Negative photosensitive resin composition

Abstract

To provide a novel negative type photosensitive resin composition.SOLUTION: A negative type photosensitive resin composition for forming a micro-lens includes: (A) the following alkali-soluble polymer; (B) at least two cross-linkable compounds having two or more polymerizable groups such as an acryloyloxy group in a molecule of 80 mass%-90 mass% to 100 mass% of the (A) constituent; (C) a photoinitiator 3 of mass%-20 mass% to 100 mass% of a total amount of the (B) constituent; and a solvent. A ternary copolymer (A) comprises a monomer having an alkali-soluble group such as a monomer having a carboxyl group; and a monomer including at least one selected from the group consisting of an acrylic acid ester compound, a methacrylic ester compound, a N-substituted maleimide compound, an acrylonitrile compound, an acrylamide compound, a methacrylamide compound, a styrene compound, and a vinyl compound, which is different from the above-mentioned monomer.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a negative-type photosensitive resin composition containing an alkali-soluble polymer, at least two crosslinkable compounds, at least one photopolymerization initiator, and a solvent, and particularly to a negative-type photosensitive resin composition for forming a microlens. [Background technology]

[0002] Conventionally, electronic devices such as CCD / CMOS image sensors have been provided with microlenses to improve light-collection efficiency. The etch-back method is known as one method for fabricating microlenses for CCD / CMOS image sensors (see Patent Documents 1 and 2). Specifically, a resist pattern is formed on a microlens resin layer formed on a color filter, and the resist pattern is reflowed by heat treatment to form a lens pattern. The lens pattern formed by reflowing the resist pattern is used as an etching mask to etch back the underlying microlens resin layer, and the lens pattern shape is transferred to the microlens resin layer, thereby fabricating the microlens. Such microlenses are required to have various properties, such as chemical resistance and high transparency.

[0003] Furthermore, photolithography properties are required when forming patterns on specific locations on electronic device elements such as CCD / CMOS image sensors, liquid crystal displays, and organic electroluminescence (EL) displays. Such photosensitive materials are required to be able to form patterns with low exposure (sensitivity characteristics) and to suppress the generation of residues after alkaline development.

[0004] Meanwhile, a photosensitive resin composition for forming microlenses containing a maleimide copolymer (Patent Document 3) and a positive resist composition containing a triazine skeleton (Patent Document 4) have been proposed. However, these patent documents require high-temperature heating above 100°C, for example, 140°C to 260°C, in order to satisfy the above-mentioned properties, particularly solvent resistance, and do not satisfy the above-mentioned properties with low-temperature heating below 100°C. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Publication No. 1-10666 [Patent Document 2] Japanese Patent Application Publication No. 6-112459 [Patent Document 3] Patent No. 5867735 [Patent Document 4] Patent No. 5673963 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made based on the above circumstances, and an object of the present invention is to provide a negative-type photosensitive resin composition which can produce a film at a baking temperature of 100°C that has high transparency, solvent resistance, sensitivity characteristics, and significantly improved residues in unexposed areas. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above-mentioned problems and have completed the present invention. Specifically, the present invention relates to a negative-type photosensitive resin composition comprising the following component (A): 80 to 90 mass % of the following component (B) relative to 100 mass % of the component (A); 3 to 20 mass % of the following component (C) relative to 100 mass % of the total amount of the component (B); and a solvent. (A): Alkali-soluble polymer (B): A group consisting of an acryloyloxy group, a methacryloyloxy group, an allyl group, and a vinyl group. At least two crosslinkable compounds having two or more polymerizable groups in one molecule selected from the group consisting of (C): at least one photopolymerization initiator

[0008] The at least two types of crosslinkable compounds include, for example, a crosslinkable compound having two acryloyloxy groups or methacryloyloxy groups as the polymerizable groups in one molecule, and a crosslinkable compound having three or more acryloyloxy groups or methacryloyloxy groups as the polymerizable groups in one molecule.

[0009] The alkali-soluble polymer has, for example, a structural unit selected from the group consisting of formula (1a), formula (1b), formula (1c), formula (1d), and formula (1e). [ka] (In the formula, R 1 represents a hydrogen atom or a methyl group; A represents an -O- group or an -NH- group; X represents a single bond, an alkylene group having 1 to 3 carbon atoms, or a divalent linking group containing an alkyleneoxy group having 1 to 3 carbon atoms; Z 1 represents a hydroxyphenyl group or a carboxyphenyl group, Z 2 represents a hydroxyphenyl group, a carboxyphenyl group, or a carboxyl group; Z 3 represents a hydrogen atom, a hydroxyphenyl group, or a carboxyphenyl group. The divalent linking group represents, for example, the alkyleneoxy group having 1 to 3 carbon atoms, or a group in which two or more alkyleneoxy groups having 1 to 3 carbon atoms are bonded together.

[0010] The alkali-soluble polymer is, for example, a copolymer further having a structural unit selected from the group consisting of the following formulae (2a), (2b), and (2c) that is different from the structural unit described above. [ka] (In the formula, R 1represents a hydrogen atom or a methyl group; A represents an -O- group or an -NH- group; X represents a single bond, an alkylene group having 1 to 3 carbon atoms, or a divalent linking group containing an alkyleneoxy group having 1 to 3 carbon atoms; Z 4 represents a linear organic group having 1 to 3 carbon atoms, or a branched or cyclic organic group having 3 to 14 carbon atoms.

[0011] The divalent linking group is, for example, the alkyleneoxy group having 1 to 3 carbon atoms, or a group in which two or more alkyleneoxy groups having 1 to 3 carbon atoms are bonded. The organic group may have at least one heteroatom such as a nitrogen atom or an oxygen atom, and may have a double bond or a triple bond between two carbon atoms or between a carbon atom and a heteroatom. Examples of the cyclic organic group include an aromatic hydrocarbon group, an alicyclic hydrocarbon group, a bridged ring hydrocarbon group, and a heterocyclic group.

