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. The resist material contains a base polymer having a sulfonium salt or salt structure in which an aryl sulfonic acid anion substituted by an iodine atom is bonded to the main chain.

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 due to the popularization of 5G high-speed communication and artificial intelligence (AI), which requires high-performance devices 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 already underway. In addition, the use of EUV lithography has also been explored in the next-generation 3nm node and the next-generation 2nm node devices. IMEC in Belgium has published Device development.

[0003] As patterns become smaller, the roughness of the line width (LWR) of line patterns and the dimensional uniformity (CDU) of hole patterns and dot patterns are considered to be problems. The uneven distribution and coagulation of base polymers and acid generators and the influence of acid diffusion have been pointed out. In addition, as the thin film of the resist film is reduced, the LWR and CDU tend to increase, and the deterioration of LWR and CDU caused by the thin film due to miniaturization has become a serious problem.

[0004] In EUV resist materials, high sensitivity, high resolution, and low LWR need to be achieved simultaneously. If the acid diffusion distance is shortened, LWR and CDU will be improved, but the sensitivity will be reduced. For example, by lowering the post-exposure bake (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] It has been proposed to add an onium salt containing an anion having an iodine atom as an acid generator to a resist material (Patent Document 1). The iodine atom having a large absorption of EUV 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] 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.

[0007] Prior art literature

[0008] Patent Literature

[0009] [Patent Document 1] Japanese Patent Application Publication No. 2018-159744 Summary of the invention

[0010] [Problems to be solved by the invention]

[0011] 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.

[0012] 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 regardless of positive or negative type and improved LWR and CDU, and to provide a pattern forming method using the same.

[0013] [Methods to solve the problem]

[0014] The inventors of the present application have conducted repeated and in-depth studies in order to achieve the aforementioned objectives, and have found that by using a polymer-bonded acid generator having a sulfonium salt or iodonium salt structure of an aromatic sulfonic acid substituted with an iodine atom bonded to a polymer main chain, a highly sensitive resist material with improved LWR and CDU, high contrast, excellent resolution, and wide process latitude can be obtained, thereby completing the present invention.

[0015] That is, the present invention provides the following resist material and pattern forming method.

[0016] 1. A resist material comprising:

[0017] The base polymer has a sulfonium salt or iodonium salt structure in which an arylsulfonic acid anion substituted with an iodine atom is bonded to the main chain.

[0018] 2. The resist material according to 1., wherein the base polymer comprises a repeating unit represented by the following formula (a).

[0019] [Chemistry 1]

[0020]

[0021] In the formula, p is an integer of 0 to 10, and q is an integer of 1 to 5.

[0022] R A A hydrogen atom or a methyl group.

[0023] R B is a hydrogen atom, or may be 1 bond and form a ring.

[0024] X 1 It is a single bond, an ester bond, a phenylene group or a naphthylene group.

[0025] X 2It is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and the hydrocarbylene group may have at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom.

[0026] X 3 It is a single bond, an ether bond, an ester bond, a sulfonate bond, a sulfonyl group or a carbonyl group.

[0027] R 1 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 1A )-C(=O)-R 1B 、-N(R 1A )-C(=O)-OR 1B or -N(R 1A )-S(=O)2-R 1B , and the hydrocarbon group, hydrocarbon oxy group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyloxy group and hydrocarbon sulfonyloxy group may contain at least one selected from fluorine atom, chlorine atom, bromine atom, iodine atom, hydroxyl group, amino group, ester bond, ether bond, carbamate bond, urea bond, carbonate bond, amide bond, sulfonate bond, carbonyl group, thioether group and sulfonyl group. 1A 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. 1B 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.

[0028] Ar is a (p+q+1)-valent aromatic hydrocarbon group having 6 to 16 carbon atoms.

[0029] M + It is a sulfonium cation or an iodonium cation.

[0030] 3. The resist material according to 2., wherein q is 2, 3 or 4.

[0031] 4. The resist material according to any one of 1. to 3., wherein the base polymer further contains a repeating unit represented by the following formula (b1) or (b2).

[0032] [Chemistry 2]

[0033]

[0034] In the formula, R Aare each independently a hydrogen atom or a methyl group.

[0035] Y 1 It 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.

[0036] Y 2 It is a single bond or an ester bond.

[0037] Y 3 It is a single bond, an ether bond or an ester bond.

[0038] R 11 and R 12 are each independently an acid-labile group.

[0039] 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.

[0040] R 14 It is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the alkanediyl group may contain at least one selected from the group consisting of a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms, a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms, an ether bond, and an ester bond.

[0041] a is an integer from 0 to 4.

[0042] 5. The resist material as described in 4., which is a chemically amplified positive resist material.

[0043] 6. The resist material according to 1., wherein the base polymer does not contain an acid-labile group.

[0044] 7. The resist material as described in 6., which is a chemically amplified negative resist material.

[0045] 8. The resist material according to any one of 1. to 7., further comprising an organic solvent.

[0046] 9. The resist material according to any one of 1. to 8., further comprising a quencher.

[0047] 10. The resist material according to any one of 1. to 9., further comprising a surfactant.

