Resist composition

Abstract

To provide a resist composition having high absorption sensitivity, which has not found in the conventional photoresist compositions for radiation such as EB, EUV.SOLUTION: A resist composition comprises the following components (A)-(E): (A) a phenol trinuclear monomer represented by the formula (1), (B) a metalalkoxide, (C) a photoacid generator, (D) a polyfunctional methylol crosslinker and (E) a solvent.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resist composition, and more specifically to a resist composition, a resist film, a pattern forming method, and a method for manufacturing an electronic device that are suitable for lithography using radiation such as an electron beam or extreme ultraviolet light. [Background technology]

[0002] In recent years, in the field of microfabrication of semiconductor devices such as ICs and LSIs, the high integration of integrated circuits has led to a demand for the formation of fine patterns in the submicron and quarter-micron regions. Accordingly, the exposure wavelength has been shortened from g-line to i-line, KrF excimer laser light, and ArF excimer laser light. Recently, development of lithography techniques using radiation such as electron beams (EB) and extreme ultraviolet rays (EUV) other than excimer laser light has also been progressing (Patent Document 1).

[0003] The lithography technique using the above-mentioned radiation is expected to be a next-generation pattern technique capable of forming ultrafine patterns with a width of several nm. However, the exposure using the radiation has a drawback that the power of the exposure light source is low, resulting in low throughput, which is an important issue. To solve this issue, improvements in the equipment, such as increasing the light source output, are being considered, while there is a demand for high sensitivity resist resins for lithography.

[0004] The use of metal oxide particles has been considered as a method for increasing sensitivity (Patent Document 2). In this method, metal oxide nanoparticles with a particle diameter of 20 nm or less absorb radiation, generating secondary electrons from polymers and the like in the resist composition. The secondary electrons are absorbed by a photoacid generator, which further promotes the decomposition of the photoacid generator, thereby functioning as an excellent positive photoresist. However, the photoresist composition of Patent Document 2 has a problem in that the efficiency of absorbing radiation gradually decreases due to aggregation of metal oxide nanoparticles.

[0005] In order to solve the above problems, the addition of an aggregation inhibitor has been considered, but the reality is that sufficient dispersion stability and sensitivity are not obtained (Patent Document 3). Furthermore, the development of a radiation photoresist using a metal complex instead of metal oxide nanoparticles that cause particle aggregation is also being considered (Patent Document 4). The negative photoresist composition of Patent Document 4 is a mixture of a metal complex compound consisting of zirconium or hafnium alkoxide and a methacrylic acid compound, and a photopolymerization initiator, and the metal complex absorbs EUV, making the exposed areas insoluble in an organic developer, thereby obtaining a resist pattern in which the unexposed areas have been removed. However, the composition of Patent Document 4 does not provide sufficient radiation absorption efficiency, and the secondary electrons generated from the metal part do not transfer efficiently to the photopolymerization initiator, so that satisfactory sensitivity cannot be obtained. As described above, for photoresist compositions for EB or EUV, there is a demand for the development of compositions that have even higher sensitivity and are suitable for producing ultrafine patterns in order to improve throughput. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2006-171440 A [Patent Document 2] WO2016 / 088655 [Patent Document 3] WO2017 / 204090 issue [Patent Document 4] JP 2015-108781 A Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a resist composition having high absorption sensitivity that is not available in conventional photoresist compositions for use with radiation such as EB and EUV. [Means for solving the problem]

[0008] As a result of intensive research aimed at solving the above-mentioned problems, the present inventors have found that a metal complex obtained from a carboxylic acid-containing trinuclear monomer and a metal alkoxide has high EB and EUV absorption properties, and also efficiently transfers electrons to a photoacid generator, and the generated acid forms a crosslinked structure between a polyfunctional methylol crosslinker and the trinuclear monomer, thereby forming a resist film with high radiation absorption sensitivity, and have completed the present invention.

