Resist material and pattern forming method

Abstract

The invention relates to a resist material and a pattern forming method. The present invention addresses the problem of providing: a resist material having high sensitivity to both positive and negative types and improved LWR and CDU; and a pattern forming method using the same. The solution of the invention is a resist material, which comprises a dionium salt, the present invention is characterized by containing: a divalent anion having an aryl sulfonic acid anion structure linked to an aromatic group having an iodine atom or a bromine atom, and a sulfonyl imide anion structure or a sulfonamide anion structure bonded to the aromatic group having an iodine atom or a bromine atom via a linking group having 1 or more carbon atoms; and an onium cation.

Description

Technical Field

[0001] The present invention relates to a resist material and a pattern forming method. Background Art

[0002] With the high integration and high speed of LSI, the miniaturization of pattern rules is progressing rapidly. The popularization of 5G high-speed communication and artificial intelligence (AI) is in progress, and high-performance devices are needed to handle them. As for the most advanced miniaturization technology, mass production of 5nm node devices using extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm is underway. Furthermore, the use of EUV lithography is also being explored in the next-generation 3nm node and the next-generation 2nm node devices, and IMEC in Belgium has announced the development of 1nm and 0.7nm devices.

[0003] As miniaturization progresses, image blurring caused by acid diffusion has become a problem. In order to ensure resolution in fine patterns with a processing size of less than 45nm, it has been proposed that in addition to the improvement of dissolution contrast that has been proposed so far, the control of acid diffusion is also important (Non-Patent Document 1). However, chemically amplified resist materials increase sensitivity and contrast by acid diffusion. If the post-exposure baking (PEB) temperature is lowered or the time is shortened to suppress acid diffusion to the limit, the sensitivity and contrast will decrease significantly.

[0004] In EUV resist materials, high sensitivity, high resolution and low LWR need to be achieved at the same time. If the acid diffusion distance is shortened, the line width roughness (LWR) of the line pattern and the size uniformity (CDU) of the hole pattern will increase, but the sensitivity will be reduced. For example, by lowering the PEB temperature, LWR and CDU will increase, but the sensitivity will be reduced. Even if the amount of quencher added is increased, LWR and CDU will still increase, but the sensitivity will be reduced. It is necessary to break the trade-off between sensitivity and LWR.

[0005] Some people have proposed resist materials that add onium salts containing anions with iodine atoms or bromine atoms as acid generators (Patent Documents 1 to 4). Since there are iodine atoms with high EUV absorption and bromine atoms with high ionization efficiency, the efficiency of acid generator decomposition during exposure is improved, resulting in high sensitivity. The increase in the amount of photon absorption can improve physical contrast.

[0006] EUV light with a wavelength of 13.5 nm has a wavelength that is more than one digit shorter than ArF excimer laser light with a wavelength of 193 nm, so it has high energy and is greatly affected by the deviation of the number of photons (Non-Patent Document 2). Therefore, it is pointed out that LWR will deteriorate (Non-Patent Document 3). In addition, the influence of LWR degradation caused by the deviation (Resist Stochastics) of resist components (polymer, PAG, quencher) as miniaturization progresses is also pointed out (Non-Patent Document 4).

[0007] A resist material containing a polymer in which an acid generator (PAG) and a quencher (PDQ) are bonded has been proposed (Patent Document 5). By integrating the polymer, PAG, and quencher, the variation therein can be suppressed, thereby improving LWR and CDU. Furthermore, a resist material containing an additive in which PAG and a quencher are bonded has also been proposed (Patent Documents 6 and 7).

[0008] Prior art literature

[0009] Patent Literature

[0010] [Patent Document 1] Japanese Patent Application Publication No. 2018-159744

[0011] [Patent Document 2] Japanese Patent Application Publication No. 2018-5224

[0012] [Patent Document 3] Japanese Patent Application Publication No. 2018-25789

[0013] [Patent Document 4] Japanese Patent Application Publication No. 2019-003175

[0014] [Patent Document 5] Japanese Patent Application Publication No. 2022-115072

[0015] [Patent Document 6] Japanese Patent Application Publication No. 2015-024989

[0016] [Patent Document 7] International Publication No. 2020 / 158313

[0017] Non-patent literature

[0018] [Non-patent document 1] SPIE Vol.6520 65203L-1 (2007)

[0019] [Non-patent document 2] SPIE Vol. 3331 535 (1998)

[0020] [Non-patent document 3] SPIE Vol.7273 727343-1 (2009)

[0021] [Non-patent document 4] SPIE Vol.9776 97760V-1 (2016) Summary of the invention

[0022] [Problems to be solved by the invention]

[0023] It is necessary to develop a resist material that has higher sensitivity than known resist materials and can improve the LWR of a line pattern and the CDU of a hole pattern.

[0024] The present invention is made in view of the above situation, and an object of the present invention is to provide a resist material having high sensitivity in both positive and negative modes and improved LWR and CDU, and a pattern forming method using the same.

[0025] [Methods to solve the problem]

[0026] The inventors of the present invention have repeatedly conducted in-depth studies to achieve the above-mentioned purpose. As a result, they have found that by using a divalent anion containing an arylsulfonic acid anion structure connected to an aromatic group having an iodine atom or a bromine atom and a sulfonyl imide anion structure or a sulfonamide anion structure bonded to the aromatic group having an iodine atom or a bromine atom via a connecting group with a carbon number of 1 or more, and a dicylon salt of an onium cation as an acid generator and quencher, the acid generator is directly excited by exposure to radiation without being affected by the diffusion of secondary electrons, thereby obtaining a resist material with high sensitivity, improved LWR and CDU, high contrast, excellent resolution, and high process latitude, and completing the present invention.

[0027] That is, the present invention provides the following resist material and pattern forming method.

[0028] 1. A resist material comprising:

[0029] A bis-onium salt comprising a divalent anion having an arylsulfonic acid anion structure linked to an aromatic group having an iodine atom or a bromine atom and a sulfonyl imide anion structure or a sulfonamide anion structure bonded to the aromatic group having an iodine atom or a bromine atom via a linking group having 1 or more carbon atoms, and an onium cation.

[0030] 2. The resist material according to 1., wherein the bis-onium salt is represented by the following formula (1):

[0031] [Chemistry 1]

[0032]

[0033] In the formula, p is an integer of 1 to 4, q is an integer of 0 to 3, and r is an integer of 1 to 6.

[0034] X BI is a bromine atom or an iodine atom,

[0035] X 1 is a hydrocarbylene group having 1 to 12 carbon atoms, and the hydrocarbylene group may contain at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom,

[0036] X 2 is a single bond, an ether bond, an ester bond, a sulfonate bond, an amide bond, a carbamate bond, a urea bond, a carbonate bond, or an alkanediyl group having 1 to 6 carbon atoms, wherein the alkanediyl group may contain at least one selected from an ether bond and an ester bond,

[0037] X 3 is a single bond, an ether bond, an ester bond, or an alkanediyl group having 1 to 6 carbon atoms, wherein the alkanediyl group may contain at least one selected from an ether bond and an ester bond,

[0038] R 1 is a single bond or a hydrocarbylene group having 1 to 12 carbon atoms, and the hydrocarbylene group may contain at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom,

[0039] But, -X 1 -R 1 -X 2 - has at least 1 carbon atom,

[0040] R 2 is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, an amino group, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon oxy group having 1 to 20 carbon atoms, a hydrocarbon oxycarbonyl group having 2 to 20 carbon atoms, a hydrocarbon carbonyloxy group having 2 to 20 carbon atoms, -N(R 2A )-C(=O)-R 2B 、-N(R 2A )-C(=O)-OR 2B or -N(R 2A )-S(=O)2-R 2B The alkyl group, alkyloxy group, alkyloxycarbonyl group and alkylcarbonyloxy group may also contain at least one selected from fluorine atom, chlorine atom, bromine atom, iodine atom, hydroxyl group, amino group, ester bond and ether bond, R 2A is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, the saturated hydrocarbon group may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms, R 2B is an aliphatic hydrocarbon group having 1 to 16 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms,

[0041] Ar is an aromatic hydrocarbon group having 6 to 10 carbon atoms and having a valence of (r+2),

[0042] Rf is a hydrogen atom, a saturated hydrocarbon group having 1 to 10 carbon atoms, a nitro group, a cyano group, a fluorine atom, an iodine atom, a trifluoromethyl group or a trifluoromethoxy group,

[0043] Q - is a group having a sulfonimide anion structure or a sulfonamide anion structure,

[0044] M + It is a sulfonium cation or an iodonium cation.

