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 regardless of the positive type or the negative type and improved LWR and CDU; and a pattern forming method using the same. [Solution] The resist material contains: a bis-onium salt; the divalent anion has a sulfonic acid anion structure directly bonded to an aromatic group substituted by an iodine atom and a carboxylic acid anion structure directly bonded to the aromatic group or bonded with a linking group containing one or more atoms therebetween.

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 also progressing rapidly. This is because the high-speed communication of 5G and the popularization of artificial intelligence (AI) have made it necessary to have high-performance devices to handle them. As for the most advanced miniaturization technology, mass production of 5nm node and 3nm node devices using extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm is already underway. In addition, in the next generation of 2nm node devices and the next generation of EUV lithography has also been explored at the node level. IMEC in Belgium has published Device development.

[0003] As the miniaturization progresses, the blurring of images caused by the diffusion of acid has also become a problem. In order to ensure the resolution of fine patterns below 45nm in size, it has been proposed that not only the improvement of the dissolution contrast advocated in the past, but also the control of acid diffusion is important (Non-patent Document 1). However, chemically amplified resist materials use the diffusion of acid to improve sensitivity and contrast, so if the post-exposure baking (PEB) temperature is reduced or the time is shortened to suppress the acid diffusion to the limit, the sensitivity and contrast will be significantly reduced. If the acid diffusion is suppressed to the limit, the sensitivity and contrast will be significantly reduced.

[0004] In EUV resist materials, high sensitivity, high resolution, and low line width roughness (LWR) need to be achieved simultaneously. If the acid diffusion distance is shortened, LWR and dimension uniformity (CDU) will be improved, but the sensitivity will be reduced. For example, by lowering the PEB temperature, LWR and CDU will be improved, but the sensitivity will be reduced. Increasing the amount of quencher added will also improve LWR and CDU, but the sensitivity will be reduced. It is necessary to break through the trade-off between sensitivity and LWR.

[0005] Some people have proposed adding an onium salt containing anions having iodine atoms or bromine atoms as an acid generator to resist materials (Patent Documents 1 to 4). The iodine atoms with high EUV absorption and the bromine atoms with high ionization efficiency can increase the efficiency of the acid generator decomposition during exposure and increase sensitivity. The amount of photon absorption increases, and the physical contrast can be improved.

[0006] EUV light with a wavelength of 13.5 nm has a single-digit shorter wavelength than ArF excimer laser with a wavelength of 193 nm, so it has high energy and is greatly affected by the variation in the number of photons (Non-Patent Document 2). Therefore, it is accused of deteriorating LWR (Non-Patent Document 3). In addition, it is also accused of the influence of LWR degradation caused by the variation (Resist Stochastics) of the components of the resist material (polymer, acid generator (PAG), quencher (PDQ)) as miniaturization progresses (Non-Patent Document 4).

[0007] Some people have proposed a resist material containing a polymer formed by bonding PAG and PDQ (Patent Document 5). By integrating the polymer, PAG and PDQ, the variation existing between them is suppressed and LWR and CDU are improved. In addition, some people have proposed a resist material containing an additive formed by bonding PAG and PDQ (Patent Documents 6 and 7).

[0008] Perfluoroalkyl compounds (PFAS) have been criticized for their health effects, and there are moves to limit the manufacture and sale of PFAS compounds in European REACH. In the field of semiconductor lithography, many compounds containing PFAS are currently used. For example, materials containing PFAS are used in surfactants, acid generators, etc.

[0009] A comparison of resist materials added with an acid generator that generates anions having fluorine atoms bonded to the polymer main chain and an acid generator that generates anions having no fluorine atoms bonded to the polymer main chain has been reported (Non-Patent Document 5). Here, it is disclosed that the polymer-bonded acid generator that generates anions having fluorine atoms is more highly resolved. Sulfonic acids with high acid strength have a higher efficiency in the deprotection reaction, and the introduction of fluorine atoms is effective in order to increase the acid strength.

[0010] There have been reports of resist materials that produce anions that increase acidity by introducing nitro or chlorine atoms instead of using fluorine atoms (Non-Patent Document 6). Resist materials to which an acid generator that produces anions substituted by nitro or chlorine atoms is added have higher rectangularity than resist materials to which an acid generator that produces anions substituted by fluorine atoms is added, but as shown in Table 2 in Non-Patent Document 6, they have the disadvantages of low sensitivity and large MEEF, which is the effect of reduced dissolution contrast caused by low acidity of anions and low deprotection reactivity.

[0011] Prior art literature

[0012] Patent Literature

[0013] [Patent Document 1] Japanese Patent Application Publication No. 2018-159744

[0014] [Patent Document 2] Japanese Patent Application Publication No. 2018-5224

[0015] [Patent Document 3] Japanese Patent Application Publication No. 2018-25789

[0016] [Patent Document 4] Japanese Patent Application Publication No. 2019-003175

[0017] [Patent Document 5] Japanese Patent Application Publication No. 2022-115072

[0018] [Patent Document 6] Japanese Patent Application Publication No. 2015-024989

[0019] [Patent Document 7] International Publication No. 2020 / 158313

[0020] Non-patent literature

[0021] [Non-patent document 1] SPIE Vol.6520 65203L-1 (2007)

[0022] [Non-patent document 2] SPIE Vol. 3331 535 (1998)

[0023] [Non-patent document 3] SPIE Vol.7273 727343-1 (2009)

[0024] [Non-patent document 4] SPIE Vol.9776 97760V-1 (2016)

[0025] [Non-patent document 5] SPIE Vol.6519 65191F-1 (2007)

[0026] [Non-patent document 6] SPIE Vol.7639 76390D-1 (2010) Summary of the invention

[0027] [Problems to be solved by the invention]

[0028] It is desired to develop a resist material that has higher sensitivity than conventional resist materials and can improve the LWR of a line pattern and the CDU of a hole pattern.

[0029] The present invention is made in view of the above circumstances, and an object of the present invention is to provide a resist material having high sensitivity regardless of positive or negative type and improved LWR and CDU, and to provide a pattern forming method using the same.

