120] Examples of acid-instable groups represented by formula (AL-1) include: tert-butoxycarbonyl, tert-butoxycarbonylmethyl, tert-pentyloxycarbonyl, tert-pentyloxycarbonylmethyl, 1,1-diethylpropyloxycarbonyl, 1,1-diethylpropyloxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyloxycarbonylmethyl, 1-ethyl-2-cyclopentenyloxycarbonyl, 1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl, 2-tetrahydropyranyloxycarbonylmethyl, 2-tetrahydrofuranyloxycarbonylmethyl, etc.

[0121] In addition, the acid-instable groups represented by formula (AL-1) can also be listed as groups represented by formulas (AL-1)-1 to (AL-1)-10.

[0122] [Chemistry 22]

[0123]

[0124] In the formula, the dashed lines represent atomic bonds.

[0125] In equations (AL-1)-1 to (AL-1)-10, c is the same as described above. R L8 Each can be independently a saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. L9 It consists of a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. R L10 It is a saturated hydrocarbon group with 2 to 10 carbon atoms or an aryl group with 6 to 20 carbon atoms. The aforementioned saturated hydrocarbon group can be any of the following: straight-chain, branched, or cyclic.

[0126] In equation (AL-2), R L2 and R L3 Each saturated hydrocarbon group is independently composed of hydrogen atoms or carbon atoms numbered 1 to 18, preferably 1 to 10. The aforementioned saturated hydrocarbon groups can be linear, branched, or cyclic, and specific examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl, n-octyl, etc.

[0127] In equation (AL-2), R L4 The hydrocarbon group may contain heteroatoms and has 1 to 18 carbon atoms, preferably 1 to 10. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Examples of the aforementioned hydrocarbon groups include saturated hydrocarbon groups with 1 to 18 carbon atoms, and a portion of their hydrogen atoms may be replaced by hydroxyl, alkoxy, oxo, amino, alkylamino, etc. Examples of such substituted saturated hydrocarbon groups are shown below.

[0128] [Chemistry 23]

[0129]

[0130] In the formula, the dashed lines represent atomic bonds.

[0131] R L2 With R L3 R L2 With R L4 、or R L3 With R L4 They can also bond with each other and form rings together with the carbon atoms they bond with, or form rings together with carbon and oxygen atoms. In this case, R participates in the ring formation. L2 and R L3 R L2 and R L4 、or R L3 and R L4 Each is an alkyldiyl group, with 1 to 18 carbon atoms, preferably 1 to 10. The ring formed by their bonding preferably has 3 to 10 carbon atoms, and 4 to 10 is more preferred.

[0132] Among the acid-instable groups represented by formula (AL-2), those that are linear or branched can be listed as those represented by formulas (AL-2)-1 to (AL-2)-69, but are not limited thereto. Furthermore, in the following formulas, dashed lines represent atomic bonds.

[0133] [Chemistry 24]

[0134]

[0135] [Chemistry 25]

[0136]

[0137] [Chemistry 26]

[0138]

[0139] [Chemistry 27]

[0140]

[0141] Among the acid-unstable groups represented by formula (AL-2), cyclic groups can be listed as: tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl, 2-methyltetrahydropyran-2-yl, etc.

[0142] Furthermore, acid-indestructible groups can be represented by groups indicated by formulas (AL-2a) or (AL-2b). These acid-indestructible groups can also be used to crosslink the base polymer intermolecularly or intramolecularly.

[0143] [Chemistry 28]

[0144]

[0145] In the formula, the dashed lines represent atomic bonds.

[0146] In formula (AL-2a) or (AL-2b), R L11 and R L12 Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms. The aforementioned saturated hydrocarbon group can be any of the following: linear, branched, or cyclic. Furthermore, R... L11 With R L12 They can also bond to each other and form rings together with the carbon atoms they bond to; in this case, R L11 and R L12 Each is an alkyldiyl group having 1 to 8 carbon atoms. R L13 Each is an independent saturated hydrocarbon group having 1 to 10 carbon atoms. The aforementioned saturated hydrocarbon group can be any of the following: linear, branched, or cyclic. d and e are independent integers from 0 to 10, preferably integers from 0 to 5, and f is an integer from 1 to 7, preferably an integer from 1 to 3.

[0147] In formula (AL-2a) or (AL-2b), L A These are aliphatic saturated hydrocarbon groups with 1 to 50 carbon atoms and a carbon number of 3 to 50 carbon atoms and a carbon number of 3 to 50 carbon atoms and a carbon number of 6 to 50 carbon atoms and a carbon number of 6 to 50 carbon atoms and a carbon number of 3 to 50 carbon atoms and a carbon number of 3 to 50 carbon atoms and a carbon number of 3 to 50 carbon atoms and a carbon number of 6 to 50 carbon atoms and a carbon number of 6 to 50 carbon atoms and a carbon number of 6 to 50 carbon atoms and a carbon number of 6 to 50 carbon atoms respectively. Furthermore, a portion of the -CH2- group in these groups may be substituted with a group containing a heteroatom, and a portion of the hydrogen atom in these groups may be substituted with a hydroxyl, carboxyl, acyl, or fluorine atom. A It is preferable to use saturated hydrocarbon groups with 1 to 20 carbon atoms, such as saturated alkylene groups, trivalent saturated hydrocarbon groups, and tetravalent saturated hydrocarbon groups; or aryl groups with 6 to 30 carbon atoms. The aforementioned saturated hydrocarbon groups can be linear, branched, or cyclic. B It is -C(=O)-O-, -NH-C(=O)-O- or -NH-C(=O)-NH-.

[0148] The cross-linked acetal group represented by formula (AL-2a) or (AL-2b) can be listed as groups represented by formulas (AL-2)-70 to (AL-2)-77.

[0149] [Chemistry 29]

[0150]

[0151] In the formula, the dashed lines represent atomic bonds.

[0152] In equation (AL-3), R L5 R L6 and R L7Each group is independently a hydrocarbon group having 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl groups having 1 to 20 carbon atoms, cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms, and aryl groups having 6 to 10 carbon atoms. Furthermore, R... L5 With R L6 R L5 With R L7 、or R L6 With R L7 They can also bond with each other and together with the carbon atoms they bond with, form alicyclic rings with 3 to 20 carbon atoms.

[0153] Groups represented by formula (AL-3) can be listed as follows: tert-butyl, 1,1-diethylpropyl, 1-ethylnorbornel, 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-isopropylcyclopentyl, 1-methylcyclohexyl, 2-(2-methyl)adamantyl, 2-(2-ethyl)adamantyl, tert-pentyl, etc.

[0154] Furthermore, the groups represented by formula (AL-3) can also be listed as groups represented by formulas (AL-3)-1 to (AL-3)-19.

[0155] [Chemistry 30]

[0156]

[0157] In the formula, the dashed lines represent atomic bonds.

[0158] In formula (AL-3)-1~(AL-3)-19, R L14 Each can be independently a saturated hydrocarbon group having 1 to 8 carbon atoms or an aryl group having 6 to 20 carbon atoms. L15 and R L17 Each can be independently a hydrogen atom or a saturated hydrocarbon group having 1 to 20 carbon atoms. R L16 It is an aryl group with 6 to 20 carbon atoms. The aforementioned saturated hydrocarbon group can be any of the following: straight-chain, branched, or cyclic. Furthermore, the aforementioned aryl group is preferably phenyl, etc. R F It can be a fluorine atom, a trifluoromethyl group, or a nitro group. g is an integer from 1 to 5.

[0159] Furthermore, acid-indestructible groups can be represented by groups with the following formulas (AL-3)-20 or (AL-3)-21. These acid-indestructible groups can also be used to crosslink polymers intramolecularly or intermolecularly.

[0160] [Chemistry 31]

[0161]

[0162] In the formula, the dashed lines represent atomic bonds.

[0163] In equations (AL-3)-20 and (AL-3)-21, R L14 Same as above. R L18 It is a saturated alkylene group with a (h+1) valence and having 1 to 20 carbon atoms, or an arylene group with a (h+1) valence and having 6 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, and nitrogen atoms. The aforementioned saturated alkylene group can be linear, branched, or cyclic. h is an integer from 1 to 3.

[0164] Monomers providing repeating units containing acid-labile groups represented by formula (AL-3) can be exemplified by (meth)acrylates containing stereoisomer structures represented by formula (AL-3)-22.

[0165] [Chemistry 32]

[0166]

[0167] In equation (AL-3)-22, R A Same as above. R Lc1 It is a saturated hydrocarbon group with 1 to 8 carbon atoms, or an aryl group with 6 to 20 carbon atoms that can be substituted. The aforementioned saturated hydrocarbon group can be any of the following: linear, branched, or cyclic. R Lc2 ~R Lc11 Each group is a hydrocarbon group with 1 to 15 carbon atoms, and may also contain heteroatoms. Examples of heteroatoms include oxygen atoms. Examples of hydrocarbon groups include alkyl groups with 1 to 15 carbon atoms and aryl groups with 6 to 15 carbon atoms. R Lc2 With R Lc3 R Lc4 With R Lc6 R Lc4 With R Lc7 R Lc5 With R Lc7 R Lc5 With R Lc11 R Lc6 With R Lc10 R Lc8 With R Lc9 、or R Lc9 With R Lc10 They can also bond with each other and form rings together with the carbon atoms they bond with. In this case, the groups involved in the bonding are hydrocarbon groups with 1 to 15 carbon atoms, and may also contain heteroatoms. Also, R Lc2 With R Lc11 R Lc8 With R Lc11 、or R Lc4 With R Lc6 It can also be formed by adjacent carbon atoms bonded together without any intervening material, thus forming a double bond. In addition, this formula is also used to represent a mirror image.