[0045] 3. The resist material as in 2., wherein Q - is a group represented by any of the following formulae (Q-1) to (Q-4),

[0046] [Chemistry 2]

[0047]

[0048] In the formula, R 3 is a saturated hydrocarbon group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may be substituted by at least one group selected from the group consisting of a halogen atom, a cyano group, a nitro group, a hydroxyl group, a saturated hydrocarbon group having 1 to 8 carbon atoms, a saturated hydrocarbon group having 2 to 8 carbon atoms carbonyloxy group, a saturated hydrocarbon group having 2 to 8 carbon atoms oxycarbonyl group, a trifluoromethoxy group, a difluoromethoxy group, a trifluoromethylthio group, and a trifluoromethyl group, and * is the same as X 1 of atomic bonds.

[0049] 4. The resist material according to any one of 1. to 3., further comprising a base polymer.

[0050] 5. The resist material according to 4., wherein the base polymer comprises a repeating unit represented by the following formula (a1) or (a2),

[0051] [Chemistry 3]

[0052]

[0053] In the formula, R A are each independently a hydrogen atom or a methyl group,

[0054] Y 1 is a single bond, a phenylene group or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, an ether bond, and a lactone ring, wherein the phenylene group, the naphthylene group, and the linking group may have at least one selected from a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms, and a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms,

[0055] Y 2 is a single bond or an ester bond,

[0056] Y 3 is a single bond, an ether bond or an ester bond,

[0057] R 11 and R 12 are each independently an acid-labile group,

[0058] R 13 is a saturated hydrocarbon group having 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group having 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group having 2 to 5 carbon atoms,

[0059] R 14 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the alkanediyl group may also contain an ether bond or an ester bond,

[0060] a is an integer from 0 to 4.

[0061] 6. The resist material as in 5. is a chemically amplified positive resist material.

[0062] 7. The resist material according to 4., wherein the base polymer does not contain an acid-labile group.

[0063] 8. The resist material as in 7. is a chemically amplified negative resist material.

[0064] 9. The resist material according to any one of 1. to 8., further comprising an organic solvent.

[0065] 10. The resist material according to any one of 1. to 9., further comprising a quencher.

[0066] 11. The resist material according to any one of 1. to 10., further comprising an acid generator.

[0067] 12. The resist material according to any one of 1. to 11., further comprising a surfactant.

[0068] 13. A pattern forming method, comprising the steps of: forming a resist film on a substrate using the resist material as described in any one of 1. to 12., exposing the resist film using high-energy rays, and developing the exposed resist film using a developer.

[0069] 14. The pattern forming method according to 13., wherein the high-energy radiation is ArF excimer laser with a wavelength of 193 nm, KrF excimer laser with a wavelength of 248 nm, electron beam or extreme ultraviolet radiation with a wavelength of 3 to 15 nm.

[0070] [Effects of the Invention]

[0071] The resist film containing a divalent anion having an aromatic sulfonic acid anion structure connected to an aromatic group having an iodine atom or a bromine atom and a sulfonyl imide anion structure or a sulfonamide anion structure bonded to the aromatic group having an iodine atom or a bromine atom via a connecting group having a carbon number of 1 or more, and a bis-onium salt of an onium cation has the characteristics of being directly excited during exposure and inhibiting acid diffusion due to the large absorption of EUV light. In this way, the reduction in resolution caused by blurring of secondary electrons and acid diffusion can be prevented. The aforementioned bis-onium salt improves the aforementioned Resist Stochastics by bonding the acid generator of the onium salt that generates sulfonic acid and the quencher of the onium salt that generates carboxylic acid, so that the acid generator and the quencher are often arranged at a certain distance, thereby improving the LWR and CDU. In this way, a resist material with high sensitivity and improved LWR and CDU can be constructed. DETAILED DESCRIPTION

[0072] [Resist material]

[0073] The resist material of the present invention comprises: a divalent anion having an arylsulfonic acid anion structure connected to an aromatic group having an iodine atom or a bromine atom, and a sulfonyl imide anion structure or a sulfonamide anion structure bonded to the aromatic group having an iodine atom or a bromine atom via a connecting group having a carbon number of 1 or more, and a di-onium salt of an onium cation. The di-onium salt is an acid generator and quencher having the functions of both an acid generator and a quencher, and has acid diffusion controllability due to absorption of iodine atoms, ionization of bromine atoms, high reactivity of fluorosulfonic acid, and the frequent presence of a quencher nearby, so that the acid diffusion is small and the diffusion distance is uniform. This can improve LWR and CDU.

[0074] The LWR and CDU enhancement effects of the dicylon salt used in the present invention are effective in both positive and negative pattern formation by alkaline aqueous solution development and negative pattern formation by organic solvent development.

[0075] [Bis-onium salt]

[0076] The bis-onium salt is preferably represented by the following formula (1).

[0077] [Chemistry 4]

[0078]

[0079] In the formula (1), p is an integer of 1-4, q is an integer of 0-3, and r is an integer of 1-6.

[0080] In formula (1), X BI It is a bromine atom or an iodine atom.

[0081] In formula (1), X 1It is a hydrocarbylene group having 1 to 12 carbon atoms, and the hydrocarbylene group may contain at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom.

[0082] In formula (1), X 2 It is a single bond, an ether bond, an ester bond, a sulfonate bond, an amide bond, a carbamate bond, a urea bond, a carbonate bond or an alkanediyl group having 1 to 6 carbon atoms. The alkanediyl group may also contain at least one selected from an ether bond and an ester bond.

[0083] In formula (1), X 3 It is a single bond, an ether bond, an ester bond, or an alkanediyl group having 1 to 6 carbon atoms. The alkanediyl group may contain at least one selected from an ether bond and an ester bond.

[0084] In formula (1), R 1 It is a single bond or a hydrocarbylene group having 1 to 12 carbon atoms, and the hydrocarbylene group may contain at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom.

[0085] But, -X 1 -R 1 -X 2 - has at least 1 carbon atom.

[0086] X 1 and R 1The alkylene group represented by may be saturated or unsaturated, and may be straight chain, branched, or cyclic. Specific examples thereof include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, 1-methylethane-1,2-diyl, 1-ethylethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, 2-methylpropane-1,1-diyl, butane-1,3-diyl, butane-1,4-diyl, butane-1,5-diyl, butane-2-diyl, butane-3-diyl, butane-4-diyl, butane-5-diyl, butane-6-diyl, butane-7-diyl, butane-8-diyl, butane-9-diyl, butane-10-diyl, butane-11-diyl, butane-12-diyl, butane-13-diyl, butane-14-diyl, butane-15-diyl, butane-16-diyl, butane-17-diyl, butane-18-diyl, butane-19-diyl, butane-20-diyl, butane-21-diyl, butane-22-diyl, butane-23-diyl, butane-24-diyl, butane-25-diyl, butane-26-diyl, butane-27-diyl, butane-28-diyl, butane-29-diyl, butane-30-diyl, butane-31-diyl, butane-32-diyl, butane-33-diyl, butane-34-diyl, butane-35-diyl, butane-36-diyl, butane-37-diyl, butane-38-diyl, butane-39-diyl, butane-40-diyl, butane-41- alkane-2,3-diyl, 1,1-dimethylpropane-1,3-diyl, 2,2-dimethylpropane-1,3-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, etc. 1 to 12 carbon atoms in an alkane diyl group; a cyclic saturated alkylene group having 3 to 12 carbon atoms such as cyclopentanediyl, cyclohexanediyl, bicyclo[2.2.2]octanediyl, norbornanediyl, and adamantanediyl; an alkene diyl group having 2 to 12 carbon atoms such as ethylenediyl, propylenediyl, and butenediyl; an alkyne diyl group having 2 to 12 carbon atoms such as ethynediyl, propynediyl, and butynediyl; a cyclic unsaturated aliphatic alkylene group having 3 to 12 carbon atoms such as cyclohexenediyl, bicyclo[2.2.2]octenediyl, and norbornanediyl; an arylene group having 6 to 12 carbon atoms such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, and ethylnaphthylene; and a group obtained by combining these.

