Positive photosensitive resin composition containing 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

Positive photosensitive resin composition containing specific copolymer

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

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

[0003] One known method for producing microlenses is the etch-back method (see, for example, Patent Document 1). Specifically, a microlens resin layer is formed on a color filter, a positive resist is applied to the resin layer, a lens pattern is formed by exposing and developing a portion of the resist and, if necessary, heating the resist, and then etching back the microlens using the lens pattern as an etching mask to transfer the lens pattern shape to the microlens resin layer, thereby producing a microlens.

[0004] On the other hand, from the viewpoint of reducing manufacturing costs, a method has been proposed in which the positive resist is used directly as a microlens. In this case, since it is necessary to have both the properties of a resist and the properties of a microlens, a photosensitive resin composition is required that not only allows positive patterning but also allows the formed microlenses to have excellent transparency and chemical resistance. Here, the shape of the microlens varies depending on the design of the element, and various shapes such as a prism, a cylinder, a truncated pyramid, a truncated cone, and a spherical indentation may be required. When producing a spherical indentation-shaped microlens, a known method involves forming a pattern such as a prism or a truncated pyramid and then reflowing (fluidizing by heating, also known as melt flow or thermal flow).

[0005] For example, Patent Document 2 proposes a photosensitive resin composition containing an alkali-soluble copolymer and a quinone diazide group-containing compound. By using this composition, a resin pattern can be formed by exposure and development, and then the phenolic hydroxyl groups and epoxy groups can be crosslinked by heating to obtain a microlens.

[0006] However, in recent years, the increasing use of devices with low heat resistance, such as organic devices and flexible devices, has led to an increasing demand for lower process temperatures. Accordingly, there is a demand for positive-type photosensitive resin compositions that can produce microlenses with good performance even in low-temperature processes. When producing microlenses with a spherical octave shape, sufficient reflow is required even at low temperatures. Specifically, the upper process temperature limit is required to be 150°C, and more recently, 130°C has become more common. The photosensitive resin composition described in Patent Document 2 employs thermal curing of phenolic hydroxyl groups and epoxy groups. However, this thermal curing reaction typically requires high-temperature conditions exceeding 150°C, and is therefore not suitable for low-temperature processes below 130°C.

[0007] Therefore, Patent Document 3 proposes a radiation-sensitive resin composition containing an alkali-soluble copolymer, a 1,2-quinone diazide compound, and a compound that generates an acid upon exposure to radiation. By using this composition, a resin pattern can be formed by exposure and development, and then a strong acid can be generated within the resin pattern by re-exposure, allowing cationic polymerization to proceed, thereby enabling a lower temperature process. However, the monomer that forms the alkali-soluble copolymer used in this composition contains a carboxylic acid or a carboxylic acid anhydride, and there is a risk of residue being generated when the copolymer is patterned. If a portion of the resin remains in the spaces between patterns, it can have a significant adverse effect on the characteristics of the device, so a photosensitive resin composition that enables positive patterning without leaving any residue is needed.

[0008] Furthermore, Patent Document 4 proposes a radiation-sensitive resin composition containing an alkali-soluble polymer, a quinone diazide compound, and a compound that generates an acid having a pKa of 4.0 or less, but the alkali-soluble polymer is not mentioned in terms of long-term reliability (HTS test, THS test, xenon arc test, etc.) other than storage stability, and its characteristics are unknown. The organic devices and flexible devices must have reliability that is durable enough for practical use, and therefore there is a demand for a photosensitive resin composition that does not deteriorate even after long-term reliability tests such as HTS test (high temperature test), THS test (high temperature and high humidity test), and xenon arc test, and that can be used to produce microlenses with good performance.

[0009] Japanese Patent Laid-Open No. 1-10666 Japanese Patent Laid-Open No. 2007-33518 Japanese Patent Laid-Open No. 2009-75329 Japanese Patent Laid-Open No. 2020-101659

[0010] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a positive photosensitive resin composition that allows positive patterning without leaving any residue, that can form microlenses having a desired spherical or hemispherical shape even in a low-temperature process at 130°C or less, and that allows the formed microlenses to have excellent transparency, chemical resistance, and long-term reliability.

[0011] The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result have completed the present invention. A first aspect of the present invention is a positive photosensitive resin composition comprising the following component (A), component (B), component (C), and a solvent: Component (A): (a1) a monomer represented by the following formula (1), (a2) a monomer containing an epoxy ring, and (a3) ​​a monomer containing a hydroxy group and having an acid dissociation constant pKa of 14 or more, the copolymer containing no carboxy group or carboxylic anhydride group; Component (B): a quinone diazide compound; and Component (C): a photoacid generator. (In the formula, 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.