[0030] [Methods to solve the problem]

[0031] The inventors of the present application have repeatedly conducted in-depth studies to achieve the above-mentioned purpose, and have found that by using the following bis-onium salt as an acid generator and quencher, the bis-onium salt contains a divalent anion having a sulfonic acid anion structure directly bonded to an aromatic group substituted by an iodine atom and a carboxylic acid anion structure directly bonded to the aromatic group or bonded via a linking group containing one or more atoms, and an onium cation; by exposure to radiation, the highly absorbing acid generator is directly excited and the influence of the diffusion of secondary electrons disappears, and then the acid diffusion is controlled by a nearby quencher, so that the influence of image blur caused by the diffusion can be suppressed to a minimum, thereby obtaining a resist material with high sensitivity, improved LWR and CDU, high contrast, excellent resolution, and wide process latitude, and thus completing the present invention.

[0032] That is, the present invention provides the following resist material and pattern forming method.

[0033] 1. A resist material comprising:

[0034] The bis-onium salt contains a divalent anion having a sulfonic acid anion structure directly bonded to an aromatic group substituted with an iodine atom and a carboxylic acid anion structure directly bonded to the aromatic group or bonded via a linking group containing one or more atoms, and an onium cation.

[0035] 2. The resist material according to 1., wherein the bis-onium salt is represented by the following formula (1).

[0036] [Chemistry 1]

[0037]

[0038] In the formula, p is an integer of 1 to 5, and q is an integer of 0 to 7.

[0039] X 1 ~X 3 are each independently a single bond, an ether bond, an ester bond or an amide bond.

[0040] R 1 ~R 3 are each independently a single bond or a hydrocarbon group having 1 to 30 carbon atoms, and the hydrocarbon group may contain at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom. 1 ~R 3 The upper limit of the total number of carbon atoms is 30.

[0041] R 4is a hydrogen atom, a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano 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, a hydrocarbon sulfonyloxy group having 1 to 20 carbon atoms, -N(R 4A )-C(=O)-R 4B 、-N(R 4A )-C(=O)-OR 4B or -N(R 4A )-S(=O) 2 -R 4B , and the hydrocarbon group, hydrocarbon oxy group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyloxy group, and hydrocarbon sulfonyloxy group may also contain at least one selected from fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, hydroxyl groups, amino groups, ester bonds, ether bonds, carbamate bonds, urea bonds, carbonate bonds, amide bonds, sulfonate bonds, carbonyl groups, thioether groups, and sulfonyl groups. 4A R is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and the saturated hydrocarbon group 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. 4B It 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.

[0042] Ar is a (p+q+1)-valent aromatic hydrocarbon group having 6 to 16 carbon atoms.

[0043] M + It is a sulfonium cation or an iodonium cation.

[0044] 3. The resist material as in 1. or 2., further comprising a base polymer.

[0045] 4. The resist material according to 3., wherein the base polymer contains a repeating unit represented by the following formula (a1) or (a2).

[0046] [Chemistry 2]

[0047]

[0048] In the formula, R A are each independently a hydrogen atom or a methyl group.

[0049] Y 1It 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, and 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.

[0050] Y 2 It is a single bond or an ester bond.

[0051] Y 3 It is a single bond, an ether bond or an ester bond.

[0052] R 11 and R 12 are each independently an acid-labile group.

[0053] R 13 It 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.

[0054] R 14 It 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.

[0055] a is an integer from 0 to 4.

[0056] 5. The resist material as described in 4., which is a chemically amplified positive resist material.

[0057] 6. The resist material according to 3., wherein the base polymer does not contain an acid-labile group.

[0058] 7. The resist material as described in 6., which is a chemically amplified negative resist material.

[0059] 8. The resist material according to any one of 1. to 7., further comprising an organic solvent.

[0060] 9. The resist material according to any one of 1. to 8., further comprising a quencher.

[0061] 10. The resist material according to any one of 1. to 9., further comprising an acid generator.

[0062] 11. The resist material according to any one of 1. to 10., further comprising a surfactant.

[0063] 12. A pattern forming method comprising the following steps:

[0064] Using the resist material as described in any one of 1. to 11. to form a resist film on a substrate,

[0065] exposing the resist film to high energy radiation, and

[0066] The exposed resist film is developed using a developer.

[0067] 13. The pattern forming method according to 12., 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 (EB) or EUV with a wavelength of 3 to 15 nm.

[0068] [Effects of the Invention]

[0069] The onium salt of an arylsulfonic acid substituted with an iodine atom has the characteristics of greater absorption of EUV light, higher acid strength, and inhibition of acid diffusion than unsubstituted arylsulfonic acid or fluorine-substituted arylsulfonic acid. The proportion of direct excitation reaction due to the high absorption characteristic increases, thereby inhibiting the diffusion of secondary electrons. The bis-onium salt having an anion structure of an arylsulfonic acid substituted with an iodine atom and further having a quencher bonded thereto is also highly effective in inhibiting acid diffusion, and can suppress image blurring caused by the diffusion of both secondary electrons and acids to the limit. The aforementioned bis-onium salt is a form in which an onium salt that generates sulfonic acid, i.e., an acid generator, is bonded to an onium salt that is a quencher, and the acid generator and the quencher are always arranged at a certain distance. Therefore, the resist film containing it will improve LWR and CDU due to the aforementioned improved Resist Stochastics. That is, by using the aforementioned bis-onium salt, a resist material with high sensitivity and improved LWR and CDU can be constructed. DETAILED DESCRIPTION

[0070] [Resist material]

[0071] The resist material of the present invention contains a di-onium salt, which contains a sulfonic acid anion structure directly bonded to an aromatic group substituted with an iodine atom and a divalent anion having a carboxylic acid anion structure directly bonded to the aromatic group or bonded via a linking group containing one or more atoms, and an onium cation. The di-onium salt has high reactivity due to absorption of iodine atoms and high acidity, and acid diffusion control interaction due to the presence of a quencher nearby, so that acid diffusion is small and the diffusion distance is uniform. This can improve LWR and CDU.

[0072] The improvement effect of LWR and CDU by the bis-onium salt is effective in both positive pattern formation and negative pattern formation by alkaline aqueous solution development and negative pattern formation by organic solvent development.

[0073] [Bis-onium salt]

[0074] The bis-onium salt is preferably represented by the following formula (1).

[0075] [Chemistry 3]

[0076]

[0077] In formula (1), p is an integer of 1-5. q is an integer of 0-7.