[0048] 11. A pattern forming method comprising the following steps:

[0049] Using the resist material as described in any one of 1. to 10., forming a resist film on a substrate,

[0050] exposing the resist film to high energy radiation, and

[0051] The exposed resist film is developed using a developer.

[0052] 12. The pattern forming method according to 11., 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.

[0053] [Effects of the Invention]

[0054] The polymer-bonded acid generator having a sulfonium salt or iodonium salt structure of an aryl sulfonic acid substituted with an iodine atom has a greater absorption of EUV and a higher acid strength than unsubstituted aryl sulfonic acid and aryl sulfonic acid substituted with a fluorine atom, and the salt structure is bonded to the polymer main chain, so it is more likely to inhibit acid diffusion. Due to the resonance effect of the aromatic group, it becomes a stronger acid when substituted with an iodine atom than when substituted with a fluorine atom. This prevents the reduction in resolution caused by blurring of acid diffusion, and suppresses the diffusion of secondary electrons by increasing the proportion of direct excitation reactions due to high absorption, and becomes a low diffusion characteristic, thereby improving LWR and CDU. This can construct a highly sensitive resist material with improved LWR and CDU. DETAILED DESCRIPTION

[0055] [Resist material]

[0056] The resist material of the present invention contains a base polymer having a sulfonium salt or iodonium salt structure in which an arylsulfonic acid anion substituted with an iodine atom is bonded to the main chain. The salt structure has a high contrast due to the high absorption of the iodine atom, the high effect of improving the acid strength of the sulfonic acid, and the interaction of the bulky arylsulfonic acid, and has a small acid diffusion due to the bond to the polymer main chain. This can improve LWR and CDU.

[0057] The effect of improving LWR and CDU by the acid generator used in the present invention is effective regardless of whether it is positive pattern formation or negative pattern formation by alkaline aqueous solution development or negative pattern formation by organic solvent development.

[0058] [Base polymer]

[0059] The base polymer preferably includes a repeating unit represented by the following formula (a) (hereinafter also referred to as repeating unit a).

[0060] [Chemistry 3]

[0061]

[0062] In formula (a), p is an integer of 0 to 10. q is an integer of 1 to 5, preferably 2, 3 or 4.

[0063] In formula (a), R A is a hydrogen atom or a methyl group. B A hydrogen atom or X 1 bond and form a ring.

[0064] In formula (a), X 1 It is a single bond, an ester bond, a phenylene group or a naphthylene group.

[0065] In formula (a), X 2 It is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and the hydrocarbylene group may have at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom.

[0066] X 2The alkylene group represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Examples of the alkylene group include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane -1,13-diyl, tetradecan-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 and other alkanediyl groups; cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, methylcyclopentanediyl, dimethylcyclopentanediyl, trimethylcyclopentanediyl , tetramethylcyclopentanediyl, cyclohexanediyl, methylcyclohexanediyl, dimethylcyclohexanediyl, trimethylcyclohexanediyl, tetramethylcyclohexanediyl, norbornanediyl, adamantanediyl and other cyclic saturated alkylene groups; ethylenediyl, propylenediyl, butenediyl and other alkenediyl groups having 2 to 20 carbon atoms; ethynediyl, propynediyl, butynediyl and other alkynediyl groups having 2 to 20 carbon atoms; phenylene, methylphenylene, ethylphenylene, n-phenylene 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 these groups, 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 part of -CH2- of the aforementioned alkylene group may be substituted by a group containing at least one selected from oxygen atoms, nitrogen atoms and sulfur atoms, and as a result, a hydroxyl group, an ester bond, an ether bond, an amide bond, a urethane bond, a urea bond and the like may be contained.

[0067] In formula (a), X 3 It is a single bond, an ether bond, an ester bond, a sulfonate bond, a sulfonyl group or a carbonyl group.

[0068] In formula (a), R 1 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 1A )-C(=O)-R 1B 、-N(R 1A)-C(=O)-OR 1B or -N(R 1A )-S(=O)2-R 1B , and the hydrocarbon group, hydrocarbon oxy group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyloxy group and hydrocarbon sulfonyloxy group may contain at least one selected from fluorine atom, chlorine atom, bromine atom, iodine atom, hydroxyl group, amino group, ester bond, ether bond, carbamate bond, urea bond, carbonate bond, amide bond, sulfonate bond, carbonyl group, thioether group and sulfonyl group. 1A 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. 1B 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.

[0069] R 1 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.

[0070] In formula (a), 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.

[0071] Specific examples of the anion of the monomer providing the repeating unit a include those shown below, but are not limited thereto.A Same as above.

[0072] [Chemistry 4]

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[0124] [Chemistry 30]

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[0126] [Chemistry 31]

[0127]

[0128] In formula (a), M + It is a sulfonium cation or an iodonium cation. The sulfonium cation is preferably represented by the following formula (a1), and the iodonium cation is preferably represented by the following formula (a2).

[0129] [Chemistry 32]

[0130]

[0131] In formula (a1) and (a2), R 2 ~R 6 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

[0132] R 2 ~R 6 Specific examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

[0133] R 2 ~R 6 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.

[0134] 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, and as a result, it 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 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.

[0135] Again, R 2 and R 3 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.

[0136] [Chemistry 33]

[0137]

[0138] In the formula, the dotted lines represent atomic bonds.

