Onium salts, resist compositions, and pattern forming methods

Abstract

This invention relates to onium salts, resist compositions, and patterning methods. The invention provides a novel onium salt for use in photolithography, which provides high sensitivity and excellent resolution for both positive and negative patterns, improved LWR and CDU, and suppresses resist pattern collapse. One onium salt is characterized by the following general formula (1). Wherein, R... ALU This indicates any of the following: a tertiary ether, tertiary carbonate, or acetal, which forms a cyclic structure together with an adjacent oxygen atom. R F It is any one of fluorine atom, fluorinated alkyl group having 1 to 6 carbon atoms, or nitro group. Also, R a It is a hydrocarbon group with 1 to 20 carbon atoms. n1 is an integer of 0 or 1. n2 and n3 are integers of 1 or 2. R F With -O-R ALU Each of the atoms in Z is bonded to an adjacent carbon atom. n4 is an integer from 0 to 3. + This indicates a ium cation.

Description

Technical Field

[0001] This invention relates to onium salts, resist compositions, and methods for pattern formation. Background Technology

[0002] With the increasing integration and speed of LSI (Lithium-ion Sensor), the miniaturization of patterning is progressing rapidly. The widespread adoption of 5G high-speed communication and artificial intelligence (AI) necessitates high-performance devices to process these technologies. As the most advanced miniaturization technology, mass production of 5nm node devices using 13.5nm extreme ultraviolet (EUV) lithography is already underway. Furthermore, the use of EUV lithography for next-generation 3nm and next-next-generation 2nm node devices is also being explored.

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

[0004] Sensitivity, resolution, and edge roughness (LER, LWR) represent a trade-off. To improve resolution, acid diffusion needs to be suppressed, but if the acid diffusion distance is shortened, sensitivity will decrease.

[0005] Adding a bulky acid-generating agent is effective in inhibiting acid diffusion. A scheme has been proposed that the polymer contain repeating units from onium salts with polymerizable unsaturated bonds. In this case, the polymer also acts as an acid-generating agent (polymer-bonded acid-generating agent). Patent Document 1 proposes a sulfonium salt or sulfonium salt with polymerizable unsaturated bonds that generates a specific sulfonic acid. Patent Document 2 proposes a sulfonium salt in which the sulfonic acid is directly bonded to the main chain.

[0006] The acid-unstable groups used in the (meth)acrylate polymers of ArF photoresist materials undergo deprotection reactions when using photoacid generators that produce sulfonic acid with α-position fluorine atom substitution, but do not undergo deprotection reactions when using acid generators that produce sulfonic acid or carboxylic acid with α-position unsubstituted fluorine atom substitution. If a sulfonium salt or ferrophosphate salt that produces sulfonic acid with α-position fluorine atom substitution is mixed with a sulfonium salt or ferrophosphate salt that produces sulfonic acid with α-position unsubstituted fluorine atom substitution, the sulfonium salt or ferrophosphate salt that produces sulfonic acid with α-position unsubstituted fluorine atom substitution will undergo ion exchange with the sulfonic acid with α-position fluorine atom substitution. Because the photo-generated sulfonic acid with α-position fluorine atom substitution returns to the sulfonium salt or ferrophosphate salt due to ion exchange, the sulfonium salt or ferrophosphate salt that produces sulfonic acid or carboxylic acid with α-position unsubstituted fluorine atom substitution acts as a quencher. A photoresist material using sulfonium salt or ferrophosphate salt that produces carboxylic acid as a quencher has been proposed (Patent Document 3).

[0007] Various sulfonate-type quenchers that produce carboxylic acids have been proposed. In particular, sulfonates of salicylic acid, β-hydroxycarboxylic acid (Patent Document 4), salicylic acid derivatives (Patent Documents 5 and 6), fluorosalicylic acid (Patent Document 7), and hydroxynaphthoic acid (Patent Document 8) have been disclosed. Especially noteworthy is the effect of salicylic acid in inhibiting acid diffusion due to the intramolecular hydrogen bond between the carboxylic acid and the hydroxyl group.

[0008] On the other hand, some have pointed out that the agglomeration of the quencher leads to a decrease in the dimensional uniformity of the resist pattern. By preventing the agglomeration of the quencher in the resist film and thus achieving a more uniform distribution, it is expected that the dimensional uniformity of the developed pattern can be improved.

[0009] For further miniaturization requirements, especially with positive resists undergoing alkaline development, swelling due to the developer and pattern collapse during the formation of fine patterns have become a challenge. To address this miniaturization challenge, it is important to develop novel resist materials. The aim is to develop onium salt-type quenchers that exhibit good sensitivity, well-controlled acid diffusion, excellent solvent solubility, and effective suppression of pattern collapse.

[0010] Existing technical documents

[0011] Patent documents

[0012] [Patent Document 1] Japanese Patent Application Publication No. 2006-045311

[0013] [Patent Document 2] Japanese Patent Application Publication No. 2006-178317

[0014] [Patent Document 3] Japanese Patent Application Publication No. 2007-114431

[0015] [Patent Document 4] WO2018 / 159560

[0016] [Patent Document 5] Japanese Patent Application Publication No. 2020-203984

[0017] [Patent Document 6] Japanese Patent Application Publication No. 2020-91404

[0018] [Patent Document 7] Japanese Patent Application Publication No. 2020-91312

[0019] [Patent Document 8] Japanese Patent Application Publication No. 2019-120760

[0020] Non-patent literature

[0021] [Non-Patent Literature 1] SPIE Vol.6520 65203L-1(2007) Summary of the Invention

[0022] [The problem the invention aims to solve]

[0023] In view of the above, the present invention aims to provide a novel onium salt for use in resist compositions that exhibit high sensitivity and excellent resolution for both positive and negative patterns in far-ultraviolet lithography and EUV lithography, improve LWR (roughness) and CDU (dimensional uniformity), and suppress resist pattern collapse.

[0024] [Methods for solving problems]

[0025] To address the aforementioned issues, the present invention provides an onium salt represented by the following general formula (1).

[0026] [Chemistry 1]

[0027]

[0028] In the formula, R ALU This refers to any of the following: a tertiary ether, tertiary carbonate, or acetal, which, together with an adjacent oxygen atom, has a cyclic structure and may also have heteroatoms. R F It is any one of fluorine atom, fluorinated alkyl group having 1 to 6 carbon atoms, or nitro group. Also, R a It can also be a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms. n1 is an integer of 0 or 1. n2 and n3 are integers of 1 or 2. When n2 and n3 are 1, R F With -OR ALU Bonded to adjacent carbon atoms. Also, when either n2 or n3, or both, are 2, R... F With -OR ALU Each of the atoms in the R group is bonded to an adjacent carbon atom. n4 is an integer from 0 to 3. When n4 ≥ 2, multiple R groups are also possible. a They bond to each other and together with the carbon atoms they are bonded to, form a ring structure. Z + This indicates a ium cation.

[0029] If this is the case, novel onyx salts are useful in photolithography for resist compositions that offer high sensitivity and excellent resolution for both positive and negative resists, improve LWR and CDU, and suppress resist pattern collapse.

[0030] Furthermore, R in the aforementioned general formula (1) ALU The structure is preferably represented by the following general formula (ALU-1) or (ALU-2).

[0031] [Chemistry 2]

[0032]

[0033] In equation (ALU-1), R 21’ R 22’ and R 23’ Each can be an independent hydrocarbon group with 1 to 12 carbon atoms, which may also have heteroatoms. 21’ R 22’ and R 23’ Any two elements in R can also bond with each other to form a loop. 21’ R 22’ and R 23’ When they are not bonded together to form a loop, at least one of them has a loop structure. t is an integer of 0 or 1. In equation (ALU-2), R 24’ and R 25’ Each is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. R 26’ It is a hydrocarbon group with 1 to 20 carbon atoms, or it can be combined with R. 24’ Or R 25’ The carbon atoms and X atoms that are bonded to each other a Together, they form heterocyclic groups with 3 to 20 carbon atoms. Furthermore, the -CH2- group in the aforementioned hydrocarbon and heterocyclic groups can also be replaced with -O- or -S-. X a Represents an oxygen atom or a sulfur atom. * indicates a bond with an adjacent oxygen atom.

[0034] If so, it would allow the onium salt to function better as an acid diffusion control agent contained in the resist composition.

[0035] Furthermore, R in the aforementioned general formula (1) F It is preferred to have a fluorine atom or any of the fluorinated alkyl groups having 1 to 6 carbon atoms.

[0036] If so, it would allow the onium salt to function better as an acid diffusion control agent contained in the resist composition.

[0037] Furthermore, Z in the aforementioned general formula (1) + A munonium cation represented by any of the following general formulas (Cation-1) to (Cation-3) is preferred.

[0038] [Chemistry 3]

[0039]

[0040] In equations (Cation-1) to (Cation-3), R 11’ ~R 19’ Each can be an independent hydrocarbon group consisting of 1 to 30 carbon atoms, which may contain heteroatoms and can be either saturated or unsaturated.

[0041] If so, it would allow the onium salt to function better as an acid diffusion control agent contained in the resist composition.

[0042] Furthermore, the present invention provides an acid diffusion control agent composed of the above-mentioned onium salt.

[0043] The onium salts of the present invention are useful as acid diffusion control agents.

[0044] Furthermore, the present invention provides a resist composition containing the above-mentioned acid diffusion control agent.

[0045] By containing the aforementioned acid diffusion control agent, it becomes a good resist composition.

[0046] It is better if it contains an acid-generating agent that produces acid.

[0047] If so, the aforementioned onium salt acts as an acid diffusion control agent, and the resist composition of the present invention will function.

[0048] The aforementioned acid generating agent is preferably an acid generating agent that produces sulfonic acid, imine acid or methyl acid.

[0049] If so, an acid-generating agent would be more ideal.

[0050] It is better if it contains organic solvents.

[0051] If this is the case, the components can be dissolved, and the coatability of the composition can be improved.

[0052] It is better if it contains more basic polymers.

[0053] If so, it is an ideal composition for resist.

[0054] The aforementioned base polymer preferably contains repeating units represented by the following general formula (a1) and / or repeating units represented by the following general formula (a2).

[0055] [Chemistry 4]

[0056]

[0057] In the formula, R AEach can be independently a hydrogen atom or a methyl group. Y 1 It is a single bond, a phenylene or naphthylene group, or a linking group containing at least one of the following: an ester bond or a lactone ring, having 1 to 12 carbon atoms. 2 It is a single bond or an ester bond. Y 3 It can be a single bond, an ether bond, or an ester bond. R 11 and R 12 Each is an unstable acid group. R 13 It is a 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 some of its carbon atoms may be replaced by ether or ester bonds. a is 1 or 2. b is an integer from 0 to 4, but 1≤a+b≤5.

[0058] If this is the case, acid-inhibitory groups would be suitable positive resist compositions.

[0059] The aforementioned resist composition is preferably a chemically amplified positive resist composition.

[0060] The resist composition of the present invention can function as a chemically amplified positive resist composition.

[0061] Ideally, the aforementioned base polymer should not contain acid-labile groups.

[0062] If so, it does not contain acid-instable groups, making it an ideal negative resist composition.

[0063] The aforementioned resist composition is preferably a chemically amplified negative resist composition.

[0064] The resist composition of the present invention can function as a chemically amplified negative resist composition.

[0065] The aforementioned base polymer preferably contains at least one repeating unit selected from the repeating units represented by the following general formulas (f1) to (f3).