[0009] That is, the present invention relates to a resist composition containing the following components (A) to (E): (A) a phenol trinuclear monomer represented by the following formula (1): (B) Metal alkoxide (C) Photoacid generator (D) Multifunctional methylol crosslinker (E) Solvent [ka] [In formula (1), R 1 and R 2 each independently represents an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group, or a halogen atom. m, n, and p each independently represent an integer of 0 to 4. R 1 If there are multiple R 1 may be the same or different. 2 If there are multiple R 2 may be the same or different. 3 R represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a structural portion having one or more substituents selected from an alkoxy group, a halogen group, and a hydroxyl group on the hydrocarbon group. 4 R represents a hydroxyl group, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, or a halogen atom. 4 If there are multiple R 4 may be the same or different.]

[0010] The present invention also relates to a resist film obtained from the above resist composition. The present invention also relates to a pattern forming method, comprising the steps of forming a resist film using the above resist composition, exposing the resist film to light, and developing the exposed resist film with a developer to form a pattern. The present invention also relates to a method for producing an electronic device, which includes the above-mentioned pattern forming method. Effect of the Invention

[0011] According to the present invention, it is possible to provide a resist composition that has high absorption sensitivity to radiation such as EB and EUV. [Brief description of the drawings]

[0012] [Figure 1] 1 is a GPC chart of the phenol trinuclear monomer (A) synthesized in Example 1. [Diagram 2] 1 is a 13C-NMR chart of the phenol trinuclear monomer (A) synthesized in Example 1. [Diagram 3] 1 is an FT-IR spectrum of the metal complex solution prepared in Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes an embodiment of the invention. In this specification, "x to y" represents a numerical range of "not less than x and not more than y." The upper and lower limit values ​​described in relation to the numerical ranges can be combined in any combination. In addition, any combination of two or more of the individual aspects of the present invention described below is also an aspect of the present invention.

[0014] A resist composition according to one embodiment of the present invention contains the following components (A) to (E). (A) a phenol trinuclear monomer represented by the following formula (1): (B) Metal alkoxide (C) Photoacid generator (D) Multifunctional methylol crosslinker (E) Solvent [ka] [In formula (1), R 1 and R 2 each independently represents an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group, or a halogen atom. m, n, and p each independently represent an integer of 0 to 4. R 1 If there are multiple R 1 may be the same or different. 2 If there are multiple R 2 may be the same or different. 3 R represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a structural portion having one or more substituents selected from an alkoxy group, a halogen group, and a hydroxyl group on the hydrocarbon group. 4 R represents a hydroxyl group, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, or a halogen atom. 4 If there are multiple R 4 may be the same or different.]

[0015] In this embodiment, the metal complex obtained from the above components (A) and (B) has high radiation absorption properties and efficiently transfers electrons to the photoacid generator (component (C)). The acid thus generated forms a crosslinked structure between the polyfunctional methylol crosslinker (component (D)) and component (A), thereby obtaining a resist composition (resist film) with high radiation sensitivity. Components (A) to (E) will be described below.

[0016] Component (A): A phenol trinuclear monomer represented by formula (1) Regarding the phenol trinuclear monomer represented by the above formula (1), in formula (1), R 1 and R 2 each independently represents an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group, or a halogen atom. The aliphatic hydrocarbon group may be linear or have a branched structure. In addition, it may have a cyclo ring structure. More specifically, examples of the alkoxy group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, a hexyl group, a cyclohexyl group, a heptyl group, an octyl group, and a nonyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propyloxy group, a butoxy group, a pentyloxy group, a hexyloxy group, and a cyclohexyloxy group.

[0017] Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and an anthryl group. Examples of the aralkyl group include a benzyl group, a phenylethyl group, a phenylpropyl group, and a naphthylmethyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0018] Among these, R 1 and R 2 is preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group. In addition, m and n in the formula (1) are integers of 0 to 4, but are more preferably integers of 1 to 3, and particularly preferably 2. In this case, two R 1 and two R 2 are preferably bonded to the 2- and 5-positions of the phenolic hydroxyl group.

[0019] In formula (1), R 3 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a structural portion having, on a hydrocarbon group, one or more substituents selected from an alkoxy group, a halogen group, and a hydroxyl group. The aliphatic hydrocarbon group having 1 to 9 carbon atoms is R 1 and R 2Examples of the "structural portion having one or more substituents selected from an alkoxy group, a halogen group, and a hydroxyl group on a hydrocarbon group" include halogenated alkyl groups, halogenated aryl groups, alkoxyalkoxy groups such as 2-methoxyethoxy groups and 2-ethoxyethoxy groups, and alkylalkoxy groups substituted with a hydroxy group. 3 is preferably a hydrogen atom.