[0012] The (a2) monomer containing an epoxy ring is, for example, a monomer represented by the following formula (2), and the (a3) ​​monomer 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). (In the formula, R ０ represents a hydrogen atom or a methyl group, 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 (5), and R ５ represents a monovalent organic group represented by the following formula (I'): (In the formula, c represents an integer of 0 to 3, d represents an integer of 1 to 3, e each independently represents an integer of 2 to 6, * represents a bond to the alkenyl group of the monomer represented by formula (2) or (3), and · represents a bond to the monovalent organic group represented by formula (4) or (5).)

[0013] The component (A) is, for example, 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). (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 (5), and e represents an integer of 2 to 6.

[0014] The weight average molecular weight of the component (A) in terms of polystyrene 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): (In the formula, R ６ represents a hydrocarbon group or a perfluoroalkyl group having 1 to 10 carbon atoms; R ７represents a linear alkyl or alkoxy group having 1 to 8 carbon atoms, or a branched alkyl or alkoxy group having 3 to 8 carbon atoms.

[0016] The positive photosensitive resin composition of the present invention may further contain the following component (D): a 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 used for producing, for example, a microlens.

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

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

[0021] A fourth aspect of the present invention is a method for producing a microlens, comprising: 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 portion of the resin film to light after the coating step; a development step of removing the exposed portions of the resin film with a developer after the first exposure step to form a pattern of unexposed portions 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 less after the second exposure step.

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

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

[0024] According to the present invention, a positive photosensitive resin composition can be provided which simultaneously contains component (A), which is a specific copolymer, component (B), which is a quinone diazide compound, and component (C), which is a photoacid generator. This allows for residue-free positive patterning, and enables the formation of microlenses having a desired spherical or hemispherical shape even in a low-temperature process at 130°C or less. The formed microlenses have excellent transparency, chemical resistance, and long-term reliability.

[0025] The positive photosensitive resin composition of the present invention will now 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 whose acid dissociation constant pKa is 14 or more, and is a copolymer containing no carboxy groups or carboxylic anhydride groups. Here, the carboxylic anhydride group is a divalent group represented by -CO-O-CO-: (In the formula, 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.

[0026] (a1) Examples of the monomer represented by 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] The ratio of the monomer (a1) represented by the formula (1) is 5 to 60 parts by mass, preferably 8 to 50 parts by mass, and more preferably 10 to 40 parts by mass, relative to 100 parts by mass of the monomers (a1), (a2), and (a3).

[0028] (a2) The epoxy ring-containing monomer 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). These monomers may be used alone or in combination of two or more.

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

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

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

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

[0033] The glass transition temperature of component (A) is 70° C. to 130° C. By setting the glass transition temperature of component (A) within this range, the component has good reflowability even in a low-temperature process at 130° C. or less, and microlenses with the desired sagittal or hemispherical shape can be produced.

[0034] [Component (B)] The 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, and for example, a condensate of a hydroxy group-containing compound with 1,2-naphthoquinonediazide sulfonic acid halide can be used. Specifically, a compound in which 10 mol % to 100 mol %, preferably 20 mol % to 95 mol %, of the hydroxy groups of the hydroxy group-containing compound are esterified with the 1,2-naphthoquinonediazide sulfonic acid halide can be used. For the condensation reaction, various known methods can be used.

[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 (polyhydroxyphenyl)alkanes such as 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 2,2,4-trimethyl-7,2',4'-trihydroxyflavan;Other compounds such as phenol, o-cresol, m-cresol, p-cresol, hydroquinone, resorcinol, catechol, methyl gallate, ethyl gallate, 2-methyl-2-(2,4-dihydroxyphenyl)-4-(4-hydroxyphenyl)-7-hydroxychroman, 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 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] The 1,2-naphthoquinone diazide sulfonic acid halide is preferably 1,2-naphthoquinone diazide sulfonic acid chloride, more preferably 1,2-naphthoquinone-2-diazide-4-sulfonic acid chloride and 1,2-naphthoquinone-2-diazide-5-sulfonic acid chloride, and even more preferably 1,2-naphthoquinone-2-diazide-5-sulfonic acid chloride.

[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 to 100 parts by mass, preferably 10 to 60 parts by mass, and more preferably 15 to 40 parts by mass, per 100 parts by mass of component (A). By setting the content of component (B) within the above range, the difference in solubility in an alkaline developer between exposed and unexposed areas can be increased without significantly reducing sensitivity, and positive patterning becomes possible with a relatively low exposure dose.