[0066] [Chemistry 5]

[0067]

[0068] In the formula, R A Each can be independently a hydrogen atom or a methyl group. Z 1 A single bond, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, an ester bond, or a combination thereof, or a group having 7 to 18 carbon atoms, or -OZ. 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -. Z 11It is a group with 7 to 18 carbons obtained by aliphatic hydrocarbon groups, phenylene, naphthylene, or combinations thereof having 1 to 6 carbon atoms, and may also contain carbonyl groups, ester bonds, ether bonds, or hydroxyl groups. 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 a group with 7 to 18 carbon atoms obtained by alkylene groups, phenylene groups, or combinations thereof having 1 to 12 carbon atoms, and may also contain carbonyl groups, ester bonds, ether bonds, iodine atoms, or bromine atoms. 4 It is methylene, 2,2,2-trifluoro-1,1-ethanediyl, or carbonyl. 5 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, trifluoromethyl-substituted phenylene, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -. Z 51 It can be an aliphatic alkylene group, phenylene, fluorinated phenylene, or trifluoromethyl-substituted phenylene, or a combination thereof, and may contain a carbonyl group, ester bond, ether bond, halogen atom, and / or hydroxyl group. R 21 ~R 28 Each group can be a halogen atom, or may contain heteroatoms and be a hydrocarbon group with 1 to 20 carbon atoms. Also, R... 23 With R 24 、or R 26 With R 27 They bond to each other and together with the sulfur atoms they are bonded to, form a ring. M - It is a non-nucleophilic relative ion.

[0069] If so, it has the function of acting as an acid-generating agent within the base polymer.

[0070] It is better if it contains more surfactants.

[0071] If this is the case, the coatability of the resist composition can be improved or controlled.

[0072] Furthermore, the present invention provides a pattern forming method, comprising the following steps:

[0073] A resist film is formed on a substrate using the above-described resist composition; the resist film is exposed to high-energy radiation; and the exposed resist film is developed using a developing solution.

[0074] Such a pattern-forming method can produce a good pattern.

[0075] The aforementioned high-energy rays can be KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet rays with wavelengths of 3–15 nm.

[0076] Using such high-energy rays can create better patterns.

[0077] [The effects of the invention]

[0078] The novel ononium salt of this invention functions well as an acid diffusion control agent (quencher) in resist compositions, exhibiting high sensitivity and excellent dissolution contrast, resulting in the construction of high-resolution pattern outlines with small LWR, CDU, and excellent rectangularity. Furthermore, it can suppress the swelling of the resist pattern during alkaline development and form a pattern resistant to collapse, providing excellent micro-pattern formation. This invention also describes resist compositions using the novel ononium salt of this invention, and a method for forming patterns using this resist composition. Detailed Implementation

[0079] We seek to develop onium salt quenchers that exhibit good sensitivity, well-controlled acid diffusion, excellent solvent solubility, and effectiveness in inhibiting pattern collapse.

[0080] In order to achieve the above objectives, the inventors of this invention have made great efforts to explore and have found that a resist composition containing an onium salt with a specific structure as an acid diffusion control agent has excellent sensitivity and resolution, and small LWR of line patterns and CDU of hole patterns. The swelling during development is suppressed and it is extremely effective for precision micro-machining. Thus, the present invention was completed.

[0081] That is, the present invention is characterized by an onium salt represented by the following general formula (1).

[0082] [Chemistry 6]

[0083]

[0084] In the formula, R ALU This refers to any of the following: a tertiary ether, tertiary carbonate, or acetal, which, together with an adjacent oxygen atom, has a cyclic structure and may also have heteroatoms. R F It is any one of fluorine atom, fluorinated alkyl group having 1 to 6 carbon atoms, or nitro group. Also, R a It can also be a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms. n1 is an integer of 0 or 1. n2 and n3 are integers of 1 or 2. When n2 and n3 are 1, R F With -OR ALU Bonded to adjacent carbon atoms. Also, when either n2 or n3, or both, are 2, R... F With -OR ALU Each of the atoms in the R group is bonded to an adjacent carbon atom. n4 is an integer from 0 to 3. When n4 ≥ 2, multiple R groups are also possible. aThey bond to each other and together with the carbon atoms they are bonded to, form a ring structure. Z + This indicates a ium cation.

[0085] The present invention will be described in detail below, but the present invention is not limited thereto.

[0086] [Salt]

[0087] The onium salts of the present invention are represented by the following general formula (1).

[0088] [Chemistry 7]

[0089]

[0090] In the formula, R ALU This refers to any of the following: a tertiary ether, tertiary carbonate, or acetal, which, together with an adjacent oxygen atom, has a cyclic structure and may also have heteroatoms. R F It is any one of fluorine atom, fluorinated alkyl group having 1 to 6 carbon atoms, or nitro group. Also, R a It can also be a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms. n1 is an integer of 0 or 1. n2 and n3 are integers of 1 or 2. When n2 and n3 are 1, R F With -OR ALU Bonded to adjacent carbon atoms. Also, when either n2 or n3, or both, are 2, R... F With -OR ALU Each of the atoms in the R group is bonded to an adjacent carbon atom. n4 is an integer from 0 to 3. When n4 ≥ 2, multiple R groups are also possible. a They bond to each other and together with the carbon atoms they are bonded to, form a ring structure. Z + This indicates a ium cation.

[0091] In the above general formula (1), R ALU It is any of the tertiary ether, tertiary carbonate, or acetal that forms a cyclic structure together with an adjacent oxygen atom, and more particularly, the following formula (ALU-1) or (ALU-2) is preferred.

[0092] [Chemistry 8]

[0093]

[0094] In the above general formula (ALU-1), R 21’ R 22’ and R 23’ Each is independently a hydrocarbon group having 1 to 12 carbon atoms, preferably 1 to 10, R 21’ R 22’ and R 23’ Any two elements in R can also bond with each other to form a loop. 21’ R 22’ and R23’ When they are not bonded together to form a ring, at least one of them has a ring structure, preferably an alicyclic structure with 3 to 30 carbon atoms, or an aromatic ring structure with 6 to 30 carbon atoms. t is an integer of 0 or 1. In formula (ALU-2), R 24’ and R 25’ Each is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. R 26’ It is a hydrocarbon group with 1 to 20 carbon atoms, or it can be combined with R. 24’ Or R 25’ The carbon atoms and X atoms that are bonded to each other a Together, they form heterocyclic groups with 3 to 20 carbon atoms. Furthermore, the -CH2- group in the aforementioned hydrocarbon and heterocyclic groups can be replaced with -O- or -S-. X a Represents an oxygen atom or a sulfur atom. * indicates a bond with an adjacent oxygen atom.

[0095] The structure represented by the above general formula (ALU-1) can be specifically listed below, but is not limited to these examples.

[0096] [Chemistry 9]

[0097]

[0098] [Chemistry 10]

[0099]

[0100] [Chemistry 11]

[0101]

[0102] The structures represented by the above general formula (ALU-2) can be specifically listed below, but are not limited to these.

[0103] [Chemistry 12]

[0104]

[0105] In the above general formula (1), R F It is any one of fluorine atom, fluorinated alkyl group having 1 to 6 carbon atoms, or nitro group. Among these, considering solvent solubility and the acidity of the conjugate acid of the onium salt anion, fluorine atom and fluorinated alkyl group having 1 to 6 carbon atoms are preferred. Trifluoromethyl is preferred as the fluorinated alkyl group having 1 to 6 carbon atoms.

[0106] In the above general formula (1), R F With -OR ALU It needs to be bonded to adjacent carbon atoms. Specifically, when n2 and n3 are 1, R F With -OR ALUBonded to adjacent carbon atoms. Also, when either n2 or n3, or both, are 2, R... F With -OR ALU Each of the atoms in the group is bonded to an adjacent carbon atom. Through this proximity, the acid-labile group transitions from -OR... ALU The increased acidity of the aromatic alcohols generated upon separation improves their solubility in alkaline developing solutions and enhances their swelling inhibition effect.

[0107] In the above general formula (1), R a It can also be a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms. Some or all of the hydrogen atoms in the above hydrocarbon group can be replaced by halogen atoms, and the -CH2- constituting the above hydrocarbon group can be replaced by -O- or -C(=O)-. The above hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and tert-butyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclohexenyl and other cyclounsaturated hydrocarbon groups with 3 to 20 carbon atoms; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining them. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- constituting the aforementioned hydrocarbon group may also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may also contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides, haloalkyl groups, etc.

[0108] In the above general formula (1), n1 is an integer of 0 or 1. When n1 = 0, it represents a benzene ring, and when n1 = 1, it represents a naphthalene ring. However, from the point of view of solvent solubility, the benzene ring with n1 = 0 is better.

[0109] In the above general formula (1), n2 and n3 are integers of 1 or 2. Considering the scheduling of raw materials, it is better for n2 and n3 to be integers of 1.

[0110] In the above general formula (1), n4 is an integer from 0 to 3. When n4≥2, there can also be multiple R. a They bond to each other and together with the carbon atoms they are bonded to form ring structures. Specifically, when forming ring structures, for example, 5-membered rings and 6-membered ring structures.

[0111] The anions of the onium salts represented by the above general formula (1) can be listed below, but are not limited thereto. Furthermore, the substitution positions of the substituents on the aromatic ring are not limited as long as the groups enclosed in n2 and n3 are arranged adjacently.

[0112] [Chemistry 13]

[0113]

[0114] [Chemistry 14]

[0115]

[0116] [Chemistry 15]

[0117]

[0118] [Chemistry 16]

[0119]

[0120] [Chemistry 17]

[0121]

[0122] [Chemistry 18]

[0123]

[0124] [Chemistry 19]

[0125]

[0126] [Chemistry 20]

[0127]

[0128] [Chemistry 21]

[0129]

[0130] [Chemistry 22]

[0131]

[0132] [Chemistry 23]

[0133]

[0134] [Chemistry 24]

[0135]

[0136] [Chemistry 25]

[0137]

[0138] [Chemistry 26]

[0139]

[0140] In the above general formula (1), Z + This indicates a sulfonium cation. Specifically, examples include sulfonium cation, monium cation, ammonium cation, phosphonium cation, etc., but the sulfonium cation, monium cation, and ammonium cation shown below are preferred.

[0141] In the above general formula (1), Z + It represents any one of the following general formulas (Cation-1) to (Cation-3).

[0142] [Chemistry 27]

[0143]

[0144] In the above general formulas (Cation-1) to (Cation-3), R 11’ ~R 19’ Each group can be an independent hydrocarbon group with 1 to 30 carbon atoms, and may also contain heteroatoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and tert-butyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclohexenyl and other cyclic unsaturated hydrocarbon groups; aryl groups such as phenyl, naphthyl, and thiophene; aralkyl groups such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combinations thereof, but aryl groups are preferred. Furthermore, a portion of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms can also be inserted between the carbon atoms of the aforementioned groups. As a result, the group may contain hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides, haloalkyl groups, etc.

[0145] Also, R 11’ and R 12’ They can also bond to each other and form rings together with the sulfur atoms they are bonded to. In this case, the sulfonium cation represented by formula (Cation-1) is represented by, for example, the following formula.

[0146] [Chemistry 28]

[0147]

[0148] In the formula, the broken line is R. 13 Atomic bonds.

[0149] The cations of sulfonium salts represented by formula (Cation-1) can be listed below, but are not limited to these.