[0087] In formula (1), R 2 is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, an amino group, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon oxy group having 1 to 20 carbon atoms, a hydrocarbon oxycarbonyl group having 2 to 20 carbon atoms, a hydrocarbon carbonyloxy group having 2 to 20 carbon atoms, -N(R 2A )-C(=O)-R 2B 、-N(R 2A )-C(=O)-OR 2B or -N(R 2A )-S(=O)2-R 2B The hydrocarbon group, hydrocarbon oxy group, hydrocarbon oxycarbonyl group and hydrocarbon carbonyloxy group may also contain at least one selected from the group consisting of a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a hydroxyl group, an amino group, an ester bond and an ether bond. 2A R is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and the saturated hydrocarbon group may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms. 2BIt is an aliphatic hydrocarbon group having 1 to 16 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms.

[0088] In formula (1), Ar is an (r+2)-valent aromatic hydrocarbon group having 6 to 10 carbon atoms. Specific examples of the (r+2)-valent aromatic hydrocarbon group include groups obtained by removing (r+2) hydrogen atoms from aromatic hydrocarbons such as benzene and naphthalene.

[0089] In the formula (1), Rf is a hydrogen atom, a saturated hydrocarbon group having 1 to 10 carbon atoms, a nitro group, a cyano group, a fluorine atom, an iodine atom, a trifluoromethyl group or a trifluoromethoxy group.

[0090] In formula (1), Q - It is a group having a sulfonyl imide anion structure or a sulfonamide anion structure. As such a group, a group represented by any of the following formulae (Q-1) to (Q-4) is preferred.

[0091] [Chemistry 5]

[0092]

[0093] In formulas (Q-1) to (Q-4), R 3 is a saturated hydrocarbon group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may be substituted by at least one group selected from the group consisting of a halogen atom, a cyano group, a nitro group, a hydroxyl group, a saturated hydrocarbon group having 1 to 8 carbon atoms, a saturated hydrocarbon group having 2 to 8 carbon atoms carbonyloxy group, a saturated hydrocarbon group having 2 to 8 carbon atoms oxycarbonyl group, a trifluoromethoxy group, a difluoromethoxy group, a trifluoromethylthio group, and a trifluoromethyl group, and * is the same as X 1 of atomic bonds.

[0094] R 3 The saturated hydrocarbon group having 1 to 12 carbon atoms may be straight-chain, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, undecyl and dodecyl; cyclopentyl, methylcyclopentyl, ethylcyclopentyl, propylcyclopentyl, isopropylcyclopentyl and the like. The cyclic saturated hydrocarbon group having 3 to 12 carbon atoms can be cyclopentyl, n-butylcyclopentyl, isobutylcyclopentyl, sec-butylcyclopentyl, tert-butylcyclopentyl, cyclohexyl, methylcyclohexyl, ethylcyclohexyl, propylcyclohexyl, isopropylcyclohexyl, n-butylcyclohexyl, isobutylcyclohexyl, sec-butylcyclohexyl, tert-butylcyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, adamantyl or the like.

[0095] Just R 3Specific examples of the aryl group having 6 to 12 carbon atoms represented by include phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, and ethylnaphthyl.

[0096] Specific examples of the anion of the bis-onium salt include those shown below, but are not limited to these.

[0097] [Chemistry 6]

[0098]

[0099] [Chemistry 7]

[0100]

[0101] [Chemistry 8]

[0102]

[0103] [Chemistry 9]

[0104]

[0105] [Chemistry 10]

[0106]

[0107] [Chemistry 11]

[0108]

[0109] [Chemistry 12]

[0110]

[0111] [Chemistry 13]

[0112]

[0113] [Chemistry 14]

[0114]

[0115] [Chemistry 15]

[0116]

[0117] [Chemistry 16]

[0118]

[0119] [Chemistry 17]

[0120]

[0121] [Chemistry 18]

[0122]

[0123] [Chemistry 19]

[0124]

[0125] [Chemistry 20]

[0126]

[0127] [Chemistry 21]

[0128]

[0129] [Chemistry 22]

[0130]

[0131] [Chemistry 23]

[0132]

[0133] [Chemistry 24]

[0134]

[0135] [Chemistry 25]

[0136]

[0137] [Chemistry 26]

[0138]

[0139] [Chemistry 27]

[0140]

[0141] [Chemistry 28]

[0142]

[0143] [Chemistry 29]

[0144]

[0145] [Chemistry 30]

[0146]

[0147] [Chemistry 31]

[0148]

[0149] [Chemistry 32]

[0150]

[0151] [Chemistry 33]

[0152]

[0153] [Chemistry 34]

[0154]

[0155] [Chemistry 35]

[0156]

[0157] [Chemistry 36]

[0158]

[0159] [Chemistry 37]

[0160]

[0161] [Chemistry 38]

[0162]

[0163] [Chemistry 39]

[0164]

[0165] In formula (1), M + is a sulfonium cation or an iodonium cation. 2 M + , one may be a sulfonium cation and the other may be an iodonium cation, both may be sulfonium cations, or both may be iodonium cations. + When both are sulfonium cations, they may be the same as or different from each other. + When both are iodonium cations, they may be the same as or different from each other.

[0166] The sulfonium cation is preferably represented by the following formula (2), and the iodonium cation is preferably represented by the following formula (3).

[0167] [Chemistry 40]

[0168]

[0169] In formula (2) and (3), R 4 ~R 8 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

[0170] Just R 4 ~R8 Specific examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

[0171] R 4 ~R 8 The hydrocarbon group having 1 to 20 carbon atoms represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecanyl, tridecyl, tetradecyl, pentadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, propenyl, butenyl, and hexenyl; Alkynyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, and butynyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms, such as cyclohexenyl and norbornenyl; aryl groups having 6 to 20 carbon atoms, such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, and tert-butylnaphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl and phenethyl; groups obtained by combining these, etc.

[0172] Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of the -CH2- of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, resulting in a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a mercapto group, a pentafluoromercapto group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like.

[0173] Again, R 4 and R 5 They may be bonded to each other and form a ring together with the sulfur atoms to which they are bonded. In this case, the ring is preferably a structure shown below.

[0174] [Chemistry 41]

[0175]

[0176] In the formula, the dotted lines represent atomic bonds.

[0177] Just M + Specific examples of the sulfonium cation represented by include those shown below, but are not limited to these.

[0178] [Chemistry 42]

[0179]

[0180] [Chemistry 43]

[0181]

[0182] [Chemistry 44]

[0183]

[0184] [Chemistry 45]

[0185]

[0186] [Chemistry 46]

[0187]

[0188] [Chemistry 47]

[0189]

[0190] [Chemistry 48]

[0191]

[0192] [Chemistry 49]

[0193]

[0194] [Chemistry 50]

[0195]

[0196] [Chemistry 51]

[0197]

[0198] [Chemistry 52]

[0199]

[0200] [Chemistry 53]

[0201]

[0202] [Chemistry 54]

[0203]

[0204] [Chemistry 55]

[0205]

[0206] [Chemistry 56]

[0207]

[0208] [Chemistry 57]

[0209]

[0210] [Chemistry 58]

[0211]

[0212] [Chemistry 59]

[0213]

[0214] [Chemistry 60]

[0215]

[0216] [Chemistry 61]

[0217]

[0218] [Chemistry 62]

[0219]

[0220] [Chemistry 63]

[0221]

[0222] [Chemistry 64]

[0223]

[0224] [Chemistry 65]

[0225]

[0226] [Chemistry 66]

[0227]

[0228] [Chemistry 67]

[0229]

[0230] [Chemistry 68]

[0231]

[0232] [Chemistry 69]

[0233]

[0234] [Chemistry 70]

[0235]

[0236] [Chemistry 71]

[0237]

[0238] [Chemistry 72]

[0239]

[0240] [Chemistry 73]

[0241]

[0242] [Chemistry 74]

[0243]

[0244] [Chemistry 75]

[0245]

[0246] [Chemistry 76]

[0247]

[0248] [Chemistry 77]

[0249]

[0250] Just M + Specific examples of the iodonium cation represented by include those shown below, but are not limited to these.

[0251] [Chemistry 78]

[0252]

[0253] [Chemistry 79]

[0254]

[0255] As for the synthesis method of the bis-onium salt represented by formula (1), for example, there can be mentioned a method of salt exchange between a sulfonium salt or iodonium salt containing a halogenated anion and an ammonium salt containing a divalent anion having an arylsulfonic acid anion structure linked to an aromatic group having an iodine atom or a bromine atom and a sulfonyl imide anion structure or a sulfonamide anion structure bonded to the aromatic group having an iodine atom or a bromine atom via a linking group having 1 or more carbon atoms.