[0020] In formula (1), R 4 represents a hydroxyl group, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, or a halogen atom. 1 and R 2 Examples of the above are given below. Furthermore, p represents an integer of 0 to 4. Among these, p is preferably 0.

[0021] In this embodiment, as the component (A), a compound having the same structure may be used alone, or a plurality of compounds having different molecular structures may be used.

[0022] Component (A) may be produced by any method, for example, it can be obtained by heating a phenol compound (a1) and a formylbenzoic acid (a2) in the presence of an acid catalyst, optionally using a solvent, at a temperature in the range of 60 to 140°C to polycondense.

[0023] The phenol compound (a1) may be a compound having, in addition to phenol, one or more substituents such as an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group, or a halogen atom on the aromatic ring of the phenol. Specific examples of these substituents include R 1 , R 2Among them, since the ability to form a fine pattern when used as a resist material is excellent, it is preferable that the compound has one to three alkyl groups having 1 to 4 carbon atoms, and it is particularly preferable that the compound has two alkyl groups. In this case, it is preferable that the two alkyl groups are bonded to the 2,5-positions of the phenolic hydroxyl group, respectively. Moreover, as the alkyl group, a methyl group is particularly preferable.

[0024] Examples of the formylbenzoic acids (a2) include formylbenzoic acid, compounds having one or more hydroxyl groups, aliphatic hydrocarbon groups having 1 to 9 carbon atoms, alkoxy groups, or halogen atoms on the aromatic ring thereof, aromatic ketones having a carboxy group such as acetylbenzoic acid, and compounds having one or more hydroxyl groups, aliphatic hydrocarbon groups having 1 to 9 carbon atoms, alkoxy groups, or halogen atoms on the aromatic ring thereof. Specific examples of the aliphatic hydrocarbon group having 1 to 9 carbon atoms, the alkoxy group, or the halogen atom include R 4 Among them, formylbenzoic acid is preferred because it has excellent reactivity with the phenol compound (a1), and 4-formylbenzoic acid is more preferred because it has a molecular structure that is easily coordinated to a metal atom.

[0025] Examples of the acid catalyst used in the production of component (A) include acetic acid, oxalic acid, sulfuric acid, hydrochloric acid, phenolsulfonic acid, paratoluenesulfonic acid, zinc acetate, and manganese acetate. These acid catalysts can be used alone or in combination of two or more. Among these acid catalysts, sulfuric acid and paratoluenesulfonic acid are preferred because of their excellent activity. The acid catalyst may be added before or during the reaction.

[0026] When a solvent is used in the production of component (A), specific examples thereof include carboxylic acid compounds such as formic acid, acetic acid, propionic acid, butyric acid, and valeric acid; glycol ether compounds such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, and ethylene glycol monophenyl ether; cyclic ether compounds such as 1,3-dioxane and 1,4-dioxane; glycol ester compounds such as ethylene glycol acetate; ketone compounds such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and aromatic hydrocarbons such as toluene and xylene. These solvents can be used alone or in combination of two or more. Among these solvents, acetic acid is preferred because of its excellent solubility in the resulting compound.

[0027] The charging ratio of the phenol compound (a1) to the formylbenzoic acids (a2) [(a1) / (a2)] is preferably in the range of 1 / 0.8 to 1 / 0.2, and more preferably in the range of 1 / 0.6 to 1 / 0.4, in terms of molar ratio, because this allows for excellent removal of the unreacted phenol compound (a1) and excellent yield and purity of the resulting compound (a).

