Positive photosensitive resin composition containing a specific copolymer

Abstract

[Problem] To provide a novel positive photosensitive resin composition. [Solution] A positive photosensitive resin composition containing the following component (A), the following component (B), the following component (C), and a solvent. Component (A): A copolymer of (a1) a monomer represented by the following formula (1), (a2) a monomer including an epoxy ring, and (a3) a monomer including a hydroxy group that has an acid dissociation constant pKa of 14 or above. Component (B): a quinone diazide compound. Component (C): a photoacid generator. (In the formula, R0 represents a hydrogen atom or a methyl group, R1 represents a single bond or an alkylene group having 1 or 2 carbon atoms, R2 represents a methyl group, a represents 1 or 2, and b represents an integer from 0 to 2).

Description

Technical Field

[0001] The present invention relates to a positive photosensitive resin composition, a cured film obtained from the resin composition, a microlens, and a method for producing the same.

Background Art

[0002] For imaging elements such as CCD image sensors and CMOS image sensors, or display elements such as liquid crystal displays and organic EL displays, minute lenses called microlenses are often used to improve performance. For example, providing a microlens on the image sensor has the effect of improving the light collection rate and enhancing the sensor sensitivity.

[0003] As one method for producing a microlens, an etch-back method is known (for example, Patent Document 1). That is, a resin layer for microlens is formed on a color filter, a positive resist is applied on the resin layer, a part of the resist is exposed and developed, and heated as necessary to form a lens pattern. The lens pattern is used as an etching mask for etch-back, and the lens pattern shape is transferred to the resin layer for microlens to produce a microlens.

[0004] On the other hand, from the viewpoint of reducing manufacturing costs, a method of directly using the positive resist as a microlens has been proposed. In this case, since it is necessary to have both the characteristics as a resist and the characteristics as a microlens, a photosensitive resin composition that is not only capable of positive patterning but also has excellent transparency and chemical resistance for the formed microlens is required. Here, the shape of the microlens varies depending on the design of the element, and various shapes such as a prism, a cylinder, a frustum of a pyramid, a frustum of a cone, and a spherical segment may be required. When producing a microlens having a spherical segment shape, a method of performing reflow (fluidization by heating, also referred to as melt flow or thermal flow) after forming a pattern such as a prism or a frustum of a pyramid is known.

[0005] For example, Patent Document 2 proposes a photosensitive resin composition containing an alkali-soluble copolymer and a quinonediazide group-containing compound. By using this composition, after forming a resin pattern by exposure and development, a microlens can be obtained by crosslinking phenolic hydroxyl groups and epoxy groups by heating.

[0006] However, in recent years, devices with low heat resistance such as organic devices and flexible devices have come to be used, and thus the demand for lowering the process temperature has been increasing. Along with this, a positive photosensitive resin composition capable of producing a microlens having good performance even in a low-temperature process is desired. When producing a microlens in a spherical segment shape, it is required to sufficiently reflow even at a low temperature. As a specific upper limit temperature of the process, 150°C is required, and particularly recently, 130°C has been required. The photosensitive resin composition described in Patent Document 2 employs thermosetting of phenolic hydroxyl groups and epoxy groups, but this thermosetting reaction usually requires high-temperature conditions exceeding 150°C, and thus it is not suitable for a low-temperature process of 130°C or lower.

[0007] Therefore, Patent Document 3 proposes a radiation-sensitive resin composition containing, in addition to an alkali-soluble copolymer and a 1,2-quinonediazide compound, a compound that generates an acid upon exposure to radiation. By using this composition, after forming a resin pattern by exposure and development, by exposing again, a strong acid can be generated inside the resin pattern, and cationic polymerization can proceed, so that the process can be made low-temperature. However, the monomers forming the alkali-soluble copolymer used in this composition have carboxylic acid or carboxylic anhydride, and there was a risk of residue generation when patterning this copolymer. If a part of the resin remains in the space between the patterns, it will have a serious adverse effect on the characteristics of the device, so a photosensitive resin composition capable of positive patterning without residue is required.

[0008] In Patent Document 4, a radiation-sensitive resin composition containing an alkali-soluble polymer, a quinonediazide compound, and a compound that generates an acid with a pKa of 4.0 or less has been proposed. Regarding the long-term reliability (HTS test, THS test, xenon arc test, etc.) excluding storage stability, the alkali-soluble polymer has not been mentioned, and its properties have been unknown. The above-mentioned organic devices and flexible devices must have reliability that can withstand practical use. Therefore, a photosensitive resin composition that does not deteriorate even after long-term reliability tests such as the HTS test (high-temperature test), THS test (high-temperature and high-humidity test), and xenon arc test, and can produce a microlens with good performance is desired.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0010] The present invention has been made based on the above circumstances, and its object is to provide a positive-type photosensitive resin composition that enables positive patterning without residue, can form a microlens having a desired spherical defect shape or hemispherical shape even in a low-temperature process of 130 °C or lower, and the formed microlens has excellent transparency, chemical resistance, and long-term reliability.

Means for Solving the Problems

[0011] As a result of intensive studies to solve the above problems, the present inventors have completed the present invention. The first aspect of the present invention is a positive photosensitive resin composition containing the following component (A), the following component (B), the following component (C), and a solvent. Component (A): A copolymer of a monomer represented by the following formula (1), a monomer containing an epoxy ring, and a monomer containing a hydroxy group having an acid dissociation constant pKa of 14 or more, which does not contain a carboxy group and a carboxylic anhydride group Component (B): A quinonediazide compound Component (C): A photoacid generator

Chemical formula

[0012] The monomer (a2) containing an epoxy ring is, for example, a monomer represented by the following formula (2), and the monomer (a3) containing a hydroxy group having an acid dissociation constant pKa of 14 or more is, for example, a monomer represented by the following formula (3).

Chemical formula

Chemical formula

[0013] The component (A) is a copolymer having a structural unit represented by the following formula (1a), a structural unit represented by the following formula (2a), and a structural unit represented by the following formula (3a).

Chemical formula

Chemical formula

[0014] The polystyrene-reduced weight average molecular weight of the component (A) is, for example, 5,000 to 30,000.

[0015] The component (C) is, for example, a nonionic photoacid generator. The nonionic photoacid generator is, for example, a photoacid generator represented by the following formula (6).

Chemical formula

[0016] The positive photosensitive resin composition of the present invention may further contain the following component (D). Component (D): Polyfunctional epoxy compound

[0017] The positive photosensitive resin composition of the present invention may further contain the following component (E). Component (E): Sensitizer

[0018] The positive photosensitive resin composition of the present invention is, for example, for producing microlenses.

[0019] The second aspect of the present invention is a cured film obtained from the positive photosensitive resin composition.

[0020] The third aspect of the present invention is a microlens produced from the positive photosensitive resin composition.