[0139] M + Specific examples of the sulfonium cation represented by include the following, but are not limited to these.

[0140] [Chemistry 34]

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[0210] [Chemistry 69]

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[0212] M + Specific examples of the iodonium cation represented by include the following, but are not limited thereto.

[0213] [Chemistry 70]

[0214]

[0215] [Chemistry 71]

[0216]

[0217] The synthesis method of the monomer providing the repeating unit a can be exemplified by: using an iodinated aromatic compound and

[0218] A method of sulfonating an onium sulfonic acid by reacting fuming sulfuric acid with iodonium, and then exchanging the obtained ammonium salt or alkali metal salt of an aromatic sulfonic acid with a sulfonium salt or iodonium salt containing a halide anion.

[0219] The repeating unit a may be used alone or in combination of two or more.

[0220] 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 (b1) (hereinafter also referred to as repeating unit b1) or a repeating unit represented by the following formula (b2) (hereinafter also referred to as repeating unit b2).

[0221] [Chemistry 72]

[0222]

[0223] In formula (b1) and (b2), R A are 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 independently acid-labile groups. 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 at least one selected from the group consisting of a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms, a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms, an ether bond, and an ester bond. a is an integer of 0 to 4.

[0224] Specific examples of the monomer providing the repeating unit b1 include the following, but are not limited thereto. A and R 11 Same as above.

[0225] [Chemistry 73]

[0226]

[0227] [Chemistry 74]

[0228]

[0229] Specific examples of monomers providing repeating unit b2 include those shown below, but are not limited thereto. A and R 12 Same as above.

[0230] [Chemistry 75]

[0231]

[0232] R 11 or R 12 There are various options for the acid-labile group represented by , and examples thereof include those represented by the following formulae (AL-1) to (AL-3).

[0233] [Chemistry 76]

[0234]

[0235] In the formula, the dotted lines are atomic bonds.

[0236] In the formula (AL-1), b is an integer of 0 to 6. L1 A tertiary hydrocarbon group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, a trihydrocarbylsilyl group in which each hydrocarbon group is a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon group having 4 to 20 carbon atoms containing a carbonyl group, an ether bond or an ester bond, or a group represented by the formula (AL-3). In addition, the tertiary hydrocarbon group means a group obtained by removing a hydrogen atom from a tertiary carbon atom of a hydrocarbon.

[0237] R L1 The tertiary hydrocarbon group represented by may be saturated or unsaturated, branched or cyclic. Specific examples thereof include tert-butyl, tert-amyl, 1,1-diethylpropyl, 1-ethylcyclopentyl, 1-butylcyclopentyl, 1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl, 2-methyl-2-adamantyl, etc. The aforementioned trihydrocarbylsilyl group includes trimethylsilyl, triethylsilyl, dimethyl-tert-butylsilyl, etc. The aforementioned saturated hydrocarbon group containing a carbonyl group, an ether bond or an ester bond may be any of a straight chain, a branched or a cyclic one, and is preferably a cyclic one. Specific examples thereof include: 3-oxocyclohexyl, 4-methyl-2-oxooxan-4-yl, 5-methyl-2-oxooxan-5-yl, 2-tetrahydropyranyl, 2-tetrahydrofuranyl, etc.

[0238] Examples of the acid-labile group represented by formula (AL-1) include tert-butoxycarbonyl, tert-butoxycarbonylmethyl, tert-amyloxycarbonyl, tert-amyloxycarbonylmethyl, 1,1-diethylpropyloxycarbonyl, 1,1-diethylpropyloxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyloxycarbonylmethyl, 1-ethyl-2-cyclopentenyloxycarbonyl, 1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl, 2-tetrahydropyranyloxycarbonylmethyl, and 2-tetrahydrofuranyloxycarbonylmethyl.

[0239] Examples of the acid-labile group represented by the formula (AL-1) include groups represented by the following formulae (AL-1)-1 to (AL-1)-10.

[0240] [Chemistry 77]

[0241]

[0242] In the formula, the dotted lines are atomic bonds.

[0243] In the formulas (AL-1)-1 to (AL-1)-10, b is the same as described above. L8 R is independently a saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. L9 R is a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. L10 It is a saturated hydrocarbon group having 2 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbon group may be linear, branched or cyclic.

[0244] In formula (AL-2), R L2 and R L3 Each of them is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The saturated hydrocarbon group may be linear, branched or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl and n-octyl.

[0245] In formula (AL-2), R L4 It is a hydrocarbon group having 1 to 18 carbon atoms and preferably 1 to 10 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. The aforementioned hydrocarbon group may include saturated hydrocarbon groups having 1 to 18 carbon atoms, and some of their hydrogen atoms may be substituted by hydroxyl, alkoxy, oxo, amino, alkylamino, etc. Such substituted saturated hydrocarbon groups may include those shown below.

[0246] [Chemistry 78]

[0247]

[0248] In the formula, the dotted lines are atomic bonds.

[0249] R L2 With R L3 , R L2 With R L4 , or R L3 With R L4 They can also form a ring with each other and with the carbon atoms to which they are bonded or with the carbon atoms and oxygen atoms. In this case, R L2 and R L3 , R L2 and R L4 , or R L3 and R L4 Each independently represents an alkanediyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The carbon number of the ring formed by these groups is preferably 3 to 10, more preferably 4 to 10 carbon atoms.