[0256] In the resist material of the present invention, the content of the bis-onium salt is preferably 0.01 to 1000 parts by mass, more preferably 0.05 to 500 parts by mass, based on 100 parts by mass of the base polymer described below, from the viewpoint of sensitivity and acid diffusion inhibition effect.

[0257] [Base polymer]

[0258] The base polymer contained in the resist material of the present invention, when being a positive resist material, contains a repeating unit containing an acid-labile group. The repeating unit containing an acid-labile group is preferably a repeating unit represented by the following formula (a1) (hereinafter, also referred to as repeating unit a1) or a repeating unit represented by formula (a2) (hereinafter, also referred to as repeating unit a2).

[0259] [Chemistry 80]

[0260]

[0261] In formula (a1) and (a2), R A are each independently a hydrogen atom or a methyl group. 1 Y is a single bond, a phenylene group or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, an ether bond, and a lactone ring. The phenylene group, the naphthylene group, and the linking group may also have at least one selected from a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms, and a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms. 2 is a single bond or an ester bond. 3 is a single bond, an ether bond or an ester bond. 11 and R 12 Each is independently an acid-labile group. 13 R is a saturated hydrocarbon group having 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group having 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group having 2 to 5 carbon atoms. 14 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the alkanediyl group may contain an ether bond or an ester bond. a is an integer of 0 to 4.

[0262] Specific examples of the monomer providing the repeating unit a1 include the following, but are not limited thereto. A and R 11 Same as above.

[0263] [Chemistry 81]

[0264]

[0265] [Chemistry 82]

[0266]

[0267] [Chemistry 83]

[0268]

[0269] Specific examples of monomers providing repeating unit a2 include the following, but are not limited thereto. A and R 12 Same as above.

[0270] [Chemistry 84]

[0271]

[0272] For R in repeating units a1 and a2 11 and R 12 Examples of the acid-labile group represented by include those described in JP-A-2013-80033 and JP-A-2013-83821.

[0273] Typically, specific examples of the acid-labile group include those represented by any of the following formulae (AL-1) to (AL-3).

[0274] [Chemistry 85]

[0275]

[0276] In the formula, the dotted lines represent atomic bonds.

[0277] In formula (AL-1) and (AL-2), R L1 and R L2 Each is independently a hydrocarbon group having 1 to 40 carbon atoms, and may also contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. As for the aforementioned hydrocarbon group, a saturated hydrocarbon group having 1 to 40 carbon atoms is preferred, and a saturated hydrocarbon group having 1 to 20 carbon atoms is more preferred.

[0278] In formula (AL-1), b is an integer of 0 to 10, preferably an integer of 1 to 5.

[0279] In formula (AL-2), R L3 and R L4 Each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. As for the aforementioned hydrocarbon group, it is preferably a saturated hydrocarbon group having 1 to 20 carbon atoms. In addition, R L2 , R L3 and R L4Any two of the above may be bonded to each other and form a ring having 3 to 20 carbon atoms together with the carbon atoms or carbon atoms and oxygen atoms to which they are bonded. The above ring is preferably a ring having 4 to 16 carbon atoms, and is particularly preferably an alicyclic ring.

[0280] In formula (AL-3), R L5 , R L6 and R L7 Each is independently a hydrocarbon group having 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. The aforementioned hydrocarbon group is preferably a saturated hydrocarbon group having 1 to 20 carbon atoms. L5 , R L6 and R L7 Any two of them may be bonded to each other and together with the carbon atoms to which they are bonded form a ring having 3 to 20 carbon atoms. The aforementioned ring is preferably a ring having 4 to 16 carbon atoms, and is particularly preferably an alicyclic ring.

[0281] The base polymer may also include a repeating unit b containing a phenolic hydroxyl group as an adhesive group. Specific examples of monomers providing the repeating unit b include the following, but are not limited to these. A Same as above.

[0282] [Chemistry 86]

[0283]

[0284] The aforementioned base polymer may also contain a repeating unit c containing a hydroxyl group other than a phenolic hydroxyl group, a lactone ring, a sultone ring, an ether bond, an ester bond, a sulfonate bond, a carbonyl group, a sulfonyl group, a cyano group or a carboxyl group as another adhesive group. Specific examples of monomers providing the repeating unit c include those shown below, but are not limited to these. In the following formula, R A Same as above.

[0285] [Chemistry 87]

[0286]

[0287] [Chemistry 88]

[0288]

[0289] [Chemistry 89]

[0290]

[0291] [Chemistry 90]

[0292]

[0293] [Chemistry 91]

[0294]

[0295] [Chemistry 92]

[0296]

[0297] [Chemistry 93]

[0298]

[0299] [Chemistry 94]

[0300]

[0301] The base polymer may also include a repeating unit d derived from indene, benzofuran, benzothiophene, acenaphthylene, chromone, coumarin, norbornadiene or a derivative thereof. Specific examples of the monomer providing the repeating unit d include the following, but are not limited thereto.

[0302] [Chemistry 95]

[0303]

[0304] The aforementioned base polymer may also include a repeating unit e derived from styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methylenedihydroindane, vinylpyridine or vinylcarbazole.

[0305] The base polymer may also contain repeating units f derived from an onium salt containing a polymerizable unsaturated bond. Japanese Patent Application Laid-Open No. 2005-84365 proposes sulfonium salts and iodonium salts containing polymerizable olefins that generate specific sulfonic acids. Japanese Patent Application Laid-Open No. 2006-178317 proposes sulfonium salts in which sulfonic acid is directly bonded to the main chain.

[0306] As specific examples of preferred repeating units f, repeating units represented by the following formula (f1) (hereinafter, also referred to as repeating units f1), repeating units represented by the following formula (f2) (hereinafter, also referred to as repeating units f2), and repeating units represented by the following formula (f3) (hereinafter, also referred to as repeating units f3). Furthermore, repeating units f1 to f3 may be used alone or in combination of two or more.

[0307] [Chemistry 96]

[0308]

[0309] In formulas (f1) to (f3), R A Each is independently a hydrogen atom or a methyl group. 1is a single bond, an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, or -OZ 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -.Z 11 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 2 It is a single bond or an ester bond. 3 Is a single bond, -Z 31 -C(=O)-O-, -Z 31 -O- or -Z 31 -OC(=O)-. Z 31 It is an aliphatic alkylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, and may contain a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom. 4 is methylene, 2,2,2-trifluoro-1,1-ethanediyl or carbonyl. 5 is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -.Z 51 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, a hydroxyl group or a halogen atom.

[0310] In formulas (f1) to (f3), R 21 ~R 28 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. Specific examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, iodine atom, etc. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include the same as those described in formulas (2) and (3). 4 ~R 8 The hydrocarbon groups represented by are the same as those exemplified. Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and part of -CH2- of the aforementioned hydrocarbon groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, resulting in hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl groups, and the like. Furthermore, R23 and R 24 or R 26 and R 27 They may also be bonded to each other and form a ring together with the sulfur atoms to which they are bonded. In this case, specific examples of the aforementioned ring include those described in formula (2). 4 and R 5 The rings that can be formed together with these bonded sulfur atoms are the same as those exemplified.

[0311] In formula (f1), M - It is a non-nucleophilic counter ion. Specific examples of the non-nucleophilic counter ion include halide ions such as chloride ion and bromide ion, fluoroalkylsulfonate ions such as trifluoromethanesulfonate ion, 1,1,1-trifluoroethanesulfonate ion and nonafluorobutanesulfonate ion, arylsulfonate ions such as toluenesulfonate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion and 1,2,3,4,5-pentafluorobenzenesulfonate ion, alkylsulfonate ions such as methanesulfonate ion and butanesulfonate ion, imide ions such as bis(trifluoromethylsulfonyl)imide ion, bis(perfluoroethylsulfonyl)imide ion and bis(perfluorobutylsulfonyl)imide ion, methide ions such as tris(trifluoromethylsulfonyl)methide ion and tris(perfluoroethylsulfonyl)methide ion.

[0312] As specific examples of the aforementioned non-nucleophilic relative ions, further examples include a sulfonate ion represented by the following formula (f1-1) in which the α-position is substituted with a fluorine atom, a sulfonate ion represented by the following formula (f1-2) in which the α-position is substituted with a fluorine atom and the β-position is substituted with a trifluoromethyl group, and the like.