[0021] The fourth aspect of the present invention includes a coating step of coating the positive photosensitive resin composition on a substrate to form a resin film, a first exposure step of exposing at least a part of the resin film after the coating step, a development step of removing the exposed portion of the resin film with a developer after the first exposure step to form a pattern of the unexposed portion of the resin film, a second exposure step of further exposing the pattern after the development step, and a post-bake step of heating the pattern at a temperature of 130°C or lower after the second exposure step, which is a method for producing a microlens.

[0022] After the development step and before the second exposure step, a reflow step of heating the pattern at a temperature of 130°C or lower may be included.

[0023] The substrate is, for example, a substrate on which a color filter is formed.

Advantages of the Invention

[0024] According to the present invention, since it simultaneously contains component (A) which is a specific copolymer, component (B) which is a quinonediazide compound, and component (C) which is a photoacid generator, positive patterning can be performed without residue, and a microlens having a desired spherical indentation shape or hemispherical shape can be formed even in a low-temperature process of 130 °C or lower, and a positive photosensitive resin composition can be provided in which the formed microlens has excellent transparency, chemical resistance, and long-term reliability.

Mode for Carrying Out the Invention

[0025] The positive photosensitive resin composition of the present invention will be described in more detail. [Component (A)] Component (A) contained in the positive photosensitive resin composition of the present invention is a copolymer of (a1) a monomer represented by the following formula (1), (a2) a monomer containing an epoxy ring, and (a3) a monomer containing a hydroxy group having an acid dissociation constant pKa of 14 or more, and is a copolymer that does not contain a carboxy group and a carboxylic anhydride group. Here, the carboxylic anhydride group is a divalent group represented by -CO-O-CO-.

Chemical formula

[0026] (a1) Examples of the monomer represented by the formula (1) include N-(2-hydroxyphenyl)(meth)acrylamide, N-(3-hydroxyphenyl)(meth)acrylamide, N-(4-hydroxyphenyl)(meth)acrylamide, N-(4-hydroxybenzyl)(meth)acrylamide, N-(4-hydroxyphenethyl)(meth)acrylamide, N-(3,5-dimethyl-4-hydroxyphenyl)(meth)acrylamide, N-(3,5-dimethyl-4-hydroxybenzyl)(meth)acrylamide, and N-(3,5-dimethyl-4-hydroxyphenethyl)(meth)acrylamide. These monomers may be used alone or in combination of two or more.

[0027] (a1) The proportion of the monomer represented by the formula (1) is 5 to 60 parts by mass, preferably 8 to 50 parts by mass, more preferably 10 to 40 parts by mass, based on 100 parts by mass of the monomers (a1), (a2), and (a3).

[0028] (a2) The monomer containing an epoxy ring is a monomer having at least one epoxy ring in the molecule, and specific examples thereof include monomers represented by the following formulas (2-1) to (2-16).

Chemical formula

[0029] (a2) The proportion of the monomer containing an epoxy ring is 20 to 80 parts by mass, preferably 30 to 70 parts by mass, more preferably 40 to 60 parts by mass, based on 100 parts by mass of the monomers (a1), (a2), and (a3).

[0030] (a3) The monomer containing a hydroxy group with an acid dissociation constant pKa of 14 or more is a monomer having at least one hydroxy group with an acid dissociation constant pKa (the lowest value in the case of polyvalent acids) of 14 or more. Specific examples thereof include monomers represented by the following formulas (3-1) to (3-25). The monomer does not contain functional groups with an acid dissociation constant pKa of 13 or less, such as silanol groups, fluoroalcohol groups, maleimide groups, carboxy groups, and phenolic hydroxy groups. [Chemical formula] These monomers may be used alone or in combination of two or more.

[0031] (a3) The proportion of the monomer containing a hydroxy group with an acid dissociation constant pKa of 14 or more is 5 to 60 parts by mass, preferably 8 to 50 parts by mass, more preferably 10 to 40 parts by mass with respect to 100 parts by mass of the monomers of (a1), (a2), and (a3).

[0032] (A) The weight average molecular weight of the component is the polystyrene equivalent weight average molecular weight M W calculated by gel permeation chromatography (GPC) and is 5,000 to 30,000, preferably 5,000 to 20,000, more preferably 5,000 to 15,000. By setting the weight average molecular weight of the (A) component within the above range, a good pattern can be formed after development without impairing chemical resistance.

[0033] (A) The glass transition temperature of the component is 70°C to 130°C. By setting the glass transition temperature of the (A) component within the above range, good reflow properties can be obtained even in a low-temperature process of 130°C or lower, and a desired spherical defect shape or hemispherical micro-lens can be produced.

[0034] [Component (B)] Component (B) contained in the positive photosensitive resin composition of the present invention is not particularly limited as long as it is a compound having a 1,2-quinonediazide group. For example, a condensate of a hydroxy group-containing compound and 1,2-naphthoquinonediazide sulfonic acid halide can be used. Specifically, among the hydroxy groups of the hydroxy group-containing compound, 10 mol% to 100 mol%, preferably 20 mol% to 95 mol% can be esterified with the 1,2-naphthoquinonediazide sulfonic acid halide. Various known methods can be adopted for the condensation reaction.

[0035] Examples of the hydroxy group-containing compound include the following compounds. Dihydroxybenzophenones such as 2,4-dihydroxybenzophenone; Trihydroxybenzophenones such as 2,3,4-trihydroxybenzophenone and 2,4,6-trihydroxybenzophenone; Tetrahydroxybenzophenones such as 2,4,2’,4’-tetrahydroxybenzophenone, 2,3,4,3’-tetrahydroxybenzophenone, 2,3,4,4’-tetrahydroxybenzophenone, 2,3,4,2’-tetrahydroxy-4’-methylbenzophenone, and 2,3,4,4’-tetrahydroxy-3’-methoxybenzophenone; Pentahydroxybenzophenones such as 2,3,4,2’,4’-pentahydroxybenzophenone and 2,3,4,2’,6’-pentahydroxybenzophenone; Hexahydroxybenzophenones such as 2,4,6,3’,4’,5’-hexahydroxybenzophenone and 3,4,5,3’,4’,5’-hexahydroxybenzophenone; 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,3,3-tris(4-hydroxyphenyl)butane, bis(2,4-dihydroxyphenyl)methane, bis(p-hydroxyphenyl)methane, tris(p-hydroxyphenyl)methane, 1,1,1-tris(p-hydroxyphenyl)ethane, bis(2,3,4-trihydroxyphenyl)methane, 2,2-bis(2,3,4-trihydroxyphenyl)propane, 1,1,3-tris(2,5-dimethyl-4-hydroxyphenyl)-3-phenylpropane, 4,4’-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl]ethylidene]bisphenol, bis(2,5-dimethyl-4-hydroxyphenyl)-2-hydroxyphenylmethane, 3,3,3’,3’-tetramethyl-1,1’-spirobiindene-5,6,7,5’,6’,7’-hexanol, and (polyhydroxyphenyl)alkanes such as 2,2,4-trimethyl-7,2’,4’-trihydroxyflavan; Phenol, o-cresol, m-cresol, p-cresol, hydroquinone, resorcinol, catechol, methyl gallate, ethyl gallate, 2-methyl-2-(2,4-dihydroxyphenyl)-4-(4-hydroxyphenyl)-7-hydroxycoumaran, 1-[1-(3-{1-(4-hydroxyphenyl)-1-methylethyl}-4,6-dihydroxyphenyl)-1-methylethyl]-3-(1-(3-{1-(4-hydroxyphenyl)-1-methylethyl}-4,6-dihydroxyphenyl)-1-methylethyl)benzene, and other compounds such as 4,6-bis{1-(4-hydroxyphenyl)-1-methylethyl}-1,3-dihydroxybenzene. Among these compounds, 2,3,4,4’-tetrahydroxybenzophenone, 1,1,1-tris(p-hydroxyphenyl)ethane, and 4,4’-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl]ethylidene]bisphenol are preferred.