[0250] Among the acid-labile groups represented by formula (AL-2), linear or branched ones include those represented by the following formulae (AL-2)-1 to (AL-2)-69, but are not limited thereto. In the following formulae, the dotted lines represent atomic bonds.

[0251] [Chemistry 79]

[0252]

[0253] [Chemistry 80]

[0254]

[0255] [Chemistry 81]

[0256]

[0257] [Chemistry 82]

[0258]

[0259] Among the acid-labile groups represented by the formula (AL-2), cyclic ones include tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl, and 2-methyltetrahydropyran-2-yl.

[0260] Examples of the acid-labile group include groups represented by the following formula (AL-2a) or (AL-2b): The base polymer can also be crosslinked between molecules or within molecules by the acid-labile group.

[0261] [Chemistry 83]

[0262]

[0263] In the formula, the dotted lines are atomic bonds.

[0264] In formula (AL-2a) or (AL-2b), R L11 and R L12 are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms. The saturated hydrocarbon group may be linear, branched or cyclic. L11 With R L12 They can also bond to each other and to the carbon atoms to which they are bonded to form a ring. In this case, R L11 and R L12 Each R is independently an alkanediyl group having 1 to 8 carbon atoms. L13 Each of them is independently a saturated alkylene group having 1 to 10 carbon atoms. The saturated alkylene group may be linear, branched or cyclic. c and d are independently an integer of 0 to 10, preferably an integer of 0 to 5, and e is an integer of 1 to 7, preferably an integer of 1 to 3.

[0265] In formula (AL-2a) or (AL-2b), L A It is an (e+1)-valent aliphatic saturated hydrocarbon group having 1 to 50 carbon atoms, a (e+1)-valent alicyclic saturated hydrocarbon group having 3 to 50 carbon atoms, an (e+1)-valent aromatic hydrocarbon group having 6 to 50 carbon atoms, or a (e+1)-valent heterocyclic group having 3 to 50 carbon atoms. In addition, part of the -CH2- in these groups may be substituted by a group containing a heteroatom, and part of the hydrogen atoms in these groups may be substituted by a hydroxyl group, a carboxyl group, an acyl group, or a fluorine atom. L A Preferred are saturated hydrocarbon groups such as saturated hydrocarbon groups having 1 to 20 carbon atoms, trivalent saturated hydrocarbon groups, tetravalent saturated hydrocarbon groups, and arylene groups having 6 to 30 carbon atoms. The saturated hydrocarbon groups may be linear, branched, or cyclic. B It is -C(=O)-O-, -NH-C(=O)-O- or -NH-C(=O)-NH-.

[0266] Examples of the cross-linked acetal group represented by the formula (AL-2a) or (AL-2b) include groups represented by the following formulae (AL-2)-70 to (AL-2)-77.

[0267] [Chemistry 84]

[0268]

[0269] In the formula, the dotted lines are atomic bonds.

[0270] In formula (AL-3), R L5 R is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. L6 and R L7Each 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 straight-chain, branched, or cyclic. Specific examples thereof include: alkyl groups having 1 to 20 carbon atoms, cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms, and aryl groups having 6 to 10 carbon atoms. In addition, R L5 With R L6 , R L5 With R L7 , or R L6 With R L7 They may also bond to each other and to form an alicyclic ring having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.

[0271] Examples of the group represented by formula (AL-3) include tert-butyl, 1,1-diethylpropyl, 1-ethylnorbornyl, 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-isopropylcyclopentyl, 1-methylcyclohexyl, 2-(2-methyl)adamantyl, 2-(2-ethyl)adamantyl, and tert-pentyl.

[0272] Furthermore, examples of the group represented by the formula (AL-3) include groups represented by the following formulae (AL-3)-1 to (AL-3)-22.

[0273] [Chemistry 85]

[0274]

[0275] In the formula, the dotted lines are atomic bonds.

[0276] In formula (AL-3)-1~(AL-3)-22, R L14 R is independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 8 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L15 and R L17 R is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 20 carbon atoms. L16 is an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbon group may be linear, branched or cyclic. The aryl group is preferably a phenyl group. L18 is a fluorine atom, an iodine atom, a nitro group, or a trifluoromethyl group. L19 Each independently represents a hydrogen atom, a fluorine atom, an iodine atom, a nitro group, a saturated hydrocarbon group having 1 to 8 carbon atoms, or a hydrocarbonoxy group having 1 to 8 carbon atoms. f represents an integer of 1-5.

[0277] In addition, examples of the acid-labile group include groups represented by the following formula (AL-3)-23 or (AL-3)-24. The acid-labile group can also crosslink the polymer intramolecularly or intermolecularly.

[0278] [Chemistry 86]

[0279]

[0280] In the formula, the dotted lines are atomic bonds.

[0281] In formula (AL-3)-23 and (AL-3)-24, R L14 Same as above. L20 It is a (g+1)-valent saturated or unsaturated alkylene group having 1 to 20 carbon atoms or a (g+1)-valent arylene group having 6 to 20 carbon atoms, and may contain heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. The saturated or unsaturated alkylene group may be straight-chain, branched, or cyclic. g is an integer of 1 to 3.