[0168] Here, the monomers represented by formula (AL-3)-22 may include those described in Japanese Patent Application Publication No. 2000-327633, etc. Specifically, those shown below may be included, but are not limited to. Furthermore, in the following formula, R... A Same as above.

[0169] [Chemistry 33]

[0170]

[0171] Monomers providing repeating units containing acid-labile groups represented by formula (AL-3) may also include (meth)acrylates containing furandiyl, tetrahydrofurandiyl, or oxanorbornenediyl groups represented by formula (AL-3)-23.

[0172] [Chemistry 34]

[0173]

[0174] In equation (AL-3)-23, R A Same as above. R Lc12 and R Lc13 Each is an independent hydrocarbon group having 1 to 10 carbon atoms. R Lc12 With R Lc13 They can also bond to each other and form alicyclic rings together with the carbon atoms they bond to. R Lc14 It is furandiyl, tetrahydrofurandiyl, or oxanorbornenediyl. R Lc15 It is a hydrocarbon group with 1 to 10 carbon atoms, which may contain hydrogen atoms or heteroatoms. The aforementioned hydrocarbon group can be linear, branched, or cyclic. Specific examples include saturated hydrocarbon groups with 1 to 10 carbon atoms.

[0175] The monomers represented by formula (AL-3)-23 can be listed below, but are not limited to. Additionally, in the following formula, R... A As mentioned above, Ac represents acetyl and Me represents methyl.

[0176] [Chemistry 35]

[0177]

[0178] [Chemistry 36]

[0179]

[0180] In addition to the aforementioned acid-indestabilized groups, acid-indestabilized groups containing aromatic groups as described in Japanese Patent No. 5565293, Japanese Patent No. 5434983, Japanese Patent No. 5407941, Japanese Patent No. 5655756 and Japanese Patent No. 5655755 may also be used.

[0181] The aforementioned base polymer may further include repeating units c containing close-knit groups selected from hydroxyl, carboxyl, lactone ring, carbonate bond, thiocarbonate bond, carbonyl, cyclic acetal, ether bond, ester bond, sulfonate bond, cyano, amide bond, -OC(=O)-S- and -OC(=O)-NH-.

[0182] Monomers providing repeating unit c can be listed below, but are not limited to. Additionally, in the following formula, R... A Same as above.

[0183] [Chemistry 37]

[0184]

[0185] [Chemistry 38]

[0186]

[0187] [Chemistry 39]

[0188]

[0189] [Chemistry 40]

[0190]

[0191] [Chemistry 41]

[0192]

[0193] [Chemistry 42]

[0194]

[0195] [Chemistry 43]

[0196]

[0197] [Chemistry 44]

[0198]

[0199] [Chemistry 45]

[0200]

[0201] [Chemistry 46]

[0202]

[0203] [Chemistry 47]

[0204]

[0205] [Chemistry 48]

[0206]

[0207] The aforementioned base polymer may also contain at least one of the repeating units represented by formula (d1) (hereinafter also referred to as repeating unit d1), the repeating unit represented by formula (d2) (hereinafter also referred to as repeating unit d2), and the repeating unit represented by formula (d3) (hereinafter also referred to as repeating unit d3).

[0208] [Chemistry 49]

[0209]

[0210] In formulas (d1) to (d3), R A Each can be independently a hydrogen atom or a methyl group. Z 1 It is a single bond, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining them, or -OZ. 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -. Z 11 It is an aliphatic hydrocarbon group, phenylene group, naphthylene group, or a combination thereof with 7 to 18 carbon atoms, having 1 to 6 carbon atoms, and may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group. 2 It is a single bond or an ester bond. Z 3 For single key, -Z 31 -C(=O)-O-、-Z 31 -O- or -Z 31 -OC(=O)-。 Z 31 It is an aliphatic hydrocarbon group with 1 to 12 carbon atoms, a phenylene group, or a group with 7 to 18 carbon atoms obtained by combining them, and may also contain a carbonyl group, an ester bond, an ether bond, a bromine atom, or an iodine atom. 4 It is methylene, 2,2,2-trifluoro-1,1-ethanediyl, or carbonyl. 5 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -. Z 51It is an aliphatic alkylene group, phenylene, fluorinated phenylene, or phenylene substituted with trifluoromethyl, having 1 to 6 carbon atoms, and may also contain a carbonyl group, ester bond, ether bond, halogen atom, or hydroxyl group. Additionally, Z 1 Z 11 Z 31 and Z 51 The aliphatic alkyl subgroups can be saturated or unsaturated, and can be linear, branched, or cyclic.

[0211] In formulas (d1) to (d3), R 21 ~R 28 Each group consists of a halogen atom or a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be found in R in formulas (1-1) and (1-2) described later. 101 ~R 105 The same as those exemplified in the description.

[0212] Also, R 23 and R 24 or R 26 and R 27 They can also bond to each other and form rings together with the sulfur atoms they bond to. In this case, the aforementioned rings can be enumerated and illustrated in the description of formula (1-1) below as R. 101 With R 102 The same type of ring is formed by the bonding of sulfur atoms and the bonds between them.

[0213] In equation (d1), M - These are non-nucleophilic relative ions. Examples of such non-nucleophilic relative ions include: halide ions such as chloride ions and bromide ions; fluoroalkyl sulfonate ions such as trifluoromethanesulfonate ions, 1,1,1-trifluoroethanesulfonate ions, and nonafluorobutanesulfonate ions; aryl sulfonate ions such as toluenesulfonate ions, benzenesulfonate ions, 4-fluorobenzenesulfonate ions, and 1,2,3,4,5-pentafluorobenzenesulfonate ions; alkyl sulfonate ions such as methanesulfonate ions and butanesulfonate ions; imide ions such as bis(trifluoromethylsulfonyl)imide ions, bis(perfluoroethylsulfonyl)imide ions, and bis(perfluorobutylsulfonyl)imide ions; and methylate ions such as tri(trifluoromethylsulfonyl)methylide ions and tri(perfluoroethylsulfonyl)methylide ions.

[0214] The aforementioned non-nucleophilic relative ions can be further listed as follows: sulfonate ions with α-position substituted by a fluorine atom represented by formula (d1-1), sulfonate ions with α-position substituted by a fluorine atom and β-position substituted by a trifluoromethyl atom represented by formula (d1-2), etc.

[0215] [Transformation 50]

[0216]

[0217] In equation (d1-1), R 31 It is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may also contain an ether bond, ester bond, carbonyl group, lactone ring, or fluorine atom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed and illustrated as R in the following formula (1A'). 111 The same applies to hydrocarbon groups.

[0218] In equation (d1-2), R 32 It is a hydrocarbon group consisting of a hydrogen atom and a hydrocarbon carbonyl group having 1 to 30 carbon atoms or a hydrocarbon carbonyl group having 2 to 30 carbon atoms. The hydrocarbon group and hydrocarbon carbonyl group may also contain an ether bond, an ester bond, a carbonyl group, or an lactone ring. The hydrocarbon group and hydrocarbon carbonyl group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated as R in the following formula (1A'). 111 The same applies to hydrocarbon groups.

[0219] The cations that provide the monomer for the repeating unit d1 can be listed below, but are not limited to. Additionally, in the following formula, R... A Same as above.

[0220] [Chemistry 51]

[0221]

[0222] Specific examples of cations of monomers providing repeating units d2 or d3 can be listed and illustrated as cations of sulfonium salts represented by formula (1-1) described later.

[0223] Anions of monomers providing repeating unit d2 can be listed below, but are not limited to. Additionally, in the following formula, R... A Same as above.

[0224] [Chemistry 52]

[0225]

[0226] [Chemistry 53]

[0227]

[0228] [Chemistry 54]

[0229]

[0230] [Chemistry 55]

[0231]

[0232] [Chemistry 56]

[0233]

[0234] [Chemistry 57]

[0235]

[0236] [Chem.58]

[0237]

[0238] [Chemistry 59]

[0239]

[0240] [Transformation 60]

[0241]

[0242] [Chemistry 61]

[0243]

[0244] [Chemistry 62]

[0245]

[0246] Anions of monomers providing repeating unit d3 can be listed below, but are not limited to. Additionally, in the following formula, R... A Same as above.

[0247] [Chemistry 63]

[0248]

[0249] [Chemistry 64]

[0250]

[0251] The repeating units d1 to d3 function as acid generators. By bonding the acid generator to the polymer backbone, acid diffusion is reduced, and resolution loss due to acid diffusion blurring is prevented. Furthermore, uniform dispersion of the acid generator improves edge roughness and CDU. In addition, when using a base polymer containing repeating units d1 to d3 (i.e., a polymer-bonded acid generator), the addition of additive acid generators described later can be omitted.

[0252] The aforementioned basic polymer may also contain repeating units e containing iodine atoms. Monomers providing repeating units e can be listed below, but are not limited to these. Additionally, in the following formula, R... A Same as above.