[0036] As the 1,2-naphthoquinonediazide sulfonic acid halide, 1,2-naphthoquinonediazide sulfonic acid chloride is preferred, 1,2-naphthoquinone-2-diazide-4-sulfonic acid chloride and 1,2-naphthoquinone-2-diazide-5-sulfonic acid chloride are more preferred, and 1,2-naphthoquinone-2-diazide-5-sulfonic acid chloride is even more preferred.

[0037] The compound of component (B) may be used alone or in combination of two or more.

[0038] The content of component (B) in the positive photosensitive resin composition of the present invention is 5 parts by mass to 100 parts by mass, preferably 10 parts by mass to 60 parts by mass, more preferably 15 parts by mass to 40 parts by mass with respect to 100 parts by mass of component (A). By setting the content of component (B) within the above range, the solubility difference in an alkaline developer between the exposed portion and the unexposed portion can be increased without significantly reducing the sensitivity, and positive patterning can be achieved with a relatively low exposure amount.

[0039] [Component (C)] Component (C) contained in the positive photosensitive resin composition of the present invention is not particularly limited as long as it is a compound that can generate an acid with an acid dissociation constant pKa of 4 or less upon exposure, and examples include ionic photoacid generators and non-ionic photoacid generators.

[0040] As the ionic photoacid generator, for example, the following products and compounds can be used. ADEKA ARCULES (registered trademark) SP-056, SP-171 (both manufactured by ADEKA CORPORATION), CPI (registered trademark)-100B(40), -100P, -101A, -110A, -110B, -110P, -200K, -210S, -300, -310B, -310FG, -400, -410B, -410S, VC-1FG, ES-1B (both manufactured by SAN-APRO LTD.), TPS-TF, TPS-CS, TPS-PFBS (all manufactured by TOYO GOSEN KOGYO CO., LTD.), TPS-102, TPS-103, TPS-105, TPS-106, TPS-109, TPS-200, TPS-300, TPS-1000, HDS-109, MDS-103, MDS-105, MDS-109, MDS-205, MDS-209, BDS-109, MNPS-109, DTS-102, DTS-103, DTS-105, DTS-200, NDS-103, NDS-105, NDS-155, and NDS-165 (all manufactured by Midori Chemical Co., Ltd.) and other arylsulfonium salts; ADEKA ARCULES (registered trademark) SP-140 (manufactured by ADEKA CORPORATION), IK-1, IK-1PC(80), IK-1FG (all manufactured by SAN-APRO LTD.), DTBPI-PFBS (manufactured by TOYO GOSEN KOGYO CO., LTD.), DPI-105, DPI-106, DPI-109, DPI-201, BI-105, MPI-105, MPI-106, MPI-109, BBI-102, BBI-103, BBI-105, BBI-106, BBI-109, BBI-110, BBI-200, BBI-201, BBI-300, and BBI-301 (all manufactured by Midori Chemical Co., Ltd.) and other aryliodonium salts.

[0041] As nonionic photoacid generators, for example, the following products and compounds can be used. ADEKA ARCULES (registered trademark) SP-082, SP-606 (both manufactured by ADEKA CORPORATION), NA-CS1, NP-TM2, NP-SE10 (all manufactured by SAN-APRO LTD.), SI-105, SI-106, PI-106, NDI-101, NDI-105, NDI-106, NDI-109, NDI-1001, NDI-1004, NAI-100, NAI-101, NAI-105, NAI-106, NAI-109, NAI-1002, NAI-1003, and NAI-1004 (all manufactured by Midori Chemical Co., Ltd.), etc., N-sulfonyloxyimides; IRGACURE (registered trademark) PAG103, PAG121, PAG203 (all manufactured by BASF Japan Ltd.), PAI-01, PAI-101, PAI-106, PAI-1001, PAI-1002, PAI-1003, and PAI-1004 (all manufactured by Midori Chemical Co., Ltd.), etc., oxime sulfonates; TAZ-100, TAZ-101, TAZ-102, TAZ-103, TAZ-104, TAZ-107, TAZ-108, TAZ-109, TAZ-110, TAZ-113, TAZ-114, TAZ-118, TAZ-122, TAZ-123, TAZ-203, and TAZ-204 (all manufactured by Midori Chemical Co., Ltd.), etc., triazines.

[0042] Among these ionic photoacid generators and nonionic photoacid generators, nonionic photoacid generators are preferred from the viewpoints of storage stability and sensitivity, N-sulfonyloxyimides are more preferred, and the compounds represented by the above formula (6) are even more preferred. Specific examples of the compounds represented by the above formula (6) include the compounds represented by the following formula (6-1) to the following formula (6-28).

Chemical formula

[0043] The compound of component (C) may be used alone or in combination of two or more.

[0044] The content of component (C) in the positive photosensitive resin composition of the present invention is 0.1 part by mass to 10 parts by mass, preferably 0.5 part by mass to 5 parts by mass, based on 100 parts by mass of component (A). By setting the content of component (C) within the above range, chemical resistance can be improved without impairing transparency.