[0039] [Component (C)] The 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 having an acid dissociation constant pKa of 4 or less upon exposure, and examples of the component (C) include ionic photoacid generators and nonionic photoacid generators.

[0040] Examples of the ionic photoacid generator that can be used include the following commercial products and compounds: ADEKA ARCLES (registered trademark) SP-056 and SP-171 (manufactured by ADEKA Corporation), CPI (registered trademark) -100B(40), -100P, -101A, -110A, -110B, -110P, -200K, -210S, -300, -310B, -310FG, -400, -410B, -410S, VC-1FG, and ES-1B (manufactured by San-Apro Co., Ltd.), TPS-TF, TPS-CS, and TPS-PFBS (manufactured by Toyo Gosei Co., Ltd.), and TPS arylsulfonium salts such as 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.); Aryliodonium salts such as ADEKA Arcles (registered trademark) SP-140 (manufactured by ADEKA Corporation), IK-1, IK-1PC (80), IK-1FG (manufactured by San-Apro Co., Ltd.), DTBPI-PFBS (manufactured by Toyo Gosei 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 (manufactured by Midori Chemical Co., Ltd.).

[0041] Examples of the nonionic photoacid generator that can be used include the following commercial products and compounds: N-sulfonyloxyimides such as ADEKA ARCLES (registered trademark) SP-082 and SP-606 (both manufactured by ADEKA Corporation), NA-CS1, NP-TM2, and NP-SE10 (both manufactured by San-Apro Co., 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 Industry Co., Ltd.); Oxime sulfonates such as IRGACURE (registered trademark) PAG103, PAG121, and 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 Industry Co., Ltd.); TAZ-100, TAZ-101, TAZ-102, TAZ-103, TAZ-104, TAZ-107, TAZ-108, TAZ-109, TAZ-110, TAZ- Triazines such as 113, TAZ-114, TAZ-118, TAZ-122, TAZ-123, TAZ-203, and TAZ-204 (all manufactured by Midori Kagaku Co., Ltd.).

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

[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-type photosensitive resin composition of the present invention is 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass, per 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)] The 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, and for example, the following products and compounds can be used. EPICLON (registered trademark) 830, 830-S, 835, 840, 840-S, 850, 850-S, 850-LC, HP-820 (all manufactured by DIC Corporation), DENACOL (registered trademark) 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, and EX-622 (all manufactured by Nagase ChemteX Corporation), jER (registered trademark) 152, jER 630, jER 825, jER 827, jER 828, jER 828EL, jER 828US, and jER 828XA (all manufactured by Mitsubishi Chemical Corporation), TETRAD (registered trademark)-C and TETRAD-X (all manufactured by Mitsubishi Gas Chemical Company, Inc.), and celloxide (registered trademark) 2021P, 2081, Epolead (registered trademark) GT401 (all manufactured by Daicel Corporation), Epotohto (registered trademark) 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 (all manufactured by Nippon Steel Chemical & Material Co., Ltd.), ADEKA RESIN (registered trademark) 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 GLYCILOR (registered trademark) ED-503, ED-503G, ED-506, ED-523T, ED-505 (all manufactured by ADEKA Corporation), Sumiepoxy (registered trademark) ELM-434, ELM-434L, E Multifunctional epoxy resins such as LM-434VL, ELM-100, ELM-100H (all manufactured by Sumitomo Chemical Co., Ltd.), Epolite M-1230, 40E, 100E, 200E, 400E, 70P, 200P, 400P, 1500NP, 1600, 80MF, 4000, and 3002(N) (all manufactured by Kyoeisha Chemical Co., Ltd.), and THI-DE (manufactured by ENEOS Corporation).

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

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

[0048] [Component (E)] The component (E) 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 that can transfer the energy of irradiated light to another substance, and examples thereof include p-toluquinone, 1-phenyl-1,2-propanedione, phenanthrene, anthracene, 9,10-diethoxyanthracene, 9,10-dipropyloxyanthracene, 9,10-dibutoxyanthracene, 9,10-dioctanoyloxyanthracene, 3,7-dimethoxyanthracene, pyrene, perylene, xanthone, thioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2-isopropylthioxanthone.

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

[0050] When the positive-type photosensitive resin composition of the present invention contains component (E), the content of component (E) is 0.01 to 5 parts by mass, preferably 0.05 to 3 parts by mass, and more preferably 0.1 to 1 part by mass, per 100 parts by mass of component (A). By keeping the content of component (E) within the above range, it is possible to effectively exhibit a sensitizing effect on the photoacid generator (C) without impairing transparency, and to improve chemical resistance.