[0253] [Chemistry 65]

[0254]

[0255] [Chemistry 66]

[0256]

[0257] [Chemistry 67]

[0258]

[0259] The aforementioned basic polymer may also contain repeating units f other than the aforementioned repeating units. Examples of repeating units f include those derived from styrene, ethylene naphthalene, indene, acenaphthene, coumarin, coumarone, etc.

[0260] In the aforementioned basic polymer, the proportions of repeating units b1, b2, c, d1, d2, d3, e, and f should preferably be 0≤b1≤0.9, 0≤b2≤0.9, 0.1≤b1+b2≤0.9, 0≤c≤0.9, 0≤d1≤0.5, 0≤d2≤0.5, 0≤d3≤0.5, 0≤d1+d2+d3≤0.5, 0≤e≤0.5, and 0≤f≤0.5, and preferably 0≤b1≤0.8, 0≤b2≤0.8, 0.2≤b1+b2≤0.8, and 0.2≤b1+b2≤0.8. 0≤c≤0.8, 0≤d1≤0.4, 0≤d2≤0.4, 0≤d3≤0.4, 0≤d1+d2+d3≤0.4, 0≤e≤0.4, and 0≤f≤0.4 are better. 0≤b1≤0.7, 0≤b2≤0.7, 0.25≤b1+b2≤0.7, 0≤c≤0.7, 0≤d1≤0.3, 0≤d2≤0.3, 0≤d3≤0.3, 0≤d1+d2+d3≤0.3, 0≤e≤0.3, and 0≤f≤0.3 are even better. However, b1+b2+c+d1+d2+d3+e+f=1.0.

[0261] To synthesize the aforementioned basic polymer, for example, a monomer providing the aforementioned repeating unit is added to an organic solvent, along with a free radical polymerization initiator and a chain transfer agent containing a sulfonium salt of a carboxylic acid anion attached to a thiol group, and the mixture is heated to carry out polymerization. By using the aforementioned chain transfer agent, the ends of the aforementioned basic polymer can be capped with a sulfonium salt containing a carboxylic acid anion attached to a thioether group. The polymerization initiator and chain transfer agent can be added at the beginning of polymerization, during polymerization, or slowly during polymerization.

[0262] Chain transfer agents are generally used to reduce the molecular weight of polymers. Polymerization occurs due to the generation of free radicals from the polymerization initiator, but activated free radicals migrate to the sulfonium salt of the present invention containing a carboxylic acid anion linked to a thiol group, thereby initiating polymerization. In this way, the sulfonium salt of the present invention containing a carboxylic acid anion linked to a thiol group is bonded to the end of the polymer.

[0263] Lower molecular weight has the advantage of reducing swelling in the developer. However, it also has the disadvantage of increased acid diffusion during PEB due to the lower glass transition temperature (Tg) of the polymer. Polymer-based quenchers are highly effective at inhibiting acid diffusion, and this effect is maintained even when the polymer molecular weight is reduced. In particular, by configuring the quencher at the polymer end as in this invention, the acid trapping ability can be improved. The object of this invention is a material that can achieve both reduced swelling in the developer due to lower molecular weight and low acid diffusion.

[0264] The amount of the aforementioned chain transfer agent used can be selected according to manufacturing conditions such as the molecular weight of the target, the monomer used as raw material, the polymerization temperature or polymerization method.

[0265] Polymerization initiators can be commercially available in the form of free radical polymerization initiators. Azo-based initiators, peroxide-based initiators, and other free radical polymerization initiators are preferred. Polymerization initiators can be used alone or in combination. The amount of polymerization initiator used can be selected according to manufacturing conditions such as the desired molecular weight, the monomers used as raw materials, the polymerization temperature, or the polymerization method. Specific examples of polymerization initiators are given below.

[0266] Specific examples of azo-based initiators include: 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylpentanitrile), 2,2'-azobis(2-methylpropionic acid) dimethyl ester, 2,2'-azobis(4-methoxy-2,4-dimethylpentanitrile), 2,2'-azobis(cyclohexane-1-carboxylonitrile), 4,4'-azobis(4-cyanopentanoic acid), and 2,2'-azobis(isobutyric acid) dimethyl ester. Specific examples of peroxide-based initiators include: benzoyl peroxide, decanoyl peroxide, lauroyl peroxide, succinic acid peroxide, tert-butyl peroxide-2-ethylhexanoate, tert-butyl peroxide-3-methylacetate, and 1,1,3,3-tetramethylbutyl peroxide-2-ethylhexanoate.

[0267] Organic solvents used in polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, and dioxane. The polymerization temperature should ideally be 50–80°C. The reaction time should be 2–100 hours, with 5–20 hours being preferred.

[0268] When copolymerizing monomers containing hydroxyl groups, the hydroxyl groups can be replaced with acetal groups such as ethoxy-ethoxy, which are easily deprotected by acids, before polymerization, and deprotection can be carried out using weak acids and water after polymerization. Alternatively, they can be replaced with acetyl, formyl, trimethylacetyl, etc., before polymerization, and alkaline hydrolysis can be carried out after polymerization.

[0269] When copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, hydroxystyrene and hydroxyvinylnaphthalene can be replaced with acetoxystyrene and acetoxyvinylnaphthalene, and the aforementioned alkaline hydrolysis can be used after polymerization to deprotect the acetoxy group to obtain hydroxystyrene and hydroxyvinylnaphthalene.

[0270] The alkali used in alkaline hydrolysis can be ammonia, triethylamine, etc. Furthermore, the reaction temperature should preferably be -20 to 100℃, with 0 to 60℃ being more ideal. The reaction time should preferably be 0.2 to 100 hours, with 0.5 to 20 hours being more ideal.

[0271] For the aforementioned base polymer, the equivalent weight-average molecular weight (Mw) of polystyrene obtained by gel permeation chromatography (GPC) using THF as a solvent should preferably be 1,000–500,000, with 2,000–30,000 being more desirable. If the Mw is too small, the resist material will have poor heat resistance; if it is too large, the alkali solubility will decrease, and the pattern will be prone to tailing after formation.

[0272] Furthermore, when the molecular weight distribution (Mw / Mn) of the aforementioned base polymer is wide, the presence of both low and high molecular weight polymers may lead to concerns about the observation of foreign matter or deterioration of the pattern shape after exposure. As the pattern becomes more regular and refined, the influence of Mw and Mw / Mn tends to increase. Therefore, in order to obtain a resist material suitable for use in fine pattern sizes, the Mw / Mn of the aforementioned base polymer should preferably be 1.0 to 2.0, with a narrow dispersion of 1.0 to 1.5 being particularly desirable.

[0273] The aforementioned base polymer may also include two or more polymers with different composition ratios, Mw, and Mw / Mn. Furthermore, polymers containing different terminal structures 'a' can be blended together, or polymers containing terminal structures 'a' can be blended with polymers not containing terminal structures 'a'.

[0274] [Acid generating agent]

[0275] The positive resist material of the present invention may also contain an acid generator that produces a strong acid (hereinafter also referred to as an additive acid generator). Here, a strong acid means a compound having an acidity sufficient to cause a deprotection reaction of the acid-indestructible groups of the base polymer.

[0276] Examples of the aforementioned acid-generating agents include compounds that react with active light or radiation to produce acids (photoacid generators). Any compound that produces acids upon exposure to high-energy rays is acceptable, but it is preferable that it produces sulfonic acid, imine acid, or methyl acid. Ideal photoacid generators include sulfonium salts, sulfonyl diazomethanes, N-sulfonyloxyimide, and oxime-O-sulfonate type acid generators. Specific examples of photoacid generators can be found in paragraphs

[0122] to

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

[0277] Alternatively, sulfonium salts represented by formula (1-1) and sulfonium salts represented by formula (1-2) can ideally be used as photoacid generators.

[0278] [Chemistry 68]

[0279]

[0280] In equations (1-1) and (1-2), R 101 ~R 105 Hydrocarbon groups with 1 to 20 carbon atoms that are independently composed of halogen atoms or may contain heteroatoms.

[0281] The aforementioned halogen atoms include: fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.

[0282] R 101 ~R 105 The hydrocarbon groups representing 1 to 20 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; and alkyl groups with 2 to 20 carbon atoms such as vinyl, propenyl, butenyl, and hexenyl. Alkenyl; alkynyl groups with 2 to 20 carbon atoms, such as ethynyl, propynyl, and butynyl; cyclic unsaturated aliphatic hydrocarbon groups with 3 to 20 carbon atoms, such as cyclohexenyl and norcamphenyl; aryl groups with 6 to 20 carbon atoms, such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, and tert-butylnaphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl and phenethyl; and groups formed by combining these groups.

[0283] Furthermore, some or all of the hydrogen atoms in these groups can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- in these groups can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, they may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentatone rings, carboxylic anhydrides, haloalkyl groups, etc.

[0284] Also, R 101 With R 102 They can also bond to each other and form rings together with the sulfur atoms they bond to. In this case, the aforementioned rings should preferably have the structure shown below.

[0285] [Chemistry 69]

[0286]

[0287] In the formula, the dashed line represents R. 103 Atomic bonds.

[0288] The cations of the sulfonium salt represented by formula (1-1) can be listed below, but are not limited to these.