[0045] [Component (D)] Component (D) contained as an optional component in the positive photosensitive resin composition of the present invention is not particularly limited as long as it is a compound having at least two epoxy rings in the molecule. For example, the following products and compounds can be used. EPICLON® 830, 830-S, 835, 840, 840-S, 850, 850-S, 850-LC, HP-820 (manufactured by DIC Corporation), DENACOL® EX-201, EX-211, EX-212, EX-252, EX-810, EX-811, EX-821, EX-830, EX-832, EX-841, EX-850, EX-851, EX-861, EX-920, EX-931, EX-991L, EX-313, EX-314, EX-321, EX-321L, EX-411, EX-421, EX-512, EX-521, EX-612, EX-614, EX-614B, EX-622 (manufactured by Nagase ChemteX Corporation), jER® 152, 630, 825, 827, 828, 828EL, 828US, 828XA (manufactured by Mitsubishi Chemical Corporation), TETRAD®-C, -X (manufactured by Mitsubishi Gas Chemical Company, Inc.), Celoxide® 2021P, 2081, Epolide® GT401 (manufactured by Daicel Corporation), Epotote® YD-115, YD-115CA, YD-127, YD-128, YD-128G, YD-128S, YD-128CA, YD-8125, YD-825GS, YDF-170, YDF-170N, YDF-8170C, YDF-870GS, ZX-1059, YH-404, YH-434, YH-434L, YH-513, YH-523, ST-3000 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), Adeka Resin® EP-4100, EP-4100G, EP-4100E, EP-4100TX, EP-4300E, EP-4100, EP-4400, EP-4520S, EP-4530, EP-4901, EP-4901E, EP-4000, EP-4005, EP-7001, EP-4080E, EPU-6, EPU-7N, EPU-11F, EPU-15F, EPU-1395, EPU-73B, EPU-17, EPU-17T-6, EPR-1415-1, EPR-2000, EPR-2007, Adeka Glycerol® ED-503, ED-503G,The same as ED-506, the same as ED-523T, the same as ED-505 (above, manufactured by ADEKA CORPORATION), Sumiepoxy (registered trademark) ELM-434, the same as ELM-434L, the same as ELM-434VL, the same as ELM-100, the same as ELM-100H (above, manufactured by Sumitomo Chemical Company, Limited), Epolite M-1230, the same as 40E, the same as 100E, the same as 200E, the same as 400E, the same as 70P, the same as 200P, the same as 400P, the same as 1500NP, the same as 1600, the same as 80MF, the same as 4000, the same as 3002(N) (above, manufactured by Kyoeisha Chemical Co., Ltd.) and THI-DE (manufactured by ENEOS Corporation), etc., are polyfunctional epoxy resins.

[0046] (D) The compound of the component may be used alone or in combination of two or more.

[0047] When the positive photosensitive resin composition of the present invention contains the (D) component, the content of the (D) component is 5 parts by mass to 100 parts by mass, preferably 10 parts by mass to 50 parts by mass, based on 100 parts by mass of the (A) component. By setting the content of the (D) component within the above range, chemical resistance can be improved.

[0048] [(E) component] The (E) component contained as an optional component in the positive photosensitive resin composition of the present invention is not particularly limited as long as it is a substance capable of transferring the energy of irradiated light to other substances. Examples thereof include p-benzoquinone, 1-phenyl-1,2-propanedione, phenanthrene, anthracene, 9,10-diethoxyanthracene, 9,10-dipropyloxyanthracene, 9,10-dibutyloxyanthracene, 9,10-dioctanoyloxyanthracene, 3,7-dimethoxyanthracene, pyrene, perylene, xanthone, thioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2-isopropylthioxanthone.

[0049] (E) The compound of the component may be used alone or in combination of two or more.

[0050] When the positive photosensitive resin composition of the present invention contains the component (E), the content of the component (E) is 0.01 to 5 parts by mass, preferably 0.05 to 3 parts by mass, more preferably 0.1 to 1 part by mass with respect to 100 parts by mass of the component (A). By setting the content of the component (E) within the above range, a sensitizing effect can be effectively exhibited on the photoacid generator of the component (C) without impairing transparency, and chemical resistance can be improved.

[0051] [Solvent] The solvent contained in the positive photosensitive resin composition of the present invention is not particularly limited as long as it can dissolve the components (A) to (C) and optional components added as necessary. For example, all organic solvents such as hydrocarbons, halogenated hydrocarbons, ethers, alcohols, aldehydes, ketones, esters, amides, and nitriles can be used.

[0052] Examples of the hydrocarbons include n-pentane, cyclopentane, methylcyclopentane, n-hexane, isohexane, cyclohexane, methylcyclohexane, ethylcyclohexane, n-heptane, benzene, toluene, o-xylene, m-xylene, p-xylene, and mesitylene.

[0053] Examples of the halogenated hydrocarbons include dichloromethane, chloroform, carbon tetrachloride, chloroethane, dichloroethane, trichloroethane, tetrachloroethane, hexachloroethane, dichloroethylene, trichloroethylene, tetrachloroethylene, chlorobenzene, hydrofluorocarbon, and perfluorocarbon.

[0054] Examples of the ethers include diethyl ether, di-n-propyl ether, diisopropyl ether, di-n-butyl ether, diisobutyl ether, di-tert-butyl ether, di-n-pentyl ether, diisopentyl ether, di-n-hexyl ether, methyl-n-propyl ether, methyl isopropyl ether, ethyl-n-propyl ether, ethyl isopropyl ether, n-butyl methyl ether, isobutyl methyl ether, tert-butyl methyl ether, n-butyl ethyl ether, isobutyl ethyl ether, tert-butyl ethyl ether, methyl-n-pentyl ether, cyclopentyl methyl ether, n-hexyl methyl ether, cyclohexyl methyl ether, tetrahydrofuran, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, and tripropylene glycol dibutyl ether, etc.

[0055] Examples of the alcohols include monohydric alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-2-butanol, neopentyl alcohol, cyclopentanol, methylcyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, cyclohexanol, methylcyclohexanol, 1-heptanol, 2-heptanol, 3-heptanol, 4-heptanol, 1-octanol, 2-octanol, 3-octanol, 4-octanol, 2-ethyl-1-hexanol, benzyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, and tripropylene glycol monobutyl ether; and polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-propanediol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-pentanediol, 1,4-pentanediol, 1,3-pentanediol, 1,2-pentanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, and 1,Examples of the dihydric alcohols include dihydric alcohols such as 2-hexanediol, and trihydric alcohols such as glycerin.

[0056] Examples of the aldehydes include ethanal, propanal, 2-methyl-1-propanal, butanal, 3-methylbutanal, pentanal, benzaldehyde, and the like.

[0057] Examples of the ketones include acetone, 2-butanone, 2-pentanone, 3-pentanone, cyclopentanone, 2,4-pentanedione, 4-methyl-2-pentanone, 4-hydroxy-4-methyl-2-pentanone, cyclohexanone, 2-heptanone, and the like.

[0058] Examples of the esters include methyl formate, ethyl formate, n-propyl formate, isopropyl formate, n-butyl formate, isobutyl formate, tert-butyl formate, n-pentyl formate, isopentyl formate, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, tert-butyl acetate, n-pentyl acetate, isopentyl acetate, cyclopentyl acetate, n-hexyl acetate, isohexyl acetate, cyclohexyl acetate, n-heptyl acetate, isoheptyl acetate, n-octyl acetate, isooctyl acetate, benzyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol diacetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, triethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol diacetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, tripropylene glycol monomethyl ether acetate, tripropylene glycol monoethyl ether acetate, tripropylene glycol monobutyl ether acetate, methyl propionate, ethyl propionate, n-propyl propionate, isopropyl propionate, n-butyl propionate, isobutyl propionate, tert-butyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, isobutyl butyrate, tert-butyl butyrate, methyl isobutyrate,Ethyl isobutyrate, n-propyl isobutyrate, isopropyl isobutyrate, n-butyl isobutyrate, isobutyl isobutyrate, tert-butyl isobutyrate, methyl lactate, ethyl lactate, n-propyl lactate, isopropyl lactate, n-butyl lactate, isobutyl lactate, tert-butyl lactate, methyl acetoacetate, ethyl acetoacetate, n-propyl acetoacetate, isopropyl acetoacetate, n-butyl acetoacetate, isobutyl acetoacetate, tert-butyl acetoacetate, dimethyl malonate, diethyl malonate, triacetin, γ-butyrolactone, γ-valerolactone, γ-caprolactone, δ-valerolactone, δ-caprolactone, and ε-caprolactone, etc. can be mentioned.