[0051] [Solvent] The solvent contained in the positive photosensitive resin composition of the present invention is not particularly limited as long as it dissolves the components (A) to (C) and any optional components added as needed. 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, hydrofluorocarbons, and perfluorocarbons.

[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, methyl-n-pentyl ether, cyclopentyl methyl ether, n-hexyl methyl ether, cyclohexyl methyl ether, tetrahydrofuran, tetrahydropyran, 1,3 ...methyl-n-pentyl ether, methyl-n-pentyl ether, cyclopentyl methyl ether, n-hexyl methyl ether, cyclohexyl methyl ether, tetrahydrofuran, tetrahydropyran, 1,3-dioxane, methyl-n-pentyl ether, methyl Examples of the olefin copolymer include olefin copolymers such as olefin copolymers, 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.

[0055] Examples of the alcohols include 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, and 2-heptanol. alcohol, 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 monomethyl ether Monohydric alcohols such as 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; 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-1,5-pentanediol,Examples include dihydric alcohols such as 3-pentanediol and 1,2-hexanediol, and trihydric alcohols such as glycerin.

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

[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, and 2-heptanone.

[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, and isopropyl acetate. Hexyl 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 ethylene 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, triplyl glycol propylene 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,Examples of the acetoacetate include 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.

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

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

[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 properties of a cured film formed by applying the positive photosensitive resin composition of the present invention onto 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 preferred.

[0063] [Surfactant and Other Additives] The positive photosensitive resin composition of the present invention may optionally contain a surfactant for the purpose of improving coatability. 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; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; Nonionic surfactants such as polyethylene sorbitan fatty acid esters, Eftop (registered trademark) EF301, EF303, EF352 (all manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Megafac (registered trademark) F-171, F-173, R-30, R-40, R-40-LM (all manufactured by DIC Corporation), Fluorad FC430, FC431 (all manufactured by Sumitomo 3M Limited), Asahiguard (registered trademark) AG710, Surflon (registered trademark) S-382, Surflon SC1 Fluorine-based surfactants such as Ftergent series (manufactured by Neos Corporation), including FTX-01, 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, and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can be mentioned. 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 to 3 parts by mass, preferably 0.005 to 1 part by mass, and more preferably 0.01 to 0.5 parts by mass, relative 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 may 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-type photosensitive resin composition] The method for preparing the positive-type photosensitive resin composition of the present invention is not particularly limited, but may be, for example, a method in which components (A) to (C) and, optionally, other components are dissolved in a solvent to prepare a homogeneous solution. 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 Microlenses] An example of 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 coated onto a substrate (e.g., a semiconductor substrate, a glass substrate, a quartz substrate, a plastic substrate, a silicon wafer, or a substrate having various metal films or elements such as color filters formed on its surface) using an appropriate coating method such as a spinner or coater, and preferably then prebaked using a heating means such as an oven or a hot plate to remove the solvent, thereby forming a resin film. Prebaking conditions are appropriately selected from the ranges of a baking temperature of 60°C to 130°C and a baking time of 20 seconds to 30 minutes. The 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 portion of the formed resin film is exposed to light through a predetermined mask. Examples of light rays that can be used for exposure include g-line, i-line, KrF excimer laser, and ArF excimer laser. The exposure dose is 20 mJ / cm. ２ ~2000mJ / cm ２ The range is appropriately selected.

[0069] <Development Step> After the first exposure step, the exposed portions of the resin film are removed with a developer to form a pattern in the unexposed portions of the resin film. The development method is not particularly limited, but examples include dipping, puddling, and spraying. 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 to 300 seconds. The developer used is not particularly limited as long as it can remove the exposed portions, but examples include alkaline aqueous solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, sodium phosphate, potassium phosphate, ammonia, tetramethylammonium hydroxide (TMAH), and tetraethylammonium hydroxide (TEAH). Alternatively, an alkaline aqueous solution to which an appropriate amount of surfactant or organic solvent has been added may be used as the developer. These developers may be used alone or in combination of two or more.

[0070] After development, the film may be rinsed with a rinse solution to wash away the developer. After development or rinsing, the film may be dried by spinning with a spinning device such as a spinner or coater, or by blowing compressed air or compressed nitrogen onto the film to remove any remaining developer or rinse solution.

[0071] <Reflow Step> The method may include a reflow step in which the pattern formed after the development step is heated using a heating means such as an oven or a hot plate before the second exposure step described below. The reflow conditions are appropriately selected from the ranges of a bake temperature of 80°C to 130°C and a bake time of 1 minute to 90 minutes. Note that although microlenses having a sagittal or hemispherical shape can be produced even if the reflow step is omitted, including the reflow step makes it possible to produce microlenses having a sagittal or hemispherical shape at a lower temperature.