[0313] [Chemistry 97]

[0314] R 31 —CF2—SO3 - (f1-1)

[0315]

[0316] In formula (f1-1), R 31 It is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. The hydrocarbon group may contain at least one selected from an ether bond, an ester bond, a carbonyl group, a lactone ring and a fluorine atom.

[0317] In formula (f1-2), R 32 It is a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a hydrocarbon carbonyl group having 2 to 30 carbon atoms, and may contain at least one selected from an ether bond, an ester bond, a carbonyl group, and a lactone ring.

[0318] R 31 or R 32The hydrocarbon part of the hydrocarbon group and the hydrocarbon carbonyl group represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and eicosyl; cyclic saturated hydrocarbon groups such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornyl, norbornylmethyl, tricyclodecanyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; alkenyl groups such as allyl; cyclic unsaturated hydrocarbon groups such as 3-cyclohexenyl; aryl groups such as phenyl, 1-naphthyl, and 2-naphthyl; and aralkyl groups such as benzyl and diphenylmethyl.

[0319] In addition, part or all of the hydrogen atoms of these groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and part of the carbon atoms of these groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate groups, lactone rings, sultone rings, carboxylic anhydrides, and haloalkyl groups may be included. Specific examples of heteroatom-containing hydrocarbon groups include tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, and 3-oxocyclohexyl.

[0320] Specific examples of the cation of the monomer providing the repeating unit f1 include those shown below, but are not limited to these. A Same as above.

[0321] [Chemistry 98]

[0322]

[0323] Specific examples of the cation of the monomer providing the repeating unit f2 or f3 include the following: + The sulfonium cation represented is the same as exemplified above.

[0324] Specific examples of monomers providing repeating unit f2 include those shown below, but are not limited to these. A Same as above.

[0325] [Chemistry 99]

[0326]

[0327] [Chemical 100]

[0328]

[0329] [Chemistry 101]

[0330]

[0331] [Chemistry 102]

[0332]

[0333] [Chemistry 103]

[0334]

[0335] [Chemistry 104]

[0336]

[0337] [Chemistry 105]

[0338]

[0339] [Chemistry 106]

[0340]

[0341] [Chemistry 107]

[0342]

[0343] [Chemistry 108]

[0344]

[0345] [Chemistry 109]

[0346]

[0347] [Chemistry 110]

[0348]

[0349] [Chemistry 111]

[0350]

[0351] [Chemistry 112]

[0352]

[0353] Specific examples of monomers providing repeating unit f3 include those shown below, but are not limited to these. A Same as above.

[0354] [Chemistry 113]

[0355]

[0356] Repeating units f1 to f3 function as acid generators. By bonding the acid generator to the polymer main chain, acid diffusion can be reduced, thereby preventing a decrease in resolution due to blurring of the acid diffusion. Furthermore, by uniformly dispersing the acid generator, LWR and CDU can be improved.

[0357] In the base polymer for positive resist material, repeating unit a1 or a2 containing an acid-labile group is essential. In this case, the content ratio of repeating units a1, a2, b, c, d, e and f is preferably 0≤a1<1.0, 0≤a2<1.0, 0<a1+a2<1.0, 0≤b≤0.9, 0≤c≤0.9, 0≤d≤0.8, 0≤e≤0.8 and 0≤f≤0.5, preferably 0≤a1≤0.9, 0≤a2≤0.9, 0.1≤a 1+a2≤0.9, 0≤b≤0.8, 0≤c≤0.8, 0≤d≤0.7, 0≤e≤0.7 and 0≤f≤0.4 are more preferred, and 0≤a1≤0.8, 0≤a2≤0.8, 0.1≤a1+a2≤0.8, 0≤b≤0.75, 0≤c≤0.75, 0≤d≤0.6, 0≤e≤0.6 and 0≤f≤0.3 are even more preferred. Moreover, when the repeating unit f is selected from at least one of the repeating units f1 to f3, f=f1+f2+f3. Moreover, a1+a2+b+c+d+e+f=1.0.

[0358] On the other hand, the base polymer used for the negative resist material does not necessarily need an acid-labile group. As for such a base polymer, there can be mentioned a polymer that contains a repeating unit b and further contains repeating units c, d, e and / or f as needed. The content ratio of these repeating units is preferably 0<b≤1.0, 0≤c≤0.9, 0≤d≤0.8, 0≤e≤0.8 and 0≤f≤0.5, preferably 0.2≤b≤1.0, 0≤c≤0.8, 0≤d≤0.7, 0≤e≤0.7 and 0≤f≤0.4, and more preferably 0.3≤b≤1.0, 0≤c≤0.75, 0≤d≤0.6, 0≤e≤0.6 and 0≤f≤0.3. Moreover, when the repeating unit f is selected from at least one of the repeating units f1 to f3, f=f1+f2+f3. Moreover, b+c+d+e+f=1.0.

[0359] In order to synthesize the aforementioned base polymer, for example, a radical polymerization initiator is added to the aforementioned monomer providing the repeating unit in an organic solvent and the mixture is heated to perform polymerization.

[0360] Specific examples of organic solvents used in polymerization include toluene, benzene, tetrahydrofuran (THF), ether, dioxane, etc. Specific examples of polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2-azobis(2-methylpropionic acid) dimethyl ester, benzoyl peroxide, lauroyl peroxide, etc. The temperature during polymerization is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

[0361] When copolymerizing hydroxyl-containing monomers, the hydroxyl groups may be replaced with acetal groups such as ethoxyethoxy groups which are easily deprotected by acids during the polymerization, and then deprotected by weak acid and water after the polymerization. Alternatively, the hydroxyl groups may be replaced with acetyl groups, formyl groups, pivaloyl groups, etc., and then hydrolyzed with alkali after the polymerization.

[0362] When copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, acetoxystyrene and acetoxyvinylnaphthalene may be used instead of hydroxystyrene and hydroxyvinylnaphthalene, and the acetoxy group may be deprotected by the above-mentioned alkaline hydrolysis after polymerization to obtain hydroxystyrene and hydroxyvinylnaphthalene.

[0363] As the base for alkaline hydrolysis, aqueous ammonia, triethylamine, etc. can be used. The reaction temperature is preferably -20 to 100°C, more preferably 0 to 60°C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0364] The polystyrene-equivalent weight average molecular weight (Mw) of the base polymer measured by gel permeation chromatography (GPC) using THF as a solvent is preferably 1000 to 500000, more preferably 2000 to 30000. When Mw is within the above range, the heat resistance and solubility of the resist film in an alkaline developer are good.

[0365] Furthermore, when the molecular weight distribution (Mw / Mn) of the base polymer is wide, there will be a concern that foreign matter may be seen on the pattern after exposure or the shape of the pattern may deteriorate due to the presence of low molecular weight and high molecular weight polymers. As the pattern rules become finer, the influence of Mw and Mw / Mn tends to become greater. Therefore, in order to obtain a resist material suitable for fine pattern sizes, the Mw / Mn of the base polymer is a narrow distribution of 1.0 to 2.0, preferably 1.0 to 1.5.

[0366] The base polymer may include two or more polymers having different composition ratios, Mw, and Mw / Mn.

[0367] [Organic solvents]

[0368] The resist material of the present invention may also contain an organic solvent. The aforementioned organic solvent is not particularly limited as long as it can dissolve the aforementioned components and the components described below. Specific examples of the aforementioned organic solvent include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentanone, and 2-heptanone described in paragraphs

[0144] to

[0145] of Japanese Patent Publication No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; propylene glycol monomethylol Ethers such as ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as 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; lactones such as γ-butyrolactone, etc.

[0369] In the resist material of the present invention, the content of the organic solvent is preferably 100 to 10,000 parts by mass, more preferably 200 to 8,000 parts by mass, based on 100 parts by mass of the base polymer. The organic solvent may be used alone or in combination of two or more.

[0370] [Quencher]

[0371] The resist material of the present invention may also contain a quencher. The quencher refers to a compound that can prevent diffusion to the unexposed area by capturing the acid generated by the acid generator in the resist material.