[0059] Examples of the amides include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylisobutylamide, N-methylpyrrolidone, and N-ethylpyrrolidone, etc.

[0060] Examples of the nitriles include acetonitrile, propionitrile, and butyronitrile, etc.

[0061] These solvents may be used alone or in combination of two or more.

[0062] Among these solvents, from the viewpoint of improving the leveling property of the cured film formed by coating the positive photosensitive resin composition of the present invention on a substrate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monopropyl ether, 2-heptanone, ethyl lactate, n-butyl lactate, cyclopentanone, and cyclohexanone are preferable.

[0063] [Surfactant, other additives] For the purpose of improving coatability, the positive photosensitive resin composition of the present invention may optionally contain a surfactant. Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkyl aryl ethers such as polyoxyethylene octyl phenyl ether and polyoxyethylene nonyl phenyl ether; polyoxyethylene / polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; nonionic surfactants; Fluorad (registered trademark) EF301, EF303, EF352 (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.); Megafac (registered trademark) F-171, F-173, R-30, R-40, R-40-LM (manufactured by DIC Corporation); Florard FC430, FC431 (manufactured by Sumitomo 3M Limited); Asahi Guard (registered trademark) AG710, Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by AGC Inc.); fluorine-based surfactants such as the Ftergent series including FTX-206D, FTX-212D, FTX-218, FTX-220D, FTX-230D, FTX-240D, FTX-212P, FTX-220P, FTX-228P, FTX-240G (manufactured by Neos Co., Ltd.); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). These surfactants may be used alone or in combination of two or more.

[0064] When the positive photosensitive resin composition of the present invention contains a surfactant, the content of the surfactant is 0.001 part by mass to 3 parts by mass, preferably 0.005 part by mass to 1 part by mass, and more preferably 0.01 part by mass to 0.5 part by mass with respect to 100 parts by mass of the total solid content excluding the solvent in the positive photosensitive resin composition.

[0065] The positive photosensitive resin composition of the present invention can further contain additives such as a curing aid, an antioxidant, an ultraviolet absorber, a plasticizer, and an adhesion aid as necessary, as long as the effects of the present invention are not impaired.

[0066] [Method for preparing positive photosensitive resin composition] The method for preparing the positive photosensitive resin composition of the present invention is not particularly limited. For example, a method of dissolving the components (A) to (C) and optionally other components in a solvent to form a uniform solution can be mentioned. Further, if necessary, the solution may be filtered using a filter having a pore size of 0.1 μm to 10 μm.

[0067] [Method for producing microlens] An example of a method for producing a microlens using the positive photosensitive resin composition of the present invention will be described. [Coating step] The positive photosensitive resin composition of the present invention is applied onto a substrate (for example, a semiconductor substrate, a glass substrate, a quartz substrate, a plastic substrate, a silicon wafer, and a substrate having elements such as various metal films or color filters formed on the surfaces thereof) by an appropriate coating method such as a spinner or a coater. Preferably, thereafter, pre-baking is performed using a heating means such as an oven or a hot plate to remove the solvent, thereby forming a resin film. The pre-baking conditions are appropriately selected from the range of a baking temperature of 60°C to 130°C and a baking time of 20 seconds to 30 minutes. The film thickness of the formed resin film is 0.1 μm to 10 μm, preferably 0.2 μm to 5 μm.

[0068] [First exposure step] After the coating step, at least a part of the formed resin film is exposed through a predetermined mask. As the light rays for exposure, for example, g-line, i-line, KrF excimer laser, and ArF excimer laser can be used. The exposure dose is appropriately selected from the range of 20 mJ / cm 2 to 2000 mJ / cm 2 and is appropriately selected from the range of 20 mJ / cm to 2000 mJ / cm

[0069] <Development step> After the first exposure step, the exposed portion of the resin film is removed with a developer to form a pattern of the unexposed portion of the resin film. The development method is not particularly limited, and examples include the dip method, the paddle method, and the spray method. The development conditions are appropriately selected from the range of a development temperature of 5°C to 50°C and a development time of 10 seconds to 300 seconds. The developer to be used is not particularly limited as long as it can remove the exposed portion. Examples include alkaline aqueous solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, sodium phosphate, potassium phosphate, ammonia, tetramethylammonium hydroxide (TMAH), and tetraethylammonium hydroxide (TEAH). Also, a developer obtained by adding an appropriate amount of a surfactant or an organic solvent to an alkaline aqueous solution may be used. These developers may be used alone or in combination of two or more.

[0070] After development, it may be rinsed with a rinse solution to wash away the developer. After development or rinsing, in order to remove the remaining developer or rinse solution, it can be dried by rotating with a spinable device such as a spinner or a coater, or by blowing compressed air or compressed nitrogen.

[0071] <Reflow step> The pattern formed after the development process may include a reflow process of heating using a heating means such as an oven or a hot plate before the second exposure process described later. The reflow conditions are appropriately selected from the range of a baking temperature of 80°C to 130°C and a baking time of 1 minute to 90 minutes. Note that even if the reflow process is omitted, a micro lens having a spherical segment shape or a hemispherical shape can be produced, but by including the reflow process, it becomes possible to produce a micro lens having a spherical segment shape or a hemispherical shape at a lower temperature.

[0072] <Second Exposure Process> After the development process or after the reflow process, the pattern is further exposed. As the light rays for exposure, for example, g-line, i-line, KrF excimer laser, and ArF excimer laser can be used. The exposure amount is appropriately selected from the range of 100 mJ / cm 2 to 5000 mJ / cm 2 and is appropriately selected from the range of 100 mJ / cm to 5000 mJ / cm.

[0073] <Post-Baking Process> After the second exposure process, the pattern is heated using a heating means such as an oven or a hot plate. The post-baking conditions are appropriately selected from the range of a baking temperature of 80°C to 130°C and a baking time of 1 minute to 90 minutes.