[0012] The negative photosensitive resin composition of the present invention is used for forming, for example, microlenses. That is, the present specification also includes the following aspects of the invention [1] to [4]. [1] A negative-tone photosensitive resin composition for forming microlenses, comprising the following component (A): 80% to 90% by mass of the following component (B) relative to 100% by mass of the component (A); 3% to 20% by mass of the following component (C) relative to 100% by mass of the total amount of the component (B); and a solvent. (A): An alkali-soluble polymer which is a terpolymer of a monomer having an alkali-soluble group, which includes at least one selected from the group consisting of a monomer having a carboxyl group, a monomer having a phenolic hydroxy group, a monomer having an acid anhydride group, and a monomer having a maleimide group, and a monomer different from the above monomer, which includes at least one selected from the group consisting of an acrylic acid ester compound, a methacrylic acid ester compound, an N-substituted maleimide compound, an acrylonitrile compound, an acrylamide compound, a methacrylamide compound, a styrene compound, and a vinyl compound. (B): at least two crosslinkable compounds each having two or more polymerizable groups selected from the group consisting of an acryloyloxy group, a methacryloyloxy group, an allyl group, and a vinyl group in one molecule; (C): at least one photopolymerization initiator [2] The negative photosensitive resin composition for forming microlenses according to [1], wherein the monomer having an alkali-soluble group includes at least one selected from the group consisting of acrylic acid, methacrylic acid, maleic anhydride, and maleimide. [3] The at least two types of crosslinkable compounds include a crosslinkable compound having two polymerizable groups in one molecule and a crosslinkable compound having three or more polymerizable groups in one molecule, The negative photosensitive resin composition for forming microlenses according to [1] or [2], wherein the crosslinkable compound having three or more polymerizable groups in one molecule is a combination of two or more crosslinkable compounds having different numbers of polymerizable groups. [4] A negative photosensitive resin composition for forming a microlens according to any one of [1] to [3]. Microlenses obtained from synthetic materials.

[0013] The present invention also provides a method for producing a microlens, comprising the steps of applying the negative photosensitive resin composition onto a substrate and pre-baking the composition to form a resin film, exposing the resin film through a mask, developing the exposed resin film with an alkaline developer, and exposing the entire surface of the developed resin film.

[0014] The method may further include a step of post-baking the resin film after or before the step of exposing the entire surface of the resin film after development. [Effects of the Invention]

[0015] By optimizing the amounts of the alkali-soluble polymer, at least two crosslinkable compounds, and at least one photopolymerization initiator added to the negative-tone photosensitive resin composition of the present invention, a film obtained using the composition at a baking temperature of 100° C. can be made to be highly transparent and sensitive, with little residue in unexposed areas and excellent solvent resistance. Therefore, the negative-tone photosensitive resin composition of the present invention is suitable as a material for forming microlenses. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention relates to a negative-type photosensitive resin composition containing component (A), 80 to 90% by mass of component (B) relative to 100% by mass of component (A), 3 to 20% by mass of component (C) relative to 100% by mass of the total amount of component (B), and a solvent. Each component of the present invention is described in detail below. The solid content of the negative-type photosensitive resin composition of the present invention, excluding the solvent, is typically 1 to 50% by mass. In this specification, the components of the negative-type photosensitive resin composition of the present invention, excluding the solvent, are defined as the solid content.

[0017] <Component (A)> The component (A) in the negative-type photosensitive resin composition of the present invention is an alkali-soluble polymer. The polymer is a polymer of raw material monomers containing a monomer having an alkali-soluble group and, optionally, other monomers. The alkali-soluble polymer of component (A) need only have an alkali-soluble group, and there are no particular limitations on the type of main chain skeleton or side chain of the polymer constituting the polymer. The weight-average molecular weight of the alkali-soluble polymer is, for example, 1,000 to 50,000, preferably 3,000 to 40,000. The weight-average molecular weight is a value obtained by gel permeation chromatography (GPC) using polystyrene as a standard sample.

[0018] Examples of the monomer having an alkali-soluble group include a monomer having a carboxyl group, a monomer having a phenolic hydroxy group, a monomer having an acid anhydride group, and a monomer having a maleimide group.

[0019] Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, mono-(2-(acryloyloxy)ethyl)phthalate, mono-(2-(methacryloyloxy)ethyl)phthalate, N-(carboxyphenyl)maleimide, N-(carboxyphenyl)methacrylamide, N-(carboxyphenyl)acrylamide, and 4-vinylbenzoic acid.

[0020] Examples of the monomer having a phenolic hydroxy group include hydroxystyrene, N-(hydroxyphenyl)acrylamide, N-(hydroxyphenyl)methacrylamide, and N-(hydroxyphenyl)maleimide.

[0021] Examples of the monomer having an acid anhydride group include maleic anhydride and itaconic anhydride. Examples include:

[0022] Examples of the monomer having a maleimide group include the above-mentioned N-(carboxyphenyl)maleimide, N-(hydroxyphenyl)maleimide, and maleimide.

[0023] Among the monomers having an alkali-soluble group, a polymer of a monomer containing at least one selected from the group consisting of acrylic acid, methacrylic acid, maleic anhydride, and maleimide is preferred.

[0024] The alkali-soluble polymer of component (A) may also be a copolymer of the monomer having an alkali-soluble group and another monomer. The copolymer is not limited to a copolymer obtained from two types of monomers, but may also be a terpolymer (ternary copolymer) obtained from three types of monomers. Specific examples of the other monomer include acrylic acid ester compounds, methacrylic acid ester compounds, N-substituted maleimide compounds, acrylonitrile compounds, acrylamide compounds, methacrylamide compounds, styrene compounds, and vinyl compounds. Specific examples of the other monomer are listed below, but are not limited to these.

[0025] Examples of the acrylic acid ester compound include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthrylmethyl acrylate, phenyl acrylate, phenoxyethyl acrylate, 2,2,2-trifluoroethyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, and 2-methyl-2-adamantyl acrylate. acrylate, 2-propyl-2-adamantyl acrylate, 8-methyl-8-tricyclodecyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2,3-dihydroxypropyl acrylate, diethylene glycol monoacrylate, caprolactone 2-(acryloyloxy)ethyl ester, poly(ethylene glycol) ethyl ether acrylate, 5-acryloyloxy-6-hydroxynorbornene-2-carboxylic-6-lactone, acryloyloxyethyl isocyanate, 8-ethyl-8-tricyclodecyl acrylate, and glycidyl acrylate.

[0026] Examples of the methacrylic acid ester compound include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methacrylate, anthrylmethyl methacrylate, phenyl methacrylate, phenoxyethyl methacrylate, 2,2,2-trifluoroethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, and 3-methoxybutyl methacrylate. methacrylate, 2-methyl-2-adamantyl methacrylate, γ-butyrolactone methacrylate, 2-propyl-2-adamantyl methacrylate, 8-methyl-8-tricyclodecyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 2,3-dihydroxypropyl methacrylate, diethylene glycol monomethacrylate, caprolactone 2-(methacryloyloxy)ethyl ester, poly(ethylene glycol) ethyl ether methacrylate, 5-methacryloyloxy-6-hydroxynorbornene-2-carboxylic-6-lactone, methacryloyloxyethyl Isocyanate, 8-ethyl-8-tricyclodecyl methacrylate, glycidyl methacrylate.