[0372] As for the above-mentioned quencher, known basic compounds can be cited. As specific examples of known basic compounds, primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having carboxyl groups, nitrogen-containing compounds having sulfonyl groups, nitrogen-containing compounds having hydroxyl groups, nitrogen-containing compounds having hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amides, imides, and carbamates can be cited. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

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

[0373] In addition, as for the above-mentioned quencher, there can be mentioned onium salts such as sulfonium salts, iodonium salts, and ammonium salts of sulfonic acids, carboxylic acids, or fluorinated alkoxides not fluorinated at the α-position as described in Japanese Patent Application Laid-Open No. 2008-158339. Sulfonic acids, imidic acids, or methide acids fluorinated at the α-position are necessary when used to deprotect the acid-labile group of carboxylic acid esters, and the sulfonic acids, carboxylic acids, or fluorinated alcohols not fluorinated at the α-position are released by salt exchange with the above-mentioned onium salts. Sulfonic acids, carboxylic acids, and fluorinated alcohols not fluorinated at the α-position do not undergo deprotection reaction, and thus they function as quenchers.

[0374] Specific examples of such quenchers include, for example, compounds represented by the following formula (4) (onium salt of sulfonic acid whose α-position is not fluorinated), compounds represented by the following formula (5) (onium salt of carboxylic acid), and compounds represented by the following formula (6) (onium salt of alkoxide).

[0375] [Chemistry 114]

[0376]

[0377] In formula (4), R 101 It is a hydrocarbon group having 1 to 40 carbon atoms which may contain a hydrogen atom or a heteroatom, but excludes those in which the hydrogen atom bonded to the carbon atom at the α-position of the sulfonic acid group is substituted with a fluorine atom or a fluoroalkyl group.

[0378] R 101 The hydrocarbon group having 1 to 40 carbon atoms represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6 ] Cyclic saturated hydrocarbon groups having 3 to 40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; alkenyl groups having 2 to 40 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 40 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 40 carbon atoms, such as phenyl, naphthyl, alkylphenyl (2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butylphenyl, etc.), di- or trialkylphenyl (2,4-dimethylphenyl, 2,4,6-triisopropylphenyl, etc.), alkylnaphthyl (methylnaphthyl, ethylnaphthyl, etc.), dialkylnaphthyl (dimethylnaphthyl, diethylnaphthyl, etc.); aralkyl groups having 7 to 40 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl, etc.

[0379] Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of the -CH2- of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, resulting in a hydroxyl group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like. Specific examples of the hydrocarbon group containing a heteroatom include heteroaryl groups such as thienyl; alkoxyphenyl groups such as 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-tert-butoxyphenyl, and 3-tert-butoxyphenyl; alkoxynaphthyl groups such as methoxynaphthyl, ethoxynaphthyl, n-propoxynaphthyl, and n-butoxynaphthyl; dialkoxynaphthyl groups such as dimethoxynaphthyl and diethoxynaphthyl; aryloxyalkyl groups such as 2-aryl-2-oxoethyl groups such as 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl; and the like.

[0380] In formula (5), R 102 is a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. 102 As specific examples of the hydrocarbon group represented by, there can be mentioned the following: 101 Other specific examples include fluorinated alkyl groups such as trifluoromethyl, trifluoroethyl, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl, 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl, and fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

[0381] In formula (6), R 103 It is a saturated hydrocarbon group having 1 to 8 carbon atoms and having at least 3 fluorine atoms, or an aryl group having 6 to 10 carbon atoms and having at least 3 fluorine atoms, and may also contain a nitro group.

[0382] In formulas (4), (5) and (6), Mq + is an onium cation. As for the onium cation, it is preferably a sulfonium cation, an iodonium cation or an ammonium cation, and more preferably a sulfonium cation. As for the specific examples of the sulfonium cation, the following can be cited as in the description of formula (1): + The sulfonium cation represented is the same as exemplified above.

[0383] As the quencher, a sulfonium salt of a carboxylic acid containing an iodinated benzene ring represented by the following formula (7) can also be preferably used.

[0384] [Chemistry 115]

[0385]

[0386] In formula (7), x is an integer of 1 to 5. y is an integer of 0 to 3. z is an integer of 1 to 3.

[0387] In formula (7), R 111 is a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano group, or a saturated hydrocarbon group having 1 to 6 carbon atoms which may be partially or entirely substituted with halogen atoms, a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon group carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon group sulfonyloxy group having 1 to 4 carbon atoms, or -N(R 111A )-C(=O)-R 111B or -N(R 111A )-C(=O)-OR 111B . R 111A is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. 111B is a saturated hydrocarbon group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbon group having 2 to 8 carbon atoms. 111 They may be the same or different from each other.

[0388] In formula (7), L 1 It is a single bond or a (z+1)-valent linking group having 1 to 20 carbon atoms, and may also include at least one selected from an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxyl group, and a carboxyl group. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyl oxy group, and saturated hydrocarbon sulfonyl oxy group may be straight-chain, branched, or cyclic.

[0389] In formula (7), R 112 , R 113 and R 114 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include the same as those in the description of formulas (2) and (3) with respect to R 4 ~R 8 The hydrocarbon groups represented are the same as those exemplified above.

[0390] Specific examples of the compound represented by formula (7) include those described in JP-A-2017-219836 and JP-A-2021-91666.

[0391] As an example other than the above-mentioned quencher, there can be mentioned a polymer quencher described in Japanese Patent Application Publication No. 2008-239918. This improves the rectangularity of the resist pattern by aligning the resist film surface. The polymer quencher also has the effect of preventing film loss and doming of the pattern when a protective film for wet exposure is used.

[0392] Furthermore, betaine-type sulfonium salts described in Japanese Patent No. 6848776 and Japanese Patent Application Laid-Open No. 2020-37544, methylated acids not containing fluorine atoms described in Japanese Patent Application Laid-Open No. 2020-55797, sulfonium salts of sulfonamides described in Japanese Patent No. 5807552, sulfonium salts of sulfonamides containing iodine atoms described in Japanese Patent Application Laid-Open No. 2019-211751, and acid generators that generate phenol, halogen, or carbonic acid can also be used as quenchers.

[0393] When the resist material of the present invention contains the quencher, the content thereof is preferably 0 to 5 parts by mass, more preferably 0 to 4 parts by mass, relative to 100 parts by mass of the base polymer. The quencher may be used alone or in combination of two or more.

[0394] [Other ingredients]

[0395] In addition to the above components, an acid generator other than the salt represented by formula (1) (hereinafter referred to as other acid generator), a surfactant, an anti-solubility agent, a crosslinking agent, a water repellency enhancer, acetylene alcohols, etc. may be contained.

[0396] As for the aforementioned other acid generators, compounds (photoacid generators) that generate acid by induction of active light or radiation can be cited. As for the composition of the photoacid generator, it is fine if it is a compound that generates acid by high-energy ray irradiation, and an acid generator that generates sulfonic acid, imidic acid or methide acid is preferred. As for the specific examples of preferred acid generators, sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate acid generators, etc. can be cited. As for the specific examples of the aforementioned acid generators, paragraphs

[0122] to

[0142] of Japanese Patent Publication No. 2008-111103, Japanese Patent Publication No. 2018-5224, and Japanese Patent Publication No. 2018-25789 can be cited. When the resist material of the present invention contains other acid generators, the content thereof is preferably 0 to 200 parts by mass, more preferably 0.1 to 100 parts by mass, based on 100 parts by mass of the base polymer.

[0397] As specific examples of the above-mentioned surfactant, those described in paragraphs

[0165] to

[0166] of Japanese Patent Publication No. 2008-111103 can be cited. By adding a surfactant, the coating property of the resist material can be further improved or controlled. When the resist material of the present invention contains a surfactant, its content is preferably 0.0001 to 10 parts by mass relative to 100 parts by mass of the base polymer. The above-mentioned surfactant can be used alone or in combination of two or more.

[0398] In the case where the resist material of the present invention is a positive type, by adding an anti-dissolving agent, the difference in dissolution rate between the exposed part and the unexposed part can be further increased, and the resolution can be further improved. As for the specific examples of the aforementioned anti-dissolving agent, a compound having a molecular weight of preferably 100 to 1000, more preferably 150 to 800, and containing two or more phenolic hydroxyl groups in the molecule, the hydrogen atoms of which are replaced by acid-labile groups at a ratio of 0 to 100 mol% on the whole, or a compound containing a carboxyl group in the molecule, the hydrogen atoms of which are replaced by acid-labile groups at an average ratio of 50 to 100 mol% on the whole. Specifically, compounds in which the hydrogen atoms of the hydroxyl group and the carboxyl group of bisphenol A, trisphenol, phenolphthalein, cresol novolac, naphthyl carboxylic acid, adamantyl carboxylic acid, and bile acid are replaced by acid-labile groups can be cited, for example, as described in paragraphs

[0155] to

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

[0399] When the resist material of the present invention is positive type and contains the anti-dissolution agent, the content thereof is preferably 0 to 50 parts by mass, more preferably 5 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The anti-dissolution agent may be used alone or in combination of two or more.