[0150] [Chemistry 29]

[0151]

[0152] [Chemistry 30]

[0153]

[0154] [Chemistry 31]

[0155]

[0156] [Chemistry 32]

[0157]

[0158] [Chemistry 33]

[0159]

[0160] [Chemistry 34]

[0161]

[0162] [Chemistry 35]

[0163]

[0164] [Chemistry 36]

[0165]

[0166] [Chemistry 37]

[0167]

[0168] [Chemistry 38]

[0169]

[0170] [Chemistry 39]

[0171]

[0172] [Chemistry 40]

[0173]

[0174] [Chemistry 41]

[0175]

[0176] [Chemistry 42]

[0177]

[0178] [Chemistry 43]

[0179]

[0180] [Chemistry 44]

[0181]

[0182] [Chemistry 45]

[0183]

[0184] [Chemistry 46]

[0185]

[0186] [Chemistry 47]

[0187]

[0188] [Chemistry 48]

[0189]

[0190] [Chemistry 49]

[0191]

[0192] [Transformation 50]

[0193]

[0194] [Chemistry 51]

[0195]

[0196] [Chemistry 52]

[0197]

[0198] [Chemistry 53]

[0199]

[0200] The ferric cations represented by the above general formula (Cation-2) can be listed below, but are not limited to.

[0201] [Chemistry 54]

[0202]

[0203] [Chemistry 55]

[0204]

[0205] The ammonium cations represented by the above general formula (Cation-3) can be listed below, but are not limited to these.

[0206] [Chemistry 56]

[0207]

[0208] The specific structure of the onium salt of the present invention can be described by any combination of the aforementioned anions and cations.

[0209] The onium salts of the present invention can be synthesized, for example, by ion exchange of hydrochloride or carbonate salts having onium cations with corresponding benzoic acid derivatives.

[0210] If the onium salt of the present invention coexists with strong acid-generating onium salts such as α-fluorinated sulfonic acids, imide acids, or methylated acids (hereinafter collectively defined as strong acids), the corresponding carboxylic acids and strong acids will be generated upon light irradiation. On the other hand, a large amount of undecomposed onium salt remains in areas with low exposure. Strong acids act as catalysts to induce deprotection reactions in the base resin, but the onium salt of the present invention hardly undergoes a deprotection reaction. The strong acid and the remaining carboxylic acid matte undergo ion exchange to become onium salts of strong acids, in which case the carboxylic acid is released. In other words, the strong acid is neutralized by the carboxylic acid onium salt due to ion exchange. That is, the onium salt of the present invention acts as a quencher (acid diffusion control agent). This onium salt-type quencher tends to reduce the LWR of the resist pattern compared to quenchers that generally use amine compounds.

[0211] The salt exchange between strong acid and carboxylic acid onium salts can repeat infinitely. The location where strong acid is finally produced after exposure differs from the location where the onium salt initially produced the strong acid. It is speculated that the repeated cycles of acid production and salt exchange caused by light average out the acid production points, thereby reducing the LWR of the resist pattern after development.

[0212] As described above, the onium salt of the present invention acts as an acid diffusion control agent in the resist composition, and it is preferable that the acid diffusion control agent composed of the onium salt of the present invention is contained in the resist composition.

[0213] The content of the onium salt of the present invention in the above-described resist composition is preferably 0.001 to 50 parts by weight relative to 100 parts by weight of the base polymer described later, and more preferably 0.01 to 40 parts by weight. The onium salt of the present invention can be used alone or in combination of two or more.

[0214] [Basic Polymers]

[0215] The photoresist material of the present invention may also contain a base polymer. When the base polymer is a positive photoresist material, it contains repeating units containing acid-labile groups. The repeating units containing acid-labile groups are preferably repeating units represented by the following general formula (a1) (hereinafter also referred to as repeating unit a1) and / or repeating units represented by the following general formula (a2) (hereinafter also referred to as repeating unit a2).

[0216] [Chemistry 57]

[0217]

[0218] In the above general formulas (a1) and (a2), R A Each can be independently a hydrogen atom or a methyl group. Y 1 It is a single bond, a phenylene or naphthylene group, or a linking group containing at least one of the following: an ester bond or a lactone ring, having 1 to 12 carbon atoms. 2 It is a single bond or an ester 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. Furthermore, when the aforementioned basic polymer contains both repeating unit a1 and repeating unit a2, R... 11 and R 12 They can be the same or different. 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 diyl group with 1 to 6 carbon atoms, and some of its carbon atoms may be replaced by ether or ester bonds. a is 1 or 2. b is an integer from 0 to 4. However, 1 ≤ a + b ≤ 5.

[0219] The monomers given as repeating unit a1 can be listed below, but are not limited to. Also, in the following formula, R... A and R 11 As stated above.

[0220] [Chem.58]

[0221]

[0222] The monomers given as repeating unit a2 can be listed below, but are not limited to. Also, in the following formula, R... A and R 12 As stated above.

[0223] [Chemistry 59]

[0224]

[0225] R in the above general formulas (1), (a1) and (a2) ALU R 11 and R 12The acid-indestructible group is represented by, for example, the acid-indestructible groups described in Japanese Patent Application Publication No. 2013-80033 and Japanese Patent Application Publication No. 2013-83821.

[0226] Generally speaking, the unstable groups of the above-mentioned acids are represented by formulas (AL-1) to (AL-3).

[0227] [Transformation 60]

[0228]

[0229] In the formula, the broken line represents an atomic bond.

[0230] In the above general formulas (AL-1) and (AL-2), R L1 and R L2 Each hydrocarbon group is an independent hydrocarbon group with 1 to 40 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Saturated hydrocarbon groups with 1 to 40 carbon atoms are preferred, while saturated hydrocarbon groups with 1 to 20 carbon atoms are even more ideal.

[0231] In the above general formula (AL-1), c is an integer from 0 to 10, and an integer from 1 to 5 is preferred.

[0232] In the above general formula (AL-2), R L3 and R L4 Each group is independently composed of a hydrogen atom or 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. Saturated hydrocarbon groups having 1 to 20 carbon atoms are preferred. Furthermore, R... L2 R L3 and R L4 Any two of them can bond to each other and together with the carbon atoms they bond to, or carbon atoms and oxygen atoms, form a ring with 3 to 20 carbon atoms. Rings with 4 to 16 carbon atoms are more ideal, especially alicyclic rings.

[0233] In equation (AL-3), R L5 R L6 and R L7 Each group is an independent hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Saturated hydrocarbon groups with 1 to 20 carbon atoms are preferred. Also, R L5 R L6 and R L7Any two of them can bond to each other and together with the carbon atoms they are bonded to form a ring with 3 to 20 carbon atoms. Rings with 4 to 16 carbon atoms are more ideal, especially alicyclic rings.

[0234] When the base polymer of the above-mentioned photoresist material contains repeating units a1 and a2, it is a chemically amplified positive photoresist material.

[0235] Ideally, the base polymer of the aforementioned resist material should not contain acid-instable groups. In this case, the aforementioned resist material is a chemically amplified negative resist material.

[0236] The aforementioned basic polymer may also contain repeating unit b, which contains a phenolic hydroxyl group as a tight-knot group. Monomers providing repeating unit b can be listed below, but are not limited to these. Furthermore, in the following formula, R... A As stated above.

[0237] [Chemistry 61]

[0238]

[0239] [Chemistry 62]

[0240]

[0241] [Chemistry 63]

[0242]

[0243] The aforementioned basic polymer may also contain repeating unit c, other than phenolic hydroxyl groups, lactone rings, sulfonyl rings, ether bonds, ester bonds, sulfonate bonds, carbonyl groups, sulfonyl groups, cyano groups, and / or carboxyl groups. Monomers giving repeating unit c are listed below, but are not limited thereto. Furthermore, in the following formula, R... A As stated above.

[0244] [Chemistry 64]

[0245]

[0246] [Chemistry 65]

[0247]

[0248] [Chemistry 66]

[0249]

[0250] [Chemistry 67]

[0251]

[0252] [Chemistry 68]

[0253]

[0254] [Chemistry 69]

[0255]

[0256] [Chemistry 70]

[0257]

[0258] [Chemistry 71]

[0259]

[0260] [Chemistry 72]

[0261]

[0262] The aforementioned basic polymers may also contain repeating units d derived from indene, benzofuran, benzothiophene, vinylnaphthalene, crromone, coumarin, norcamphediene, or derivatives thereof. Monomers giving repeating units d are listed below, but are not limited thereto.

[0263] [Chemistry 73]

[0264]

[0265] The aforementioned base polymer may also contain repeating units e derived from styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methylene dihydroindene, vinylpyridine, or vinylcarbazole.

[0266] The aforementioned basic polymer may also contain repeating units f from onium salts containing polymerizable unsaturated bonds. Ideal repeating units f include, for example, repeating units represented by the following general formula (f1) (hereinafter also referred to as repeating unit f1.), repeating units represented by the following general formula (f2) (hereinafter also referred to as repeating unit f2.), and repeating units represented by the following general formula (f3) (hereinafter also referred to as repeating unit f3.). Furthermore, repeating units f1 to f3 may be used individually or in combination of two or more.

[0267] [Chemistry 74]

[0268]

[0269] In the above general formulas (f1) to (f3), R A Each can be independently a hydrogen atom or a methyl group. Z 1 A single bond, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, an ester bond, or a combination thereof, or a group having 7 to 18 carbon atoms, or -OZ. 11 -、-C(=O)-OZ 11-or-C(=O)-NH-Z 11 -. Z 11 It is a group with 7 to 18 carbons obtained by aliphatic hydrocarbon groups, phenylene, naphthylene, or combinations thereof having 1 to 6 carbon atoms, and may also contain carbonyl groups, ester bonds, ether bonds, or hydroxyl groups. 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 a group with 7 to 18 carbon atoms obtained by alkylene groups, phenylene groups, or combinations thereof having 1 to 12 carbon atoms, and may also contain carbonyl groups, ester bonds, ether bonds, iodine atoms, or bromine atoms. 4 It is methylene, 2,2,2-trifluoro-1,1-ethanediyl, or carbonyl. 5 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, trifluoromethyl-substituted phenylene, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -. Z 51 It can be an aliphatic alkylene group, phenylene, fluorinated phenylene, or phenylene substituted with trifluoromethyl, or a combination thereof, and may also contain carbonyl groups, ester bonds, ether bonds, halogen atoms, and / or hydroxyl groups.

[0270] In the above general formulas (f1) to (f3), R 21 ~R 28 Each hydrocarbon group consists independently of a halogen atom or may contain heteroatoms and has 1 to 20 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and described in the explanations of the general formulas (Cation-1) to (Cation-3). 11’ ~R 19’ The hydrocarbon group represented is an example of the same. Some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, some of the carbon atoms in these groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, the group may contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonyl lactone ring, carboxylic anhydride, or haloalkyl groups. 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 are bonded to. In this case, the aforementioned rings can be listed and described in the explanation of the general formula (Cation-1).11’ and R 12’ The same example illustrates the rings that can be formed by bonding and together with the sulfur atoms they are bonded to.

[0271] In the above general formula (f1), M - These are non-nucleophilic relative ions. Examples of 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.

[0272] Other examples of the aforementioned non-nucleophilic relative ions include sulfonate ions represented by the following general formula (f1-1) with fluorine atom substitution at the α-position, and sulfonate ions represented by the following general formula (f1-2) with fluorine atom substitution at the α-position and trifluoromethyl substitution at the β-position.

[0273] [Chemistry 75]

[0274]

[0275] In the above general formula (f1-1), R 31 It is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. This hydrocarbon group may also contain ether bonds, ester bonds, carbonyl groups, lactone rings, or fluorine atoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and discussed in the formula (3A') below. 111 The hydrocarbon group shown is an example of the same.

[0276] In the above general formula (f1-2), R 32 The hydrocarbon group consists of a hydrogen atom and a hydrocarbon group having 1 to 30 carbon atoms or a hydrocarbon carbonyl group having 6 to 20 carbon atoms. This hydrocarbon group and hydrocarbon carbonyl group may also contain ether bonds, ester bonds, carbonyl groups, or lactone rings. 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 discussed in the formula (3A') below. 111 The hydrocarbon group shown is an example of the same.

[0277] The cations that give the repeating unit f1 to the monomer can be listed below, but are not limited to. Also, in the following formula, R... A As stated above.