[0078] In formula (1), X 1 ~X 3 are each independently a single bond, an ether bond, an ester bond or an amide bond.

[0079] In formula (1), R 1 ~R 3 are each independently a single bond or a hydrocarbon group having 1 to 30 carbon atoms, and the hydrocarbon group may contain at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom. 1 ~R 3 The upper limit of the total number of carbon atoms is 30.

[0080] R 1 ~R 3The alkylene group represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include alkylene groups having 1 to 24 carbon atoms in which a part or all of the hydrogen atoms are substituted by iodine atoms or bromine atoms. Examples of the alkylene groups having 1 to 24 carbon atoms 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, and 1,13-diyl. -diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, heptadecan-1,17-diyl, octadecane-1,18-diyl, nonadecan-1,19-diyl, eicosane-1,20-diyl, etc.; cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, methylcyclopentanediyl, dimethylcyclopentanediyl, trimethylcyclopentanediyl Cyclic saturated alkylene groups such as pentanediyl, tetramethylcyclopentanediyl, cyclohexanediyl, methylcyclohexanediyl, dimethylcyclohexanediyl, trimethylcyclohexanediyl, tetramethylcyclohexanediyl, norbornanediyl, and adamantanediyl; alkenediyl groups having 2 to 20 carbon atoms such as ethylenediyl, propylenediyl, and butenediyl; alkynediyl groups having 2 to 20 carbon atoms such as ethynediyl, propynediyl, and butynediyl; phenylene, methylphenylene, and ethylphenylene , n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, sec-butylnaphthylene, tert-butylnaphthylene, tetrahydronaphthylene, biphenyldiyl, methylbiphenyldiyl, dimethylbiphenyldiyl and the like arylene groups; groups obtained by combining them, etc. In addition, part or all of the hydrogen atoms of the aforementioned alkylene group may be substituted by a group containing at least one selected from oxygen atoms, nitrogen atoms, sulfur atoms and halogen atoms, and the -CH 2 - may be substituted with a group containing at least one selected from an oxygen atom, a nitrogen atom and a sulfur atom, and as a result, may contain a hydroxyl group, an ester bond, an ether bond, an amide bond, a urethane bond, a urea bond or the like.

[0081] In formula (1), R 4 is a hydrogen atom, a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano 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, a hydrocarbon sulfonyloxy group having 1 to 20 carbon atoms, -N(R 4A )-C(=O)-R 4B 、-N(R 4A )-C(=O)-OR4B or -N(R 4A )-S(=O) 2 -R 4B , and the hydrocarbon group, hydrocarbon oxy group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyloxy group, and hydrocarbon sulfonyloxy group may also contain at least one selected from fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, hydroxyl groups, amino groups, ester bonds, ether bonds, carbamate bonds, urea bonds, carbonate bonds, amide bonds, sulfonate bonds, carbonyl groups, thioether groups, and sulfonyl groups. 4A R is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and the saturated hydrocarbon group 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. 4B It 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.

[0082] R 4 The hydrocarbon radical represented by and the hydrocarbon radical part of the hydrocarbon radical oxy, hydrocarbon radical oxycarbonyl, hydrocarbon radical carbonyloxy and hydrocarbon radical sulfonyloxy may be saturated or unsaturated, and may be straight chain, branched or cyclic. Specific examples thereof include: alkyl radicals having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl; cyclic saturated hydrocarbon radicals having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl and adamantyl; vinyl, propenyl, butenyl, hexenyl Alkenyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, butynyl, etc.; alkynyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, butynyl, etc.; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms, such as cyclohexenyl and norbornyl, etc.; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl, etc.; aralkyl groups having 7 to 20 carbon atoms, such as benzyl and phenethyl, and groups derived from combinations thereof.

[0083] In formula (1), Ar is a (p+q+1)-valent aromatic hydrocarbon group having 6 to 16 carbon atoms. Specific examples of the aromatic hydrocarbon group include groups obtained by removing (p+q+1) hydrogen atoms from aromatic hydrocarbons such as benzene, naphthalene, anthracene, and pyrene.

[0084] Specific examples of the anion of the bis-onium salt include those shown below, but are not limited thereto.

[0085] [Chemistry 4]

[0086]

[0087] [Chemistry 5]

[0088]

[0089] [Chemistry 6]

[0090]

[0091] [Chemistry 7]

[0092]

[0093] [Chemistry 8]

[0094]

[0095] [Chemistry 9]

[0096]

[0097] [Chemistry 10]

[0098]

[0099] [Chemistry 11]

[0100]

[0101] [Chemistry 12]

[0102]

[0103] [Chemistry 13]

[0104]

[0105] [Chemistry 14]

[0106]

[0107] [Chemistry 15]

[0108]

[0109] [Chemistry 16]

[0110]

[0111] [Chemistry 17]

[0112]

[0113] [Chemistry 18]

[0114]

[0115] [Chemistry 19]

[0116]

[0117] [Chemistry 20]

[0118]

[0119] [Chemistry 21]

[0120]

[0121] [Chemistry 22]

[0122]

[0123] [Chemistry 23]

[0124]

[0125] [Chemistry 24]

[0126]

[0127] [Chemistry 25]

[0128]

[0129] [Chemistry 26]

[0130]

[0131] [Chemistry 27]

[0132]

[0133] [Chemistry 28]

[0134]

[0135] [Chemistry 29]

[0136]

[0137] [Chemistry 30]

[0138]

[0139] [Chemistry 31]

[0140]

[0141] In formula (1), M + is a sulfonium cation or an iodonium cation. 2 M+ One of them may be a sulfonium cation and the other may be an iodonium cation, or both may be sulfonium cations, or both may be iodonium cations. + When both of M are sulfonium cations, they may be the same or different from each other. + When both are iodonium cations, they may be the same as or different from each other.

[0142] The sulfonium cation is preferably represented by the following formula (2), and the iodonium cation is preferably represented by the following formula (3).

[0143] [Chemistry 32]

[0144]

[0145] In formula (2) and (3), R 5 ~R 9 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

[0146] R 5 ~R 9 Specific examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

[0147] R 5 ~R 9 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, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, etc.; cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl, etc.; ethenyl, propenyl, butenyl, hexenyl Alkenyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, butynyl, etc.; alkynyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, butynyl, etc.; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms, such as cyclohexenyl and norbornyl, etc.; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl, etc.; aralkyl groups having 7 to 20 carbon atoms, such as benzyl and phenethyl, and groups derived from combinations thereof.