[0282] In addition to these acid-labile groups, aromatic group-containing acid-labile groups described in Japanese Patent Nos. 5565293, 5434983, 5407941, 5655756, and 5655755 may also be used.

[0283] The aforementioned base polymer may also contain a repeating unit c containing a phenolic hydroxyl group as an 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.

[0284] [Chemistry 87]

[0285]

[0286] The base polymer may also contain a repeating unit d 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 d include the following, but are not limited thereto. In the following formula, R A Same as above.

[0287] [Chemistry 88]

[0288]

[0289] [Chemistry 89]

[0290]

[0291] [Chemistry 90]

[0292]

[0293] [Chemistry 91]

[0294]

[0295] [Chemical formula 92]

[0296]

[0297] [Chemical formula 93]

[0298]

[0299] [Chemical formula 94]

[0300]

[0301] [Chemical formula 95]

[0302]

[0303] The foregoing base polymer may also contain repeating unit e derived from indene, benzofuran, benzothiophene, acenaphthene, chromone, coumarin, norbornadiene or their derivatives. Specific examples of the monomer providing repeating unit e may be those shown below, but are not limited thereto.

[0304] [Chemical formula 96]

[0305]

[0306] The foregoing base polymer may also contain repeating unit f derived from styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methyleneindane, vinylpyridine or vinylcarbazole.

[0307] The base polymer for a positive resist material needs to contain repeating unit b1 or b2 having an acid-labile group in addition to containing repeating unit a. At this time, the content ratios of repeating units a, b1, b2, c, d, e and f are preferably 0 < a ≤ 0.5, 0 ≤ b1 < 1.0, 0 ≤ b2 < 1.0, 0 < b1 + b2 < 1.0, 0 ≤ c ≤ 0.9, 0 ≤ d ≤ 0.9, 0 ≤ e ≤ 0.8 and 0 ≤ f ≤ 0.8, more preferably 0.02 ≤ a ≤ 0.4, 0 ≤ b1 ≤ 0.9, 0 ≤ b2 ≤ 0.9, 0.1 ≤ b1 + b2 ≤ 0.9, 0 ≤ c ≤ 0.8, 0 ≤ d ≤ 0.8, 0 ≤ e ≤ 0.7 and 0 ≤ f ≤ 0.7, and still more preferably 0.05 ≤ a ≤ 0.35, 0 ≤ b1 ≤ 0.8, 0 ≤ b2 ≤ 0.8, 0.1 ≤ b1 + b2 ≤ 0.8, 0 ≤ c ≤ 0.75, 0 ≤ d ≤ 0.75, 0 ≤ e ≤ 0.6 and 0 ≤ f ≤ 0.6. Also, a + b1 + b2 + c + d + e + f = 1.0.

[0308] On the other hand, for the base polymer for negative resist materials, acid-labile groups are not necessary. Such base polymers may include those containing repeating unit a and repeating unit c, and optionally further containing repeating units d, e, and / or f. The content ratios of these repeating units are preferably 0 < a ≤ 0.5, 0 < c ≤ 1.0, 0 ≤ d ≤ 0.9, 0 ≤ e ≤ 0.8, and 0 ≤ f ≤ 0.8, more preferably 0.02 ≤ a ≤ 0.4, 0.2 ≤ c ≤ 1.0, 0 ≤ d ≤ 0.8, 0 ≤ e ≤ 0.7, and 0 ≤ f ≤ 0.7, and even more preferably 0.05 ≤ a ≤ 0.35, 0.3 ≤ c ≤ 1.0, 0 ≤ d ≤ 0.75, 0 ≤ e ≤ 0.6, and 0 ≤ f ≤ 0.6. Also, a + c + d + e + f = 1.0.

[0309] When synthesizing the aforementioned base polymer, for example, monomers providing the aforementioned repeating units are added with a radical polymerization initiator and heated in an organic solvent to carry out polymerization.

[0310] Specific examples of the organic solvents used in the polymerization include: toluene, benzene, tetrahydrofuran (THF), diethyl ether, dioxane, etc. Specific examples of the polymerization initiators include: 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2-azobis(2-methylpropionate), 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.

[0311] When copolymerizing a hydroxyl group-containing monomer, the hydroxyl group can be replaced with an acetal group such as ethoxyethoxy that is easily deprotected by acid in advance during polymerization, and deprotection is carried out using a weak acid and water after polymerization. It is also possible to replace it with an acetyl group, a formyl group, a trimethylacetyl group, etc. in advance and carry out base hydrolysis after polymerization.

[0312] When copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, hydroxystyrene and hydroxyvinylnaphthalene can also be replaced with acetoxystyrene and acetoxyvinylnaphthalene, and after polymerization, the acetoxy group is deprotected by the aforementioned base hydrolysis to become hydroxystyrene and hydroxyvinylnaphthalene.

[0313] The base used in the base hydrolysis can be ammonia water, triethylamine, etc. Also, 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.

[0314] The polystyrene-equivalent weight-average molecular weight (Mw) of the aforementioned base polymer determined by gel permeation chromatography (GPC) using THF as a solvent is preferably 1000 to 500000, more preferably 2000 to 30000. If Mw is within the aforementioned range, the heat resistance of the resist film and its solubility in an alkaline developer are good.