[0289] [Chemistry 70]

[0290]

[0291] [Chemistry 71]

[0292]

[0293] [Chemistry 72]

[0294]

[0295] [Chemistry 73]

[0296]

[0297] [Chemistry 74]

[0298]

[0299] [Chemistry 75]

[0300]

[0301] [Chemistry 76]

[0302]

[0303] [Chemistry 77]

[0304]

[0305] [Chemistry 78]

[0306]

[0307] [Chemistry 79]

[0308]

[0309] [Chemistry 80]

[0310]

[0311] [Chemistry 81]

[0312]

[0313] [Chemistry 82]

[0314]

[0315] [Chemistry 83]

[0316]

[0317] [Chemistry 84]

[0318]

[0319] [Chemistry 85]

[0320]

[0321] [Chemistry 86]

[0322]

[0323] [Chemistry 87]

[0324]

[0325] [Chemistry 88]

[0326]

[0327] [Chemistry 89]

[0328]

[0329] [Chemistry 90]

[0330]

[0331] [Chemistry 91]

[0332]

[0333] [Chemistry 92]

[0334]

[0335] The cations of the monazine salts represented by formula (1-2) can be listed below, but are not limited to these.

[0336] [Chemistry 93]

[0337]

[0338] [Chemistry 94]

[0339]

[0340] In equations (1-1) and (1-2), Xa - The anions are selected from formulas (1A) to (1D).

[0341] [Chem. 95]

[0342]

[0343] In equation (1A), R fa It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain fluorine atoms or heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed and illustrated as R in the following formula (1A'). 111 The same applies to hydrocarbon groups.

[0344] The anion represented by formula (1A) should preferably be represented by formula (1A').

[0345] [Chemistry 96]

[0346]

[0347] In equation (1A'), R HF It can be a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R 111 The hydrocarbon group may contain heteroatoms and has 1 to 38 carbon atoms. The aforementioned heteroatoms are preferably oxygen, nitrogen, sulfur, or halogen atoms, with oxygen atoms being more preferred. Considering the need for high resolution in the formation of fine patterns, hydrocarbon groups with 6 to 30 carbon atoms are particularly preferred.

[0348] R 111The hydrocarbon group can be saturated or unsaturated, and can be any of the following: straight-chain, branched, or cyclic. Specific examples include: alkyl groups with 1 to 38 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and eicosyl; cyclic saturated hydrocarbon groups with 3 to 38 carbon atoms, such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norcamphenyl, norcamphenylmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups with 2 to 38 carbon atoms, such as allyl and 3-cyclohexenyl; aryl groups with 6 to 38 carbon atoms, such as phenyl, 1-naphthyl, and 2-naphthyl; aralkyl groups with 7 to 38 carbon atoms, such as benzyl and diphenylmethyl; and groups obtained by combining them.

[0349] Furthermore, some or all of the hydrogen atoms in these groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, a portion of the -CH2- group can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, these groups may contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulopentalide ring, carboxylic anhydride, or haloalkyl groups. Examples of hydrocarbon groups containing heteroatoms include: tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidemethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, and 3-oxocyclohexyl.

[0350] For details on the synthesis of sulfonium salts containing anions represented by formula (1A'), please refer to Japanese Patent Application Publication Nos. 2007-145797, 2008-106045, 2009-7327, and 2009-258695. Additionally, sulfonium salts described in Japanese Patent Application Publication Nos. 2010-215608, 2012-41320, 2012-106986, and 2012-153644 may also be used appropriately.

[0351] The anions represented by formula (1A) can be listed and exemplified as those represented by formula (1A) in Japanese Patent Application Publication No. 2018-197853.

[0352] In equation (1B), R fb1 and R fb2Each of the above-mentioned hydrocarbon groups consists independently of a fluorine atom or may contain heteroatoms and has 1 to 40 carbon atoms. These hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed and illustrated as R in formula (1A'). 111 The same applies to hydrocarbon groups. R fb1 and R fb2 It should preferably be a fluorine atom or a straight-chain fluorinated alkyl group having 1 to 4 carbon atoms. Also, R fb1 With R fb2 It can also bond with each other and with groups (-CF2-SO2-N) - SO2-CF2-) together form a ring, at which point R fb1 With R fb2 The groups formed by mutual bonding should preferably be fluorinated ethylidene or fluorinated propyleneide.

[0353] In equation (1C), R fc1 R fc2 and R fc3 Each of the above-mentioned hydrocarbon groups consists independently of a fluorine atom or may contain heteroatoms and has 1 to 40 carbon atoms. These hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed and illustrated as R in formula (1A'). 111 The same applies to hydrocarbon groups. R fc1 R fc2 and R fc3 It should preferably be a fluorine atom or a straight-chain fluorinated alkyl group having 1 to 4 carbon atoms. Also, R fc1 With R fc2 They can also bond to each other and to groups that are bonded to them (-CF2-SO2-C) - SO2-CF2-) together form a ring, at which point R fc1 With R fc2 The groups formed by mutual bonding should preferably be fluorinated ethylidene or fluorinated propyleneide.

[0354] In equation (1D), R fd It can be a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated as R in formula (1A'). 111 The same applies to hydrocarbon groups.

[0355] For details on the synthesis of sulfonium salts containing anions represented by formula (1D), please refer to Japanese Patent Application Publication No. 2010-215608 and Japanese Patent Application Publication No. 2014-133723.

[0356] The anions represented by formula (1D) can be listed and exemplified as those represented by formula (1D) in Japanese Patent Application Publication No. 2018-197853.

[0357] Furthermore, photoacid generators containing anions represented by formula (1D) possess sufficient acidity to cleave acid-indestructible groups in the base polymer because they lack a fluorine atom at the α-position of the sulfonyl group but have two trifluoromethyl groups at the β-position. Therefore, they can be used as photoacid generators.

[0358] Photoacid generators can also ideally be represented by the following formula (2).

[0359] [Chemistry 97]

[0360]

[0361] In equation (2), R 201 and R 202 Each group consists of a halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 30 carbon atoms. R 203 It can also contain a hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. Also, R 201 R 202 and R 203 Any two atoms in the ring can also bond to each other and form a ring together with the sulfur atoms they bond to. In this case, the aforementioned ring can be exemplified as R in the description of formula (1-1). 101 With R 102 The same type of ring is formed by the bonding of sulfur atoms and the bonds between them.

[0362] R 201 and R 202 The hydrocarbon group represented can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, and other alkyl groups with 1 to 30 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclic [5.2.1.0] 2,6[Cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms, such as decyl and adamantyl; aryl groups with 6 to 30 carbon atoms, such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl, and anthracene; and groups obtained by combining these groups. Furthermore, some or all of the hydrogen atoms in these groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- group may also be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, these groups may contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulopentalide ring, carboxylic anhydride, or haloalkyl groups.]

[0363] R 203 The derivatized hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, heptadecane-1,1... Alkyl groups with 1 to 30 carbon atoms, such as 7-diyl; cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norcamphenediyl, and adamantanediyl; aryl groups with 6 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 formed by combining these groups. Furthermore, some or all of the hydrogen atoms in these groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, a portion of the -CH2- group can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, these groups may contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride, or haloalkyl groups. The aforementioned heteroatoms should preferably be oxygen atoms.

[0364] In equation (2), L CIt is a hydrocarbon group with 1 to 20 carbon atoms, which can be a single bond, an ether bond, or may contain heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated as R. 203 The same applies to the subhydrocarbon group.

[0365] In equation (2), X A X B X C and X D Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. However, X A X B X C and X D At least one of them is a fluorine atom or a trifluoromethyl atom.

[0366] In equation (2), t is an integer from 0 to 3.

[0367] The photoacid generator represented by formula (2) should preferably be represented by the following formula (2').

[0368] [Chem. 98]

[0369]

[0370] In equation (2'), L C Same as above. R HF It can be a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R 301 R 302 and R 303 Each hydrocarbon group consists independently of a hydrogen atom or may contain heteroatoms and has 1 to 20 carbon atoms. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed and illustrated as R in formula (1A'). 111 The same applies to hydrocarbon groups. x and y are independent integers from 0 to 5, and z is an integer from 0 to 4.

[0371] The photoacid generator represented by formula (2) can be listed and exemplified as the photoacid generator represented by formula (2) in Japanese Patent Application Publication No. 2017-26980.

[0372] Among the aforementioned photoacid generators, those containing anions represented by formula (1A') or (1D) are particularly preferred due to their low acid diffusion and excellent solvent solubility. Furthermore, those represented by formula (2') are particularly preferred due to their extremely low acid diffusion.

[0373] The aforementioned photoacid generators can also be sulfonium or monazine salts containing anions with aromatic rings substituted with iodine or bromine atoms. Such salts can be represented by formulas (3-1) or (3-2).

[0374] [Chemistry 99]

[0375]

[0376] In equations (3-1) and (3-2), p is an integer satisfying 1 ≤ p ≤ 3. q and r are integers satisfying 1 ≤ q ≤ 5, 0 ≤ r ≤ 3, and 1 ≤ q + r ≤ 5. q should preferably be an integer satisfying 1 ≤ q ≤ 3, preferably 2 or 3. r should preferably be an integer satisfying 0 ≤ r ≤ 2.

[0377] In equations (3-1) and (3-2), X BI When the atoms are iodine or bromine, and p and / or q are 2 or more, they can be the same or different.