[0027] Examples of the vinyl compound include methyl vinyl ether, benzyl vinyl ether, vinyl naphthalene, vinyl anthracene, vinyl biphenyl, vinyl carbazole, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, and propyl vinyl ether.

[0028] Examples of the styrene compound include styrene, methylstyrene, chlorostyrene, and bromostyrene.

[0029] Examples of the N-substituted maleimide compound include N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide.

[0030] The acrylonitrile compound includes, for example, acrylonitrile.

[0031] The ratio of the monomer having an alkali-soluble group to the other monomers is preferably 5 to 50% by mass (monomer having an alkali-soluble group) / 50 to 95% by mass (other monomers). If the ratio of the monomer having an alkali-soluble group to the other monomers is too low, the unexposed area will not dissolve in the developer, which may result in a residual film or residue. If the ratio of the monomer having an alkali-soluble group to the other monomers is too high, the exposed area may not be cured sufficiently, making it impossible to form a pattern.

[0032] The method for obtaining the alkali-soluble polymer of component (A) is not particularly limited, but it is generally obtained by polymerizing raw material monomers including the monomer having the alkali-soluble group described above in a polymerization solvent, usually at a temperature of 50°C to 110°C.

[0033] The alkali-soluble polymer obtained by the above method has a structural unit selected from the group consisting of formula (1a), formula (1b), formula (1c), formula (1d), and formula (1e). The alkali-soluble polymer may further have a structural unit different from the above structural unit selected from the group consisting of formula (2a), formula (2b), and formula (2c).

[0034] The content of the component (A) in the negative photosensitive resin composition of the present invention is usually 48 to 55% by mass based on the content in the solid content of the composition.

[0035] <(B) component> The component (B) in the negative-type photosensitive resin composition of the present invention is at least two crosslinkable compounds each having two or more polymerizable groups selected from the group consisting of acryloyloxy, methacryloyloxy, allyl, and vinyl groups per molecule. A preferred component (B) is a combination of a crosslinkable compound having two such polymerizable groups per molecule and a crosslinkable compound having three or more such polymerizable groups per molecule. The polymerizable groups are present at the molecular terminals of the crosslinkable compounds.

[0036] The crosslinkable compound of component (B) is preferably a compound having a weight average molecular weight of 200 to 1,000, from the viewpoints of having good compatibility with the other components of the negative-type photosensitive resin composition of the present invention and not affecting the developability.

[0037] Examples of the crosslinkable compound include dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, and pentaerythritol triacrylate. acrylate, pentaerythritol trimethacrylate, pentaerythritol diacrylate, pentaerythritol dimethacrylate, tetramethylolpropane tetraacrylate, tetramethylolpropane tetramethacrylate, tetramethylolmethane tetraacrylate, tetramethylolmethane tetramethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,3,5-triacryloylhexahydro-S-triazine, 1,3,5-trimethacryloylhexahydro-S-triazine, tris(hydroxyethylacryloyl)isocyanurate, tris(hydroxyethylmethacryloyl)isocyanurate, triacryloyl formal, trimethacryloyl formal, 1,6-hexanediol acrylate, 1,6-hexanediol methacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, ethanediol diacrylate, ethanediol dimethacrylate, 2-hydroxyethyl acrylate hydroxypropanediol diacrylate, 2-hydroxypropanediol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, isopropylene glycol diacrylate, isopropylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, N,N'-bis(acryloyl)cysteine, N,N'-bis(methacryloyl)cysteine, thiodiglycol diacrylate, thiodiglycol dimethacrylate, bisphenol A diacrylate, bisphenol A dimethacrylate, bisphenol F diacrylate, bisphenol F dimethacrylate, bisphenol S diacrylate, bisphenol S dimethacrylate, bisphenoxyethanol fluorene diacrylate, bisphenoxyethanol fluorene dimethacrylate, diallyl ether bisphenol A, o,o'-diallyl bisphenol A, diallyl maleate, and triallyl trimellitate.

[0038] The crosslinking compound is readily available as a commercially available product, and examples thereof include KAYARAD (registered trademark) T-1420, KAYARAD DPHA, KAYARAD DPHA-2C, KAYARAD D-310, KAYARAD D-330, KAYARAD DPCA-20, KAYARAD DPCA-30, KAYARAD DPCA-60, KAYARAD DPCA-120, KAYARAD DN-0075, KAYARAD DN-2475, KAYARAD R-526, KAYARAD NPGDA, KAYARAD PEG400DA, KAYARAD MANDA, KAYARAD R-167, and KAYARAD HX- 220, HX620, R-551, R-712, R-604, R-684, GPO-303, TMPTA, THE-330, TPA-320, TPA-330, PET-30 , RP-1040 (manufactured by Nippon Kayaku Co., Ltd.); Aronix (registered trademark) M-210, M-208, M-211B, M-215, M-220, M-225, M-270, M-240 , M-6100, M-6250, M-6500, M-6200, M-309, M-310, M-321, M-350, M-360, M-313, M-315, M-306, M-303, M-452, M-408, M-403, M-400, M-402, M-405, M-406, M-450, M-460, M-510, M-520, M-110 0, M-1200, M-6100, M-6200, M-6250, M-6500, M-7100, M8030, M8060, M8100, M8530, M-8560, M9 050 (manufactured by Toagosei Co., Ltd.); Viscoat 295, 300, 360, GPT, 3PA, 400, 260, 312, 335HP, 700 (manufactured by Osaka Organic Chemical Industry Co., Ltd.);A-200、A-400、A-600、A-1000、AB1206PE、ABE-300、A-BPE-10、A-BPE-20、A-BPE-30、A-BPE-4、A-BPEF、A-BPP-3、A-DCP、A-DOD-N、A-HD-N、A-NOD-N、APG-100、APG-200、APG-400、APG-700、A-PTMG-65、A-9300、A-9300-1CL、A-GLY-9E、A-GLY-20E、A-TMM-3、A-TMM-3L、A-TMM-3LM-N、A-TMPT、AD-TMP、ATM-35E、A-TMMT、A-9550、A-DPH、TMPT、9PG、701A、1206PE、NPG、NOD-N、HD-N、DOD-N、DCP、BPE-1300; N, BPE-900, BPE-200, BPE-100, BPE-80N, 23G, 14G, 9G, 4G, 3G, 2G, 1G (all manufactured by Shin-Nakamura Chemical Co., Ltd.); Light Ester EG, 2EG, 3EG, 4EG, 9EG, 14EG, 1.4BG, NP, 1.6HX, 1.9ND, G-101P, G-201P, DCP-M, BP-2EMK, BP-4EM, BP-6EM, TMP, Light Acrylate 3EG-A, 4EG-A, 9EG-A, 14EG-A, PTMGA-250, NP-A, MPD-A, 1.6HX-A, 1 9ND-A, MOD-A, DCP-A, BP-4PA, BA-134, BP-10EA, HPP-A, G-201P, TMP-A, TMP-3EO-A, TMP-6EO-3A, ​​PE-3A, PE-4A, DPE-6A, Epoxy Ester 40EM, 70PA, 200PA, 80MFA, 3002M, 3002A, 3000MK, 3000A, EX-0205, AH-600, AT-600, UA-306H, UA-306T, UA-306I, UA-510H, UF-8001G, DAUA-167 (manufactured by Kyoeisha Chemical Co., Ltd.);EBECRYL® TPGDA, 145, 150, PEG400DA, 11, HPNDA, PETIA, PETRA, TMPTA, TMPEOTA, OTA480, DPHA, 180, 40, 140, 204, 205, 210, 215, 220, 6202, 230, 244, 245, 264, 265, 270, 280 / 15IB, 284, 285, 294 / 25HD, 1259, KRM8200, 4820, 4858, and 512 9, 8210, 8301, 8307, 8402, 8405, 8411, 8804, 8807, 9260, 9270, KRM7735, KRM8296, KRM8452, 8311, 8701, 9227EA, 80, 436, 438, 446, 450, 505, 524, 525, 770, 800, 810, 811, 812, 1830, 846, 851, 852, 853, 1870, 884, 885, 600, 605, 645, 648, 860, 1606, 3500, 3608, 3700, 3701, 3702, 3703, 3708, and 6040 (manufactured by Daicel-Allnex Co., Ltd.); SR212, SR213, SR230, SR238F, SR259, SR268, SR272, SR306H, SR344, SR349, SR508, CD560, CD561, CD564, SR601, SR602, SR610, SR833S, SR9003, CD9043, SR9045, SR9209, SR205, SR206, and S Examples include R209, SR210, SR214, SR231, SR239, SR248, SR252, SR297, SR348, SR480, CD540, CD541, CD542, SR603, SR644, SR9036, SR351S, SR368, SR415, SR444, SR454, SR492, SR499, CD501, SR502, SR9020, CD9021, SR9035, SR350, SR295, SR355, SR399, SR494, and SR9041 (manufactured by Sartomer).