[0148] 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 the -CH2 - may also be substituted by a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, etc., and as a result, may contain 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 pentafluorosulfanyl 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, etc.

[0149] Again, R 5 and R 6 They may also be bonded to each other and to form a ring together with the sulfur atom to which they are bonded. In this case, the aforementioned ring is preferably a structure shown below.

[0150] [Chemistry 33]

[0151]

[0152] In the formula, the dotted lines represent atomic bonds.

[0153] M + Specific examples of the sulfonium cation represented by include the following, but are not limited to these.

[0154] [Chemistry 34]

[0155]

[0156] [Chemistry 35]

[0157]

[0158] [Chemistry 36]

[0159]

[0160] [Chemistry 37]

[0161]

[0162] [Chemistry 38]

[0163]

[0164] [Chemistry 39]

[0165]

[0166] [Chemistry 40]

[0167]

[0168] [Chemistry 41]

[0169]

[0170] [Chemistry 42]

[0171]

[0172] [Chemistry 43]

[0173]

[0174] [Chemistry 44]

[0175]

[0176] [Chemistry 45]

[0177]

[0178] [Chemistry 46]

[0179]

[0180] [Chemistry 47]

[0181]

[0182] [Chemistry 48]

[0183]

[0184] [Chemistry 49]

[0185]

[0186] [Chemistry 50]

[0187]

[0188] [Chemistry 51]

[0189]

[0190] [Chemistry 52]

[0191]

[0192] [Chemistry 53]

[0193]

[0194] [Chemistry 54]

[0195]

[0196] [Chemistry 55]

[0197]

[0198] [Chemistry 56]

[0199]

[0200] [Chemistry 57]

[0201]

[0202] [Chemistry 58]

[0203]

[0204] [Chemistry 59]

[0205]

[0206] [Chemistry 60]

[0207]

[0208] [Chemistry 61]

[0209]

[0210] [Chemistry 62]

[0211]

[0212] [Chemistry 63]

[0213]

[0214] [Chemistry 64]

[0215]

[0216] [Chemistry 65]

[0217]

[0218] [Chemistry 66]

[0219]

[0220] [Chemistry 67]

[0221]

[0222] [Chemistry 68]

[0223]

[0224] M + Specific examples of the iodonium cation represented by include the following, but are not limited thereto.

[0225] [Chemistry 69]

[0226]

[0227] [Chemistry 70]

[0228]

[0229] The synthesis method of the above-mentioned dichonium salt can be, for example, a method of salt-exchanging a sulfonium salt or iodonium salt containing a halide anion with an ammonium salt containing a divalent anion having a sulfonic acid anion structure directly bonded to an aromatic group having an iodine atom or a bromine atom and a carboxylic acid anion structure bonded to the aromatic group having an iodine atom or a bromine atom via a linking group having one or more carbon atoms.

[0230] 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.

[0231] [Base polymer]

[0232] The base polymer contained in the resist material of the present invention, in the case of 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 the following formula (a2) (hereinafter also referred to as repeating unit a2).

[0233] [Chemistry 71]

[0234]

[0235] 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, and 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 are each 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.

[0236] 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.

[0237] [Chemistry 72]

[0238]

[0239] [Chemistry 73]

[0240]

[0241] [Chemistry 74]

[0242]

[0243] Specific examples of monomers providing repeating unit a2 include, but are not limited to, those shown below. A and R 12 Same as above.

[0244] [Chemistry 75]

[0245]

[0246] 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.

[0247] Representative examples of the acid-labile group include those represented by any one of the following formulae (AL-1) to (AL-3).

[0248] [Chemistry 76]

[0249]

[0250] In the formula, the dotted lines represent atomic bonds.

[0251] In formula (AL-1) and (AL-2), R L1 and R L2 Each of the above hydrocarbon groups is independently a hydrocarbon group having 1 to 40 carbon atoms, and may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The above hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. The above hydrocarbon group is preferably a saturated hydrocarbon group having 1 to 40 carbon atoms, and more preferably a saturated hydrocarbon group having 1 to 20 carbon atoms.

[0252] In the formula (AL-1), b is an integer of 0-10, preferably an integer of 1-5.

[0253] In formula (AL-2), R L3 and R L4 Each of them is independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. The hydrocarbon group is preferably a saturated hydrocarbon group having 1 to 20 carbon atoms. L2 , R L3 and R L4 Any two of them may be bonded to each other and together with the carbon atom to which they are bonded or with the carbon atom and oxygen atom 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.

[0254] In formula (AL-3), R L5 , R L6 and R L7 Each of them is independently a hydrocarbon group having 1 to 20 carbon atoms, and may 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 straight-chain, 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.

[0255] The aforementioned base polymer may also contain 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 thereto. In the following formula, R A Same as above.

[0256] [Chemistry 77]

[0257]

[0258] The 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 the following, but are not limited thereto. In the following formula, R A Same as above.

[0259] [Chemistry 78]

[0260]

[0261] [Chemistry 79]

[0262]

[0263] [Chemistry 80]

[0264]

[0265] [Chemistry 81]

[0266]

[0267] [Chemistry 82]

[0268]

[0269] [Chemistry 83]

[0270]

[0271] [Chemistry 84]

[0272]

[0273] [Chemistry 85]

[0274]

[0275] The base polymer may contain a repeating unit d derived from indene, benzofuran, benzothiophene, acenaphthene, 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.

[0276] [Chemistry 86]

[0277]

[0278] The aforementioned base polymer may contain a repeating unit e derived from styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methylenedihydroindane, vinylpyridine or vinylcarbazole.

[0279] The base polymer may contain repeating units f derived from an onium salt containing a polymerizable unsaturated bond. Japanese Patent Application Laid-Open No. 2005-84365 proposes a sulfonium salt or iodonium salt containing a polymerizable olefin that generates a specific sulfonic acid. Japanese Patent Application Laid-Open No. 2006-178317 proposes a sulfonium salt in which a sulfonic acid is directly bonded to the main chain.

[0280] Specific examples of desirable repeating units f include: 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). In addition, repeating units f1 to f3 may be used alone or in combination of two or more.