[0278] [Chemistry 76]

[0279]

[0280] Specific examples of cations of monomers given repeating units f2 and f3 can be listed as the same examples as those of cations of sulfonium salts represented by formula (Cation-1).

[0281] The anions given to the monomers of repeating unit f2 can be listed below, but are not limited to. Also, in the following formula, R... A As stated above.

[0282] [Chemistry 77]

[0283]

[0284] [Chemistry 78]

[0285]

[0286] [Chemistry 79]

[0287]

[0288] [Chemistry 80]

[0289]

[0290] [Chemistry 81]

[0291]

[0292] [Chemistry 82]

[0293]

[0294] [Chemistry 83]

[0295]

[0296] [Chemistry 84]

[0297]

[0298] [Chemistry 85]

[0299]

[0300] [Chemistry 86]

[0301]

[0302] [Chemistry 87]

[0303]

[0304] [Chemistry 88]

[0305]

[0306] The anions given to the monomers of repeating unit f3 can be listed below, but are not limited to. Also, in the following formula, R... A As stated above.

[0307] [Chemistry 89]

[0308]

[0309] [Chemistry 90]

[0310]

[0311] The repeating units f1 to f3 described above function as acid generators. By bonding the acid generator to the polymer backbone, acid diffusion can be reduced, and the blurring caused by acid diffusion can be prevented from leading to a decrease in resolution. Furthermore, uniform dispersion of the acid generator can improve LWR and CDU. Also, when using a base polymer containing repeating unit f, the blending of the additive acid generator described later can be omitted.

[0312] In the aforementioned basic polymer, the following ratios of repeating units a1, a2, b, c, d, e, f1, f2, and f3 are considered ideal: 0≤a1≤0.9, 0≤a2≤0.9, 0≤a1+a2≤0.9, 0≤b≤0.9, 0≤c≤0.9, 0≤d≤0.5, 0≤e≤0.5, 0≤f1≤0.5, 0≤f2≤0.5, 0≤f3≤0.5, and 0≤f1+f2+f3≤0.5. Ratios of 0≤a1≤0.8, 0≤a2≤0.8, 0≤a1+a2≤0.8, and 0≤... The following are better: b≤0.8, 0≤c≤0.8, 0≤d≤0.4, 0≤e≤0.4, 0≤f1≤0.4, 0≤f2≤0.4, 0≤f3≤0.4, 0≤f1+f2+f3≤0.4. The following are more ideal: 0≤a1≤0.7, 0≤a2≤0.7, 0≤a1+a2≤0.7, 0≤b≤0.7, 0≤c≤0.7, 0≤d≤0.3, 0≤e≤0.3, 0≤f1≤0.3, 0≤f2≤0.3, 0≤f3≤0.3, 0≤f1+f2+f3≤0.3. However, a1+a2+b+c+d+f1+f2+f3+e=1.0.

[0313] To synthesize the above-mentioned basic polymer, for example, the monomers given to the repeating units can be placed in an organic solvent, a free radical polymerization initiator can be added, and the mixture can be heated to carry out polymerization.

[0314] Organic solvents used in polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, and dioxane. Polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid) ester, benzoyl peroxide, and lauroyl peroxide. The preferred polymerization temperature is 50–80°C. The preferred reaction time is 2–100 hours, more preferably 5–20 hours.

[0315] When copolymerizing monomers containing hydroxyl groups, the hydroxyl groups can be replaced with acetal groups such as ethoxyethoxy, which are easily deprotected by acids, and then deprotected by weak acids and water after polymerization. Alternatively, they can be replaced with acetyl, formyl, trimethylacetyl, etc., and then subjected to alkaline hydrolysis after polymerization.

[0316] When copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, acetoxystyrene and acetoxyvinylnaphthalene can be used instead of hydroxystyrene and hydroxyvinylnaphthalene. After polymerization, the acetoxy groups are deprotected by alkaline hydrolysis to obtain hydroxystyrene and hydroxyvinylnaphthalene.

[0317] The alkali used in alkaline hydrolysis can be ammonia, triethylamine, etc. Furthermore, the preferred reaction temperature is -20 to 100°C, more preferably 0 to 60°C. The preferred reaction time is 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0318] The aforementioned base polymer, obtained by gel permeation chromatography (GPC) using THF as a solvent, has a preferred equivalent weight-average molecular weight (Mw) of 1,000 to 500,000, more preferably 2,000 to 30,000 for polystyrene. If Mw is within the above range, the resist film exhibits good heat resistance and solubility in alkaline developing solutions.

[0319] Furthermore, when the molecular weight distribution (Mw / Mn) of the aforementioned base polymer is sufficiently narrow, since there are no low- or high-molecular-weight polymers, there is no risk of foreign matter appearing on the pattern or the pattern shape deteriorating 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 with fine pattern sizes, the aforementioned base polymer has a narrow dispersion of Mw / Mn of 1.0 to 2.0, especially 1.0 to 1.5.

[0320] The aforementioned basic polymer may also contain two or more polymers with different composition ratios, Mw, and Mw / Mn.

[0321] [Acid generating agent]

[0322] The resist material of the present invention may also contain an acid-generating agent that produces a strong acid (hereinafter also referred to as an additive acid-generating agent). The term "strong acid" as used herein, in the case of a chemically amplified positive resist material, refers to a compound having sufficient acidity to cause a deprotection reaction of the acid-indestructible groups of the base polymer; in the case of a chemically amplified negative resist material, it refers to a compound having sufficient acidity to cause a polarity change reaction or crosslinking reaction caused by the acid. By containing such an acid-generating agent, the aforementioned onium salt acts as a quencher, and the resist material of the present invention can function as either a chemically amplified positive resist material or a chemically amplified negative resist material.

[0323] The aforementioned acid-generating agents include, for example, compounds that generate acids in response to active light or radiation (photoacid generators). Any compound that produces acid upon irradiation with high-energy rays is acceptable as a photoacid generator, but those that produce sulfonic acids, imine acids, or methyl acids are preferred. Ideal photoacid generators include sulfonium salts, sulfonyl diazomethanes, N-sulfonyloxyimides, and oxime-O-sulfonate ester type acid generators. Specific examples of photoacid generators are described in paragraphs

[0122] to

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

[0324] Furthermore, the photoacid generating agent should preferably be a sulfonium salt represented by the following general formula (3-1) or a sulfonium salt represented by the following general formula (3-2).

[0325] [Chemistry 91]

[0326]

[0327] In the above general formulas (3-1) and (3-2), R 101 ~R 105 Each hydrocarbon group consists independently of a halogen atom or may contain heteroatoms and has 1 to 20 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed in the descriptions of formulas (Cation-1) to (Cation-3) regarding R. 11’ ~R 19’ The hydrocarbon group represented is an example of the same. Also, R 101 With R 102 They can also bond to each other and form rings together with the sulfur atoms they are bonded to. In this case, the aforementioned rings can be listed and described in the explanation of equation (Cation-1) regarding R. 11’ and R 12’ The same example illustrates the rings that can be formed by bonding and together with the sulfur atoms they are bonded to.

[0328] The cations of sulfonium salts represented by the above general formula (3-1) can be exemplified by the cations of sulfonium salts represented by formula (Cation-1), but are not limited thereto.

[0329] The cations of zirconia represented by the general formula (3-2) above are examples of the same type as those represented by formula (Cation-2), but are not limited thereto.

[0330] In the above general formulas (3-1) and (3-2), Xa - The anions are selected from formulas (3A) to (3D).

[0331] [Chemistry 92]

[0332]

[0333] In the above general formula (3A), R fa It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain fluorine atoms or heteroatoms. The hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and discussed in the formula (3A') below. 111 The hydrocarbon group shown is an example of the same.

[0334] The anion represented by formula (3A) is preferably represented by the following general formula (3A').

[0335] [Chemistry 93]

[0336]

[0337] In the above general formula (3A'), R HF It can be a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R 111 Hydrocarbon groups with 1 to 38 carbon atoms that can also contain heteroatoms are preferred. Ideal heteroatoms include oxygen, nitrogen, sulfur, and halogen atoms, with oxygen atoms being the most desirable. For these hydrocarbon groups, considering the need to achieve high resolution during the formation of fine patterns, those with 6 to 30 carbon atoms are particularly advantageous.

[0338] R 111 The hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 38 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and icosyl; cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornel, norbornelmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; allyl and 3-cyclohexenyl, unsaturated aliphatic hydrocarbon groups with 2 to 38 carbon atoms; 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.

[0339] Furthermore, some or all of the hydrogen atoms in the aforementioned groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, some of the carbon atoms in these groups 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. Hydrocarbon groups containing heteroatoms include, for example, tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidemethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, and 3-oxocyclohexyl.

[0340] For the synthesis of sulfonium salts containing anions represented by the above general formula (3A'), please refer to Japanese Patent Application Publication Nos. 2007-145797, 2008-106045, 2009-7327, and 2009-258695. Furthermore, sulfonium salts described in Japanese Patent Application Publication Nos. 2010-215608, 2012-41320, 2012-106986, and 2012-153644 are also suitable.

[0341] The anion represented by the above general formula (3A) is, for example, the same example as the anion represented by formula (1A) in Japanese Patent Application Publication No. 2018-197853.

[0342] In the above general formula (3B), R fb1 and R fb2 Each hydrocarbon group consists independently of a fluorine atom or may contain heteroatoms and has 1 to 40 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and related to R in the above general formula (3A'). 111 The hydrocarbon group represented is an example of the same. R fb1 and R fb2 Preferably, it is a straight-chain fluorinated alkyl group having fluorine atoms or 1 to 4 carbon atoms. Also, R fb1 With R fb2 They can also bond to each other and to the groups they are bonded to (-CF2-SO2-N). - -SO2-CF2-) together form a ring, at which point R fb1 With R fb2 The groups obtained by mutual bonding are preferably fluorinated ethylidene or fluorinated propylene.

[0343] In the above general formula (3C), R fc1 Rfc2 and R fc3 Each hydrocarbon group consists independently of a fluorine atom or may contain heteroatoms and has 1 to 40 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and related to R in the above general formula (3A'). 111 The hydrocarbon examples shown are the same. R fc1 R fc2 and R fc3 Preferably, it is a straight-chain fluorinated alkyl group having fluorine atoms or 1 to 4 carbon atoms. Also, R fc1 With R fc2 They can also bond to each other and to the groups they are bonded to (-CF2-SO2-C). - -SO2-CF2-) together form a ring, at which point R fc1 With R fc2 The groups obtained by mutual bonding are preferably fluorinated ethylidene or fluorinated propylene.

[0344] In the above general formula (3D), R fd It can also contain hydrocarbon groups with 1 to 40 carbon atoms and heteroatoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated by R in formula (3A'). 111 The hydrocarbon group shown is an example of the same.

[0345] For details on the synthesis of sulfonium salts containing anions represented by the above general formula (3D), please refer to Japanese Patent Application Publication No. 2010-215608 and Japanese Patent Application Publication No. 2014-133723.

[0346] The anions represented by the above general formula (3D) can be exemplified by the same examples as those represented by formula (1D) in Japanese Patent Application Publication No. 2018-197853.

[0347] Furthermore, the photoacid generator containing the anion represented by the above general formula (3D) has no fluorine atom at the α-position of the sulfonium group, but has two trifluoromethyl groups at the β-position, thus possessing sufficient acidity to cleave the acid-unstable groups in the base polymer. Therefore, it can be used as a photoacid generator.

[0348] The photoacid generator should also be the photoacid generator represented by the following general formula (4).