[0315] 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.

[0316] The base polymer may contain two or more polymers having different composition ratios, Mw, and Mw / Mn.

[0317] [Organic solvents]

[0318] 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.

[0319] 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.

[0320] [Quencher]

[0321] 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.

[0322] 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.

[0323] 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.

[0324] Specific examples of such quenchers include compounds represented by the following formula (1) (onium salt of sulfonic acid whose α-position is not fluorinated), compounds represented by the following formula (2) (onium salt of carboxylic acid), and compounds represented by the following formula (3) (onium salt of alkoxide).

[0325] [Chemistry 97]

[0326]

[0327] In formula (1), 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.

[0328] 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[5.2.1.02,6 ] 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.

[0329] Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and part of the -CH2- of the aforementioned hydrocarbon group may be substituted by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, it may contain hydroxyl groups, cyano 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. 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.

[0330] In formula (2), 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.

[0331] In formula (3), 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.

[0332] In formulas (1), (2) and (3), 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.

[0333] As the quencher, a sulfonium salt of a carboxylic acid containing an iodinated benzene ring represented by the following formula (4) can also be preferably used.

[0334] [Chemistry 98]

[0335]

[0336] In formula (4), 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.

[0337] In formula (4), 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.

[0338] In formula (4), 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.

[0339] In formula (4), 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 (a1) and (a2): 2 ~R 6The same examples are given for the hydrocarbon groups represented.

[0340] Specific examples of the compound represented by formula (4) include those described in JP-A-2017-219836 and JP-A-2021-91666.

[0341] 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.

[0342] 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.

[0343] 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.

[0344] [Other ingredients]

[0345] In addition to the above-mentioned components, an acid generator, a surfactant, a dissolution inhibitor, a crosslinking agent, a water repellency improving agent, acetylene alcohols, etc. may be contained.

[0346] The aforementioned acid generator can be exemplified by 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 generator can be listed: 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 an acid generator, 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.

[0347] 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.

[0348] 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.

[0349] 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.

[0350] 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.

[0351] Specific examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0352] 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.

[0353] 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.

[0354] 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.

[0355] Specific examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0356] Specific examples of the azide compound include 1,1′-biphenyl-4,4′-bisazide, 4,4′-methylenebisazide, and 4,4′-oxybisazide.

[0357] 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.

[0358] 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.

[0359] 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.

[0360] 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.

[0361] [Pattern Formation Method]

[0362] 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.

[0363] First, the resist material of the present invention is applied to 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 coating film thickness of 0.01 to 2 μm. The resist material is then pre-baked at 60 to 150° C., 10 seconds to 30 minutes, and preferably at 80 to 120° C., 30 seconds to 20 minutes on a hot plate to form a resist film.

[0364] 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.

[0365] 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.

[0366] 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.

[0367] 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.

[0368] 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.

[0369] 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.

[0370] 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.

[0371] 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.

[0372] Specific examples of the aromatic solvent include toluene, xylene, ethylbenzene, cumene, tert-butylbenzene, mesitylene, and the like.

[0373] 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.

[0374] 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.

[0375] Example

[0376] 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.

[0377] The monomers PM-1 to PM-16, cPM-1, cPM-2, AM-1 to AM-5 and FM-1 used in the synthesis of the base polymer are as follows. PM-1 to PM-16 were synthesized by ion exchange of ammonium salt of iodinated benzenesulfonic acid providing the following anions and sulfonium chloride providing the following cations. The Mw of the polymer is a polystyrene-converted measurement value obtained by GPC using THF as a solvent.

[0378] [Chemistry 99]

[0379]

[0380] [Chemical 100]

[0381]

[0382] [Chemistry 101]

[0383]

[0384] [Chemistry 102]

[0385]

[0386] [Chemistry 103]

[0387]

[0388] [Synthesis Example 1] Synthesis of Polymer P-1

[0389] In a 2L flask, add 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.8g of 4-hydroxystyrene, 8.1g of PM-1, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After warming to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-1. The composition of polymer P-1 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0390] [Chemistry 104]

[0391]

[0392] [Synthesis Example 2] Synthesis of Polymer P-2

[0393] In a 2L flask, add 9.0g of 1-vinyl-1-cyclopentyl methacrylate, 4.8g of 3-hydroxystyrene, 9.8g of PM-2, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After warming to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-2. The composition of polymer P-2 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0394] [Chemistry 105]

[0395]

[0396] [Synthesis Example 3] Synthesis of Polymer P-3

[0397] Add 11.1 g of AM-1, 4.8 g of 3-hydroxystyrene, 11.3 g of PM-3, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 ° C in a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After warming to room temperature, add 1.2 g of AIBN as a polymerization initiator, raise the temperature to 60 ° C and react for 15 hours. Add the reaction solution to 1 L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60 ° C to obtain polymer P-3. The composition of polymer P-3 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0398] [Chemistry 106]

[0399]

[0400] [Synthesis Example 4] Synthesis of Polymer P-4

[0401] In a 2L flask, add 8.1g of AM-2, 2.7g of AM-4, 4.8g of 3-hydroxystyrene, 10.4g of PM-4, and 40g of THF as a solvent. Cool the reaction vessel to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing three times. After warming to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-4. The composition of polymer P-4 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0402] [Chemistry 107]