[0028] After the reaction is completed, the component (A) can be purified and isolated by, for example, pouring the reaction solution into a poor solvent (S1) in which the reaction product is insoluble or poorly soluble, filtering off the resulting precipitate to obtain a crude product, redissolving the crude product in a solvent (S2) that is also miscible with the poor solvent (S1) and can dissolve the reaction product, pouring the solution into the poor solvent (S1) again, and filtering off the resulting precipitate. In addition, when an aromatic hydrocarbon such as toluene or xylene is used as the reaction solvent, the product component (A) dissolves in the solvent by heating at 80°C or higher, and by cooling as it is, crystals of component (A) are precipitated, and the component (A) can be isolated by filtering off the crystals. In this case, it is not necessary to use the poor solvent (S1) and the solvent (S2).

[0029] Examples of the poor solvent (S1) include water, monoalcohols such as methanol, ethanol, and propanol, aliphatic hydrocarbons such as n-hexane, n-heptane, n-octane, and cyclohexane, and aromatic hydrocarbons such as toluene and xylene. Among these poor solvents (S1), water and methanol are preferred because they can efficiently remove the acid catalyst at the same time.

[0030] Examples of the solvent (S2) include monoalcohols such as methanol, ethanol, and propanol; polyols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, trimethylene glycol, diethylene glycol, polyethylene glycol, and glycerin; glycol ethers such as 2-ethoxyethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, and ethylene glycol monophenyl ether; cyclic ethers such as 1,3-dioxane and 1,4-dioxane; glycol esters such as ethylene glycol acetate; and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. When water is used as the poor solvent (S1), acetone is preferable as the solvent (S2). The poor solvent (S1) and the solvent (S2) can each be used alone or in combination of two or more kinds.

[0031] The purity of component (A) is preferably 90% or more, more preferably 94% or more, and particularly preferably 98% or more, as calculated from a gel permeation chromatography (GPC) chart. The GPC measurement conditions are as described in the Examples.

[0032] Component (B): Metal alkoxide Metal alkoxides are used as ligands. - (R is a hydrocarbon group having 1 to 22 carbon atoms), which when mixed with component (A) undergoes ligand exchange to form a metal complex having component (A) as a ligand. By using a metal alkoxide, a resist film with excellent photosensitivity and alkali solubility can be obtained. R is preferably a hydrocarbon group having 2 to 6 carbon atoms, specifically, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an isobutyl group, an s-butyl group, an n-pentyl group, a neopentyl group, an s-pentyl group, an isopentyl group, a t-pentyl group, various hexyl groups, and the like.

[0033] Examples of the central metal of the metal alkoxide include magnesium, aluminum, calcium, titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, silver, cadmium, indium, tin, antimony, cesium, and hafnium. Among these, zirconium, tin, and hafnium are preferred. The valence of the central metal is not particularly limited, and the complex may have any valence. The metal alkoxide may be used alone or in combination of two or more kinds.

[0034] The mixing ratio of component (A) and component (B) is preferably in the range of 0.5 to 10 moles, and more preferably in the range of 2 to 6 moles, of component (A) per mole of the central metal of component (B), in order to fully exert the effects of the present invention.

[0035] Ingredient (C): Photoacid generator Examples of the photoacid generator include onium salt compounds, sulfonimide compounds, halogen-containing compounds, diazoketone compounds, etc. Among these, onium salt compounds are preferred. Examples of the onium salt compound include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts, and pyridinium salts.

[0036] Examples of sulfonium salts include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo[2.2.1]hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium camphorsulfonate, 4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, and 4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate. diphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo[2.2.1]hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium camphorsulfonate, 4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium Phenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium 2-bicyclo[2.2.1]hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium camphorsulfonate, triphenylsulfonium 2-(1-adamantyl)-1,1-difluoroethanesulfonate, triphenylsulfonium triphenylsulfonium 6-(1-adamantylcarbonyloxy)-1,1,2,2-tetrafluorohexane-1-sulfonate, triphenylsulfonium 6-(1-adamantylcarbonyloxy)-1,1,2-trifluorobutane-1-sulfonate, triphenylsulfonium 2-(4-oxo-1-adamantylcarbonyloxy)-1,1,3,3,3-pentafluoropropane-1-sulfonate, and triphenylsulfonium 2-bicyclo[2.2.1]hept-2-yl-1,1-difluoroethanesulfonate.