[0378] In equations (3-1) and (3-2), L 1 It is a saturated hydrocarbon group with 1 to 6 carbon atoms, consisting of a single bond, ether bond, or ester bond, or may also contain ether or ester bonds. The aforementioned saturated hydrocarbon group may be linear, branched, or cyclic.

[0379] In equations (3-1) and (3-2), L 2 When p is 1, it is a single bond or a divalent linker with 1 to 20 carbon atoms; when p is 2 or 3, it is a (p+1) valent linker with 1 to 20 carbon atoms, and the linker may also contain oxygen, sulfur or nitrogen atoms.

[0380] In equations (3-1) and (3-2), R 401 The carbon group may be a hydroxyl, carboxyl, fluorine, chlorine, bromine, or amino group, or may contain a fluorine, chlorine, bromine, hydroxyl, amino, or ether bond, and may be a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon oxy group having 1 to 20 carbon atoms, a hydrocarbon carbonyl group having 2 to 20 carbon atoms, a hydrocarbon oxycarbonyl group having 2 to 20 carbon atoms, or a hydrocarbon sulfonyl oxy group having 1 to 20 carbon atoms, or -N(R) 401A (R) 401B ), -N(R 401C )-C(=O)-R 401D or -N(R) 401C )-C(=O)-OR 401D R 401A and R 401B Each can be independently a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 401C It is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms. R 401DIt is an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 15 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyl oxy group having 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon group may be saturated or unsaturated, and may be any of straight-chain, branched, or cyclic. The aforementioned hydrocarbon group, hydrocarbon oxy group, hydrocarbon carbonyl group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyl oxy group, and hydrocarbon sulfonyl oxy group may be any of straight-chain, branched, or cyclic. When p and / or r is 2 or more, each R 401 They can be the same or different.

[0381] Among them, R 401 It is advisable to use hydroxyl groups, -N(R) 401C )-C(=O)-R 401D -N(R) 401C )-C(=O)-OR 401D Fluorine atoms, chlorine atoms, bromine atoms, methyl groups, methoxy groups, etc.

[0382] In equations (3-1) and (3-2), Rf 1 ~Rf 4 Each of these can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them must be a fluorine atom or a trifluoromethyl group. Also, Rf 1 With Rf 2 They can also combine to form carbonyl groups. Rf 3 and Rf 4 All of them are fluorine atoms, which is of excellent quality.

[0383] In equations (3-1) and (3-2), R 402 ~R 406 Each hydrocarbon group consists of 1 to 20 carbon atoms, and may also contain heteroatoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples are given in the descriptions of formulas (1-1) and (1-2) as R. 101 ~R 105 The same applies to hydrocarbon groups. Furthermore, some or all of the hydrogen atoms in these groups may be replaced by hydroxyl, carboxyl, halogen, cyano, nitro, mercapto, sulfonyl lactone ring, sulfonyl, or sulfonium salt-containing groups, and part of the -CH2- group may be replaced by ether, ester, carbonyl, amide, carbonate, or sulfonate bonds. Also, R 402 and R 403 They can also bond to each other and form rings together with the sulfur atoms they bond to. In this case, the aforementioned rings can be exemplified as R in the description of formula (1-1). 101 With R 102 The same type of ring is formed by the bonding of sulfur atoms and the bonds between them.

[0384] The cations of the sulfonium salt represented by formula (3-1) can be listed and exemplified as those of the sulfonium salt represented by formula (1-1). Similarly, the cations of the zirconia salt represented by formula (3-2) can be listed and exemplified as those of the zirconia salt represented by formula (1-2).

[0385] The anions of onium salts represented by formula (3-1) or (3-2) can be listed below, but are not limited to these. Additionally, in the following formula, X... BI Same as above.

[0386] [Chemistry 100]

[0387]

[0388] [Chemistry 101]

[0389]

[0390] [Chemistry 102]

[0391]

[0392] [Chemistry 103]

[0393]

[0394] [Chemistry 104]

[0395]

[0396] [Chemistry 105]

[0397]

[0398] [Chemistry 106]

[0399]

[0400] [Chemistry 107]

[0401]

[0402] [Chemistry 108]

[0403]

[0404] [Chemistry 109]

[0405]

[0406] [Chemical 110]

[0407]

[0408] [Chemistry 111]

[0409]

[0410] [Chemistry 112]

[0411]

[0412] [Chemistry 113]

[0413]

[0414] [Chemistry 114]

[0415]

[0416] [Chemistry 115]

[0417]

[0418] [Chemistry 116]

[0419]

[0420] [Chemistry 117]

[0421]

[0422] [Chemistry 118]

[0423]

[0424] [Chemistry 119]

[0425]

[0426] [Chemistry 120]

[0427]

[0428] [Chemistry 121]

[0429]

[0430] [Chemistry 122]

[0431]

[0432] When the positive resist material of the present invention contains an additive acid generator, its content relative to 100 parts by weight of the base polymer is preferably 0.1 to 50 parts by weight, and more preferably 1 to 40 parts by weight. The aforementioned additive acid generator can be used alone or in combination of two or more types. By containing repeating units d1 to d3 and / or by containing the additive acid generator, the positive resist material of the present invention can function as a chemically amplified positive resist material.

[0433] [Organic solvents]

[0434] The positive resist material of the present invention may also contain organic solvents. There are no particular limitations on the organic solvents used, provided they are capable of dissolving the aforementioned components and the components described later. 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 Publication No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; and propylene glycol monomethyl ether, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether. Ethers such as diethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate (L-form), ethyl lactate (D-form), ethyl lactate (DL-form), 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, etc.

[0435] In the positive resist material of the present invention, the content of the aforementioned organic solvent relative to 100 parts by weight of the base polymer is preferably 100 to 10,000 parts by weight, and more preferably 200 to 8,000 parts by weight. The aforementioned organic solvent may be used alone or in combination with two or more solvents.

[0436] [Quenching Agent]

[0437] The positive resist material of the present invention has a sulfonate-type quencher at the end of the polymer, but may also contain an additional quencher. Furthermore, the quencher refers to a compound that can prevent the diffusion of acid generated from the acid-generating agent in the resist material toward the unexposed area by capturing it.

[0438] The aforementioned quenching agents can include known basic compounds. Known basic compounds include: primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds with carboxyl groups, nitrogen-containing compounds with sulfonyl groups, nitrogen-containing compounds with hydroxyl groups, nitrogen-containing compounds with hydroxyl phenyl groups, alcoholic nitrogen-containing compounds, amides, imides, carbamates, etc. Especially preferred are the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Publication No. 2008-111103, amine compounds having hydroxyl groups, ether bonds, ester bonds, lactone rings, cyano groups, sulfonate bonds, or compounds having carbamate groups as described in Japanese Patent No. 3790649. By adding such basic compounds, for example, the diffusion rate of acid in the resist film can be further suppressed or the shape can be modified.

[0439] Furthermore, the aforementioned quenchers include, for example, onium salts such as sulfonic acids, carboxylic acids, or fluorinated alkoxides (such as sulfonium, urethane, or ammonium salts) that are not fluorinated at the α-position, as described in Japanese Patent Application Publication No. 2008-158339. Sulfonic acids, imides, or methyl acids that are fluorinated at the α-position are necessary to deprotect the unstable acid groups of carboxylic acid esters, and through salt exchange with onium salts that are not fluorinated at the α-position, sulfonic acids, carboxylic acids, or fluorinated alcohols are released. Sulfonic acids, carboxylic acids, or fluorinated alcohols that are not fluorinated at the α-position do not cause deprotection reactions, and therefore function as quenchers.

[0440] Such quenchers can be exemplified by, for example, the compound represented by formula (4) (onium salt of sulfonic acid that is not fluorinated at the α-position), the compound represented by formula (5) (onium salt of carboxylic acid), and the compound represented by formula (6) (onium salt of alkoxide).

[0441] [Chemistry 123]

[0442]

[0443] In equation (4), R 501 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain hydrogen atoms or heteroatoms, but excludes those in which the hydrogen atom at the α-position of the sulfonate group is replaced by a fluorine atom or a fluorinated alkyl group.

[0444] The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, and other alkyl groups with 1 to 40 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclic [5.2.1.0] 2,6 Cyclic saturated hydrocarbon groups with 3 to 40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; alkenyl groups with 2 to 40 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated aliphatic hydrocarbon groups with 3 to 40 carbon atoms, such as cyclohexenyl; aryl groups with 6 to 40 carbon atoms, such as phenyl, naphthyl, alkylphenyl (2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butylphenyl, etc.), dialkylphenyl (2,4-dimethylphenyl, etc.), 2,4,6-triisopropylphenyl, alkylnaphthyl (methylnaphthyl, ethylnaphthyl, etc.), and dialkylnaphthyl (dimethylnaphthyl, diethylnaphthyl, etc.); and aralkyl groups with 7 to 40 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl.

[0445] Furthermore, a portion of the hydrogen atom in the aforementioned hydrocarbon group may be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and a portion of the -CH2- group in the aforementioned hydrocarbon group may also be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, it may contain hydroxyl, cyano, carbonyl, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulfonolactone ring, carboxylic anhydride, or haloalkyl group. Examples of hydrocarbon groups containing heteroatoms include: thiophene, indolyl, and other heteroaryl groups; 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; aryloxoalkyl groups such as 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl; and aryloxoalkyl groups such as 2-aryl-2-oxoethyl.