[0349] [Chemistry 94]

[0350]

[0351] In the above general formula (4), R 201 and R 202 Each is an independent halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 30 carbon atoms. R203 It can also contain a hydrocarbon group with 1 to 30 carbon atoms and a heteroatom. Also, R 201 R 202 and R 203 Any two atoms in the group can also bond to each other and form a ring together with the sulfur atoms they are bonded to. In this case, the aforementioned rings can be listed and described in the explanation of the above general formula (Cation-1). 11’ With R 12’ The same example illustrates the rings that can be formed by bonding and together with the sulfur atoms they are bonded to.

[0352] R 201 and R 202 The hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 30 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornel, oxanorbornel, and 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 the above groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the carbon atoms in the above groups may also be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, groups may also contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulopentalide ring, carboxylic anhydride, or haloalkyl groups.]

[0353] R 203The 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, and heptadecane-1,17-diyl. - Dialkyl groups with 1 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 obtained by combining these groups. Furthermore, some or all of the hydrogen atoms in the aforementioned groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, some of the carbon atoms in these groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen. As a result, the groups may contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonyl lactone ring, carboxylic anhydride, or haloalkyl groups. Oxygen atoms are preferred among the aforementioned heteroatoms.

[0354] In the above general formula (4), L A It 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 groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and discussed in relation to R. 203 The examples representing the alkylene groups are the same.

[0355] In the above general formula (4), X A X B X C and X D Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. But X A X B X C and X D At least one of them is a fluorine atom or a trifluoromethyl group.

[0356] In the above general formula (4), d is an integer from 0 to 3.

[0357] The photoacid generator represented by the above general formula (4) is preferably represented by the following general formula (4').

[0358] [Chemistry 95]

[0359]

[0360] In the above general formula (4'), L A As mentioned 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. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated by R in formula (3A'). 111 The hydrocarbon group is an example of the same. x and y are each independent integers from 0 to 5, and z is an integer from 0 to 4.

[0361] The photoacid generator represented by the above general formula (4) can be exemplified by the same example as the photoacid generator represented by formula (2) in Japanese Patent Application Publication No. 2017-026980.

[0362] Among the aforementioned photoacid generators, those containing anions represented by the general formula (3A') or (3D) exhibit low acid diffusion and excellent solvent solubility, making them particularly desirable. Furthermore, photoacid generators represented by formula (4') exhibit extremely low acid diffusion, making them particularly desirable.

[0363] The aforementioned photoacid generators may also be sulfonate or tungsten salts containing anions with aromatic rings substituted with iodine or bromine atoms. Such salts are, for example, represented by the following general formulas (5-1) or (5-2).

[0364] [Chemistry 96]

[0365]

[0366] In the above general formulas (5-1) and (5-2), 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. Ideally, q should be an integer satisfying 1 ≤ q ≤ 3, with 2 or 3 being even more ideal. It is preferable for r to be an integer satisfying 0 ≤ r ≤ 2.

[0367] In the above general formulas (5-1) and (5-2), 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.

[0368] In the above general formulas (5-1) and (5-2), L 1It 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.

[0369] In the above general formulas (5-1) and (5-2), 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. This linker may also contain oxygen, sulfur, or nitrogen atoms.

[0370] In the above general formulas (5-1) and (5-2), R 401 The carbon group can be a hydroxyl, carboxyl, fluorine, chlorine, bromine, or amino group, or may contain a hydroxyl, chlorine, bromine, hydroxyl, amino, or ether, ester, or amide bond, and can be a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms, or a hydrocarbon sulfonyl group with 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 is 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 oxygen 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 401D It can be an aliphatic hydrocarbon group with 1 to 16 carbon atoms, an aryl group with 6 to 14 carbon atoms, or an aralkyl group with 7 to 15 carbon atoms. It may also contain a halogen atom, a hydroxyl group, a saturated alkyloxy group with 1 to 6 carbon atoms, a saturated alkyl carbonyl group with 2 to 6 carbon atoms, or a saturated alkyl carbonyloxy group with 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. The aforementioned saturated hydrocarbon group, saturated alkyloxy group, saturated alkyloxycarbonyl group, saturated alkyl carbonyl group, and saturated alkyl carbonyloxy group can be linear, branched, or cyclic. When p and / or r are 2 or more, each R... 401 They can be the same or different.

[0371] Among them, R 401 Hydroxyl group, -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. are preferred.

[0372] In the above general formulas (5-1) and (5-2), Rf 1 ~Rf 4 Each of them is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, with at least one of them being a fluorine atom or a trifluoromethyl group. Also, Rf 1 With Rf 2 They can also combine to form carbonyl groups. Especially Rf 3 and Rf 4 Both are preferred if they contain fluorine atoms.

[0373] In the above general formulas (5-1) and (5-2), R 402 ~R 406 Each group is an independent hydrocarbon group consisting of halogen atoms, or may contain heteroatoms, and has 1 to 20 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and described in the explanation of the above general formula (Cation-1). 11’ ~R 19’ The hydrocarbon group represented is an example of the same. Furthermore, some or all of the hydrogen atoms in the aforementioned groups may be replaced by hydroxyl, carboxyl, halogen, cyano, nitro, mercapto, sulfonyl ring, sulfone, or sulfonate-containing groups, and some of the carbon atoms in the aforementioned groups may be replaced by ether, ester, carbonyl, amide, carbonate, or sulfonate bonds. Moreover, R... 402 With R 403 They can also bond to each other and form rings together with the sulfur atoms they are bonded to. In this case, the aforementioned rings can be listed and described in the explanation of the above general formula (Cation-1), regarding R... 11’ With R 12’ The same example can be seen in the rings that can be formed by mutual bonding and together with the sulfur atoms they are bonded to.

[0374] The cations of sulfonium salts represented by the above general formula (5-1) can be exemplified by examples of the cations of sulfonium salts represented by the above general formula (Cation-1). Similarly, the cations of zirconia salts represented by formula (5-2) can be exemplified by examples of the cations of zirconia salts represented by the above general formula (Cation-2).

[0375] The anions of onium salts represented by the above general formulas (5-1) or (5-2) can be listed below, but are not limited to these. Furthermore, in the following formula, X... BI As stated above.

[0376] [Chemistry 97]

[0377]

[0378] [Chem. 98]

[0379]

[0380] [Chemistry 99]

[0381]

[0382] [Chemistry 100]

[0383]

[0384] [Chemistry 101]

[0385]

[0386] [Chemistry 102]

[0387]

[0388] [Chemistry 103]

[0389]

[0390] [Chemistry 104]

[0391]

[0392] [Chemistry 105]

[0393]

[0394] [Chemistry 106]

[0395]

[0396] [Chemistry 107]

[0397]

[0398] [Chemistry 108]

[0399]

[0400] [Chemistry 109]

[0401]

[0402] [Chemical 110]

[0403]

[0404] [Chemistry 111]

[0405]

[0406] [Chemistry 112]

[0407]

[0408] [Chemistry 113]

[0409]

[0410] [Chemistry 114]

[0411]

[0412] [Chemistry 115]

[0413]

[0414] [Chemistry 116]

[0415]

[0416] [Chemistry 117]

[0417]

[0418] [Chemistry 118]

[0419]

[0420] [Chemistry 119]

[0421]

[0422] When the resist material of the present invention contains an additive acid generator, its content is ideally 0.1 to 50 parts by mass relative to 100 parts by mass of the base polymer, and more ideally 1 to 40 parts by mass. The resist material of the present invention, by having the aforementioned base polymer containing any of the repeating units f1 to f3, and containing / or containing an additive acid generator, can function as a chemically amplified resist material.

[0423] [Organic solvents]

[0424] The resist material of the present invention may also contain organic solvents. The organic solvents described above need only be able to dissolve the above-mentioned components and the components described below, and there are no particular limitations. The aforementioned organic solvents include, for example, 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; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate; and lactones such as γ-butyrolactone.

[0425] In the resist material of the present invention, the content of the above-mentioned organic solvent is preferably 100 to 10,000 parts by mass relative to 100 parts by mass of the base polymer, and more preferably 200 to 8,000 parts by mass. The above-mentioned organic solvent can be used alone or in combination of two or more.

[0426] [Other ingredients]

[0427] In addition to the above-mentioned components, the resist material of the present invention may also contain surfactants, dissolution inhibitors, crosslinking agents, quenchers other than the onium salts of the present invention (hereinafter referred to as other quenchers), water repellency enhancers, acetylene alcohols, etc.

[0428] The surfactants mentioned above can be exemplified by those described in 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 resist material of the present invention contains the aforementioned surfactants, their content relative to 100 parts by weight of the base polymer is preferably 0.0001 to 10 parts by weight. The aforementioned surfactants can be used alone or in combination of two or more.

[0429] When the resist material of the present invention is positive, a dissolution inhibitor can be incorporated to increase the difference in dissolution rate between the exposed and unexposed areas, thereby improving resolution. Examples of such dissolution inhibitors include compounds with a molecular weight preferably 100-1,000, more preferably 150-800, and containing two or more phenolic hydroxyl groups, wherein the hydrogen atom of the phenolic hydroxyl group is replaced by an acid-unstable group in a proportion of 0-100 mol% overall; or compounds containing a carboxyl group, wherein the hydrogen atom of the carboxyl group is replaced by an acid-unstable group in a proportion of an average of 50-100 mol% overall. Specifically, examples include compounds such as bisphenol A, triphenol, phenolphthalein, cresol phenolic varnish, naphtholic acid, adamantane carboxylic acid, and cholic acid, wherein the hydrogen atoms of the hydroxyl and carboxyl groups are replaced by acid-unstable groups, as described in paragraphs

[0155] to

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

[0430] When the resist material of the present invention is positive and contains the aforementioned dissolution inhibitor, its content relative to 100 parts by weight of the base polymer is ideally 0 to 50 parts by weight, and more ideally 5 to 40 parts by weight. The aforementioned dissolution inhibitor can be used alone or in combination of two or more.

[0431] On the other hand, when the resist material of the present invention is negative, a negative pattern can be obtained by adding a crosslinking agent to reduce the dissolution rate of the exposed portion. Examples of such crosslinking agents include epoxy compounds, melamine compounds, guanidine compounds, urea compounds, isocyanate compounds, azide compounds, and compounds containing double bonds such as alkoxy groups, which are substituted with at least one group selected from hydroxymethyl, alkoxymethyl, and acyloxymethyl groups. These can also be used as additives or introduced into the polymer side chain as suspending groups. Furthermore, compounds containing hydroxyl groups can also be used as crosslinking agents.

[0432] Examples of the aforementioned epoxy compounds include tris(2,3-epoxypropyl)isocyanurate, trimethylolpropane triepoxypropyl ether, trimethylolpropane triepoxypropyl ether, and triethylolethane triepoxypropyl ether.

[0433] Examples of the melamine compounds mentioned above include hexahydroxymethyl melamine, hexamethoxymethyl melamine, compounds of hexahydroxymethyl melamine in which 1 to 6 hydroxymethyl groups are methoxymethylated, or mixtures thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, compounds of hexahydroxymethyl melamine in which 1 to 6 hydroxymethyl groups are acyloxymethylated, or mixtures thereof.

[0434] Examples of the aforementioned guanidine compounds include tetrahydroxymethylguanidine, tetramethoxymethylguanidine, compounds of tetrahydroxymethylguanidine in which 1 to 4 hydroxymethyl groups are methoxymethylated, or mixtures thereof, tetramethoxyethylguanidine, tetraacyloxyguanidine, compounds of tetrahydroxymethylguanidine in which 1 to 4 hydroxymethyl groups are acyloxymethylated, or mixtures thereof.