[0281] [Chemistry 87]

[0282]

[0283] In formulas (f1) to (f3), R A are each independently a hydrogen atom or a methyl group. 1 is 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 groups, 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 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 them, and may contain a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom. 4 Z 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.

[0284] 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 heteroatom. Specific examples of the aforementioned halogen atom include fluorine atom, chlorine atom, bromine atom, iodine atom, etc. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include and In the description of formula (2) and (3), R is exemplified as 5 ~R 9 The same examples are given for the hydrocarbon groups represented by . In addition, part or all of the hydrogen atoms of the aforementioned hydrocarbon groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and the -CH 2- may be substituted with a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro 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, etc. 23 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 atom to which they are bonded. In this case, specific examples of the aforementioned ring include the following: 5 and R 6 The same example is true of the rings that can be formed by bonding to each other and to the sulfur atoms to which they are bonded.

[0285] In formula (f1), M - It is a non-nucleophilic counter ion. Specific examples of the aforementioned non-nucleophilic counter ions include: halide ions such as chloride ion and bromide ion; fluoroalkyl sulfonate ions such as trifluoromethanesulfonate ion, 1,1,1-trifluoroethanesulfonate ion, nonafluorobutanesulfonate ion; aryl sulfonate ions such as toluenesulfonate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion, 1,2,3,4,5-pentafluorobenzenesulfonate ion; alkyl sulfonate ions such as methanesulfonate ion and butanesulfonate ion; imide ions such as bis(trifluoromethylsulfonyl)imide ion, bis(perfluoroethylsulfonyl)imide ion, bis(perfluorobutylsulfonyl)imide ion; methylated ions such as tris(trifluoromethylsulfonyl)methylated ion and tris(perfluoroethylsulfonyl)methylated ion.

[0286] Specific examples of the aforementioned non-nucleophilic relative ions include: sulfonate ions represented by the following formula (f1-1) in which the α-position is substituted with a fluorine atom, sulfonate ions 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, etc.

[0287] [Chemistry 88]

[0288]

[0289] In formula (f1-1), R 31 It is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and 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.

[0290] 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 the group consisting of an ether bond, an ester bond, a carbonyl group, and a lactone ring.

[0291] R31 or R 32 The hydrocarbon radical of the hydrocarbon radical and hydrocarbon carbonyl radical 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, heptadecyl, 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; aralkyl groups such as benzyl and diphenylmethyl; and the like.

[0292] Furthermore, 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 contained. 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.

[0293] Specific examples of the cation of the monomer providing the repeating unit f1 include the following, but are not limited thereto. A Same as above.

[0294] [Chemistry 89]

[0295]

[0296] Specific examples of the cation of the monomer providing the repeating unit f2 or f3 include: + The same example is represented by the sulfonium cation.

[0297] Specific examples of monomers providing repeating unit f2 include, but are not limited to, the following. A Same as above.

[0298] [Chemistry 90]

[0299]

[0300] [Chemistry 91]

[0301]

[0302] [Chemistry 92]

[0303]

[0304] [Chemistry 93]

[0305]

[0306] [Chemistry 94]

[0307]

[0308] [Chemistry 95]

[0309]

[0310] [Chemistry 96]

[0311]

[0312] [Chemistry 97]

[0313]

[0314] [Chemistry 98]

[0315]

[0316] [Chemistry 99]

[0317]

[0318] [Chemical 100]

[0319]

[0320] [Chemistry 101]

[0321]

[0322] [Chemistry 102]

[0323]

[0324] [Chemistry 103]

[0325]

[0326] Specific examples of monomers providing repeating unit f3 include those shown below, but are not limited thereto. A Same as above.

[0327] [Chemistry 104]

[0328]

[0329] The repeating units f1 to f3 function as an acid generator. By bonding the acid generator to the polymer main chain, acid diffusion can be reduced, and a decrease in resolution due to blurred acid diffusion can be prevented. Also, by uniformly dispersing the acid generator, LWR and CDU are improved.

[0330] The base polymer for a positive resist material needs to have the repeating unit a1 or a2 containing an acid-labile group. At this time, the content ratios of the repeating units a1, a2, b, c, d, e, and f should be 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. It is more preferable that 0 ≤ a1 ≤ 0.9, 0 ≤ a2 ≤ 0.9, 0.1 ≤ a1 + a2 ≤ 0.9, 0 ≤ b ≤ 0.8, 0 ≤ c ≤ 0.8, 0 ≤ d ≤ 0.7, 0 ≤ e ≤ 0.7, and 0 ≤ f ≤ 0.4. It is still more preferable that 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. Additionally, when the repeating unit f is at least one selected from the repeating units f1 to f3, f = f1 + f2 + f3. Also, a1 + a2 + b + c + d + e + f = 1.0.

[0331] On the other hand, for the base polymer for a negative resist material, an acid-labile group is not necessary. Examples of such a base polymer include those containing the repeating unit b and, if necessary, further containing the repeating units c, d, e, and / or f. The content ratios of these repeating units should be 0 < b ≤ 1.0, 0 ≤ c ≤ 0.9, 0 ≤ d ≤ 0.8, 0 ≤ e ≤ 0.8, and 0 ≤ f ≤ 0.5. It is more preferable that 0.2 ≤ b ≤ 1.0, 0 ≤ c ≤ 0.8, 0 ≤ d ≤ 0.7, 0 ≤ e ≤ 0.7, and 0 ≤ f ≤ 0.4. It is still more preferable that 0.3 ≤ b ≤ 1.0, 0 ≤ c ≤ 0.75, 0 ≤ d ≤ 0.6, 0 ≤ e ≤ 0.6, and 0 ≤ f ≤ 0.3. Additionally, when the repeating unit f is at least one selected from the repeating units f1 to f3, f = f1 + f2 + f3. Also, b + c + d + e + f = 1.0.

[0332] When synthesizing the aforementioned base polymer, for example, monomers providing the aforementioned repeating units are added with a radical polymerization initiator in an organic solvent and heated to carry out polymerization.

[0333] Specific examples of organic solvents used in polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl 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.

[0334] When copolymerizing hydroxyl-containing monomers, the hydroxyl groups may be replaced with acetal groups such as ethoxyethoxy groups which are easily deprotected by acid during polymerization, and then deprotected using weak acid and water after polymerization. Alternatively, the hydroxyl groups may be replaced with acetyl groups, formyl groups, trimethylacetyl groups, etc., and then alkaline hydrolysis may be performed after polymerization.