[0446] In equation (5), R 502 It can also contain hydrocarbon groups with 1 to 40 carbon atoms and heteroatoms. R 502 The hydrocarbon group can be listed and exemplified as R 501 The same applies to hydrocarbon groups. Other specific examples include: fluoroalkyl groups such as trifluoromethyl, trifluoroethyl, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl, and 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl; and fluoroaryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

[0447] In equation (6), R 503 It is a saturated hydrocarbon group having at least 3 fluorine atoms and having 1 to 8 carbon atoms, or an aryl group having at least 3 fluorine atoms and having 6 to 10 carbon atoms, and may also contain a nitro group.

[0448] In equations (4) to (6), Mq + The cation is a sulfonium cation. The aforementioned sulfonium cation is preferably a sulfonium cation, a monazine cation, or an ammonium cation, with sulfonium cation or monazine cation being more preferred. Examples of the aforementioned sulfonium cations can be those that are cations of the sulfonium salt represented by formula (1-1). Similarly, examples of the aforementioned monazine cations can be those that are cations of the monazine salt represented by formula (1-2).

[0449] Alternatively, the sulfonium salt of a carboxylic acid containing an iodinated benzene ring, represented by formula (7), can be ideally used as a quencher.

[0450] [Chemistry 124]

[0451]

[0452] In equation (7), R 601The 1-6 carbon saturated hydrocarbon group, 1-6 carbon saturated hydrocarbon oxygen group, 2-6 carbon saturated hydrocarbon carbonyl oxygen group, or 1-4 carbon saturated hydrocarbon sulfonyl oxygen group, or -N(R) group may be substituted by a halogen atom, and may also be partially or wholly substituted by a hydroxyl, fluorine, chlorine, bromine, amino, nitro, cyano, or hydrogen atom. 601A )-C(=O)-R 601B or -N(R) 601A )-C(=O)-OR 601B R 601A It consists of a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 601B It is a saturated hydrocarbon group with 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbon group with 2 to 8 carbon atoms.

[0453] In equation (7), x' is an integer from 1 to 5. y' is an integer from 0 to 3. z' is an integer from 1 to 3. L 11 It is a single bond or a (z'+1) valence linking group having 1 to 20 carbon atoms, and may also contain at least one selected from ether bonds, carbonyl groups, ester bonds, amide bonds, sulfonyl lactone rings, lactam rings, carbonate bonds, halogen atoms, hydroxyl groups, and carboxyl groups. The aforementioned saturated hydrocarbon groups, saturated hydrocarbon oxy groups, saturated hydrocarbon carbonyl oxy groups, and saturated hydrocarbon sulfonyl oxy groups may be linear, branched, or cyclic. When y' and / or z' are 2 or more, each R... 601 They can be the same or different.

[0454] In equation (7), R 602 R 603 and R 604 Each hydrocarbon group consists of 1 to 20 carbon atoms, and may also contain heteroatoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated as R in formulas (1-1) and (1-2). 101 ~R 105 The same applies to the hydrocarbon group. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by hydroxyl, carboxyl, halogen, oxo, cyano, nitro, sulfonyl lactone ring, sulfonyl, or sulfonate-containing groups; and a portion of the -CH2- group in the aforementioned hydrocarbon group may be replaced by ether, ester, carbonyl, amide, carbonate, or sulfonate bonds. Also, R 602 With R 603 They can also bond to each other and form rings together with the sulfur atoms they bond to.

[0455] Specific examples of compounds represented by formula (7) can be found in Japanese Patent Application Publication No. 2017-219836.

[0456] Other examples of the aforementioned quenchers include the polymer-type quencher disclosed in Japanese Patent Application Publication No. 2008-239918. This quencher improves the rectangularity of the resist pattern by aligning with the surface of the resist film. The polymer-type quencher also prevents film loss and dome-shaped formation of the pattern when using a protective film for immersion exposure.

[0457] When the positive resist material of the present invention contains the aforementioned quencher, its content relative to 100 parts by weight of the base polymer is preferably 0 to 5 parts by weight, and more preferably 0 to 4 parts by weight. The aforementioned quencher can be used alone or in combination of two or more.

[0458] [Other ingredients]

[0459] In addition to the aforementioned components, the positive resist material of the present invention may also contain surfactants, dissolution inhibitors, water-repellent improvers, acetylene alcohols, etc.

[0460] The aforementioned surfactants can be exemplified by paragraphs

[0165] to

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

[0461] By incorporating a dissolution inhibitor into the positive resist material of the present invention, the difference in dissolution rate between the exposed and unexposed areas can be further increased, and the resolution can be further improved. Regarding the aforementioned dissolution inhibitor, its molecular weight is preferably 100 to 1,000, more preferably 150 to 800, and examples include compounds containing two or more phenolic hydroxyl groups in the molecule, in which the hydrogen atom of the phenolic hydroxyl group is replaced by an acid-unstable group at a ratio of 0 to 100 mol% overall, or compounds containing a carboxyl group in the molecule, in which the hydrogen atom of the carboxyl group is replaced by an acid-unstable group at an average ratio of 50 to 100 mol% overall. Specific examples include compounds in which the hydrogen atoms of the hydroxyl and carboxyl groups of bisphenol A, triphenol, phenolphthalein, cresol phenolic varnish resin, naphtholic acid, adamantane carboxylic acid, and cholic acid are replaced by acid-unstable groups, as described in paragraphs

[0155] to

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

[0462] When the positive resist material of the present invention contains the aforementioned dissolution inhibitor, its content relative to 100 parts by weight of the base polymer is preferably 0 to 50 parts by weight, and more preferably 5 to 40 parts by weight. The aforementioned dissolution inhibitor may be used alone or in combination of two or more.

[0463] The aforementioned water-repellent improver enhances the water repellency of the resist film surface and can be used in immersion lithography without a topcoat. The aforementioned water-repellent improver is preferably a polymer containing fluorinated alkyl groups, or a polymer with a specific structure containing 1,1,1,3,3,3-hexafluoro-2-propanol residues, as exemplified in Japanese Patent Application Publication Nos. 2007-297590 and 2008-111103. The aforementioned water-repellent improver needs to be soluble in alkaline or organic solvent developing solutions. The aforementioned specific water-repellent improver containing 1,1,1,3,3,3-hexafluoro-2-propanol residues exhibits good solubility in developing solutions. Regarding water-repellent improvers, polymers containing repeating units containing amino or amine salts are highly effective in preventing acid evaporation during PEB development and thus preventing poor opening of the hole pattern after development. When the positive resist material of the present invention contains a water-repellent improver, its content relative to 100 parts by weight of the base polymer is preferably 0 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight. The aforementioned water-repellent improver can be used alone or in combination of two or more.

[0464] The aforementioned acetylenic alcohols can be exemplified by paragraphs

[0179] to

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

[0465] [Pattern Formation Method]

[0466] When the positive resist material of the present invention is used in the manufacture of various integrated circuits, known photolithography techniques can be employed. For example, a patterning method may include the following steps:

[0467] A resist film is formed on the substrate using the aforementioned positive resist material.

[0468] The aforementioned resist film was exposed to high-energy radiation, and

[0469] The previously exposed resist film was developed using a developer.

[0470] First, the positive resist material of the present invention is coated onto a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective film, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.) using appropriate coating methods such as spin coating, roll coating, flow coating, dip coating, spray coating, or blade coating, with a coating film thickness of 0.01 to 2 μm. The resist film is then formed by pre-baking the material on a hot plate, preferably at 60 to 150°C for 10 seconds to 30 minutes, or more preferably at 80 to 120°C for 30 seconds to 20 minutes.

[0471] Then, the aforementioned photoresist film is exposed using high-energy radiation. Examples of such high-energy radiation include: ultraviolet light, far ultraviolet light, EB, EUV (wavelength 3–15 nm), X-rays, soft X-rays, excimer lasers, gamma rays, and synchrotron radiation. When using ultraviolet light, far ultraviolet light, EUV, X-rays, soft X-rays, excimer lasers, gamma rays, or synchrotron radiation as the aforementioned high-energy radiation, it can be used to directly irradiate or a mask used to form the desired pattern can be applied, with the exposure dose preferably being approximately 1–200 mJ / cm². 2 And it becomes approximately 10–100 mJ / cm 2 A better method of irradiation is to use EB as the aforementioned high-energy ray. The exposure dose should be approximately 0.1–100 μC / cm². 2 And even better, approximately 0.5–50 μC / cm 2 The pattern can be drawn directly or using a mask to form the desired pattern. Furthermore, the positive resist material of the present invention is particularly suitable for micro-patterning using high-energy radiation such as KrF excimer lasers, ArF excimer lasers, EB, EUV, i-rays, X-rays, soft X-rays, gamma rays, and synchrotron radiation, especially for micro-patterning using EB or EUV.

[0472] After exposure, PEB can also be applied on a heating plate or in an oven at a temperature of 50–150°C for 10–30 seconds, with 60–120°C for 30–20 seconds being even better.

[0473] After exposure or PEB, the exposed resist film is developed for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, using a developer solution containing 0.1% to 10% by mass and more preferably 2% to 5% by mass of alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), or tetrabutylammonium hydroxide (TBAH). This process dissolves the exposed areas in the developer solution while leaving the unexposed areas undissolved, thus forming the desired positive pattern on the substrate.