[0435] The aforementioned glycourea compounds include, for example, tetrahydroxymethylglycourea, tetramethoxyglycourea, tetramethoxymethylglycourea, compounds of tetrahydroxymethylglycourea in which 1 to 4 hydroxymethyl groups are methoxymethylated, or mixtures thereof, compounds of tetrahydroxymethylglycourea in which 1 to 4 hydroxymethyl groups are acylmethylated, or mixtures thereof.

[0436] The aforementioned urea compounds include, for example, tetrahydroxymethylurea, tetramethoxymethylurea, compounds of tetrahydroxymethylurea in which 1 to 4 hydroxymethyl groups are methoxymethylated, or mixtures thereof, tetramethoxyethylurea, etc.

[0437] The aforementioned isocyanate compounds include, for example, methyl phenylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, etc.

[0438] The aforementioned azide compounds include, for example, 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylene bisazide, and 4,4'-oxy bisazide.

[0439] The compounds containing olefins mentioned above include, for example, ethylene glycol diethylene ether, triethylene glycol diethylene ether, 1,2-propanediol diethylene ether, 1,4-butanediol diethylene ether, tetramethylene glycol diethylene ether, neopentyl glycol diethylene ether, trimethylolpropane triethylene ether, hexanediol diethylene ether, 1,4-cyclohexanediol diethylene ether, neopentyl tetraethylene ether, neopentyl tetraethylene ether, sorbitol tetraethylene ether, sorbitol pentaethylene ether, trimethylolpropane triethylene ether, etc.

[0440] When the resist material of the present invention is negative and contains a crosslinking agent, its content relative to 100 parts by weight of the base polymer is ideally 0.1 to 50 parts by weight, and more ideally 1 to 40 parts by weight. The aforementioned crosslinking agent can be used alone or in combination of two or more.

[0441] Other quenching agents mentioned above include known basic compounds. Known basic compounds include primary, secondary, or 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, and carbamates. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Publication No. 2008-111103, especially amine compounds with hydroxyl groups, ether bonds, ester bonds, lactone rings, cyano groups, or sulfonate bonds, or compounds with carbamate groups described in Japanese Patent No. 3790649, are preferred. 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.

[0442] Furthermore, as other quenching agents, examples include onium salts such as sulfonium salts, uranium salts, and ammonium salts of α-unfluorinated sulfonic acids and carboxylic acids, as described in Japanese Patent Application Publication No. 2008-158339. While α-fluorinated sulfonic acids, imides, or methyl acids are necessary to deprotect the unstable acid groups of carboxylic acid esters, they release α-unfluorinated sulfonic acids or carboxylic acids through salt exchange with α-unfluorinated onium salts. Since α-unfluorinated sulfonic acids and carboxylic acids do not undergo deprotection reactions, they function as quenching agents.

[0443] Other quenching agents include the polymer-type quenching agent disclosed in Japanese Patent Application Publication No. 2008-239918. By aligning with the surface of the resist film, it improves the rectangularity of the resist pattern. The polymer-type quenching agent also has the effect of preventing film loss and rounding at the top of the pattern when using a protective film for immersion exposure.

[0444] When the corrosion resist material of the present invention contains other quenching agents, it is ideal for their content to be 0-5 parts by mass relative to 100 parts by mass of the base polymer, and even more ideal to be 0-4 parts by mass. Other quenching agents can be used alone or in combination of two or more.

[0445] The aforementioned water-repellent enhancer is used to improve the water repellency of the resist film surface, enabling its application in immersion lithography without a topcoat. For the aforementioned water-repellent enhancer, polymers containing fluorinated alkyl groups or polymers with specific structures containing 1,1,1,3,3,3-hexafluoro-2-propanol residues are preferred, with examples such as Japanese Patent Application Publication No. 2007-297590 and Japanese Patent Application Publication No. 2008-111103 being more ideal. The aforementioned water-repellent enhancer needs to be soluble in alkaline or organic solvent developing solutions. The aforementioned specific water-repellent enhancer containing 1,1,1,3,3,3-hexafluoro-2-propanol residues exhibits good solubility in developing solutions. As a water-repellent enhancer, polymers containing repeating units containing amino or ammonium salts prevent the evaporation of acid in the PEB, thus effectively preventing poor opening of the hole pattern after development. When the corrosion resist material of the present invention contains a water-repellent enhancer, its content is ideally 0 to 20 parts by weight relative to 100 parts by weight of the base polymer, and more ideally 0.5 to 10 parts by weight. The aforementioned water-repellent enhancer can be used alone or in combination of two or more.

[0446] The aforementioned acetylene alcohols are illustrated in paragraphs

[0179] to

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

[0447] [Pattern Formation Method]

[0448] The resist material of the present invention can be used in the manufacture of various integrated circuits using known photolithography techniques. For example, a patterning method may include the following steps: forming a resist film on a substrate using the above-described chemically amplified resist material; exposing the above-described resist film to high-energy radiation; and developing the exposed resist film using a developing solution.

[0449] First, the 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 doctor blade coating, so that the coating film thickness is 0.01 to 2 μm. The resist film is then pre-baked on a hot plate, preferably at 60 to 150°C for 10 to 30 seconds, more preferably at 80 to 120°C for 30 to 20 seconds, to form a resist film.

[0450] Then, the resist film is exposed using high-energy rays. Examples of such high-energy rays include ultraviolet light, far ultraviolet light, EB (electron beam), EUV (extreme ultraviolet light) with wavelengths of 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, the exposure dose is preferably 1–200 mJ / cm², either directly or using a mask used to form the desired pattern. 2 Around 10-100 mJ / cm² is preferred. 2 Irradiation is performed in a left-right manner. When using EB (exposed beam) for high-energy rays, the optimal exposure dose is 0.1–300 μC / cm. 2 The optimal range is approximately 0.5–200 μC / cm. 2 The pattern can be drawn directly on the left and right sides or drawn using a mask to form the desired pattern. Furthermore, the resist material of the present invention is particularly suitable for micro-patterning using high-energy rays, including KrF excimer lasers, ArF excimer lasers, EB, EUV, X-rays, soft X-rays, gamma rays, and synchrotron radiation. The use of KrF excimer lasers, ArF excimer lasers, EB, or EUV with wavelengths of 3–15 nm is ideal, and EB or EUV is particularly suitable for micro-patterning.

[0451] After exposure, PEB can be performed on a hot plate or in an oven, preferably at 30–150°C for 10–30 minutes, more preferably at 50–120°C for 30–20 minutes, but it can also be omitted.

[0452] After exposure or PEB, the exposed resist film is developed using a developer solution containing 0.1-10% by mass, preferably 2-5% by mass, of an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, or tetrabutylammonium hydroxide, for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, using conventional methods such as dip, immersion, or spraying, to form the desired pattern. With positive resist materials, the exposed areas dissolve in the developer solution, while the unexposed areas do not, forming a positive pattern on the substrate. With negative resist materials, the situation is the opposite; that is, the exposed areas do not dissolve in the developer solution, while the unexposed areas dissolve.

[0453] Alternatively, positive resist materials containing acid-inhibitory groups from a base polymer can be used, and negative patterns can be obtained by developing with organic solvents. 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, and ethyl crotonate. The following organic solvents are listed: 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. One of these organic solvents can be used alone or in combination.

[0454] Rinsing is performed at the end of development. The rinsing solution should preferably be a solvent that is miscible with the developer but does not dissolve the resist film. Ideally, such solvents should be alcohols with 3 to 10 carbon atoms, ether compounds with 8 to 12 carbon atoms, alkanes, alkenes, alkynes, or aromatic solvents with 6 to 12 carbon atoms.

[0455] Alcohols with 3 to 10 carbon atoms, such as 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.

[0456] The aforementioned ether compounds with 8 to 12 carbon atoms include, for example, di-n-butyl ether, diisobutyl ether, disec-butyl ether, di-n-pentyl ether, diisopentyl ether, disec-pentyl ether, ditert-pentyl ether, and di-n-hexyl ether.

[0457] Alkanes having 6 to 12 carbon atoms include, for example, hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, and cyclononane. Alkenes having 6 to 12 carbon atoms include, for example, hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Alkynes having 6 to 12 carbon atoms include, for example, hexyne, heptyne, and octyne.

[0458] The solvents in the above-mentioned aromatic systems include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, mesitylene, etc.

[0459] Rinsing can reduce the collapse of the resist pattern and the occurrence of defects. Furthermore, rinsing is not always necessary; by omitting rinsing, the amount of solvent used can be reduced.

[0460] The developed hole and trench patterns can also be shrunk using heat transfer, RELACS, or DSA techniques. By coating the hole pattern with a shrinkage agent, the shrinkage agent cross-links on the surface of the resist film during baking, thanks to the diffusion of an acid catalyst from the resist film. The shrinkage agent adheres to the sidewalls of the hole pattern. The preferred baking temperature is 70–180°C, more preferably 80–170°C, and the preferred baking time is 10–300 seconds. This removes excess shrinkage agent, reducing the size of the hole pattern.

[0461] [Example]

[0462] The following examples, embodiments, and comparative examples illustrate the present invention in detail, but the present invention is not limited to the following embodiments. Furthermore, the apparatus used is shown below.

[0463] MALDI TOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[0464] [1] Synthesis of onium salts

[0465] [Example 1-1] Synthesis of SQ-1

[0466] [Chemistry 120]

[0467]

[0468] (1) Synthesis of intermediate In-1

[0469] Under nitrogen atmosphere, sodium hydride (55% by mass, 10.9 g) was suspended in THF (60 ml), and a solution of 1-isopropylcyclopentanol (35.3 g) and THF (30 ml) was added dropwise. After addition, the mixture was heated under reflux for 4 hours to prepare a metal alkoxide. Then, starting material SM-1 (48.3 g) was added dropwise, and the mixture was heated under reflux for 18 hours to mature. The reaction solution was cooled in an ice bath, and the reaction was stopped with water (100 ml). The target compound was extracted twice with a solvent consisting of toluene (100 ml) and hexane (100 ml), followed by a standard aqueous work-up. After distilling off the solvent, the mixture was purified by distillation to obtain 51.2 g of a colorless oily intermediate, In-1 (68% yield).

[0470] (2) Synthesis of intermediate In-2

[0471] Grenian reagent was prepared under nitrogen atmosphere from magnesium (4.1 g), intermediate In-1 (51.2 g), and THF (200 ml). This genian reagent was added dropwise to a suspension of THF (500 ml) on dry ice (200 g). After addition, the mixture was allowed to mature until the dry ice sublimated. After maturation, the reaction solution was kept below 10°C, and 5% hydrochloric acid (150 g) was added dropwise to stop the reaction. The mixture was then extracted with ethyl acetate (600 ml), followed by a standard aqueous work-up. After distillation off the solvent, the mixture was recrystallized in hexane to obtain white crystals of intermediate In-2 (yield 26.8 g, 58% yield).

[0472] (3) Synthesis of onium salt SQ-1

[0473] Under nitrogen atmosphere, intermediate In-2 (4.0 g) and starting material SM-2 (4.5 g) were dissolved in dichloromethane (50 g) and water (40 g) and stirred for 20 minutes. The reaction solution was separated, and the organic layer was subjected to a conventional aqueous work-up to remove the solvent, yielding 5.8 g of a colorless oily onium salt SQ-1 (yield 73%).

[0474] The TOF-MS results for onium salt SQ-1 are shown below.

[0475] MALDI TOF-MS: POSITIVE M + 261 (equivalent to C) 18 H 13 S + )

[0476] NEGATIVE M - 265 (equivalent to C) 15 H 18 FO3- )

[0477] [Examples 1-2 to 1-9] Synthesis of SQ-2 to SQ-9

[0478] Various onium salts are synthesized through various organic synthesis reactions. The structures of the onium salts used in chemically amplified resist compositions are shown below.