[0403]

[0404] [Synthesis Example 5] Synthesis of Polymer P-5

[0405] Add 11.6 g of AM-3, 5.2 g of 3-hydroxystyrene, 8.7 g of PM-5, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 ° C in a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After warming to room temperature, add 1.2 g of AIBN as a polymerization initiator, raise the temperature to 60 ° C and react for 15 hours. The reaction solution is added to 1 L of isopropanol, and the precipitated white solid is filtered. The obtained white solid is dried under reduced pressure at 60 ° C to obtain polymer P-5. The composition of polymer P-5 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0406] [Chemistry 108]

[0407]

[0408] [Synthesis Example 6] Synthesis of Polymer P-6

[0409] Add 8.3 g of AM-5, 4.8 g of 3-hydroxystyrene, 10.2 g of PM-6, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 ° C in a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After warming to room temperature, add 1.2 g of AIBN as a polymerization initiator, raise the temperature to 60 ° C and react for 15 hours. Add the reaction solution to 1 L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60 ° C to obtain polymer P-6. The composition of polymer P-6 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0410] [Chemistry 109]

[0411]

[0412] [Synthesis Example 7] Synthesis of Polymer P-7

[0413] In a 2L flask, add 11.1g of AM-1, 3.4g of 3-hydroxystyrene, 3.2g of monomer FM-1, 10.1g of PM-7, and 40g of THF as a solvent. Cool the reaction vessel to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing three times. After warming to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-7. The composition of polymer P-7 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0414] [Chemistry 110]

[0415]

[0416] [Synthesis Example 8] Synthesis of Polymer P-8

[0417] Add 11.1 g of AM-1, 4.8 g of 3-hydroxystyrene, 9.9 g of PM-8, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 ° C in a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After heating to room temperature, add 1.2 g of AIBN as a polymerization initiator, heat to 60 ° C and react for 15 hours. Add the reaction solution to 1 L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60 ° C to obtain polymer P-8. The composition of polymer P-8 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0418] [Chemistry 111]

[0419]

[0420] [Synthesis Example 9] Synthesis of Polymer P-9

[0421] Add 12.1 g of AM-1, 4.8 g of 4-hydroxystyrene, 10.5 g of PM-9, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 ° C in a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After warming to room temperature, add 1.2 g of AIBN as a polymerization initiator, raise the temperature to 60 ° C and react for 15 hours. The reaction solution is added to 1 L of isopropanol, and the precipitated white solid is filtered. The obtained white solid is dried under reduced pressure at 60 ° C to obtain polymer P-9. The composition of polymer P-9 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0422] [Chemistry 112]

[0423]

[0424] [Synthesis Example 10] Synthesis of Polymer P-10

[0425] Add 12.0 g of AM-1, 4.8 g of 4-hydroxystyrene, 10.4 g of PM-10, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 ° C in a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After warming to room temperature, add 1.2 g of AIBN as a polymerization initiator, raise the temperature to 60 ° C and react for 15 hours. The reaction solution is added to 1 L of isopropanol, and the precipitated white solid is filtered. The obtained white solid is dried under reduced pressure at 60 ° C to obtain polymer P-10. The composition of polymer P-10 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0426] [Chemistry 113]

[0427]

[0428] [Synthesis Example 11] Synthesis of Polymer P-11

[0429] Add 12.0 g of AM-1, 4.8 g of 4-hydroxystyrene, 11.0 g of PM-11, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 ° C in a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After warming to room temperature, add 1.2 g of AIBN as a polymerization initiator, raise the temperature to 60 ° C and react for 15 hours. Add the reaction solution to 1 L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60 ° C to obtain polymer P-11. The composition of polymer P-11 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0430] [Chemistry 114]

[0431]

[0432] [Synthesis Example 12] Synthesis of Polymer P-12

[0433] Add 12.0 g of AM-1, 4.8 g of 4-hydroxystyrene, 10.2 g of PM-12, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 ° C in a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After warming to room temperature, add 1.2 g of AIBN as a polymerization initiator, raise the temperature to 60 ° C and react for 15 hours. The reaction solution is added to 1 L of isopropanol, and the precipitated white solid is filtered. The obtained white solid is dried under reduced pressure at 60 ° C to obtain polymer P-12. The composition of polymer P-12 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0434] [Chemistry 115]

[0435]

[0436] [Synthesis Example 13] Synthesis of Polymer P-13

[0437] Add 12.0 g of AM-1, 4.8 g of 4-hydroxystyrene, 10.5 g of PM-13, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 ° C in a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After heating to room temperature, add 1.2 g of AIBN as a polymerization initiator, heat to 60 ° C and react for 15 hours. Add the reaction solution to 1 L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60 ° C to obtain polymer P-13. The composition of polymer P-13 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0438] [Chemistry 116]

[0439]