[0474] Alternatively, negative development can be achieved by using the aforementioned positive resist material and developing with organic solvents to obtain a negative pattern. Examples of developers used in this case include: 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methyl acetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, methyl valerate, methyl valerate, methyl crotonate, croton... Ethyl propionate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, ethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in combination of two or more.

[0475] Rinsing is performed at the end of development. The rinsing solution should be a solvent that is miscible with the developer and does not dissolve the resist film. Ideally, solvents such as alcohols with 3 to 10 carbon atoms, ether compounds with 8 to 12 carbon atoms, alkanes, alkenes, alkynes, and aromatic solvents with 6 to 12 carbon atoms should be used.

[0476] Specifically, alcohols with 3 to 10 carbon atoms can be listed as follows: n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentanol, neopentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, 1-octanol, etc.

[0477] Ether compounds with 8 to 12 carbon atoms include: di-n-butyl ether, diisobutyl ether, di(sec-butyl) ether, di-n-pentyl ether, diisopentyl ether, di(sec-pentyl) ether, di(tert-pentyl) ether, di-n-hexyl ether, etc.

[0478] Alkanes with 6 to 12 carbon atoms include: hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane, etc. Alkenes with 6 to 12 carbon atoms include: hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, etc. Alkynes with 6 to 12 carbon atoms include: hexyne, heptyne, octyne, etc.

[0479] Aromatic solvents include: toluene, xylene, ethylbenzene, cumene, tert-butylbenzene, mesitylene, etc.

[0480] Rinsing can reduce the collapse of the resist pattern and the occurrence of defects. Furthermore, rinsing is not always necessary; omitting rinsing can reduce the amount of solvent used.

[0481] The developed hole and groove patterns can also be shrunk using heat transfer, RELACS, or DSA techniques. A shrinking agent is applied to the hole pattern, and during baking, the diffusion of an acid catalyst from the resist film causes cross-linking of the shrinking agent on the surface of the resist film. The shrinking agent adheres to the sidewalls of the hole pattern. The baking temperature is preferably 70–180°C, with 80–170°C being more ideal, and the baking time is preferably 10–300 seconds. This removes excess shrinking agent and reduces the size of the hole pattern.

[0482] [Example]

[0483] The present invention will be specifically described below with examples of synthesis, embodiments and comparative examples, but the present invention is not limited to the following embodiments.

[0484] The chain transfer agents CTA-1 to CTA-16 used in the synthesis of the basic polymers are described below.

[0485] [Chemistry 125]

[0486]

[0487] [Chemistry 126]

[0488]

[0489] [Chemistry 127]

[0490]

[0491] [Chemistry 128]

[0492]

[0493] [1] Synthesis of basic polymers

[0494] The monomers PM-1 to PM-3 and AM-1 to AM-10, FM-1, and FM-2 used in the synthesis of the basic polymer are described below. Furthermore, the Mw of the polymer is a polystyrene conversion value determined by GPC using THF as a solvent.

[0495] [Chemistry 129]

[0496]

[0497] [Chemistry 130]

[0498]

[0499] [Chemistry 131]

[0500]

[0501] [Synthetic Example 1] Synthesis of Polymer P-1

[0502] 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 6.0 g of 4-hydroxystyrene, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen purging were repeated three times. After heating to room temperature, 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 2.2 g of CTA-1 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-1. The composition of polymer P-1 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0503] [Chemistry 132]

[0504]

[0505] [Synthetic Example 2] Synthesis of Polymer P-2

[0506] 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 4-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the process of degassing under reduced pressure and nitrogen blowing was repeated three times. After heating to room temperature, 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 2.5 g of CTA-2 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-2. The composition of polymer P-2 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0507] [Chemistry 133]

[0508]

[0509] [Synthetic Example 3] Synthesis of Polymer P-3

[0510] 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the process of degassing under reduced pressure and nitrogen blowing was repeated three times. After heating to room temperature, 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 3.0 g of CTA-3 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-3. The composition of polymer P-3 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0511] [Chemistry 134]

[0512]

[0513] [Synthetic Example 4] Synthesis of Polymer P-4

[0514] 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.8 g of 3-hydroxystyrene, 8.2 g of monomer PM-3, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen purging were repeated three times. After heating to room temperature, 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 3.1 g of CTA-6 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-4. The composition of polymer P-4 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0515] [Chemistry 135]

[0516]

[0517] [Synthetic Example 5] Synthesis of Polymer P-5

[0518] 11.1 g of monomer AM-1, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen blowing were repeated three times. After heating to room temperature, 1.2 g of 2,2'-azobis(isobutyrate) dimethyl ester and 2.2 g of CTA-5 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-5. The composition of polymer P-5 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0519] [Chemistry 136]

[0520]

[0521] [Synthetic Example 6] Synthesis of Polymer P-6

[0522] 8.2 g of monomer AM-2, 4.0 g of monomer AM-3, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen blowing were repeated three times. After heating to room temperature, 1.2 g of 2,2'-azobis(isobutyrate) dimethyl ester and 3.3 g of CTA-4 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-6. The composition of polymer P-6 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0523] [Chemistry 137]

[0524]

[0525] [Synthesis Example 7] Synthesis of Polymer P-7

[0526] Add 6.7 g of monomer AM-1, 3.8 g of monomer AM-4, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as solvent to a 2 L flask. Cool the reaction vessel to -70 °C under nitrogen atmosphere, repeating the degassing and nitrogen purging process three times. After heating to room temperature, add 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 2.5 g of CTA-7 as polymerization initiators, and heat to 60 °C for 15 hours. Add the reaction solution to 1 L of isopropanol, and filter out the precipitated white solid. Dry the obtained white solid under reduced pressure at 60 °C to obtain polymer P-7. The composition of polymer P-7 is determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0527] [Chemistry 138]

[0528]

[0529] [Synthetic Example 8] Synthesis of Polymer P-8

[0530] 9.0 g of monomer AM-5, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen blowing were repeated three times. After heating to room temperature, 1.2 g of 2,2'-azobis(isobutyrate) dimethyl ester and 4.8 g of CTA-8 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-8. The composition of polymer P-8 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0531] [Chemistry 139]

[0532]

[0533] [Synthetic Example 9] Synthesis of Polymer P-9

[0534] 10.8 g of monomer AM-6, 4.2 g of 3-hydroxystyrene, 11.0 g of monomer PM-2, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen blowing were repeated three times. After heating to room temperature, 1.2 g of 2,2'-azobis(isobutyrate) dimethyl ester and 3.1 g of CTA-9 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-9. The composition of polymer P-9 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0535] [Chemistry 140]

[0536]

[0537] [Synthetic Example 10] Synthesis of Polymer P-10

[0538] 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 3.0 g of 3-hydroxystyrene, 3.2 g of monomer FM-1, 11.0 g of monomer PM-2, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the process of degassing under reduced pressure and nitrogen purging was repeated three times. After heating to room temperature, 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 2.2 g of CTA-5 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-10. The composition of polymer P-10 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0539] [Chemistry 141]

[0540]

[0541] [Synthetic Example 11] Synthesis of Polymer P-11

[0542] 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 3.0 g of 3-hydroxystyrene, 2.7 g of monomer FM-2, 11.0 g of monomer PM-2, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen purging were repeated three times. After heating to room temperature, 1.2 g of 2,2'-azobis(isobutyrate) dimethyl ester and 2.2 g of CTA-5 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-11. The composition of polymer P-11 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0543] [Chemistry 142]

[0544]

[0545] [Synthetic Example 12] Synthesis of Polymer P-12

[0546] 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen purging were repeated three times. After heating to room temperature, 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 3.3 g of CTA-10 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-12. The composition of polymer P-12 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0547] [Chemistry 143]

[0548]

[0549] [Synthetic Example 13] Synthesis of Polymer P-13

[0550] 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen blowing were repeated three times. After heating to room temperature, 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 4.5 g of CTA-11 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-13. The composition of polymer P-13 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0551] [Chemistry 144]

[0552]

[0553] [Synthetic Example 14] Synthesis of Polymer P-14

[0554] 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen purging were repeated three times. After heating to room temperature, 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 3.3 g of CTA-12 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-14. The composition of polymer P-14 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0555] [Chemistry 145]

[0556]

[0557] [Synthetic Example 15] Synthesis of Polymer P-15

[0558] 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen blowing were repeated three times. After heating to room temperature, 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 1.9 g of CTA-13 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-15. The composition of polymer P-15 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0559] [Chemistry 146]

[0560]

[0561] [Synthetic Example 16] Synthesis of Polymer P-16

[0562] 13.2 g of monomer AM-7, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen blowing were repeated three times. After heating to room temperature, 1.2 g of 2,2'-azobis(isobutyrate) dimethyl ester and 2.2 g of CTA-14 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-16. The composition of polymer P-16 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0563] [Chemistry 147]

[0564]

[0565] [Synthetic Example 17] Synthesis of Polymer P-17

[0566] 12.4 g of monomer AM-8, 4.2 g of 3-hydroxystyrene, 11.9 g of monomer PM-1, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen blowing were repeated three times. After heating to room temperature, 1.2 g of 2,2'-azobis(isobutyrate) dimethyl ester and 4.4 g of CTA-15 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-17. The composition of polymer P-17 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0567] [Chemistry 148]

[0568]