[0335] When copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, acetoxystyrene and acetoxyvinylnaphthalene may be used instead of hydroxystyrene and hydroxyvinylnaphthalene, and after polymerization, the acetoxy group may be deprotected by alkaline hydrolysis to obtain hydroxystyrene and hydroxyvinylnaphthalene.

[0336] The base used in the alkaline hydrolysis may be aqueous ammonia, triethylamine, etc. The reaction temperature is preferably -20 to 100°C, more preferably 0 to 60°C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0337] 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.

[0338] In addition, when the molecular weight distribution (Mw / Mn) of the base polymer is wide, there will be low molecular weight and high molecular weight polymers, so there is a concern that foreign matter may be observed on the pattern after exposure, and the shape of the pattern may deteriorate. As the pattern rules become finer, the influence of Mw and Mw / Mn is also likely to become greater. Therefore, in order to obtain a resist material that can be ideally used in a fine pattern size, the Mw / Mn of the base polymer is preferably 1.0 to 2.0, and a narrow distribution of 1.0 to 1.5 is particularly preferred.

[0339] The base polymer may contain two or more polymers having different composition ratios, Mw, and Mw / Mn.

[0340] [Organic solvents]

[0341] 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-pentyl ketone, 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 monomethylolpropane; 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.

[0342] 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.

[0343] [Quencher]

[0344] The resist material of the present invention may contain a quencher. The quencher refers to a compound that can prevent the acid generated from the acid generator in the resist material from diffusing to the unexposed area by trapping the acid.

[0345] The quencher can be a known basic compound. Specific examples of known basic compounds include: primary, secondary, 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 hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amides, imides, carbamates, etc. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

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

[0346] In addition, the quencher may be an onium salt such as a sulfonium salt, an iodonium salt, or an ammonium salt of a sulfonic acid, a carboxylic acid, or a fluorinated alkoxide whose α-position is not fluorinated as described in Japanese Patent Application Laid-Open No. 2008-158339. The sulfonic acid, imidic acid, or methylated acid whose α-position is fluorinated is necessary to deprotect the acid-labile group of the carboxylate, and the sulfonic acid, carboxylic acid, or fluorinated alcohol whose α-position is not fluorinated is released by salt exchange with the onium salt. The sulfonic acid, carboxylic acid, and fluorinated alcohol whose α-position is not fluorinated do not cause a deprotection reaction, and thus function as a quencher.

[0347] Specific examples of such quenchers include 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).

[0348] [Chemistry 105]

[0349]

[0350] In formula (4), R 101 It is a hydrocarbon group having 1 to 40 carbon atoms which may contain a hydrogen atom or a hetero atom, but excludes those in which the hydrogen atom bonded to the carbon atom at the α-position of the sulfonic group is substituted by a fluorine atom or a fluoroalkyl group.

[0351] 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.

[0352] 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 the -CH 2 - may also be substituted by a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, etc., and as a result, may contain 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, etc. Specific examples of heteroatom-containing hydrocarbon groups 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.

[0353] In formula (5), R 102 It is a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. 102 Specific examples of the hydrocarbon group represented by can be listed and exemplified as R 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.

[0354] 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 contain a nitro group.

[0355] In formulas (4), (5) and (6), Mq + The onium cation is preferably a sulfonium cation, an iodonium cation or an ammonium cation, and is more preferably a sulfonium cation. Specific examples of the sulfonium cation include the following: + The same example is represented by the sulfonium cation.

[0356] 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.

[0357] [Chemistry 106]

[0358]

[0359] In formula (7), x is an integer of 1 to 5, y is an integer of 0 to 3, and z is an integer of 1 to 3.

[0360] 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, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms, or a saturated hydrocarbon sulfonyloxy group having 1 to 4 carbon atoms, wherein a part or all of the hydrogen atoms may be substituted with halogen 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. When y and / or z is 2 or more, each R 111 They can be the same or different.

[0361] 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 contain at least one selected from an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxyl group, and a carboxyl group. The saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyl oxy group, and saturated hydrocarbon sulfonyl oxy group may be straight-chain, branched, or cyclic.

[0362] 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 those exemplified as R in the description of formulas (2) and (3): 5 ~R 9 The same examples are given for the hydrocarbon groups represented.

[0363] Specific examples of the compound represented by formula (7) include those described in JP-A-2017-219836 and JP-A-2021-91666.

[0364] Other examples of the quencher include polymer quenchers described in Japanese Patent Application Publication No. 2008-239918. This improves the rectangularity of the resist pattern by being aligned on the resist film surface. The polymer quencher also has the effect of preventing film loss and doming of the pattern when using a protective film for immersion exposure.

[0365] In addition, 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.

[0366] 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.

[0367] [Other ingredients]

[0368] 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, a dissolution inhibitor, a crosslinking agent, a water repellency improver, acetylene alcohols, etc. may be contained.

[0369] The aforementioned other acid generators can include compounds (photoacid generators) that are responsive to active light or radiation and generate acid. If the component of the photoacid generator is a compound that generates acid due to high-energy ray irradiation, any one of them is fine, and it is preferably an acid generator that generates sulfonic acid, imidic acid or methylated acid. Specific examples of ideal photoacid generators include: sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate acid generators, etc. Specific examples of the aforementioned acid generators include: paragraphs

[0122] to

[0142] of Japanese Patent Publication No. 2008-111103, Japanese Patent Publication No. 2018-5224, and Japanese Patent Publication No. 2018-25789. 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.

[0370] Specific examples of the above-mentioned surfactant include the examples described in paragraphs

[0165] to

[0166] of Japanese Patent Publication No. 2008-111103. 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.