Examples

[0074] Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

[0075] The apparatus and conditions used for measuring the polystyrene-reduced weight average molecular weight M of the copolymer are as follows. W The apparatus and conditions used for measuring the polystyrene-reduced weight average molecular weight M of the copolymer are as follows. Apparatus: GPC system manufactured by JASCO Corporation Columns: Shodex (registered trademark) KF-804L and KF-803L Column oven: 40°C Flow rate: 1 mL / min Eluent: Tetrahydrofuran Sample concentration: 10 mg / mL Sample injection volume: 20 μL Standard substance: Monodisperse polystyrene Detector: Differential refractometer

[0076] The compounds used in the examples and comparative examples are as follows. <Component (B)> B-1: Condensate of 1 mol of 4,4’-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol and 1.5 mol of 1,2-naphthoquinone-2-diazide-5-sulfonic acid chloride <Component (C)> C-1: Adeka Arcles (registered trademark) SP-606 (manufactured by ADEKA CORPORATION) C-2: CPI-110P (manufactured by San-Apro Ltd.) <Component (D)> D-1: Epolead (registered trademark) GT401 (manufactured by Daicel Corporation) <Component (E)> E-1: 2-Isopropylthioxanthone (manufactured by Tokyo Chemical Industry Co., Ltd.) <Surfactant> R-40: Megafac (registered trademark) R-40 (manufactured by DIC Corporation)

[0077] [Synthesis of Component (A)] <Synthesis Example 1> A stir bar and 50 g of propylene glycol monomethyl ether as a solvent were placed in a flask, which was then immersed in a heated oil bath and maintained at 87°C. Next, a solution prepared by mixing 30 g of N-(4-hydroxyphenyl)methacrylamide as the monomer represented by the formula (1), 60 g of 3,4-epoxycyclohexylmethyl methacrylate (the formula (2-6)) as the monomer containing an epoxy ring, 10 g of 2-hydroxyethyl methacrylate (the formula (3-5)) as the monomer containing a hydroxy group with an acid dissociation constant pKa of 14 or more, 4.5 g of 2,2'-azobisisobutyronitrile as a thermal radical generator, and 194 g of propylene glycol monomethyl ether as a solvent was placed in a dropping funnel, connected to the flask, purged with nitrogen, and then added dropwise over 3 hours with stirring. After completion of the addition, the mixture was further reacted for 15 hours to obtain a copolymer solution (solid content concentration: 30% by mass). The weight average molecular weight M W in terms of polystyrene of the obtained copolymer was 8,000. Hereinafter, in this specification, the copolymer obtained in Synthesis Example 1 is represented as A-1.

[0078] <Synthesis Example 2> A copolymer solution (solid content concentration: 30% by mass) was obtained in the same manner as in Synthesis Example 1, except that 25 g of N-(4-hydroxyphenyl)methacrylamide, 15 g of 2-hydroxyethyl methacrylate, and 4.6 g of 2,2'-azobisisobutyronitrile were used. The weight average molecular weight M W in terms of polystyrene of the obtained copolymer was 8,000. Hereinafter, in this specification, the copolymer obtained in Synthesis Example 2 is represented as A-2.

[0079] <Synthesis Example 3> A copolymer solution (solid content concentration: 30% by mass) was obtained in the same manner as in Synthesis Example 1, except that 20 g of N-(4-hydroxyphenyl)methacrylamide, 20 g of 2-hydroxyethyl methacrylate, and 4.7 g of 2,2'-azobisisobutyronitrile were used. The weight average molecular weight M W in terms of polystyrene of the obtained copolymer was 8,000. Hereinafter, in this specification, the copolymer obtained in Synthesis Example 3 is represented as A-3.

[0080] <Synthesis Example 4> A stir bar and 50 g of propylene glycol monomethyl ether as a solvent were placed in a flask, which was then immersed in a heated oil bath and maintained at 80°C. Next, a solution prepared by mixing 40 g of N-(4-hydroxyphenyl)methacrylamide and 60 g of 3,4-epoxycyclohexylmethyl methacrylate as monomers, 4.4 g of 2,2'-azobisisobutyronitrile as a thermal radical generator, and 194 g of propylene glycol monomethyl ether as a solvent was placed in a dropping funnel, connected to the said flask, purged with nitrogen, and then added dropwise with stirring over 3 hours. After completion of the dropping, the mixture was further reacted for 15 hours to obtain a copolymer solution (solid content concentration: 30% by mass). The polystyrene-reduced weight average molecular weight M W was 11,000. Hereinafter, in this specification, the copolymer obtained in Synthesis Example 4 is represented as A-4.

[0081] <Synthesis Example 5> A stir bar and 90 g of propylene glycol monomethyl ether as a solvent were placed in a flask, which was then immersed in a heated oil bath and maintained at 70°C. Next, a solution prepared by mixing 10 g of acrylic acid, 30 g of 4-hydroxybutyl acrylate, and 60 g of styrene as monomers, 4.5 g of 2,2'-azobisisobutyronitrile as a thermal radical generator, and 105 g of propylene glycol monomethyl ether as a solvent was placed in a dropping funnel, connected to the said flask, purged with nitrogen, and then added dropwise with stirring over 3 hours. After completion of the dropping, the mixture was further reacted for 15 hours to obtain a copolymer solution (solid content concentration: 35% by mass). The polystyrene-reduced weight average molecular weight M W was 18,000. Hereinafter, in this specification, the copolymer obtained in Synthesis Example 5 is represented as A-5.

[0082] [Preparation of Positive-Type Photosensitive Resin Composition] <Example 1> As component (A), 70.0 g (21.0 g as solid content) of copolymer A-1 obtained in Synthesis Example 1, 4.8 g of B-1 as component (B), 0.2 g of C-1 as component (C), 6.3 g of D-1 as component (D), 0.01 g of R-40 as surfactant, 6.6 g of propylene glycol monomethyl ether and 23.8 g of propylene glycol monomethyl ether acetate as solvents were blended to form a homogeneous solution. Then, it was filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solid content concentration: 29% by mass).

[0083] <Example 2> As component (A), 70.0 g (21.0 g as solid content) of copolymer A-1 obtained in Synthesis Example 1, 4.8 g of B-1 as component (B), 0.3 g of C-2 as component (C), 6.3 g of D-1 as component (D), 0.01 g of R-40 as surfactant, 6.8 g of propylene glycol monomethyl ether and 23.9 g of propylene glycol monomethyl ether acetate as solvents were blended to form a homogeneous solution. Then, it was filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solid content concentration: 29% by mass).

[0084] <Example 3> As component (A), 70.0 g (21.0 g as solid content) of copolymer A-2 obtained in Synthesis Example 2, 4.8 g of B-1 as component (B), 0.2 g of C-1 as component (C), 6.3 g of D-1 as component (D), 0.01 g of R-40 as surfactant, 6.6 g of propylene glycol monomethyl ether and 23.8 g of propylene glycol monomethyl ether acetate as solvents were blended to form a homogeneous solution. Then, it was filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solid content concentration: 29% by mass).

[0085] <Example 4> As component (A), 70.0 g (21.0 g as solid content) of copolymer A-3 obtained in Synthesis Example 3, 4.8 g of B-1 as component (B), 0.2 g of C-1 as component (C), 6.3 g of D-1 as component (D), 0.01 g of R-40 as surfactant, 30.2 g of propylene glycol monomethyl ether and 79.2 g of propylene glycol monomethyl ether acetate as solvents were blended to obtain a homogeneous solution. Then, it was filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solid content concentration: 17% by mass).