[0037] Tetrahydrothiophenium salts include 1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophenium trifluoromethanesulfonate, 1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophenium perfluoro-n-octanesulfonate, 1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophenium 2-bicyclo[2.2. 1]Hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophenium camphorsulfonate, 1-(6-n-butoxynaphthalen-2-yl)tetrahydrothiophenium trifluoromethanesulfonate, 1-(6-n-butoxynaphthalen-2-yl)tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1-(6-n-butoxynaphthalen-2-yl)tetrahydrothiophenium perfluorosulfonate Fluoro-n-octanesulfonate, 1-(6-n-butoxynaphthalen-2-yl)tetrahydrothiophenium 2-bicyclo[2.2.1]hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1-(6-n-butoxynaphthalen-2-yl)tetrahydrothiophenium camphorsulfonate, 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium trifluoromethanesulfonate, 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium trifluoromethanesulfonate Hydrothiophenium nonafluoro-n-butanesulfonate, 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium perfluoro-n-octanesulfonate, 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium 2-bicyclo[2.2.1]hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium camphorsulfonate, and the like.

[0038] Among the onium salt compounds, sulfonium salts are preferred, and triarylsulfonium salts are more preferred. For example, the following triarylsulfonium is preferred. The anion is SbF 6 , P.F. 6 , B(C 6 F 5 ) 4 etc.

[0039] [ka]

[0040] The content of component (C) is preferably within a range from 1 to 50 mass%, and more preferably from 5 to 20 mass%, of the solid content of the resist composition. The solid content of the resist composition refers to the total of all components in the resist material other than the solvent.

[0041] Component (D): Multifunctional methylol crosslinker The polyfunctional methylol compound may be any compound having two or more methylol groups. Specific examples include the following compounds.

[0042] [ka]

[0043] [ka]

[0044] [ka]

[0045] In one embodiment, the polyfunctional methylol compound is preferably a compound represented by the following formula (2). [ka] (In formula (2), Ra represents an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, or a halogen atom. q represents an integer of 2 to 4, r represents an integer of 0 to 3, and s represents an integer of 1 to 4. When there are multiple Ra, the multiple Ra may be the same or different.)

[0046] Examples of the aliphatic hydrocarbon group having 1 to 9 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, a hexyl group, a cyclohexyl group, a heptyl group, an octyl group, and a nonyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propyloxy group, a butoxy group, a pentyloxy group, a hexyloxy group, and a cyclohexyloxy group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0047] In one embodiment, in formula (2), s is preferably 1. Also, r is preferably 1. Also, q is preferably 2.

[0048] The component (D) may be used alone or in combination of two or more types. The amount of component (D) is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, based on 100 parts by mass of the total of components (A) and (B), in order to obtain good sensitivity and a desired pattern, and is preferably 30 parts by mass or less, more preferably 15 parts by mass or less.

[0049] Component (E): Solvent The solvent is not particularly limited as long as it can dissolve the above-mentioned components (A) and (B). Specific examples include monoalcohols such as methanol, ethanol, propanol, and butanol; polyols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, trimethylene glycol, diethylene glycol, polyethylene glycol, and glycerin; glycol ethers such as 2-ethoxyethanol, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, ethylene glycol monophenyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether; methylcello ethylene glycol alkyl ether acetates such as ethyl cellosolve acetate, propylene glycol alkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, cyclic ethers such as tetrahydrofuran, 1,3-dioxane, 1,4-dioxane, glycol esters such as ethylene glycol acetate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl oxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl formate, ethyl acetate, butyl acetate, methyl acetoacetate, ethyl acetoacetate, nitrile compounds such as acetonitrile, acrylonitrile, propionitrile, butyronitrile, etc. The solvent may be used alone or in the form of a mixture of two or more kinds.

[0050] The amount of component (E) used is not particularly limited and is adjusted appropriately depending on the specific application, etc. In particular, the solid content concentration in the resist composition is preferably in the range of 0.1 to 50 mass %, since this allows a uniform film thickness to be obtained when applying by a method such as spin coating.