[0371] When the resist material of the present invention is positive type, by mixing a dissolution inhibitor, the difference in dissolution rate between the exposed part and the unexposed part can be further enlarged, and the resolution can be further improved. Specific examples of the above-mentioned dissolution inhibitor include: a compound having a molecular weight of preferably 100 to 1000 and more preferably 150 to 800, and a compound in which the hydrogen atom of the phenolic hydroxyl group in the compound containing two or more phenolic hydroxyl groups in the molecule is replaced by an acid-labile group at a ratio of 0 to 100 mol% as a whole, or a compound in which the hydrogen atom of the carboxyl group in the compound containing a carboxyl group in the molecule is replaced by an acid-labile group at an average ratio of 50 to 100 mol% as a whole. Specifically, compounds in which the hydrogen atoms of the hydroxyl group and the carboxyl group of bisphenol A, trisphenol, phenolphthalein, cresol novolac resin, naphthalenecarboxylic acid, adamantanecarboxylic acid, and bile acid are replaced by acid-labile groups, etc., are described in paragraphs

[0155] to

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

[0372] When the resist material of the present invention is positive type and contains the dissolution inhibitor, 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 dissolution inhibitor may be used alone or in combination of two or more.

[0373] 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 part. Specific examples of the above-mentioned crosslinking agent include: epoxy compounds substituted with at least one group selected from hydroxymethyl, alkoxymethyl and acyloxymethyl, melamine compounds, guanamine compounds, glycoluril compounds or urea compounds, isocyanate compounds, azide compounds, compounds containing double bonds such as alkenyloxy groups, etc. They can be used in the form of additives and can also be introduced into the side chains of polymers as pendant groups. In addition, hydroxyl-containing compounds can also be used as crosslinking agents.

[0374] Specific examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0375] Specific examples of the melamine compound include hexamethylolmelamine, hexamethoxymethylmelamine, a compound in which 1 to 6 hydroxymethyl groups in hexamethylolmelamine are methoxymethylated, or a mixture thereof, hexamethoxyethylmelamine, hexaacyloxymethylmelamine, a compound in which 1 to 6 hydroxymethyl groups in hexamethylolmelamine are acyloxymethylated, or a mixture thereof, and the like.

[0376] Specific examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, a compound in which 1 to 4 hydroxymethyl groups of tetramethylolguanamine are methoxymethylated, or a mixture thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, a compound in which 1 to 4 hydroxymethyl groups of tetramethylolguanamine are acyloxymethylated, or a mixture thereof, and the like.

[0377] Specific examples of the glycoluril compound include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which 1 to 4 hydroxymethyl groups in tetramethylol glycoluril are methoxymethylated, or mixtures thereof, compounds in which 1 to 4 hydroxymethyl groups in tetramethylol glycoluril are acyloxymethylated, or mixtures thereof, etc. Specific examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, compounds in which 1 to 4 hydroxymethyl groups in tetramethylol urea are methoxymethylated, or mixtures thereof, and tetramethoxyethyl urea, etc.

[0378] Specific examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0379] Specific examples of the azide compound include 1,1′-biphenyl-4,4′-bisazide, 4,4′-methylenebisazide, and 4,4′-oxybisazide.

[0380] Specific examples of the alkenyloxy group-containing compound include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol 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.

[0381] 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.

[0382] The aforementioned water repellency improver is a material that improves the water repellency of the surface of the resist film and can be used in immersion lithography without using a top coat. The aforementioned water repellency improver is preferably a polymer containing a fluorinated alkyl group, a polymer containing a 1,1,1,3,3,3-hexafluoro-2-propanol residue of a specific structure, and the like, and is preferably an example illustrated in Japanese Patent Publication No. 2007-297590, Japanese Patent Publication No. 2008-111103, and the like. The aforementioned water repellency improver must be dissolved in an alkaline developer or an organic solvent developer. The aforementioned specific water repellency improver having a 1,1,1,3,3,3-hexafluoro-2-propanol residue has good solubility in a developer. As for the water repellency improver, a polymer containing a repeating unit containing an amino group or an amine salt has a high effect of preventing the evaporation of the acid during PEB and preventing the poor opening of the hole pattern after development. When the resist material of the present invention contains the water repellency improver, its content is preferably 0 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, based on 100 parts by mass of the base polymer. The water repellency improver may be used alone or in combination of two or more.

[0383] 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.

[0384] [Pattern Formation Method]

[0385] 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.

[0386] First, the resist material of the present invention is applied to a substrate (Si, SiO2) for integrated circuit manufacturing by a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, or blade coating so that the coating film thickness becomes 0.01 to 2 μm. 2 , SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflection film, etc.) or substrates for mask circuit manufacturing (Cr, CrO, CrON, MoSi 2 、SiO 2 This is pre-baked on a hot plate preferably at 60 to 150° C. for 10 seconds to 30 minutes, more preferably at 80 to 120° C. for 30 seconds to 20 minutes, to form a resist film.

[0387] Then, the resist film is exposed using high-energy radiation. Specific examples of the high-energy radiation 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 radiation, the exposure amount is preferably about 1 to 200 mJ / cm2, either directly or using a mask for forming a desired pattern. 2 More preferably, it is about 10 to 100 mJ / cm 2 When using EB, the exposure dose is preferably about 0.1 to 300 μC / cm 2 More preferably, it is 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.

[0388] 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, but it is not necessary to perform PEB.

[0389] After exposure or PEB, the resist film is exposed for 3 seconds to 3 minutes and preferably for 5 seconds to 2 minutes by a common method such as dipping, puddle, spraying, etc., and developed using a developer of an alkaline aqueous solution of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, etc., preferably 0.1 to 10% by mass and ideally 2 to 5% by mass, to form a desired pattern. In the case of a positive resist material, the portion irradiated with light will dissolve in the developer, while the portion not exposed will not dissolve, and a desired positive pattern will be formed on the substrate. In the case of a negative resist material, the portion irradiated with light will not dissolve in the developer, while the portion not exposed will dissolve, as opposed to the positive resist material.

[0390] A negative pattern can also be obtained by using a positive resist material containing a base polymer containing an acid-labile group and 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, Ethyl crotonate, 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. These organic solvents may be used alone or in combination of two or more.

[0391] At the end of the development, rinsing is performed. The rinsing solution is preferably a solvent that is miscible with the developer and does not dissolve the resist film. Such solvents can preferably be 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.

[0392] 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, and 1-octanol.

[0393] 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-pentyl ether, diisopentyl ether, di(sec-pentyl) ether, di(tert-pentyl) ether, and di-n-hexyl ether.

[0394] Specific examples of the 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 alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, etc. Specific examples of the alkynes having 6 to 12 carbon atoms include hexyne, heptyne, octyne, etc.