[0086] <Example 5> As component (A), 70.0 g (21.0 g as solid content) of copolymer A-3 obtained in Synthesis Example 3, 4.8 g of B-1 as component (B), 0.2 g of C-1 as component (C), 0.01 g of R-40 as surfactant, 25.1 g of propylene glycol monomethyl ether and 74.1 g of propylene glycol monomethyl ether acetate as solvents were blended to obtain a homogeneous solution. Then, it was filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solid content concentration: 15% by mass).

[0087] <Example 6> As component (A), 84.0 g (25.2 g as solid content) of copolymer A-3 obtained in Synthesis Example 3, 5.8 g of B-1 as component (B), 0.2 g of C-1 as component (C), 7.6 g of D-1 as component (D), 0.05 g of E-1 as component (E), 0.01 g of R-40 as surfactant, 36.2 g of propylene glycol monomethyl ether and 95.0 g of propylene glycol monomethyl ether acetate as solvents were blended to obtain a homogeneous solution. Then, it was filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solid content concentration: 17% by mass).

[0088] <Comparative Example 1> 70.0 g (21.0 g as solid content) of copolymer A-4 obtained in Synthesis Example 4 not corresponding to component (A), 4.8 g of B-1 as component (B), 0.2 g of C-1 as component (C), 6.3 g of D-1 as component (D), 0.01 g of R-40 as surfactant, 9.4 g of propylene glycol monomethyl ether and 25.0 g of propylene glycol monomethyl ether acetate as solvents were blended to obtain a homogeneous solution. Then, it was filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solid content concentration: 28 mass%).

[0089] <Comparative Example 2> 60.0 g (21.0 g as solid content) of copolymer A-5 obtained in Synthesis Example 5 not corresponding to component (A), 4.8 g of B-1 as component (B), 0.2 g of C-1 as component (C), 10.5 g of D-1 as component (D), 0.01 g of R-40 as surfactant, 3.8 g of propylene glycol monomethyl ether and 35.1 g of propylene glycol monomethyl ether acetate as solvents were blended to obtain a homogeneous solution. Then, it was filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solid content concentration: 32 mass%).

[0090] The components contained in the positive photosensitive resin compositions of Examples 1 to 6, and the contents of components (B) to (E) with respect to 100 parts by mass of component (A) are shown in Table 1.

Table 1

[0091] [Patternability Evaluation] The positive photosensitive resin compositions prepared in Examples 1 to 6 and Comparative Examples 1 and 2 were each applied onto a silicon wafer using a spin coater, prebaked on a hot plate at 80°C for 90 seconds to form a resin film having the film thickness described in Table 2. Next, for the resin film, first exposure was performed at the exposure amount described in Table 2 through a predetermined mask using an i-line stepper (NSR-2205i12D, NA = 0.63, manufactured by Nikon Corporation). Here, as the mask, a mask for forming a 4-μm × 4-μm square dot pattern / 4-μm space was used for the resin film with a film thickness of 4 μm (Examples 1 to 3 and Comparative Examples 1 and 2), and a mask for forming a 1-μm × 1-μm square dot pattern / 1-μm space was used for the resin film with a film thickness of 1 μm (Examples 4 to 6). Then, within 10 minutes from the first exposure, development was performed using an aqueous solution of tetramethylammonium hydroxide (TMAH) with a concentration of 2.38% by mass to form a 4-μm × 4-μm square dot pattern for the resin film with a film thickness of 4 μm and a 1-μm × 1-μm square dot pattern for the resin film with a film thickness of 1 μm. The formed square dot pattern was observed at a magnification of 5000 times using a scanning electron microscope. When the residue of the resin film could be clearly visually recognized in the space portion between adjacent square dot patterns, it was evaluated as patterning property “×”, and when the residue of the resin film could not be visually recognized, it was evaluated as patterning property “○”. The evaluation results are shown in Table 2.

[0092] [Table 2]

[0093] [Lens Shape Evaluation] Using the positive photosensitive resin compositions prepared in Examples 1 to 6 and Comparative Examples 1 and 2, a square dot pattern of 4 μm × 4 μm was formed on a resin film with a thickness of 4 μm, and a square dot pattern of 1 μm × 1 μm was formed on a resin film with a thickness of 1 μm on a silicon wafer according to the procedure described in the [Patterning Property Evaluation]. Subsequently, the square dot pattern was baked on a hot plate at the reflow temperature shown in Table 2 for 5 minutes. Further, after performing the second exposure on the entire surface of the square dot pattern at 500 mJ / cm 2 using the i-line stepper, a microlens was fabricated by baking on a hot plate at the post-bake temperature shown in Table 2 for 10 minutes. Further, without baking at the reflow temperature (indicated as "none" for the reflow temperature in Table 2) on the entire surface of a 1 μm × 1 μm square dot pattern formed using the positive photosensitive resin composition prepared in Example 4, after performing the second exposure at 500 mJ / cm 2 using the i-line stepper, a microlens was fabricated by baking on a hot plate at the post-bake temperature shown in Table 2 for 10 minutes. Those having a square prism or frustum of a square pyramid shape among the fabricated microlenses were evaluated as "□", and those having a spherical segment shape or a hemispherical shape were evaluated as "〇". The evaluation results are shown in Table 2.

[0094] [Drug Resistance Evaluation] The positive photosensitive resin compositions prepared in Examples 1 to 6 and Comparative Examples 1 and 2 were each applied onto a silicon wafer using a spin coater, pre-baked on a hot plate at 80 °C for 90 seconds to form a resin film having the film thickness shown in Table 2. Next, 500 mJ / cm 2After exposure at , baking was performed on a hot plate at the post-bake temperature shown in Table 2 for 10 minutes to form a cured film. The silicon wafer on which the cured film was formed was immersed in propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, and an aqueous solution of tetramethylammonium hydroxide (TMAH) with a concentration of 2.38% by mass at 23°C for 5 minutes each. The film thickness of the cured film before and after immersion was measured, and the change in film thickness before and after immersion was calculated. Among the solvents used for the immersion, if there is a film thickness increase or decrease of 10% or more with respect to the film thickness before immersion for any one of them, the chemical resistance is evaluated as "×", and if the film thickness increase or decrease for all solvents is less than 10%, the chemical resistance is evaluated as "○". The evaluation results are shown in Table 2.

[0095] [Transparency Evaluation] The positive photosensitive resin compositions prepared in Examples 1 to 6 and Comparative Examples 1 and 2 were each applied onto a quartz substrate using a spin coater, and pre-baked on a hot plate at 80°C for 90 seconds to form a resin film having the film thickness shown in Table 2. Next, with respect to the entire surface of the resin film, exposure was performed at 500 mJ / cm 2 using the i-line stepper. After that, baking was performed on a hot plate at the post-bake temperature shown in Table 2 for 10 minutes to form a cured film. The transmittance of the quartz substrate on which the cured film was formed was measured at a wavelength of 400 nm using an ultraviolet-visible spectrophotometer UV-2550 (manufactured by Shimadzu Corporation). If the transmittance at a wavelength of 400 nm is less than 90%, the transparency is evaluated as "×", and if it is 90% or more, the transparency is evaluated as "○". The evaluation results are shown in Table 2.