[0039] Two or more types of crosslinkable compounds of component (B) are used in combination. As a combination of two or more types, a crosslinkable compound having two polymerizable groups per molecule and a crosslinkable compound having three or more polymerizable groups per molecule are preferred. The crosslinkable compound having three or more polymerizable groups per molecule may be a combination of two or more crosslinkable compounds having different numbers of polymerizable groups. Furthermore, the polymerizable group is preferably an acryloyloxy group or a methacryloyloxy group.

[0040] The content of the component (B) in the negative photosensitive resin composition of the present invention is 80 to 90% by mass relative to 100% by mass of the component (A).

[0041] <(C) component> The component (C) in the negative photosensitive resin composition of the present invention is at least one photopolymerization initiator. The photopolymerization initiator (C) is any photopolymerization initiator that absorbs light from the light source used for photocuring. However, there is no particular limitation.

[0042] Examples of the photopolymerization initiator include tert-butylperoxy-iso-butyrate, 2,5-dimethyl-2,5-bis(benzoyldioxy)hexane, 1,4-bis[α-(tert-butyldioxy)-iso-propoxy]benzene, di-tert-butyl peroxide, 2,5-dimethyl-2,5-bis(tert-butyldioxy)hexene hydroperoxide, α-(iso-propylphenyl)-iso-propyl hydroperoxide, tert-butyl hydroperoxide, 1,1-bis(tert-butyldioxy)-3,3,5-trimethylcyclohexane, butyl-4,4-bis(tert-butyldioxy)valerate, cyclohexanone peroxide, 2,2′,5,5′-tetra(tert-butylperoxycarbonyl)benzophenone, 3,4-dimethyl-2,5-bis(tert-butyldioxy)-iso-propoxybenzene, 2,5 ... Organic peroxides such as 3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, 3,3',4,4'-tetra(tert-amylperoxycarbonyl)benzophenone, 3,3',4,4'-tetra(tert-hexylperoxycarbonyl)benzophenone, 3,3'-bis(tert-butylperoxycarbonyl)-4,4'-dicarboxybenzophenone, tert-butyl peroxybenzoate, and di-tert-butyl diperoxyisophthalate; quinones such as 9,10-anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, octamethylanthraquinone, and 1,2-benzanthraquinone; benzoin derivatives such as benzoin methyl, benzoin ethyl ether, α-methylbenzoin, and α-phenylbenzoin;2,2-Dimethoxy-1,2-diphenylethan-1-one, 1-Hydroxycyclohexyl phenyl ketone, 2-Hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-Hydroxy-1-[4-{4-(2-hydroxy-2-methyl-propionyl)benzyl}-phenyl]-2-methyl-propan-1-one, Phenylglyoxylic acid methyl ester, 2-Methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl) )-1-butanone, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one and other alkylphenone compounds; bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and other acylphosphine oxide compounds; 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione, 1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone and other oxime ester compounds;

[0043] The photopolymerization initiator is commercially available, and examples thereof include OMNIRAD (registered trademark) 651, 184, 500, 2959, 127, 754, 907, 369, 379, 379EG, 819, 819DW, 1700, 1870, 784, 1173, MBF, 4265, and TPO (all of which are IGM Resins) [formerly IRGACURE(R) 651, 184, 500, 2959, 127, 754, 907, 369, 379, 379EG, 819, 819DW, 1700, 1870, 784, 1173, MBF, 4265, and TPO (all manufactured by BASF Japan Ltd.)], IRGACURE(R) 1800, IRGACURE OXE01, and IRGACURE OXE02 (all manufactured by BASF Japan Ltd.), KAYACURE(R) DETX, MBP, DMBI, EPA, and OA (all manufactured by Nippon Kayaku Co., Ltd.), VICURE-10 and VICURE-55 (all manufactured by STAUFFER Co.LTD), ESACURE (registered trademark) KIP150, TZT, 1001, KTO46, KB1, KL200, KS300, EB3, Triazine-PMS, Triazine A, Triazine B (all manufactured by DKSH Japan Co., Ltd.), Adeka Optomer N-1717, N-1414 and N-1606 (manufactured by ADEKA Corporation).