[0440] [Synthesis Example 14] Synthesis of Polymer P-14

[0441] Add 12.0 g of AM-1, 4.8 g of 4-hydroxystyrene, 10.7 g of PM-14, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 ° C in a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After warming to room temperature, add 1.2 g of AIBN as a polymerization initiator, raise the temperature to 60 ° C and react for 15 hours. The reaction solution is added to 1 L of isopropanol, and the precipitated white solid is filtered. The obtained white solid is dried under reduced pressure at 60 ° C to obtain polymer P-14. The composition of polymer P-14 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0442] [Chemistry 117]

[0443]

[0444] [Synthesis Example 15] Synthesis of Polymer P-15

[0445] Add 12.0 g of AM-1, 4.8 g of 3-hydroxystyrene, 7.2 g of PM-15, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 ° C in a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After heating to room temperature, add 1.2 g of AIBN as a polymerization initiator, heat to 60 ° C and react for 15 hours. Add the reaction solution to 1 L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60 ° C to obtain polymer P-15. The composition of polymer P-15 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0446] [Chemistry 118]

[0447]

[0448] [Synthesis Example 16] Synthesis of Polymer P-16

[0449] Add 12.0 g of AM-1, 4.8 g of 3-hydroxystyrene, 6.8 g of PM-16, and 40 g of THF as a solvent to a 2 L flask. Cool the reaction vessel to -70 ° C in a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After heating to room temperature, add 1.2 g of AIBN as a polymerization initiator, raise the temperature to 60 ° C and react for 15 hours. The reaction solution is added to 1 L of isopropanol, and the precipitated white solid is filtered. The obtained white solid is dried under reduced pressure at 60 ° C to obtain polymer P-16. The composition of polymer P-16 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0450] [Chemistry 119]

[0451]

[0452] [Comparative Synthesis Example 1] Synthesis of Comparative Polymer cP-1

[0453] A comparative polymer cP-1 was synthesized in the same manner as in Synthesis Example 1 except that PM-1 was changed to cPM-1.

[0454] [Chemistry 120]

[0455]

[0456] [Comparative Synthesis Example 2] Synthesis of Comparative Polymer cP-2

[0457] A comparative polymer cP-2 was synthesized in the same manner as in Synthesis Example 1 except that PM-1 was changed to cPM-2.

[0458] [Chemistry 121]

[0459]

[0460] [Examples 1 to 18, Comparative Examples 1 and 2] Preparation and Evaluation of Resist Materials

[0461] (1) Preparation of resist materials

[0462] The solution in which each component was dissolved in the composition shown in Table 1 was filtered through a filter with a size of 0.2 μm to obtain a resist material.

[0463] In Table 1, the components are as follows.

[0464] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0465] EL(ethyl lactate)

[0466] DAA (Diacetone Alcohol)

[0467] Acid generator: PAG-1, PAG-2

[0468] [Chemistry 122]

[0469]

[0470] Quencher: Q-1~Q-5

[0471] [Chemistry 123]

[0472]

[0473] (2) EUV lithography evaluation

[0474] 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) 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 60 nm. The resist film was exposed using an EUV scanning exposure machine NXE3400 manufactured by ASML (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, a mask with a hole pattern having a size of 40 nm pitch on the wafer and a bias voltage of +20%), 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 a hole pattern having a size of 20 nm.

[0475] The exposure amount when the hole size was 20 nm was measured using a Hitachi High-Tech (co., Ltd.) length measurement SEM (CG6300), and this was taken as sensitivity. The size of 50 holes at this time was measured, and the value (3σ) three times the standard deviation (σ) obtained from the results was taken as CDU. The results are shown in Table 1.

[0476] [Table 1]

[0477]

[0478] From the results shown in Table 1, it is understood that the resist material of the present invention containing a base polymer having a sulfonium salt or iodonium salt structure in which an arylsulfonic acid anion substituted with an iodine atom is bonded to the main chain has high sensitivity and good CDU.

Claims

1. A resist material comprising: The base polymer has a sulfonium salt or iodonium salt structure in which an arylsulfonic acid anion substituted with an iodine atom is bonded to the main chain.

2. The resist material according to claim 1, wherein The base polymer contains a repeating unit represented by the following formula (a); In the formula, p is an integer from 0 to 10; q is an integer from 1 to 5; R A is a hydrogen atom or a methyl group; R B is a hydrogen atom, or may be 1 Bond and form rings; X 1 is a single bond, an ester bond, a phenylene group or a naphthylene group; X 2 is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and the hydrocarbylene group may also have at least one selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom; X 3 is a single bond, an ether bond, an ester bond, a sulfonate bond, a sulfonyl group or a carbonyl group; R 1 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 1A )-C(=O)-R 1B 、-N(R 1A )-C(=O)-OR 1B or -N(R 1A )-S(=O)2-R 1B , and the hydrocarbon group, hydrocarbon oxy group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyloxy group and hydrocarbon sulfonyloxy group may 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, 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 1A 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 1B 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.

3. The resist material according to claim 2, wherein q is 2, 3 or 4.

4. The resist material according to claim 1, wherein The base polymer further contains a repeating unit represented by the following formula (b1) or (b2); 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 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the alkanediyl group may contain at least one selected from the group consisting of a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms, a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms, an ether bond, and 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 1, 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 a surfactant.

11. 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 10, exposing the resist film to high energy radiation, and The exposed resist film is developed using a developing solution.

12. The pattern forming method according to claim 11, 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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