[0400] On the other hand, in the case where the resist material of the present invention is negative, a crosslinking agent can be added to reduce the dissolution rate of the exposure portion, thereby obtaining a negative pattern. As for the specific examples of the aforementioned crosslinking agent, epoxy compounds, melamine compounds, guanamine compounds, glycoluril compounds or urea compounds, isocyanate compounds, azide compounds, compounds containing double bonds such as alkenyloxy groups, etc., which are substituted by at least one group selected from hydroxymethyl, alkoxymethyl and acyloxymethyl, can be listed. They can be used as additives, and can also be introduced as pendant groups on the side chains of polymers. In addition, hydroxyl-containing compounds can also be used as crosslinking agents.

[0401] Specific examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0402] Specific examples of the melamine compound include hexamethylolmelamine, hexamethoxymethylmelamine, a compound in which 1 to 6 hydroxymethyl groups of hexamethylolmelamine are methoxymethylated, or a mixture thereof, hexamethoxyethylmelamine, hexaacyloxymethylmelamine, a compound in which 1 to 6 hydroxymethyl groups of hexamethylolmelamine are acyloxymethylated, or a mixture thereof, and the like.

[0403] Specific examples of the guanamine compounds include tetrakishydroxymethylguanamine, tetramethoxymethylguanamine, compounds in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethylguanamine are methoxymethylated, or mixtures thereof, tetrakismethoxyethylguanamine, tetrakisacyloxyguanamine, compounds in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethylguanamine are acyloxymethylated, or mixtures thereof, and the like.

[0404] Specific examples of the glycoluril compound include tetrakishydroxymethyl glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethyl glycoluril are methoxymethylated, or mixtures thereof, compounds in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethyl glycoluril are acyloxymethylated, or mixtures thereof. Specific examples of the urea compound include tetrakishydroxymethyl urea, tetramethoxymethyl urea, compounds in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethyl urea are methoxymethylated, or mixtures thereof, and tetramethoxyethyl urea.

[0405] Specific examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0406] Specific examples of the azide compound include 1,1′-biphenyl-4,4′-bisazide, 4,4′-methylenebisazide, and 4,4′-oxybisazide.

[0407] Specific examples of the alkenyloxy group-containing compound include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propylene glycol divinyl ether, 1,4-butylene glycol divinyl ether, butanediol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0408] When the resist material of the present invention is negative type and contains the crosslinking agent, the content thereof is preferably 0.1 to 50 parts by mass, more preferably 1 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The crosslinking agent may be used alone or in combination of two or more.

[0409] The aforementioned water repellency enhancer is a device that enhances the water repellency of the surface of the resist film and can be used in immersion lithography without using a surface coating. As for the aforementioned water repellency enhancer, a polymer containing a fluorinated alkyl group, a polymer containing a specific structure 1,1,1,3,3,3-hexafluoro-2-propanol residue, etc. are preferred, and those exemplified in Japanese Patent Publication No. 2007-297590 and Japanese Patent Publication No. 2008-111103 are preferred. The aforementioned water repellency enhancer needs to be dissolved in an alkaline developer or an organic solvent developer. The aforementioned water repellency enhancer having a specific 1,1,1,3,3,3-hexafluoro-2-propanol residue has good solubility in the developer. As for the water repellency enhancer, a polymer containing repeating units containing an amino group or an ammonium salt has a high effect of preventing poor opening of the hole pattern after development because it prevents the evaporation of the acid in the PEB. When the resist material of the present invention contains the water repellency enhancer, the content thereof is preferably 0 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of the base polymer. The water repellency enhancer may be used alone or in combination of two or more.

[0410] Specific examples of the acetylene alcohols include those described in paragraphs

[0179] to

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

[0411] [Pattern Formation Method]

[0412] When the resist material of the present invention is used in the manufacture of various integrated circuits, known photolithography techniques can be used. For example, as for the pattern forming method, a method comprising the following steps can be cited: using the resist material to form a resist film on a substrate, exposing the resist film to high-energy rays, and developing the exposed resist film using a developer.

[0413] First, the resist material of the present invention is coated on a substrate (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflection film, etc.) for integrated circuit manufacturing or a substrate (Cr, CrO, CrON, MoSi2, SiO2, etc.) for mask circuit manufacturing using a suitable coating method such as spin coating, roller coating, flow coating, dip coating, spray coating, scraping coating, etc. Make the coating film thickness become 0.01 to 2 μm. It is preferably pre-baked at 60 to 150° C., 10 seconds to 30 minutes, more preferably at 80 to 120° C., 30 seconds to 20 minutes on a hot plate to form a resist film.

[0414] Then, the resist film is exposed using high-energy rays. Specific examples of the high-energy rays include ultraviolet rays, far ultraviolet rays, EB, EUV with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer lasers, gamma rays, synchrotron radiation, etc. When ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer lasers, gamma rays, synchrotron radiation, etc. are used as the high-energy rays, irradiation is performed directly or using a mask for forming a target pattern, so that the exposure amount is about 1 to 200 mJ / cm 2 Preferably, more preferably about 10 to 100 mJ / cm 2 When EB is used as high energy radiation, the exposure amount is preferably about 0.1 to 300 μC / cm 2 , preferably about 0.5 to 200 μC / cm 2 The resist material of the present invention is particularly suitable for fine patterning by KrF excimer laser, ArF excimer laser, EB, EUV, X-ray, soft X-ray, gamma ray, synchrotron radiation among high-energy rays, and is particularly suitable for fine patterning by EB or EUV.

[0415] After the exposure, PEB may be performed on a hot plate or in an oven, preferably at 30 to 150° C. for 10 seconds to 30 minutes, more preferably at 50 to 120° C. for 30 seconds to 20 minutes, or it may not be performed.

[0416] After exposure or PEB, a developer of an alkaline aqueous solution of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, etc., with a concentration of 0.1 to 10% by mass, preferably 2 to 5% by mass, is used, and the exposed resist film is developed by a conventional method such as a dip method, a puddle method, or a spray method for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, to form a target pattern. In the case of a positive resist material, the portion irradiated with light will dissolve in the developer, and the unexposed portion will not dissolve, thereby forming a target positive pattern on the substrate. In the case of a negative resist material, in contrast to the case of a positive resist material, the portion irradiated with light will not dissolve in the developer, and the unexposed portion will dissolve.

[0417] A positive resist material containing a base polymer containing an acid-labile group can also be used to obtain a negative pattern by developing with an organic solvent. Specific examples of the developer used at this time include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonate, and methyl crotonate. Ethyl beanate, 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, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. The above organic solvents may be used alone or in combination of two or more.

[0418] When the development is finished, rinsing is performed. As for the rinsing liquid, it is preferably a solvent that is miscible with the developer and does not dissolve the resist film. As for such a solvent, alcohols having 3 to 10 carbon atoms, ether compounds having 8 to 12 carbon atoms, alkanes, alkenes, alkynes, and aromatic solvents having 6 to 12 carbon atoms are preferably used.

[0419] Specific examples of the alcohol having 3 to 10 carbon atoms include n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentanol, neopentyl alcohol, 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.

[0420] Specific examples of the ether compound having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di-sec-butyl ether, di-n-amyl ether, diisoamyl ether, di-sec-amyl ether, di-tert-amyl ether, and di-n-hexyl ether.

[0421] Specific examples of the aforementioned alkanes having 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane, etc. Specific examples of the aforementioned alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, etc. Specific examples of the aforementioned alkynes having 6 to 12 carbon atoms include hexyne, heptyne, octyne, etc.

[0422] Specific examples of the aromatic solvent include toluene, xylene, ethylbenzene, cumene, tert-butylbenzene, mesitylene, and the like.

[0423] By performing rinsing, the collapse of the resist pattern and the generation of defects can be reduced. In addition, rinsing is not essential, and the amount of solvent used can be reduced by not performing rinsing.

[0424] The developed hole pattern and groove pattern can also be shrunk by heat flow, RELACS technology or DSA technology. When a shrinking agent is applied to the hole pattern, the shrinking agent will crosslink on the surface of the resist film due to the diffusion of the acid catalyst from the resist film being baked, and the shrinking agent will adhere to the side wall of the hole pattern. The baking temperature is preferably 70-180°C, more preferably 80-170°C, and the baking time is preferably 10-300 seconds to remove the excess shrinking agent and shrink the hole pattern.