[0044] The photopolymerization initiator (C) can be used either individually or in combination of two or more.

[0045] The content of the component (C) in the negative photosensitive resin composition of the present invention is 3 to 20% by mass relative to 100% by mass of the total amount of the component (B).

[0046] <Solvent> The negative photosensitive resin composition of the present invention contains a solvent. There are no particular limitations on the solvent as long as it dissolves the components (A), (B), and (C).

[0047] Examples of the solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol monobutyl ether, propylene glycol monobutyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, and γ-butyrolactone.

[0048] Among the above solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, 2-heptanone, ethyl lactate, butyl lactate, and cyclohexanone are preferred from the viewpoint of improving the leveling properties of the coating film.

[0049] The solvents may be used alone or in combination of two or more.

[0050] <Surfactant> The negative-type photosensitive resin composition of the present invention may contain a surfactant to improve coating properties. Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; polyoxyethylene-polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; and polyoxyethylene sorbitan monoesters. nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; F-Top (registered trademark) EF301, EF303, and EF352 (all manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.); Megafac (registered trademark) F-171, F-173, R-30, R-40, and R-40-LM (all manufactured by DIC Corporation); Fluorad FC430 and FC431 (all manufactured by 3M Japan Limited); Asahiguard (registered trademark) AG710, Surflon (registered trademark) S-382, and Surflon SC Examples of suitable surfactants include fluorine-based surfactants such as SC101, SC102, SC103, SC104, SC105, and SC106 (manufactured by AGC Corporation), FTX-206D, FTX-212D, FTX-218, FTX-220D, FTX-230D, FTX-240D, FTX-212P, FTX-220P, FTX-228P, and FTX-240G from the Futergent series (manufactured by Neos Corporation), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0051] The surfactants can be used alone or in combination of two or more. When the surfactant is used, the content of the surfactant in the negative photosensitive resin composition of the present invention is 3% by mass or less, for example, 0.0001 to 3% by mass, preferably 0.001 to 1% by mass, and more preferably 0.01 to 0.5% by mass, based on the content of the surfactant in the solid content of the composition.

[0052] <Other additives> The negative-type photosensitive resin composition of the present invention may contain other additives, such as a curing aid, an ultraviolet absorber, a sensitizer, a plasticizer, an antioxidant, an adhesion aid, or a dissolution promoter such as a polyhydric phenol or a polycarboxylic acid, as needed, as long as the effects of the present invention are not impaired.

[0053] <Method for preparing the composition> The method for preparing the negative-type photosensitive resin composition of the present invention is not particularly limited, but may include, for example, a method in which the alkali-soluble polymer (A) is dissolved in the solvent, and the crosslinkable compound (B) and the photopolymerization initiator (C) are mixed with the resulting solution in a predetermined ratio to prepare a homogeneous solution. Furthermore, at an appropriate stage of this preparation method, the other additives may be further added and mixed, if necessary.

[0054] <Use of negative photosensitive resin composition> The negative photosensitive resin composition of the present invention is applied onto a substrate (for example, a semiconductor substrate such as silicon coated with a silicon oxide film, a semiconductor substrate such as silicon coated with a silicon nitride film or a silicon oxynitride film, a silicon nitride substrate, a quartz substrate, a glass substrate (including alkali-free glass, low-alkali glass, and crystallized glass), or a glass substrate on which an indium tin oxide (ITO) film has been formed) by an appropriate application method such as a spinner or coater, and then prebaked using a heating means such as a hot plate to form a coating film.

[0055] The pre-baking conditions are appropriately selected from a baking temperature of 80° C. to 150° C. and a baking time of 0.3 to 60 minutes, and preferably a baking temperature of 80° C. to 100° C. and a baking time of 0.5 to 5 minutes.

[0056] The thickness of the film formed from the negative photosensitive resin composition of the present invention is, for example, 0.005 μm to 20 μm, and preferably 0.01 μm to 15 μm.

[0057] Next, the resulting film is exposed through a mask (reticle) to form a predetermined pattern. For example, g-line, i-line, or KrF excimer laser can be used for the exposure. After exposure, a post-exposure bake is performed as needed. The post-exposure bake conditions are appropriately selected from a heating temperature of 80°C to 100°C and a heating time of 0.3 to 60 minutes. The film is then developed with an alkaline developer.

[0058] Examples of the alkaline developer include aqueous alkaline solutions such as aqueous solutions of alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, aqueous solutions of quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide and choline, and aqueous amine solutions such as ethanolamine, propylamine and ethylenediamine. Furthermore, surfactants may be added to these developers.

[0059] The development conditions are appropriately selected from a development temperature of 5°C to 50°C and a development time of 10 seconds to 300 seconds. A film formed from the negative photosensitive resin composition of the present invention can be easily developed at room temperature using an aqueous tetramethylammonium hydroxide solution. After development, the film is appropriately rinsed using, for example, ultrapure water as a rinse solution.

[0060] The developed film is then exposed to g-line, i-line, or KrF excimer laser, for example. Furthermore, the developed film may be post-baked using a heating means such as a hot plate before or after the overall exposure. The post-baking conditions are appropriately selected from a baking temperature of 80°C to 100°C and a baking time of 0.5 to 60 minutes, for example. [Example]

[0061] The present invention will be described in more detail below with reference to synthesis examples and examples, but the present invention is not limited to the following examples.

[0062] [Measurement of weight-average molecular weight] Equipment: GPC system manufactured by JASCO Corporation Column: Shodex (registered trademark) GPC KF-804L and GPC KF-803L Column oven: 40°C Flow rate: 1ml / min Eluent: tetrahydrofuran Standard material: Polystyrene

[0063] [Synthesis Example 1] 60 g of methacrylic acid, 240 g of methyl methacrylate, and 7.6 g of 2,2'-azobisisobutyronitrile were dissolved in 132 g of propylene glycol monomethyl ether, and the solution was then added dropwise over 3 hours to a flask containing 440 g of propylene glycol monomethyl ether maintained at 70°C. After the addition was complete, the mixture was allowed to react for 18 hours to obtain a solution (solids concentration 35% by mass) of an alkali-soluble polymer (copolymer) having structural units represented by the following formula (1b-1) and structural units represented by the following formula (2a-1). The weight-average molecular weight Mw of the resulting copolymer was 35,000 (polystyrene equivalent). [ka]