[0051] In addition to the above-mentioned components (A) to (E), the resist composition of this embodiment can contain known additives, such as a curing agent, a photosensitizer, a filler, a pigment, a surfactant such as a leveling agent, an adhesion improver, a dissolution promoter, etc. When additives are added, the proportion of components (A) and (B) relative to the total mass of the components other than component (E) of the resist composition is preferably 50 mass% or more, more preferably 75 mass% or more, and particularly preferably 90 mass% or more, in order to fully exhibit the effects of the present invention.

[0052] The resist composition of this embodiment can be prepared by mixing and stirring the above-mentioned components (A) to (E) and, if necessary, additives. The mixing order of each component is not particularly limited. In one embodiment, the above-mentioned components (A) and (B) may be mixed in a solvent to prepare a metal complex solution, and then other components may be added. As the solvent, the same one as the above-mentioned component (E) can be used. The amount of the solvent used is not particularly limited, but is preferably in the range of 1 to 500 parts by mass per part by mass of the total of components (A) and (B). The temperature conditions when components (A) and (B) are mixed are not particularly limited, and may be room temperature of about 20 to 25° C., or may be appropriately heated as necessary. The formation of a metal complex can be seen, for example, at 1400 cm in the IR spectrum. -1 This can be confirmed from the peak.

[0053] When the resist composition of the present embodiment contains solids such as a filler, a pigment, etc., it is preferable to disperse and mix the composition using a dispersing device such as a dissolver, a homogenizer, a three-roll mill, etc. In addition, in order to remove coarse particles and impurities, the composition can also be filtered using a mesh filter, a membrane filter, etc.

[0054] The resist composition of the present embodiment can be used for pattern formation in the same manner as a general resist material. One example of such a method includes a process of forming a resist film using the resist composition, a process of exposing the resist film, and a process of developing the exposed resist film with a developer to form a pattern.

[0055] In the step of forming a resist film, the coating method is not particularly limited, and may be any method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor blade coating, etc. After coating, the solvent, which is component (E), is removed by pre-baking at a temperature condition of 60 to 150°C to obtain a coating film (resist film). In addition, examples of the object to be coated include a silicon substrate, a silicon carbide substrate, a gallium nitride substrate, a transparent conductive film, etc., and can be appropriately selected depending on the application, etc.

[0056] In the exposure step, the resist is exposed through a mask on which a pattern is drawn. Examples of the exposure light source include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams. The resist composition of the present embodiment is highly sensitive and can form a fine pattern, so that it can be suitably used for exposure with extreme ultraviolet light or electron beams.

[0057] The alkaline developer used in the development step can be a wide variety of alkaline developer solutions used in general alkaline development applications, including inorganic alkaline substances such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; and cyclic amines such as pyrrole and piheridine. These alkaline developers can also be used by appropriately adding alcohol, surfactants, and the like, as necessary. The alkaline concentration of the alkaline developer is usually preferably in the range of 2 to 5% by mass, and a 2.38% by mass aqueous solution of tetramethylammonium hydroxide is generally used.

[0058] The pattern forming method of the present invention is suitably used in the manufacturing process of electronic devices, such as household electrical appliances, office automation equipment, media-related equipment, optical equipment, and communication equipment. EXAMPLES

[0059] The present invention will be described in more detail below with reference to specific examples. The number average molecular weight (Mn), weight average molecular weight (Mw), and polydispersity (Mw / Mn) of the synthesized resins were measured under the following GPC measurement conditions. [GPC measurement conditions] Measurement equipment: Tosoh Corporation "HLC-8220 GPC" Column: Showa Denko K.K. "Shodex KF802": 8.0mmΦ×300mm +Showa Denko KF802: 8.0mmΦ×300mm +Showa Denko KF803: 8.0mmΦ×300mm +Showa Denko KF804: 8.0mmΦ×300mm Column temperature: 40℃ Detector: RI (differential refractometer) Data processing: Tosoh Corporation "GPC-8020 Model II Version 4.30" Developing solvent: Tetrahydrofuran Flow rate: 1.0mL / min Sample: 0.5% by mass of tetrahydrofuran solution (resin solid content equivalent) filtered through a microfilter Injection volume: 0.1mL Standard sample: monodisperse polystyrene as follows (Standard sample: monodisperse polystyrene) "A-500" manufactured by Tosoh Corporation "A-2500" manufactured by Tosoh Corporation "A-5000" manufactured by Tosoh Corporation "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation "F-10" manufactured by Tosoh Corporation "F-20" manufactured by Tosoh Corporation