[0425] [Example]

[0426] Hereinafter, the present invention will be specifically described with reference to synthesis examples, examples and comparative examples, but the present invention is not limited to the following examples.

[0427] The structures of bis-onium salts PAG-PDQ-1 to PAG-PDQ-14, which are acid generators and quenchers used in resist materials, are shown below.

[0428] [Chemistry 116]

[0429]

[0430] [Chemistry 117]

[0431]

[0432] [Chemistry 118]

[0433]

[0434] [Chemistry 119]

[0435]

[0436] [Chemistry 120]

[0437]

[0438] [Chemistry 121]

[0439]

[0440] [Chemistry 122]

[0441]

[0442] [Synthesis Example] Synthesis of base polymers (polymers P-1 to P-4)

[0443] The monomers were combined and copolymerized in THF as a solvent, and then added to methanol. The precipitated solid was washed with hexane, isolated, and dried to obtain the base polymers (polymers P-1 to P-4) with the following compositions. 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC (solvent: THF, standard: polystyrene).

[0444] [Chemistry 123]

[0445]

[0446] [Examples 1 to 19, Comparative Examples 1 to 3] Preparation and Evaluation of Resist Materials

[0447] (1) Preparation of resist materials

[0448] A solution prepared by dissolving each component in the composition shown in Table 1 was filtered through a filter having a size of 0.2 μm to prepare a resist material.

[0449] In Table 1, the components are as follows.

[0450] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0451] EL(ethyl lactate)

[0452] DAA (Diacetone Alcohol)

[0453] Comparative Acid Generators: cPAG-1, cPAG-PDQ-1

[0454] [Chemistry 124]

[0455]

[0456] Mixed acid generator: bPAG-1

[0457] [Chemistry 125]

[0458]

[0459] Comparison Quencher: cPDQ-1

[0460] [Chemistry 126]

[0461]

[0462] (2) EUV lithography evaluation

[0463] Each resist material shown in Table 1 was spin-coated on a Si substrate formed with a 20 nm thick silicon-containing spin-coated hard mask SHB-A940 (silicon content of 43 mass%) manufactured by Shin-Etsu Chemical Co., Ltd., and pre-baked at 105°C for 60 seconds using a hot plate to obtain a resist film with a thickness of 40 nm. The resist film was exposed using an EUV scanning exposure machine NXE3400 manufactured by ASML (NA 0.33, σ 0.9 / 0.7, dipole illumination), and PEB was performed for 60 seconds on a hot plate at the temperature described in Table 1, and developed for 30 seconds with a 2.38 mass % TMAH aqueous solution to form lines and spaces with a pitch of 32 nm and a line width of 16 nm. Examples 1 to 18 and Comparative Examples 1 and 2 are positive resist materials, and Example 19 and Comparative Example 3 are negative resist materials.

[0464] Using a Hitachi Advanced Technology Co., Ltd. length measurement SEM (CG6300), the exposure amount formed so that the line pattern had a size of 16 nm±1.6 nm was obtained, and the line edge roughness (LWR) at the exposure amount was measured. The results are shown in Table 1.

[0465] [Table 1]

[0466]

[0467]

[0468] From the results shown in Table 1, it can be seen that the resist material of the present invention comprising a divalent anion having an arylsulfonic acid anion structure linked to an aromatic group having an iodine atom or a bromine atom and a sulfonyl imide anion structure or a sulfonamide anion structure bonded to the aromatic group having an iodine atom or a bromine atom via a linking group having 1 or more carbon atoms, and an onium cation, has high sensitivity and good LWR.

Claims

1. A resist material comprising: A bis-onium salt comprising a divalent anion having an arylsulfonic acid anion structure linked to an aromatic group having an iodine atom or a bromine atom and a sulfonyl imide anion structure or a sulfonamide anion structure bonded to the aromatic group having an iodine atom or a bromine atom via a linking group having 1 or more carbon atoms, and an onium cation.

2. The resist material according to claim 1, wherein The bis-onium salt is represented by the following formula (1): In the formula, p is an integer of 1 to 4, q is an integer of 0 to 3, and r is an integer of 1 to 6. X BI is a bromine atom or an iodine atom, X 1 is a hydrocarbylene group having 1 to 12 carbon atoms, and the hydrocarbylene group may contain at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom, X 2 is a single bond, an ether bond, an ester bond, a sulfonate bond, an amide bond, a carbamate bond, a urea bond, a carbonate bond, or an alkanediyl group having 1 to 6 carbon atoms, wherein the alkanediyl group may contain at least one selected from an ether bond and an ester bond, X 3 is a single bond, an ether bond, an ester bond, or an alkanediyl group having 1 to 6 carbon atoms, wherein the alkanediyl group may contain at least one selected from an ether bond and an ester bond, R 1 is a single bond or a hydrocarbylene group having 1 to 12 carbon atoms, and the hydrocarbylene group may also contain at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom, But, -X 1 -R 1 -X 2 - has at least 1 carbon atom, R 2 is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, an amino group, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon oxy group having 1 to 20 carbon atoms, a hydrocarbon oxycarbonyl group having 2 to 20 carbon atoms, a hydrocarbon carbonyloxy group having 2 to 20 carbon atoms, -N(R 2A )-C(=O)-R 2B 、-N(R 2A )-C(=O)-OR 2B or -N(R 2A )-S(=O)2-R 2B The alkyl group, alkyloxy group, alkyloxycarbonyl group and alkylcarbonyloxy group may also contain at least one selected from fluorine atom, chlorine atom, bromine atom, iodine atom, hydroxyl group, amino group, ester bond and ether bond, R 2A is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, the saturated hydrocarbon group may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms, R 2B is an aliphatic hydrocarbon group having 1 to 16 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms, Ar is an aromatic hydrocarbon group having 6 to 10 carbon atoms and having a valence of (r+2), Rf is a hydrogen atom, a saturated hydrocarbon group having 1 to 10 carbon atoms, a nitro group, a cyano group, a fluorine atom, an iodine atom, a trifluoromethyl group or a trifluoromethoxy group, Q - is a group having a sulfonimide anion structure or a sulfonamide anion structure, M + It is a sulfonium cation or an iodonium cation.

3. The resist material according to claim 2, wherein Q - is a group represented by any of the following formulae (Q-1) to (Q-4), In the formula, R 3 is a saturated hydrocarbon group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may be substituted by at least one group selected from the group consisting of a halogen atom, a cyano group, a nitro group, a hydroxyl group, a saturated hydrocarbon group having 1 to 8 carbon atoms, a saturated hydrocarbon group having 2 to 8 carbon atoms carbonyloxy group, a saturated hydrocarbon group having 2 to 8 carbon atoms oxycarbonyl group, a trifluoromethoxy group, a difluoromethoxy group, a trifluoromethylthio group, and a trifluoromethyl group, and * is the same as X 1 of atomic bonds. The resist material according to claim 1 , further comprising a base polymer.

5. The resist material according to claim 4, wherein The base polymer comprises a repeating unit represented by the following formula (a1) or (a2), In the formula, R A are each independently 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 and containing at least one selected from an ester bond, an ether bond, and a lactone ring, wherein the phenylene group, the naphthylene group, and the linking group may have at least one selected from a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms, and a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms, 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 are each independently an acid-labile group, R 13 is a saturated hydrocarbon group having 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group having 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group having 2 to 5 carbon atoms, R 14 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the alkanediyl group may also contain an ether bond or an ester bond, a is an integer from 0 to 4. The resist material according to claim 5 , which is a chemically amplified positive resist material.

7. The resist material according to claim 4, wherein The base polymer is free of acid-labile groups.

8. The resist material according to claim 7, which is a chemically amplified negative resist material.

9. The resist material according to claim 1, further comprising an organic solvent. 10 . The resist material according to claim 1 , further comprising a quencher. The resist material according to claim 1 , further comprising an acid generator. The resist material according to claim 1 , further comprising a surfactant.

13. A pattern forming method, comprising the steps of: forming a resist film on a substrate using the resist material according to any one of claims 1 to 12, exposing the resist film using high-energy rays, and developing the exposed resist film using a developer.

14. The pattern forming method according to claim 13, wherein: The high-energy radiation is ArF excimer laser with a wavelength of 193 nm, KrF excimer laser with a wavelength of 248 nm, electron beam, or extreme ultraviolet radiation with a wavelength of 3 to 15 nm.

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