[0064] [Synthesis Example 2] 61 g of methacrylic acid, 122 g of methyl methacrylate, 122 g of styrene, and 7.6 g of 2,2'-azobisisobutyronitrile were dissolved in 134 g of propylene glycol monomethyl ether, and this solution was then added dropwise over 3 hours to a flask containing 446 g of propylene glycol monomethyl ether maintained at 70°C. After the addition was completed, the mixture was allowed to react for 18 hours to obtain a solution (solids concentration 35% by mass) of an alkali-soluble polymer (terpolymer) having structural units represented by the following formula (1b-1), structural units represented by the following formula (2a-1), and structural units represented by the following formula (2b-1). The weight-average molecular weight Mw of the resulting copolymer was 35,000 (polystyrene equivalent). [ka]

[0065] [Example 1] The solution of the alkali-soluble polymer (A) obtained in Synthesis Example 1 (solid concentration 35%) 19.7 g (by volume), 3.4 g of PET-30 (manufactured by Nippon Kayaku Co., Ltd.) and 2.1 g of ABE-300 (manufactured by Shin-Nakamura Chemical Co., Ltd.) as crosslinkable compounds (B), 0.21 g of IRGACURE® OXE01 (manufactured by BASF Japan Ltd.) and 0.62 g of OMNIRAD® 184 (manufactured by IGM Resins) [formerly IRGACURE® 184 (manufactured by BASF Japan Ltd.)] as photopolymerization initiators (C), and 0.0040 g of DFX-18 (manufactured by Neos Co., Ltd.) as surfactant were dissolved in 5.6 g of propylene glycol monomethyl ether and 18.4 g of propylene glycol monomethyl ether acetate to prepare a solution. The solution was then filtered using a polyethylene microfilter with a pore size of 1 μm to prepare a negative-type photosensitive resin composition.

[0066] [Example 2] 19.6 g of the alkali-soluble polymer solution (solids concentration 35% by mass) (Component A) obtained in Synthesis Example 1, 4.1 g of PET-30 (manufactured by Nippon Kayaku Co., Ltd.) and 2.1 g of ABE-300 (manufactured by Shin-Nakamura Chemical Co., Ltd.) as crosslinkable compounds (Component B), 0.21 g of IRGACURE® OXE01 (manufactured by BASF Japan Ltd.) as a photopolymerization initiator (Component C), and 0.0040 g of DFX-18 (manufactured by Neos Corporation) as a surfactant were dissolved in 5.6 g of propylene glycol monomethyl ether and 18.4 g of propylene glycol monomethyl ether acetate to form a solution. The solution was then filtered using a polyethylene microfilter with a pore size of 1 μm to prepare a negative-type photosensitive resin composition.

[0067] [Example 3] 18.8 g of the alkali-soluble polymer solution (solid content concentration 35% by mass) as component (A) obtained in Synthesis Example 1, 3.9 g of PET-30 (manufactured by Nippon Kayaku Co., Ltd.) and 2.0 g of ABE-300 (manufactured by Shin-Nakamura Chemical Co., Ltd.) as crosslinkable compounds as component (B), 0.20 g of IRGACURE (registered trademark) OXE01 (manufactured by BASF Japan Ltd.) and 0.59 g of OMNIRAD (registered trademark) 184 (manufactured by IGM Resins) [formerly IRGACURE (registered trademark) 184 (manufactured by BASF Japan Ltd.)] as photopolymerization initiators as component (C), and 0.0040 g of DFX-18 (manufactured by Neos Corporation) were dissolved in 6.2 g of propylene glycol monomethyl ether and 18.4 g of propylene glycol monomethyl ether acetate to prepare a solution. Thereafter, the mixture was filtered using a polyethylene microfilter with a pore size of 1 μm to prepare a negative photosensitive resin composition.

[0068] [Example 4] A solution was prepared by dissolving 23.7 g of the alkali-soluble polymer solution (solid content concentration 35% by mass) as component (A) obtained in Synthesis Example 2, 5.0 g of PET-30 (manufactured by Nippon Kayaku Co., Ltd.) and 2.5 g of ABE-300 (manufactured by Shin-Nakamura Chemical Co., Ltd.) as crosslinkable compounds as component (B), 0.25 g of IRGACURE (registered trademark) OXE01 (manufactured by BASF Japan Ltd.) and 0.75 g of OMNIRAD (registered trademark) 184 (manufactured by IGM Resins) [formerly IRGACURE (registered trademark) 184 (manufactured by BASF Japan Ltd.)] as photopolymerization initiators as component (C) and 0.0050 g of DFX-18 (manufactured by Neos Corporation) in 1.2 g of propylene glycol monomethyl ether and 16.6 g of propylene glycol monomethyl ether acetate. Thereafter, the mixture was filtered using a polyethylene microfilter with a pore size of 1 μm to prepare a negative photosensitive resin composition.

[0069] [Comparative Example 1] 20.8 g of the alkali-soluble polymer solution (solid content concentration 35% by mass) as component (A) obtained in Synthesis Example 1, 2.9 g of PET-30 (manufactured by Nippon Kayaku Co., Ltd.) and 2.2 g of ABE-300 (manufactured by Shin-Nakamura Chemical Co., Ltd.) as crosslinking compounds as component (B), 0.22 g of IRGACURE (registered trademark) OXE01 (manufactured by BASF Japan Ltd.) and OMNIRAD (registered trademark) 184 (manufactured by IGM Resins) as photopolymerization initiators as component (C). 0.65 g of [old IRGACURE (registered trademark) 184 (manufactured by BASF Japan Ltd.)] and 0.0040 g of DFX-18 (manufactured by Neos Corporation) as a surfactant were dissolved in 4.9 g of propylene glycol monomethyl ether and 18.4 g of propylene glycol monomethyl ether acetate to prepare a solution. The solution was then filtered using a polyethylene microfilter with a pore size of 1 μm to prepare a negative-type photosensitive resin composition. The content of component (B) in the negative-type photosensitive resin composition of this comparative example was outside the range of the present invention.

[0070] Comparative Example 2 15.6 g of the alkali-soluble polymer solution (solids concentration 35% by mass) (component (A)) obtained in Synthesis Example 1, 3.3 g of PET-30 (manufactured by Nippon Kayaku Co., Ltd.) and 3.3 g of ABE-300 (manufactured by Shin-Nakamura Chemical Co., Ltd.) (component (B)) as crosslinkable compounds, 1.3 g of IRGACURE® OXE01 (manufactured by BASF Japan Ltd.) (component (C)) as a photopolymerization initiator, and 0.0040 g of DFX-18 (manufactured by Neos Corporation) as a surfactant were dissolved in 8.3 g of propylene glycol monomethyl ether and 18.5 g of propylene glycol monomethyl ether acetate to form a solution. The solution was then filtered using a polyethylene microfilter with a pore size of 1 μm to prepare a negative-tone photosensitive resin composition. The content of component (B) in the negative-tone photosensitive resin composition of this comparative example was outside the range of the present invention.