[0395] Specific examples of the aromatic solvent include toluene, xylene, ethylbenzene, cumene, tert-butylbenzene, mesitylene, and the like.

[0396] By performing rinsing, the occurrence of collapse and defects in the resist pattern can be reduced. In addition, rinsing is not essential, and by not performing rinsing, the amount of solvent used can be reduced.

[0397] The hole pattern and groove pattern after development can also be shrunk by heat flow, RELACS technology or DSA technology. A shrinking agent is coated on the hole pattern, and the diffusion of the acid catalyst from the resist film during baking will cause cross-linking of the shrinking agent on the surface of the resist film, and the shrinking agent will adhere to the side wall of the hole pattern. The baking temperature should be 70-180°C, preferably 80-170°C, and the baking time should be 10-300 seconds to remove the excess shrinking agent and shrink the hole pattern.

[0398] Example

[0399] 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.

[0400] The structures of bis-onium salts PAG-PDQ-1 to PAG-PDQ-15 as an acid generator and quencher used in the resist material are shown below.

[0401] [Chemistry 107]

[0402]

[0403] [Chemistry 108]

[0404]

[0405] [Chemistry 109]

[0406]

[0407] [Chemistry 110]

[0408]

[0409] [Chemistry 111]

[0410]

[0411] [Chemistry 112]

[0412]

[0413] [Chemistry 113]

[0414]

[0415] [Synthesis Example] Synthesis of base polymers (polymers P-1 to P-4)

[0416] Each monomer combination was copolymerized in THF as a solvent, and then placed in methanol. The precipitated solid was washed with hexane, separated and dried to obtain base polymers (polymers P-1 to P-4) with the following compositions. 1 The molecular weight was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC (solvent: THF, standard: polystyrene).

[0417] [Chemistry 114]

[0418]

[0419] [Examples 1 to 20, Comparative Examples 1 to 3] Preparation and Evaluation of Resist Materials

[0420] (1) Preparation of resist materials

[0421] A solution in which each component was dissolved in the composition shown in Table 1 was filtered using a filter having a size of 0.2 μm to prepare a resist material.

[0422] In Table 1, the components are as follows.

[0423] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0424] EL(ethyl lactate)

[0425] DAA (Diacetone Alcohol)

[0426] Comparative Acid Generators: cPAG-1, cPAG-PDQ-1

[0427] [Chemistry 115]

[0428]

[0429] Blended acid generator: bPAG-1

[0430] [Chemistry 116]

[0431]

[0432] Comparison Quencher: cPDQ-1

[0433] [Chemistry 117]

[0434]

[0435] (2) EUV lithography evaluation

[0436] Each resist material shown in Table 1 was spin-coated on a Si substrate on which a silicon-containing spin-coating hard mask SHB-A940 (containing 43% by mass of silicon) manufactured by Shin-Etsu Chemical Co., Ltd. was formed with a film thickness of 20 nm, and pre-baked at 105° C. for 60 seconds using a hot plate to obtain a resist film with a film thickness of 40 nm. The resist film was exposed using an EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9 / 0.7, dipole illumination) manufactured by ASML, and PEB was performed for 60 seconds on a hot plate at the temperature described in Table 1, and then developed for 30 seconds using a 2.38% by 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 19 and Comparative Examples 1 and 2 are positive resist materials, and Example 20 and Comparative Example 3 are negative resist materials.

[0437] Using a length measurement SEM (CG6300) manufactured by Hitachi High-Tech Co., Ltd., an exposure dose was obtained to form a line pattern with a size of 16 nm±1.6 nm, and the LWR at this exposure dose was measured.

[0438] [Table 1]

[0439]

[0440]

[0441] From the results shown in Table 1, it can be seen that the resist material of the present invention containing a bis-onium salt containing a divalent anion having a sulfonic acid anion structure directly bonded to an aromatic group substituted with an iodine atom and a carboxylic acid anion structure directly bonded to the aromatic group or bonded via a linking group containing one or more atoms, and an onium cation has high sensitivity and good LWR.

Claims

1. A resist material comprising: The bis-onium salt contains a divalent anion having a sulfonic acid anion structure directly bonded to an aromatic group substituted with an iodine atom and a carboxylic acid anion structure directly bonded to the aromatic group or bonded via a linking group containing one or more 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 from 1 to 5; q is an integer from 0 to 7; X 1 ~X 3 are independently a single bond, an ether bond, an ester bond or an amide bond; R 1 ~R 3 are each independently a single bond or an alkylene group having 1 to 30 carbon atoms, and the alkylene group may also contain at least one selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom; however, R 1 ~R 3 The upper limit of the total number of carbon atoms is 30; R 4 is a hydrogen atom, a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano 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, a hydrocarbon sulfonyloxy group having 1 to 20 carbon atoms, -N(R 4A )-C(=O)-R 4B 、-N(R 4A )-C(=O)-OR 4B or -N(R 4A )-S(=O)2-R 4B , and the hydrocarbon group, hydrocarbon oxy group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyloxy group, and hydrocarbon sulfonyloxy group may contain at least one selected from a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a hydroxyl group, an amino group, an ester bond, an ether bond, a carbamate bond, a urea bond, a carbonate bond, an amide bond, a sulfonate bond, a carbonyl group, a thioether group, and a sulfonyl group; R 4A 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; R 4B It 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 a (p+q+1)-valent aromatic hydrocarbon group having 6 to 16 carbon atoms; M + It is a sulfonium cation or an iodonium cation. The resist material according to claim 1 , further comprising a base polymer.

4. The resist material according to claim 3, wherein The base polymer contains a repeating unit represented by the following formula (a1) or (a2); In the formula, R A are 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, and 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; 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 It 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 4 , which is a chemically amplified positive resist material.

6. The resist material according to claim 3, wherein The base polymer does not contain acid-labile groups. The resist material according to claim 6 , which is a chemically amplified negative resist material. The resist material according to claim 1 , further comprising an organic solvent.

9. The resist material according to claim 1, further comprising a quencher.

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

12. A pattern forming method comprising the following steps: forming a resist film on a substrate using the resist material according to any one of claims 1 to 11, exposing the resist film to high energy radiation, and The exposed resist film is developed using a developing solution.

13. The pattern forming method according to claim 12, 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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