[0479] [Chemistry 121]

[0480]

[0481] [2][Synthetic Example] Synthesis of basic polymers (P-1 to 5)

[0482] The monomers were combined and copolymerized in THF as solvent, followed by crystallization in methanol, washing with hexane, and repeating this process. After separation and drying, the base polymers (P-1 to P-5) with the compositions shown below were obtained. The composition of the obtained base polymers is based on... 1 H-NMR confirmed Mw and Mw / Mn were confirmed by GPC (solvent: THF, standard: polystyrene).

[0483] [Chemistry 122]

[0484]

[0485] [Chemistry 123]

[0486]

[0487] [3][Examples 2-1 to 2-20, Comparative Examples 1-1 to 1-12] Preparation of corrosion resist materials

[0488] (1) Preparation of corrosion-resistant materials

[0489] The solutions containing the components as shown in Tables 1 and 2 were filtered through a 0.2 μm filter to prepare the photoresist material. The photoresist materials of Examples 2-1 to 2-18 and Comparative Examples 1-1 to 1-10 are positive types, while the photoresist materials of Examples 2-19 and 2-20 and Comparative Examples 1-11 and 1-12 are negative types.

[0490] The components are shown in Table 1.

[0491] • Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0492] DAA (diacetone alcohol)

[0493] • Photoacid generators: PAG-1 to PAG-5

[0494] [Chemistry 124]

[0495]

[0496] • Blending quenchers: bQ-1, bQ-2

[0497] [Chemistry 125]

[0498]

[0499] • Comparison of quenching agents: cSQ-1~cSQ-4

[0500] [Chemistry 126]

[0501]

[0502] [Table 1]

[0503]

[0504]

[0505] [Table 2]

[0506]

[0507] [4] Evaluation of EUV lithography (1)

[0508] [Examples 3-1 to 3-20, Comparative Examples 2-1 to 2-12]

[0509] The chemically amplified resist compositions (R-1 to R-20, CR-1 to CR-12) shown in Tables 1 and 2 were spin-coated onto a Si substrate with a 20 nm thick silicon-containing spin-coated hard mask (SHB-A940, 43% by mass) manufactured by Shin-Etsu Chemical Industry Co., Ltd. The substrate was pre-baked at 100°C for 60 seconds using a hot plate to produce a 50 nm thick resist film. This resist film was then used in an ASML EUV scanning exposure machine (NXE3300, NA 0.33, σ 0.9 / 0.6, dipole illumination) while varying the exposure and focus (exposure pitch: 1 mJ / cm). 2 LS patterns with a size of 18 nm and a pitch of 36 nm were exposed on the wafer at a focal pitch of 0.020 μm. After exposure, PEB was performed for 60 seconds at the temperatures shown in Tables 3 and 4. Then, development was performed for 30 seconds with a 2.38% (w / w) TMAH aqueous solution, followed by rinsing with a surfactant-containing rinsing material and spin drying. Positive patterns were obtained in Examples 3-1 to 3-18 and Comparative Examples 2-1 to 2-10. Negative patterns were obtained in Examples 3-19 and 3-20 and Comparative Examples 2-11 and 2-12.

[0510] LS patterns observed using a Hitachi Advanced Technology Co., Ltd. measuring SEM (CG6300) were evaluated for sensitivity, exposure margin (EL), light-reflecting ratio (LWR), depth of focus (DOF), and collapse limit using the following methods. The results are shown in Tables 3 and 4.

[0511] [Sensitivity Evaluation]

[0512] Find the optimal exposure E for obtaining an LS pattern with a linewidth of 18nm and a pitch of 36nm. op (mJ / cm 2 This value is defined as sensitivity. The smaller the value, the higher the sensitivity.

[0513] [EL Review]

[0514] The exposure amount formed by the above LS pattern within a spacing width of 18 nm and a range of ±10% (16.2–19.8 nm) is calculated using the following formula (unit: %). The larger this value, the better the performance.

[0515] EL(%)=(|E1-E2| / E op )×100

[0516] E1: Optimal exposure for an LS pattern with a linewidth of 16.2nm and a pitch of 36nm.

[0517] E2: Optimal exposure for an LS pattern with a linewidth of 19.8nm and a pitch of 36nm.

[0518] E op : Optimal exposure for an LS pattern with a linewidth of 18nm and a pitch of 36nm

[0519] [LWR Evaluation]

[0520] For E op The dimensions of the LS pattern obtained by irradiation are measured at 10 points along the long side of the line. The standard deviation (σ) of the results is calculated as three times the value (3σ), which is defined as LWR. The smaller this value, the smaller the roughness and the more uniform the linewidth of the pattern.

[0521] [DOF Rating]

[0522] For the evaluation of focal depth, the focal range is determined within ±10% (16.2–19.8 nm) of the 18 nm dimension in the aforementioned LS pattern. The larger this value, the wider the focal depth.

[0523] [Collapse Limit Assessment of Line Patterns]

[0524] For the aforementioned LS pattern, the line dimensions at various exposures under the optimal focal point were measured at 10 points along the long side. The finest line dimension obtained without collapse is defined as the collapse limit dimension. The smaller this value, the better the collapse limit.

[0525] [Table 3]

[0526]

[0527] [Table 4]

[0528]

[0529] The results shown in Tables 3 and 4 demonstrate that the chemically amplified resist composition containing the quencher of this invention exhibits good sensitivity in both positive and negative modes, and excellent EL, LWR, and DOF. Furthermore, a small collapse limit value was confirmed, indicating resistance to pattern collapse even during the formation of fine patterns.

[0530] [5] Evaluation of EUV lithography (2)

[0531] [Examples 4-1 to 4-20, Comparative Examples 3-1 to 3-12]

[0532] The photoresist materials shown in Tables 1 and 2 were spin-coated onto a Si substrate with a silicon spin-coated hard mask SHB-A940 (silicon content of 43% by mass) manufactured by Shin-Etsu Chemical Industry Co., Ltd. with a film thickness of 20 nm. The substrate was pre-baked at 100°C for 60 seconds using a hot plate to produce a photoresist film with a thickness of 60 nm. Then, the aforementioned resist film was exposed using an ASML NXE3400 EUV scanning exposure machine (NA 0.33, σ 0.9 / 0.6, quadruple illumination, mask for a hole pattern with a pitch of 44 nm and a +20% deviation on the wafer). The PEB was performed on a hot plate at the temperatures listed in Tables 5 and 6 for 60 seconds, followed by development with a 2.38% by mass TMAH aqueous solution for 30 seconds. Hole patterns with a size of 22 nm were obtained in Examples 4-1 to 4-18 and Comparative Examples 3-1 to 3-10, and dot patterns with a size of 22 nm were obtained in Examples 4-19, 4-20 and Comparative Examples 3-11 and 3-12.

[0533] Using a length-measuring SEM (CG6300) manufactured by Hitachi Advanced Technology Co., Ltd., the exposure amount when a hole or point is formed with a size of 22 nm was measured, which was defined as the sensitivity. Furthermore, the size of 50 holes or points at this time was measured, and the value of 3 times the standard deviation (σ) (3σ) was calculated from the results, which was defined as the CDU. The results are shown in Tables 5 and 6.

[0534] [Table 5]

[0535]

[0536] [Table 6]

[0537]

[0538] The results shown in Tables 5 and 6 confirm that the chemically amplified resist composition containing the quencher of the present invention exhibits good sensitivity in both the positive and negative forms, and excellent CDU.

[0539] This specification includes the following specifications.

[0540] [1]: An onium salt, characterized by being represented by the following general formula (1),

[0541] [Chemistry 127]

[0542]

[0543] In the formula, R ALU This refers to any of the following: a tertiary ether, tertiary carbonate, or acetal, which, together with an adjacent oxygen atom, has a cyclic structure and may also have heteroatoms. R F It is any one of fluorine atom, fluorinated alkyl group having 1 to 6 carbon atoms, or nitro group. Also, R a It can also be a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms. n1 is an integer of 0 or 1. n2 and n3 are integers of 1 or 2. When n2 and n3 are 1, R F With -OR ALU Bonded to adjacent carbon atoms. Also, when either n2 or n3, or both, are 2, R... F With -OR ALU Each of the atoms in the R group is bonded to an adjacent carbon atom. n4 is an integer from 0 to 3. When n4 ≥ 2, multiple R groups are also possible. a They bond to each other and together with the carbon atoms they are bonded to, form a ring structure. Z + This indicates a ium cation.

[0544] [2]: such as the onium salts in [1], wherein R in the general formula (1) ALU The structure is represented by the following general formula (ALU-1) or (ALU-2).

[0545] [Chemistry 128]

[0546]

[0547] In equation (ALU-1), R 21’ R 22’ and R 23’ Each can be an independent hydrocarbon group with 1 to 12 carbon atoms, and can also be R. 21’ R 22’ and R 23’ Any two elements in R are bonded together to form a loop. 21’ R 22’and R 23’ When they are not bonded together to form a loop, at least one of them has a loop structure. t is an integer of 0 or 1. In equation (ALU-2), R 24’ and R 25’ Each is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. R 26’ It is a hydrocarbon group with 1 to 20 carbon atoms, or it can be combined with R. 24’ Or R 25’ The carbon atoms and X atoms that are bonded to each other a Together, they form heterocyclic groups with 3 to 20 carbon atoms. Furthermore, the -CH2- group in the aforementioned hydrocarbon and heterocyclic groups can also be replaced with -O- or -S-. X a Represents an oxygen atom or a sulfur atom. * indicates a bond with an adjacent oxygen atom.

[0548] [3]: such as the onium salts of [1] or [2], R in the aforementioned general formula (1) F It is a fluorine atom or any of the fluorinated alkyl groups having 1 to 6 carbon atoms.

[0549] [4]: For any of the onium salts in [1] to [3], Z in the aforementioned general formula (1) + The onium cation is represented by any of the following general formulas (Cation-1) to (Cation-3).

[0550] [Chemistry 129]

[0551]

[0552] In equations (Cation-1) to (Cation-3), R 11’ ~R 19’ Each can be an independent hydrocarbon group consisting of 1 to 30 carbon atoms, which may contain heteroatoms and can be either saturated or unsaturated.

[0553] [5]: An acid diffusion control agent, characterized in that it is composed of an onium salt of any one of [1] to [4].

[0554] [6]: A corrosion resist composition characterized by containing an acid diffusion control agent such as [5].

[0555] [7]: Such as the resist composition of [6], it contains an acid-generating agent that produces acid.

[0556] [8]: such as [6] or [7] of the resist composition, wherein the aforementioned acid generating agent is an acid generating agent that generates sulfonic acid, imine acid or methyl acid.

[0557] [9]: The resist composition of any of [6] to [8] contains an organic solvent.

[0558]

[10] : The resist compositions of [6] to [9] contain a base polymer.

[0559]

[11] : The resist composition of

[10] , wherein the aforementioned base polymer contains repeating units represented by the following general formula (a1) and / or repeating units represented by the following general formula (a2),

[0560] [Chemistry 130]

[0561]

[0562] In the formula, R A Each can be independently a hydrogen atom or a methyl group. Y 1 It is a single bond, a phenylene or naphthylene group, or a linking group containing at least one of the following: an ester bond or a lactone ring, having 1 to 12 carbon atoms. 2 It is a single bond or an ester bond. Y 3 It can be a single bond, an ether bond, or an ester bond. R 11 and R 12 Each is an unstable acid group. R 13 It is a 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 diyl group with 1 to 6 carbon atoms, and some of its carbon atoms may be replaced by ether or ester bonds. a is 1 or 2. b is an integer from 0 to 4. However, 1 ≤ a + b ≤ 5.

[0563]

[12] : such as the resist composition of

[11] , wherein the aforementioned resist composition is a chemically amplified positive resist composition.