[0071] Comparative Example 3 24.5 g of the alkali-soluble polymer solution (solids concentration 35% by mass) (component A) obtained in Synthesis Example 1, 4.3 g of PET-30 (manufactured by Nippon Kayaku Co., Ltd.) as a crosslinking compound (component B), 0.13 g of IRGACURE® OXE01 (manufactured by BASF Japan Ltd.) as a photopolymerization initiator (component C), and 0.0039 g of DFX-18 (manufactured by Neos Corporation) as a surfactant were dissolved in 2.6 g of propylene glycol monomethyl ether and 18.5 g of propylene glycol monomethyl ether acetate to form a solution. The solution was then filtered through a polyethylene microfilter with a pore size of 1 μm to prepare a negative-tone photosensitive resin composition. The negative-tone photosensitive resin composition of this comparative example had a component (B) content outside the range of the present invention, and the component (B) did not contain a crosslinking compound having two polymerizable groups per molecule.

[0072] Comparative Example 4 23.2 g of the alkali-soluble polymer solution (solids concentration 35% by mass) (component (A)) obtained in Synthesis Example 1, 4.1 g of PET-30 (manufactured by Nippon Kayaku Co., Ltd.) as a crosslinking compound (component (B)), 0.8 g of IRGACURE® OXE01 (manufactured by BASF Japan Ltd.) as a photopolymerization initiator (component (C)), and 0.0039 g of DFX-18 (manufactured by Neos Corporation) as a surfactant were dissolved in 3.4 g of propylene glycol monomethyl ether and 18.5 g of propylene glycol monomethyl ether acetate to form a solution. The solution was then filtered through a polyethylene microfilter with a pore size of 1 μm to prepare a negative-tone photosensitive resin composition. The negative-tone photosensitive resin composition of this comparative example had a component (B) content outside the range of the present invention, and the component (B) did not contain a crosslinking compound having two polymerizable groups per molecule.

[0073] Comparative Example 5 19.5 g of the alkali-soluble polymer solution (solid content concentration 35% by mass) as component (A) obtained in Synthesis Example 1, 4.1 g of PET-30 (manufactured by Nippon Kayaku Co., Ltd.) and 2.0 g of ABE-300 (manufactured by Shin-Nakamura Chemical Co., Ltd.) as crosslinking compounds as component (B), 0.061 g of IRGACURE (registered trademark) OXE01 (manufactured by BASF Japan Ltd.) as a photopolymerization initiator as component (C), and 0.0039 g of DFX-18 (manufactured by Neos Corporation) as a surfactant were dissolved in 5.9 g of propylene glycol monomethyl ether and 18.5 g of propylene glycol monomethyl ether acetate to prepare a solution. The mixture was filtered using a polyethylene microfilter to prepare a negative photosensitive resin composition. The content of component (C) in the negative photosensitive resin composition of this comparative example was outside the range of the present invention.

[0074] Comparative Example 6 17.1 g of the alkali-soluble polymer solution (solids concentration 35% by mass) (component A) obtained in Synthesis Example 1, 3.6 g of PET-30 (manufactured by Nippon Kayaku Co., Ltd.) and 1.8 g of ABE-300 (manufactured by Shin-Nakamura Chemical Co., Ltd.) (component B) as crosslinkable compounds, 1.6 g of IRGACURE® OXE01 (manufactured by BASF Japan Ltd.) (component C) as a photopolymerization initiator, and 0.0039 g of DFX-18 (manufactured by Neos Corporation) as a surfactant were dissolved in 7.4 g of propylene glycol monomethyl ether and 18.5 g of propylene glycol monomethyl ether acetate to form a solution. The solution was then filtered using a polyethylene microfilter with a pore size of 1 μm to prepare a negative-tone photosensitive resin composition. The content of component C in the negative-tone photosensitive resin composition of this comparative example was outside the range of the present invention.

[0075] Comparative Example 7 24.9 g of the alkali-soluble polymer solution (solids concentration 35% by mass) (Component A) obtained in Synthesis Example 2, 5.3 g of PET-30 (manufactured by Nippon Kayaku Co., Ltd.) as the crosslinkable compound (Component B), 0.26 g of IRGACURE® OXE01 (manufactured by BASF Japan Ltd.) and 0.78 g of OMNIRAD® 184 (manufactured by IGM Resins) [formerly IRGACURE® 184 (manufactured by BASF Japan Ltd.)] as the photopolymerization initiator (Component C), and 0.0045 g of DFX-18 (manufactured by Neos Co., Ltd.) as the surfactant were dissolved in 1.3 g of propylene glycol monomethyl ether and 17.5 g of propylene glycol monomethyl ether acetate to form a solution. The solution was then filtered using a polyethylene microfilter with a pore size of 1 μm to prepare a negative-type photosensitive resin composition. In the negative photosensitive resin composition of this comparative example, the content of component (B) is outside the range of the present invention, and component (B) does not contain a crosslinkable compound having two polymerizable groups in one molecule.

[0076] [Transmittance measurement] Each of the negative photosensitive resin compositions prepared in Examples 1 to 4 and Comparative Examples 1 to 7 was applied to a quartz substrate using a spin coater and prebaked on a hot plate at 100°C for 90 seconds to form a resin film with the thickness shown in Table 1. Next, the coating was irradiated with ultraviolet light at 365 nm at a dose of 1000 mJ / cm using an ultraviolet irradiation device PLA-501(F) (Canon Inc.). 2 The entire surface of the resin film was irradiated with ultraviolet light of 1000 mJ / cm 2. Thereafter, the resin film was post-baked on a hot plate at 100°C for 5 minutes. Further, the resin film was exposed to a 365 nm UV light of 1000 mJ / cm 2 using a batch-type UV irradiation device (one 2 kW high-pressure mercury lamp) (manufactured by Eye Graphics Co., Ltd.). 2 A cured film was formed on the quartz substrate by irradiating the entire surface of the resin film with ultraviolet light. Both the pre-baking and post-baking were carried out in the atmosphere. The transmittance of these cured films was measured using a UV-2550 ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation) by changing the wavelength in 2 nm increments in the range of 400 nm to 800 nm. The minimum transmittance values ​​measured in the wavelength range of 400 nm to 800 nm are shown in Table 2. The closer the value is to 100%, the more transparent the film obtained is.