[0060] 13 The measurement conditions for C-NMR are as follows: Equipment: JNM-ECA500 manufactured by JEOL Ltd. Measurement mode: Decoupling with inverse gate Solvent: Deuterated dimethyl sulfoxide Pulse angle: 30° pulse Sample concentration: 30% by mass Accumulation count: 4000 times Chemical shift standard: Dimethyl sulfoxide peak: 39.5 ppm

[0061] Example 1 (1) Synthesis of phenol trinuclear monomer (A) 293.2g (2.4mol) of 2,5-xylenol and 150g (1mol) of 4-formylbenzoic acid were charged into a 2000mL four-neck flask equipped with a cooling tube, and dissolved in 500mL of acetic acid. 5mL of sulfuric acid was added while cooling in an ice bath, and then the mixture was heated to 100°C with a mantle heater and reacted for 2 hours while stirring. After the reaction was completed, water was added to the resulting solution to precipitate the crude product. The crude product was then redissolved in acetone, and water was added to reprecipitate. The precipitate was filtered and dried in vacuum, obtaining 292g of phenol trinuclear monomer (A) as pale pink crystals.

[0062] Regarding the obtained monomer (A), 13 As a result of C-NMR spectrum measurement, it was confirmed that the compound was represented by the following structural formula. The purity calculated from the GPC chart was 95.3%. The GPC chart of monomer (A) is shown in Figure 1. 13 The C-NMR chart is shown in Figure 2. [ka]

[0063] (2) Preparation of metal complex solution 3.76 g (10 mmol) of the phenol trinuclear monomer (A) obtained in (1) above, 2.308 g (2.52 mmol as Zr element) of zirconium(IV) dibutoxide (Orgatix ZC-580 (Matsumoto Fine Chemical Co., Ltd.)), and 24.24 g of tetrahydrofuran (THF) were mixed in a 50 mL screw tube at room temperature for 30 minutes to obtain a metal complex solution. The FT-IR spectrum of the obtained metal complex solution is shown in FIG.

[0064] (3) Preparation of resist composition To the obtained metal complex solution, 0.25 g of a photoacid generator (CPI-101A manufactured by San-Apro Co., Ltd.) and 0.038 g of a polyfunctional methylol crosslinking agent (2,6-Bis(hydroxymethyl)-P-cresol manufactured by Tokyo Chemical Industry Co., Ltd.) were added, and the mixture was mixed at room temperature for 30 minutes. After that, the mixture was precision-filtered using a polytetrafluoroethylene (PTFE) disk filter having a pore size of 0.1 μm to prepare a resist composition.

[0065] Example 2 A resist composition was prepared in the same manner as in Example 1, except that the amount of photoacid generator was changed to 1.25 g, the amount of polyfunctional methylol crosslinking agent was changed to 0.19 g, and the amount of THF was changed to 23.28 g.

[0066] Example 3 A resist composition was prepared in the same manner as in Example 1, except that the amount of photoacid generator was changed to 2.51 g, the amount of polyfunctional methylol crosslinking agent was changed to 0.38 g, and the amount of THF was changed to 28.82 g.

[0067] Comparative Example 1 A resist composition was prepared in the same manner as in Example 1, except that the photoacid generator and the polyfunctional methylol crosslinking agent were not added, and the amount of THF was changed to 23.72 g.

[0068] Comparative Example 2 (1) Synthesis of Zr complexes containing polymerizable groups In a flask, 0.95 g of zirconium butoxide, 1.27 g of methacrylic acid, and 20 g of dichloromethane as a solvent were stirred for 60 minutes at room temperature of 23° C. The resulting solution was washed with methyl tert-butyl ether (TBME), filtered, and dried under reduced pressure for 5 hours to obtain a zirconia complex.