[0569] [Synthetic Example 18] Synthesis of Polymer P-18

[0570] 3.6 g of 1-methyl-1-cyclopentyl methacrylate, 5.8 g of monomer AM-4, 3.6 g of 3-hydroxystyrene, 2.4 g of 2-hydroxystyrene, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen purging were repeated three times. After heating to room temperature, 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 1.9 g of CTA-14 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-18. The composition of polymer P-18 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0571] [Chemistry 149]

[0572]

[0573] [Synthetic Example 19] Synthesis of Polymer P-19

[0574] 3.6 g of 1-methyl-1-cyclopentyl methacrylate, 5.3 g of monomer AM-9, 4.8 g of 4-hydroxystyrene, 1.0 g of styrene, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the degassing and nitrogen blowing were repeated three times. After heating to room temperature, 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 1.9 g of CTA-14 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-19. The composition of polymer P-19 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0575] [Chemistry 150]

[0576]

[0577] [Synthetic Example 20] Synthesis of Polymer P-20

[0578] 3.6 g of 1-methyl-1-cyclopentyl methacrylate, 5.4 g of monomer AM-10, 3.0 g of 3-hydroxystyrene, 3.0 g of 2-hydroxystyrene, and 40 g of THF as solvent were added to a 2 L flask. The reaction vessel was cooled to -70 °C under nitrogen atmosphere, and the process of degassing under reduced pressure and nitrogen blowing was repeated three times. After heating to room temperature, 1.2 g of dimethyl 2,2'-azobis(isobutyrate) and 2.7 g of CTA-16 as polymerization initiators were added, and the mixture was heated to 60 °C and reacted for 15 hours. The reaction solution was added to 1 L of isopropanol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 °C to obtain polymer P-20. The composition of polymer P-20 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0579] [Chemistry 151]

[0580]

[0581] [Comparative Synthesis Example 1] Synthesis of Comparative Polymer cP-1

[0582] Comparative polymer cP-1 was obtained using the same method as in Synthesis Example 1, without the use of CTA-1. The composition of comparative polymer cP-1 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0583] [Chemistry 152]

[0584]

[0585] [Comparative Synthesis Example 2] Synthesis of Comparative Polymer cP-2

[0586] CTA-1 was replaced with 2-mercaptoethanol as the chain transfer agent, and the comparative polymer cP-2 was obtained using the same method as in Synthesis Example 1. The composition of the comparative polymer cP-2 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0587] [Chemistry 153]

[0588]

[0589] [Comparative Synthesis Example 3] Comparative Synthesis of Polymer cP-3

[0590] Comparative polymer cP-3 was obtained using the same method as in Synthesis Example 2, without the use of CTA-2. The composition of comparative polymer cP-3 was determined using... 13 C-NMR and 1 H-NMR was used for confirmation, and Mw and Mw / Mn were confirmed using GPC.

[0591] [Chemistry 154]

[0592]

[0593] [2] Preparation and evaluation of positive corrosion resist materials

[0594] [Examples 1-22, Comparative Examples 1-3]

[0595] (1) Preparation of positive resist materials

[0596] A positive resist material was prepared by dissolving the components in a solvent containing 50 ppm of PolyFox PF-636 (manufactured by OMNOVA Corporation) as a surfactant, according to the composition shown in Table 1. The solution was then filtered using a 0.02 μm high-density polyethylene filter.

[0597] The components are shown in Table 1.

[0598] • Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0599] DAA (diacetone alcohol)

[0600] EL (L-form ethyl lactate)

[0601] • Acid generating agents: PAG-1, PAG-2

[0602] [Chemistry 155]

[0603]

[0604] Quenching agents: Q-1 to Q-3

[0605] [Chemistry 156]

[0606]

[0607] (2) Evaluation of EUV lithography

[0608] The positive resist materials shown in Table 1 were spin-coated onto a Si substrate that had been formed with a silicon-containing spin-coated hard mask SHB-A940 (43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. with a film thickness of 20 nm. The resist film was pre-baked at 105°C for 60 seconds using a hot plate to obtain a resist film with a thickness of 60 nm. The resist film was exposed using an ASML EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, mask with a hole pattern of 46 nm pitch and +20% deviation on wafer). The resist film was then subjected to PEB at the temperature shown in Table 1 for 60 seconds on a hot plate, followed by development with a 2.38% by mass TMAH aqueous solution for 30 seconds to obtain a hole pattern with a size of 23 nm.

[0609] The exposure amount at which the hole size was formed was measured at 23 nm, and this value was set as the sensitivity. Furthermore, the size of 50 holes was measured using a Hitachi High-Tech (CG6300) length-measuring SEM, and three times the standard deviation (σ) calculated from the results (3σ) was taken as the CDU. The results are summarized in Table 1.

[0610] [Table 1]

[0611]

[0612]

[0613] As shown in Table 1, the positive resist material of the present invention, which is based on a sulfonium salt containing a carboxylic acid anion linked to a thioether group, exhibits good CDU.

Claims

1. A positive resist material comprising: a base polymer terminally capped by a sulfonate containing a carboxylic acid anion attached to a sulfide group; in, The structure of this end is represented by the following formula (a); In the formula, X 1 It is a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may also contain at least one of the following: hydroxyl group, ether bond, thioether group, ester bond, carbonate bond, carbamate bond, lactone ring, sulcinolone ring and halogen atom; R 1 ~R 3 Each is independently a hydrocarbon group having 1 to 20 carbon atoms, and may also contain at least one selected from oxygen, sulfur, nitrogen, and halogen atoms; furthermore, R 1 With R 2 They can also bond to each other and form rings together with the sulfur atoms they bond to; The dashed lines represent atomic bonds.

2. The positive resist material according to claim 1, wherein, The basic polymer comprises a repeating unit b1, which is formed by replacing hydrogen atoms containing carboxyl groups with acid-indestabilized groups, or a repeating unit b2, which is formed by replacing hydrogen atoms of phenolic hydroxyl groups with acid-indestabilized groups.

3. The positive resist material according to claim 2, wherein, Repeating unit b1 is represented by the following formula (b1), and repeating unit b2 is represented by the following formula (b2); In the formula, R A Each can be independently a hydrogen atom or a methyl group; Y 1 It is a single bond, a phenylene or naphthylene group, or contains a linking group with 1 to 12 carbon atoms selected from ester bonds, ether bonds and lactone rings; Y 2 It can be a single bond, ester bond, or amide bond; Y 3 It can be a single bond, an ether bond, or an ester bond; R 11 and R 12 Each is an acid-labile group; R 13 It is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbon group having 1 to 6 carbon atoms; R 14 It is a single bond or an alkyl diel with 1 to 6 carbon atoms, and the alkyl diel may also contain an ether bond or an ester bond; a is 1 or 2; b is an integer from 0 to 4; however, 1 ≤ a + b ≤ 5.

4. The positive resist material according to claim 1 or 2, wherein, The base polymer is a repeating unit c containing a close-knit group selected from hydroxyl, carboxyl, lactone ring, carbonate bond, thiocarbonate bond, carbonyl, cyclic acetal, ether bond, ester bond, sulfonate bond, cyano, amide bond, -OC(=O)-S- and -OC(=O)-NH-.

5. The positive resist material according to claim 1 or 2, wherein, The basic polymer is one that further contains repeating units represented by any of the following formulas (d1) to (d3); In the formula, R A Each can be independently a hydrogen atom or a methyl group; Z 1 It is a single bond, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining them, or -OZ. 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -;Z 11 It is an aliphatic hydrocarbon group, phenylene group, naphthylene group or a combination thereof with 7 to 18 carbon atoms, and may also contain a carbonyl group, ester bond, ether bond or hydroxyl group; Z 2 It is a single bond or an ester bond; Z 3 For single key, -Z 31 -C(=O)-O-、-Z 31 -O- or -Z 31 -OC(=O)-;Z 31 It is an aliphatic hydrocarbon group with 1 to 12 carbon atoms, a phenylene group, or a group with 7 to 18 carbon atoms obtained by combining them, and may also contain a carbonyl group, an ester bond, an ether bond, a bromine atom, or an iodine atom; Z 4 It is methylene, 2,2,2-trifluoro-1,1-ethanediyl or carbonyl; Z 5 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -;Z 51 It is an aliphatic alkylene group, phenylene, fluorinated phenylene, or phenylene substituted with trifluoromethyl, having 1 to 6 carbon atoms, and may also contain carbonyl groups, ester bonds, ether bonds, halogen atoms, or hydroxyl groups; R 21 ~R 28 Each of the following groups is a hydrocarbon group with 1 to 20 carbon atoms, which may be independently composed of halogen atoms or may also contain heteroatoms; furthermore, R 23 and R 24 or R 26 and R 27 They can also bond to each other and form rings together with the sulfur atoms they bond to; M - It is a non-nucleophilic relative ion.

6. The positive resist material according to claim 1 or 2 further contains an acid generating agent.

7. The positive resist material according to claim 1 or 2 further contains an organic solvent.

8. The positive resist material according to claim 1 or 2 further contains a quenching agent.

9. The positive resist material according to claim 1 or 2 further contains a surfactant.

10. A method for forming a pattern, comprising the following steps: A resist film is formed on a substrate using the positive resist material according to any one of claims 1 to 9. The resist film was exposed to high-energy rays, and The exposed resist film was developed using a developer.

11. The pattern forming method according to claim 10, wherein, The high-energy rays are i-rays, KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet rays with wavelengths of 3–15 nm.

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