[0077] [Solvent resistance test] Each of the negative photosensitive resin compositions prepared in Examples 1 to 4 and Comparative Examples 1 to 7 was applied to a silicon wafer using a spin coater and prebaked on a hot plate at 100°C for 90 seconds to form a resin film with the thickness shown in Table 1. Next, the film was exposed to an ultraviolet ray irradiation device PLA-501(F) (Canon Inc.) at a dose of 1000 mJ / cm at 365 nm. 2 The entire surface of the resin film was irradiated with ultraviolet light of 1000 kJ / cm. Thereafter, the resin film was developed using an alkaline developer containing tetramethylammonium hydroxide at the concentration shown in Table 1. The wafer was developed for 60 seconds using an aqueous trimethylammonium hydroxide (TMAH) solution, rinsed for 20 seconds with ultrapure water, and dried. As a result, the resin films formed from the negative photosensitive resin compositions prepared in Comparative Examples 3 and 5 were removed from the silicon wafer. The remaining resin films were then post-baked on a hot plate at 100°C for 5 minutes. Finally, the wafer was exposed to light at 365 nm at a dose of 1000 mJ / cm using a batch-type UV irradiation device (one 2kW high-pressure mercury lamp) (manufactured by Eye Graphics Co., Ltd.). 2 A cured film was formed on the silicon wafer by irradiating the entire surface of the resin film with ultraviolet light. Both the pre-baking and post-baking were performed in the atmosphere. These cured films were then immersed in propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, methyl 3-methoxypropionate, and 2.38% by mass aqueous tetramethylammonium hydroxide (TMAH) solutions at 23°C for 2 minutes. The change in thickness of the cured film was measured before and after immersion. Solvent resistance was evaluated as follows: "X" if the film thickness increased or decreased by 10% or more compared to the pre-immersion thickness in any one of the solvents used in the immersion test; "△" if the film thickness increased or decreased by less than 10% but by 5% or more; "○" if the film thickness increased or decreased by less than 5% in all solvents; and "-" if the measurement was impossible. The evaluation results are shown in Table 2.

[0078] [Residual film rate, sensitivity and residue evaluation] Each of the negative-type photosensitive resin compositions prepared in Examples 1 to 4 and Comparative Examples 1 to 7 was applied to a silicon wafer using a spin coater and prebaked on a hot plate at 100°C for 90 seconds to form a resin film with the thickness shown in Table 1. The prebaking was carried out in the atmosphere. The thickness of each resin film was measured using a Lambda Ace VM-2110 optical interference film thickness measurement system (manufactured by SCREEN Semiconductor Solutions Co., Ltd.). The resin film was then exposed through a binary mask using an i-line stepper NSR-2205i12D (NA = 0.63) (manufactured by Nikon Corporation). The resin film was then developed for 60 seconds using an aqueous solution of tetramethylammonium hydroxide (TMAH) with the concentration shown in Table 1 as an alkaline developer, rinsed with ultrapure water for 20 seconds, and dried. As a result, a 7 mm x 7 mm rectangular pattern was formed on the silicon wafer from the resin films formed from the negative photosensitive resin compositions prepared in Examples 1 to 4, Comparative Examples 1, 2, 4, 6, and 7. On the other hand, no rectangular pattern was formed from the resin films formed from the negative photosensitive resin compositions prepared in Comparative Examples 3 and 5. The film thickness of the structure formed on the silicon wafer was measured using the same method as for measuring the film thickness of the resin film. The remaining film ratio (%) was evaluated by comparing it with the film thickness of the resin film immediately after pre-baking. The results are shown in Table 2. The remaining film ratio was calculated using the formula (film thickness after development / film thickness after pre-baking) x 100. The closer the value is to 100%, the more difficult it is for the exposed portion of the resin film to dissolve in the developer, which is preferable.

[0079] Furthermore, the minimum exposure dose that maximized the remaining film ratio was evaluated. The results are shown in Table 2. The exposure dose was 800 mJ / cm 2 If the residual film rate is not maximized even after the above, or if a 7 mm x 7 mm rectangular pattern is not formed, it is considered unmeasurable and is indicated as "-." The smaller the minimum exposure dose, the higher the sensitivity of the resin film.

[0080] Furthermore, the thickness of the unexposed portion of the resin film was measured using an optical interference film thickness measuring device Lambda Ace VM-2110 (manufactured by SCREEN Semiconductor Solutions Co., Ltd.). The thinner the film thickness, the less residue there was. The residue was evaluated as follows: if the film thickness was 10 nm or more, it was marked "x", if it was less than 10 nm and 5 nm or more, it was marked "△", and if it was less than 5 nm, it was marked "○". The evaluation results are shown in Table 2.

[0081] [Table 1] [Table 2]

Claims

1. A microlens obtained from a negative-tone photosensitive resin composition for forming a microlens, which comprises the following component (A): 80% by mass to 90% by mass of the following component (B) relative to 100% by mass of the component (A); 3% by mass to 20% by mass of the following component (C) relative to 100% by mass of the total amount of the component (B); and a solvent. (A): An alkali-soluble polymer which is a binary or ternary copolymer having a structural unit represented by the following formula (1b) and further having a structural unit selected from the group consisting of the following formulas (2a) and (2b) which are different from the structural unit represented by the following formula (1b): (B): at least two crosslinkable compounds each having two or more polymerizable groups selected from the group consisting of an acryloyloxy group, a methacryloyloxy group, an allyl group, and a vinyl group in one molecule; (C): At least one photopolymerization initiator 【Chemistry 1】 (In the formula, R １ represents a hydrogen atom or a methyl group, X represents a single bond, Z ２ represents a carboxyl group.) 【Chemistry 2】 (In the formula, R １ represents a hydrogen atom or a methyl group, A represents an —O— group, X represents a single bond, Z ４ represents a linear organic group having 1 to 3 carbon atoms or a phenyl group.

2. The microlens according to claim 1, wherein the alkali-soluble polymer is a binary copolymer having a structural unit represented by the following formula (1b-1) and a structural unit represented by the following formula (2a-1), or a ternary copolymer having a structural unit represented by the following formula (1b-1), a structural unit represented by the following formula (2a-1), and a structural unit represented by the following formula (2b-1). 【Transformation 3】 【Chemistry 4】

3. the at least two types of crosslinkable compounds include a crosslinkable compound having two polymerizable groups in one molecule and a crosslinkable compound having three or more polymerizable groups in one molecule, 3. The microlens according to claim 1, wherein the crosslinkable compound having three or more polymerizable groups in one molecule is a combination of two or more crosslinkable compounds having different numbers of polymerizable groups.

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