[0069] (2) Preparation of resist composition 1 g of the zirconia complex obtained in (1) above, 0.1 g of a polymerization initiator (2,2-dimethoxy-2-phenylacetophenone), and 11 g of propylene glycol monomethyl ether were stirred at room temperature (23° C.) for 5 minutes in a 30 mL screw tube to prepare a resist composition.

[0070] [Contrast rating] The resist compositions prepared in the Examples and Comparative Examples were applied to a silicon wafer having a diameter of 5 inches using a spin coater to a thickness of approximately 5 μm, and then prebaked at 110° C. for 60 seconds to form a resist film. The wafer having the resist film was irradiated with an electron beam (EB) at a dose of 500 kGy using an electron beam irradiation device (manufactured by Hamamatsu Photonics KK: EES-30L-DIC01). The resist films not exposed to EB and the resist films exposed to EB were each subjected to post-exposure bake (PEB) at 130°C for 90 seconds, followed by paddle development in a tetrahydrofuran solution for 5 seconds, and the wafers were rinsed with pure water for 10 seconds. The thickness of the resist film on the resulting wafer was evaluated, and the solvent dissolution rate was calculated from the degree of film thickness reduction before and after development using the following formula. Solvent dissolution rate (Å / Sec) = film reduction rate before and after the solvent (Å) / 5 (Sec)

[0071] The solvent dissolution rate of the resist film not exposed to EB was designated as DR1, and the solvent solubility was evaluated as follows. The results are shown in Table 1. 〇:DR1 is 2500 or more ×:DR1 is less than 2500

[0072] The solvent dissolution rate of the resist film irradiated with EB was defined as DR2, and the negative resist characteristics were evaluated based on the contrast value of DR1 / DR2 as follows. The results are shown in Table 1. 〇: Contrast is 5 or more ×: Contrast is less than 5 It can be said that the higher the contrast, the higher the EB sensitivity.

[0073] [Table 1]

[0074] From Table 1, it can be seen that the resist films obtained from the resist compositions of the Examples provide higher contrast upon EB irradiation than the Comparative Examples, and therefore have higher absorption sensitivity to EB.

Claims

1. A resist composition comprising the following components (A) to (E): (A) a phenol trinuclear monomer represented by the following formula (1): (B) Metal alkoxide (C) Photoacid generator (D) Polyfunctional methylol crosslinking agent (E) Solvent 【Chemistry 9】 [In formula (1), R １ and R ２ each independently represents an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group, or a halogen atom. m, n, and p each independently represent an integer of 0 to 4. R １ If there are multiple R １ may be the same or different. ２ If there are multiple R ２ may be the same or different. ３ R represents a structural portion having a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a hydrocarbon group having one or more substituents selected from an alkoxy group, a halogen group, and a hydroxyl group. ４ represents a hydroxyl group, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, or a halogen atom. ４ If there are multiple R ４ may be the same or different.

2. 2. The resist composition according to claim 1, wherein m and n in formula (1) each independently represent an integer of 1 to 3, and p is 0.

3. R in the above formula (1) １ and R ２ are each independently an alkyl group having 1 to 4 carbon atoms; R ３ 3. The resist composition according to claim 1, wherein is a hydrogen atom.

4. 4. The resist composition according to claim 1, wherein the component (B) is a metal alkoxide having a central metal selected from the group consisting of zirconium, tin and hafnium.

5. 5. The resist composition according to claim 1, wherein the component (C) is a sulfonium salt.

6. 6. The resist composition according to claim 1, wherein the component (D) is a compound represented by the following formula (2): 【Chemistry 10】 (In formula (2), Ra represents an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, or a halogen atom. q represents an integer of 2 to 4, r represents an integer of 0 to 3, and s represents an integer of 1 to 4. When there are multiple Ra's, the multiple Ra's may be the same or different from each other.)

7. A resist film obtained from the resist composition according to any one of claims 1 to 6.

8. forming a resist film using the resist composition according to any one of claims 1 to 6; exposing the resist film to light; and developing the exposed resist film with a developer to form a pattern.

9. The pattern forming method according to claim 8 , wherein the exposure is performed by exposure to an electron beam or extreme ultraviolet light.

10. A method for manufacturing an electronic device, comprising the pattern formation method according to claim 8 or 9.

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