[0096] [Long-Term Reliability Evaluation] [HTS Test] Using the positive photosensitive resin compositions prepared in Examples 1 to 6, a cured film was formed on a quartz substrate according to the procedure described in [Transparency Evaluation]. After heating the quartz substrate on which the cured film was formed in an oven at 100 °C for 1,000 hours, the transmittance at a wavelength of 400 nm was measured using the ultraviolet-visible spectrophotometer. When the transmittance increased or decreased by 5% or more with respect to the transmittance at a wavelength of 400 nm before heating for 1,000 hours, it was evaluated as "×", and when the transmittance increase or decrease was less than 5%, it was evaluated as "○". The evaluation results are shown in Table 2.

[0097] <THS Test> Using the positive photosensitive resin compositions prepared in Examples 1 to 6, a cured film was formed on a quartz substrate according to the procedure described in [Transparency Evaluation]. After storing the quartz substrate on which the cured film was formed in a thermostatic and humidistatic chamber maintained at 85 °C inside and 85% relative humidity for 1,000 hours, the transmittance at a wavelength of 400 nm was measured using the ultraviolet-visible spectrophotometer. When the transmittance increased or decreased by 5% or more with respect to the transmittance at a wavelength of 400 nm before storage for 1,000 hours, it was evaluated as "×", and when the transmittance increase or decrease was less than 5%, it was evaluated as "○". The evaluation results are shown in Table 2.

[0098] <Xenon Arc Test> Using the positive photosensitive resin compositions prepared in Examples 1 to 6, a cured film was formed on a quartz substrate according to the procedure described in [Transparency Evaluation]. A cut filter (L38, manufactured by Shibuya Optics Co., Ltd.) was attached to the quartz substrate on which the cured film was formed, and after exposure in a xenon arc tester (Q-SUN Xe-1, manufactured by Q-Lab Corporation) for 25 million [lx·h], the transmittance at a wavelength of 400 nm was measured using the ultraviolet-visible spectrophotometer. When the transmittance increased or decreased by 5% or more with respect to the transmittance at a wavelength of 400 nm before exposure by the xenon arc tester, it was evaluated as "×", and when the transmittance increase or decrease was less than 5%, it was evaluated as "○".

[0099] From the results in Table 2, by using the positive photosensitive resin composition of the present invention, positive patterning can be achieved without residue, and even in a low-temperature process of 130°C or lower, micro-lenses in a spherical defect shape or a hemispherical shape can be formed, and it has been shown that these micro-lenses have excellent transparency, chemical resistance, and long-term reliability.

Claims

1. A positive photosensitive resin composition comprising the following component (A), the following component (B), the following component (C), and a solvent. Component (A): A copolymer of a monomer represented by the following formula (1), a monomer containing an epoxy ring, and a monomer containing a hydroxy group having an acid dissociation constant pKa of 14 or more, the copolymer not containing a carboxy group and a carboxylic anhydride group Component (B): A quinonediazide compound Component (C): A photoacid generator 【Chemical 1】 (wherein, R ０ represents a hydrogen atom or a methyl group, R １ represents a single bond or an alkylene group having 1 or 2 carbon atoms, R ２ represents a methyl group, a represents 1 or 2, and b represents an integer of 0 to 2.)

2. The monomer containing an epoxy ring in the component (a2) is a monomer represented by the following formula (2), and the monomer containing a hydroxy group having an acid dissociation constant pKa of 14 or more in the component (a3) is as follows The positive photosensitive resin composition according to claim 1, which is a monomer represented by the formula (3). [Chemical Formula 2] (wherein, R ０ each independently represents a hydrogen atom or a methyl group, and R ３ represents a divalent organic group represented by the following formula (I), and R ４ represents a monovalent organic group represented by the following formula (4) or the following formula (5), and R ５ represents a monovalent organic group represented by the following formula (I´). ) [Chemical Formula 3] (In the formula, c represents an integer from 0 to 3, d represents an integer from 1 to 3, e each independently represents an integer from 2 to 6, * represents a bond with an alkenyl group of the monomer represented by the formula (2) or the formula (3), and · represents a bond with a monovalent organic group represented by the formula (4) or the formula (5).)

3. The positive photosensitive resin composition according to claim 1, wherein the component (A) is a copolymer having a structural unit represented by the following formula (1a), a structural unit represented by the following formula (2a), and a structural unit represented by the following formula (3a). 【Chemical Formula 4】 (In the formula, R ０ each independently represents a hydrogen atom or a methyl group, R １ represents a single bond or an alkylene group having 1 or 2 carbon atoms, R ２ represents a methyl group, b represents an integer of 0 to 2, R ４ represents a monovalent organic group represented by the following formula (4) or the following formula (5), and e represents an integer of 2 to 6.) 【Chemical Formula 5】

4. The positive photosensitive resin composition according to claim 1, wherein the polystyrene-reduced weight average molecular weight of the component (A) is from 5,000 to 30,000.

5. The positive photosensitive resin composition according to claim 1, wherein the component (C) is a nonionic photoacid generator.

6. The positive photosensitive resin composition according to claim 5, wherein the nonionic photoacid generator is a photoacid generator represented by the following formula (6). [Chemical Formula 6] (In the formula, R ６ represents a hydrocarbon group or a perfluoroalkyl group having 1 to 10 carbon atoms, and R ７ represents a linear alkyl group or alkoxy group having 1 to 8 carbon atoms, or a branched alkyl group or alkoxy group having 3 to 8 carbon atoms.)

7. The positive photosensitive resin composition according to claim 1, further comprising the following component (D). Component (D): A polyfunctional epoxy compound

8. The positive photosensitive resin composition according to claim 1, further comprising the following component (E). Component (E): A sensitizer

9. The positive photosensitive resin composition according to claim 1, which is for producing microlenses.

10. A cured film obtained from the positive photosensitive resin composition according to any one of claims 1 to 9.

11. A microlens produced from the positive photosensitive resin composition according to any one of claims 1 to 9.

12. A method for manufacturing a microlens, comprising: a coating step of coating a positive photosensitive resin composition according to any one of claims 1 to 9 on a substrate to form a resin film; a first exposure step of exposing at least a part of the resin film after the coating step; a development step of removing the exposed portion of the resin film with a developer after the first exposure step to form a pattern of the unexposed portion of the resin film; a second exposure step of further exposing the pattern after the development step; and a post-bake step of heating the pattern at a temperature of 130 °C or lower after the second exposure step.

13. The method for manufacturing a microlens according to claim 12, further comprising a reflow step of heating the pattern at a temperature of 130 °C or lower after the development step and before the second exposure step.

14. The method for manufacturing a microlens according to claim 12, wherein the substrate is a substrate on which a color filter is formed.

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