[0564]

[13] : such as the resist composition of

[10] , wherein the aforementioned base polymer does not contain acid-labile groups.

[0565]

[14] : such as the resist composition of

[13] , wherein the aforementioned resist composition is a chemically amplified negative resist composition.

[0566]

[15] : The resist composition of any one of

[10] to

[14] , wherein the aforementioned base polymer further contains at least one repeating unit selected from the following general formulas (f1) to (f3),

[0567] [Chemistry 131]

[0568]

[0569] In the formula, R A Each can be independently a hydrogen atom or a methyl group. Z 1 A single bond, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, an ester bond, or a combination thereof, or a group having 7 to 18 carbon atoms, or -OZ.11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -. Z 11 It is a group with 7 to 18 carbons obtained by aliphatic hydrocarbon groups, phenylene, naphthylene, or combinations thereof having 1 to 6 carbon atoms, and may also contain carbonyl groups, ester bonds, ether bonds, or hydroxyl groups. 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 a group with 7 to 18 carbon atoms obtained by alkylene groups, phenylene groups, or combinations thereof having 1 to 12 carbon atoms, and may also contain carbonyl groups, ester bonds, ether bonds, iodine atoms, or bromine atoms. 4 It is methylene, 2,2,2-trifluoro-1,1-ethanediyl, or carbonyl. 5 Single bond, methylene, ethylene, phenylene, fluorinated phenylene, trifluoromethyl-substituted phenylene, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -. Z 51 It can be an aliphatic alkylene group, phenylene, fluorinated phenylene, or trifluoromethyl-substituted phenylene, or a combination thereof, and may contain a carbonyl group, ester bond, ether bond, halogen atom, and / or hydroxyl group. R 21 ~R 28 Each group can be a halogen atom, or may contain heteroatoms and be a hydrocarbon group with 1 to 20 carbon atoms. Also, R... 23 With R 24 Or R 26 With R 27 They bond to each other and together with the sulfur atoms they are bonded to, form a ring. M - It is a non-nucleophilic relative ion.

[0570]

[16] : The resist composition of any of [6] to

[15] contains a surfactant.

[0571]

[17] : A method for forming a pattern, characterized by comprising the following steps:

[0572] A resist film is formed on the substrate using a resist composition such as any one of [6] to

[16] ;

[0573] The aforementioned resist film was exposed to high-energy radiation; and

[0574] The exposed resist film is developed using a developer.

[0575]

[18] : The pattern forming method of

[17] uses KrF excimer laser, ArF excimer laser, electron beam or extreme ultraviolet light with wavelength of 3 to 15 nm as the aforementioned high-energy rays.

[0576] Furthermore, the present invention is not limited to the embodiments described above. As illustrated above, any embodiments that have substantially the same structure and perform the same effect as the technical concept described in the claims of this invention are included within the technical scope of this invention.

Claims

1. An onium salt characterized by the following general formula (1), ###0001### wherein R1 to R4 each independently represent a hydrogen atom or a substituent, and the hetero atom is selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom and a halogen atom. In the formula, R F It is any one of fluorine atom, fluorinated alkyl group having 1 to 6 carbon atoms, or nitro group, and R a It can also be a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, where n1 is an integer of 0 or 1, n2 and n3 are integers of 1 or 2, and when n2 and n3 are 1, R F With -OR ALU Bonded to adjacent carbon atoms, and when either n2 or n3, or both, are 2, R F With -OR ALU Each of the atoms in the R group is bonded to an adjacent carbon atom, and n4 is an integer from 0 to 3. When n4 ≥ 2, multiple R groups are also possible. a They bond to each other and together with the carbon atoms they bond to form 5-membered or 6-membered ring structures, Z + Indicates a iumonium cation; R in the general formula (1) ALU The structure of the above-mentioned R is represented by the following general formula (ALU-1) or (ALU-2). R 21’ , R 22’ , and R 23’ each independently is a hydrocarbon group having a carbon number of 1 to 12 which can also have a hetero atom, R 21’ , R 22’ , and R 23’ any two of which can also be bonded to each other to form an alicyclic structure having a carbon number of 3 to 30; R 21’ , R 22’ , and R 23’ when not bonded to each other to form a ring, at least one of which has an alicyclic structure having a carbon number of 3 to 30 or an aromatic ring structure having a carbon number of 6 to 30, t is an integer of 0 or 1, in the formula (ALU-2), R 24’ , and R 25’ each independently is a hydrogen atom or a hydrocarbon group having a carbon number of 1 to 10, R 26’ is a hydrocarbon group having a carbon number of 1 to 20 or can also be bonded to R 24’ or R 25’ to each other to form a heterocyclic group having a carbon number of 3 to 20 together with the carbon atom to which they are bonded and X a , and further, -CH2- contained in the hydrocarbon group and the heterocyclic group can also be replaced with -O- or -S-, X a represents an oxygen atom or a sulfur atom, and * represents a bond to the adjacent oxygen atom, 2. The onium salt according to claim 1, wherein the hetero atom is an oxygen atom.

2. The onium salt of claim 1, wherein, R in the general formula (1) is any one of a fluorine atom or a fluorine-containing alkyl group having a carbon number of 1 to 6. F R in the general formula (1) is any one of a fluorine atom or a fluorine-containing alkyl group having a carbon number of 1 to 6.

3. The onium salt of claim 1, wherein, Z in the general formula (1) + Onium cations represented by any one of the following general formulae (Cation-1) to (Cation-3), In formulae (Cation-1) to (Cation-3), R 11’ ~R 19’ each independently is a hydrocarbon group having 1 to 30 carbons which can contain a hetero atom, and can be linear, branched, or cyclic, and can be saturated or unsaturated.

4. An acid diffusion control agent characterized by comprising 3. The onium salt according to any one of claims 1 to 2, wherein R1 to R4 each independently represent a hydrogen atom or a substituent selected from the group consisting of an alkyl group, an aryl group, a heteroaryl group, a heteroalkyl group, a halogen atom, a cyano group, a hydroxyl group, an alkoxy group, an aryloxy group, an acyl group, an acyloxy group, an amino group, an amido group, a sulfonyl group, a sulfinyl group, a sulfo group, a sulfamoyl group, a carbamoyl group, a ureido group, a mercapto group, an alkylthio group, an arylthio group, a heteroarylthio group, a heteroalkylthio group, a carbonyl group, an oxycarbonyl group, an imino group, an oximo group, a sulfonyloxy group, a sulfinyloxy group, a sulfoxy group, a sulfonylamine group, a sulfinylamine group, a sulfoamine group, a carbamoyloxy group, a ureidoxy group, a carbamoylamine group, a ureidoamine group, a carbonylimino group, an oximoxy group, a carbonylsulfonyl group, a carbonylsulfinyl group, a carbonylsulfo group, a sulfonylcarbonyl group, a sulfinylcarbonyl group, a sulfo carbonyl group, a sulfonylimino group, a sulfinylimino group, a sulfoimino group, a sulfonyloxyimino group, a sulfinyloxyimino group, a sulfooxyimino group, a sulfonylaminocarbonyl group, a sulfinylaminocarbonyl group, a sulfoaminocarbonyl group, a carbonylsulfonyloxy group, a carbonylsulfinyloxy group, a carbonylsulfoxy group, a sulfonylcarbonyloxy group, a sulfinylcarbonyloxy group, a sulfo carbonyloxy group, a sulfonyliminooxy group, a sulfinyliminooxy group, a sulfoiminooxy group, a sulfonylaminocarbonyloxy group, a sulfinylaminocarbonyloxy group, a sulfoaminocarbonyloxy group, a carbonylsulfonylimino group, a carbonylsulfinylimino group, a carbonylsulfoimino group, a sulfonylcarbonylimino group, a sulfinylcarbonylimino group, a sulfo carbonylimino group, a sulfonylcarbonylsulfonyl group, a sulfinylcarbonylsulfonyl group, a sulfo carbonylsulfonyl group, a sulfonylcarbonylsulfinyl group, a sulfinylcarbonylsulfinyl group, a sulfo carbonylsulfinyl group, a sulfonylcarbonylsulfo group, a sulfinylcarbonylsulfo group, a sulfo carbonylsulfo group, a sulfonylcarbonylsulfonyloxy group, a sulfinylcarbonylsulfonyloxy group, a sulfo carbonylsulfonyloxy group, a sulfonylcarbonylsulfinyloxy group, a sulfinylcarbonylsulfinyloxy group, a sulfo carbonylsulfinyloxy group, a sulfonylcarbonylsulfoxy group, a sulfinylcarbonylsulfoxy group, a sulfo carbonylsulfoxy group, a sulfonylcarbonylsulfonylamine group, a sulfinylcarbonylsulfonylamine group, a sulfo carbonylsulfonylamine group, a sulfonylcarbonylsulfinylamine group, a sulfinylcarbonylsulfinylamine group, a sulfo carbonylsulfinylamine group, a sulfonylcarbonyls ​ ​ 7. The resist composition according to claim 6, wherein, ​ ​ ​ ​ wherein R A each independently is a hydrogen atom or a methyl group, Y 1 is a single bond, a phenylene group or a naphthylene group, or a linking group having 1 to 12 carbon atoms containing at least one selected from an ester bond and a lactone ring, Y 2 is a single bond or an ester bond, Y 3 is a single bond, an ether bond or an ester bond, R 11 and R 12 each independently is an acid-labile group, R 13 is a fluorine atom, a trifluoromethyl group, a cyano group or a saturated hydrocarbon group having 1 to 6 carbon atoms, R 14 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, a part of the carbon atoms of which can also be replaced by an ether bond or an ester bond, a is 1 or 2, and b is an integer of 0 to 4, but 1 ≤ a + b ≤ 5.

11. The resist composition according to claim 10, wherein, ​ 12. The resist composition according to claim 9, wherein, ​ 13. The resist composition according to claim 12, wherein, ​ 14. The resist composition according to claim 9, wherein, ​ in which R A each independently is a hydrogen atom or a methyl group; Z 1 a group having a carbon number of 7 to 18 obtained by - a single bond, an aliphatic hydrocarbylene group having a carbon number of 1 to 6, a phenylene group, a naphthylene group, an ester bond, or a combination thereof, or -O-Z 11 -, -C(=O)-O-Z 11 -, or -C(=O)-NH-Z 11 -, Z 11 a group having a carbon number of 7 to 18 obtained by combining a carbon number 1 to 6 aliphatic alkylene, phenylene, naphthylene or the like, and can also contain a carbonyl group, an ester bond, an ether bond or a hydroxyl group; Z 2 is a single or ester bond; Z 3 is a single bond, -Z 31 -C(=O)-O-, -Z 31 -O- or -Z 31 -O-C(=O)-, Z 31 a group having a carbon number of 7 to 18 obtained by combining a hydrocarbylene group having a carbon number of 1 to 12, a phenylene group, or a combination thereof, and can also contain a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom; Z 4 is methylene, 2,2,2-trifluoro-1,1 -ethanediyl or carbonyl; Z 5 is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -O-Z 51 -, -C(=O)-O-Z 51 - or -C(=O)-NH-Z 51 - Z 51 R1is a C1-6aliphatic hydrocarbylene, phenylene, fluorinated phenylene, or trifluoromethyl-substituted phenylene group, and can also be a combination thereof, and can contain a carbonyl group, an ester linkage, an ether linkage, a halogen atom, and / or a hydroxyl group; R 21 ~R 28 each independently is a halogen atom, or a hydrocarbon group having a carbon number of 1 to 20 which can also contain a hetero atom, and also, R 23 and R 24 , or R 26 and R 27 are mutually bonded and form a ring together with the sulfur atom to which they are bonded; M - are non-nucleophilic counterions. ​ ​ ​ ​ ​ ​

Images