[0072] <Second Exposure Step> After the development step or the reflow step, the pattern is further exposed to light. Examples of light rays that can be used for exposure include g-line, i-line, KrF excimer laser, and ArF excimer laser. The exposure dose is 100 mJ / cm. ２~5000mJ / cm ２ The range is appropriately selected.

[0073] <Post-baking step> After the second exposure step, 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 ranges of a baking temperature of 80° C. to 130° C. and a baking time of 1 minute to 90 minutes.

[0074] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0075] The weight average molecular weight M of the copolymer in terms of polystyrene Ｗ The apparatus and conditions used for the measurement are as follows: Apparatus: GPC system manufactured by JASCO Corporation Column: 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 amount: 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 mole of 4,4'-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl]ethylidene]bisphenol and 1.5 moles 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 Co., 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 flask was charged with a stirrer and 50 g of propylene glycol monomethyl ether as a solvent, and the flask was immersed in a heated oil bath maintained at 87°C. Next, a solution containing 30 g of N-(4-hydroxyphenyl)methacrylamide as a monomer represented by formula (1) above, 60 g of 3,4-epoxycyclohexylmethyl methacrylate (formula (2-6) above) as an epoxy ring-containing monomer, 10 g of 2-hydroxyethyl methacrylate (formula (3-5) above) as a hydroxy group-containing monomer having an acid dissociation constant pKa of 14 or greater, 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 and connected to the flask. After the atmosphere was purged with nitrogen, the mixture was added dropwise over 3 hours with stirring. After the dropwise addition was completed, the mixture was allowed to react for an additional 15 hours to obtain a copolymer solution (solids concentration: 30% by mass). The polystyrene-equivalent weight average molecular weight M of the obtained copolymer Ｗ The molecular weight was 8,000. Hereinafter, in this specification, the copolymer obtained in Synthesis Example 1 will be referred to 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 polystyrene-equivalent weight average molecular weight M Ｗ The molecular weight was 8,000. Hereinafter, in this specification, the copolymer obtained in Synthesis Example 2 will be referred to 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 polystyrene-equivalent weight average molecular weight M Ｗ The molecular weight was 8,000. Hereinafter, in this specification, the copolymer obtained in Synthesis Example 3 will be referred to as A-3.

[0080] Synthesis Example 4 A flask was charged with a stirrer and 50 g of propylene glycol monomethyl ether as a solvent, and the flask was immersed in a heated oil bath and maintained at 80°C. Next, a solution containing 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 and connected to the flask. After purging with nitrogen, the mixture was added dropwise over 3 hours with stirring. After completion of the dropping, the mixture was allowed to react for an additional 15 hours to obtain a copolymer solution (solids concentration 30% by mass). The polystyrene-equivalent weight average molecular weight M of the obtained copolymer was 1.0 g. Ｗ The molecular weight of the copolymer obtained in Synthesis Example 4 is 11,000. Hereinafter, in this specification, the copolymer obtained in Synthesis Example 4 is referred to as A-4.

[0081] Synthesis Example 5 A flask was charged with a stirrer and 90 g of propylene glycol monomethyl ether as a solvent, and the flask was immersed in a heated oil bath and maintained at 70°C. Next, a solution containing 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 and connected to the flask. After the atmosphere was replaced with nitrogen, the mixture was added dropwise over 3 hours with stirring. After the dropwise addition was completed, the reaction was continued for a further 15 hours, yielding a copolymer solution (solids concentration 35% by mass). The polystyrene-equivalent weight average molecular weight M of the obtained copolymer was 10 g. Ｗ The molecular weight of the copolymer obtained in Synthesis Example 5 is 18,000. Hereinafter, in this specification, the copolymer obtained in Synthesis Example 5 is referred to as A-5.

[0082] [Preparation of Positive Photosensitive Resin Composition] Example 1 70.0 g (21.0 g as solids) of copolymer A-1 obtained in Synthesis Example 1 as 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, and 6.6 g of propylene glycol monomethyl ether and 23.8 g of propylene glycol monomethyl ether acetate as solvents were blended to obtain a homogeneous solution. The solution was then filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solids concentration 29% by mass).

[0083] Example 2 70.0 g (21.0 g as solids) of copolymer A-1 obtained in Synthesis Example 1 as component (A), 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, and 6.8 g of propylene glycol monomethyl ether and 23.9 g of propylene glycol monomethyl ether acetate as solvents were blended to obtain a homogeneous solution. The solution was then filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solids concentration 29% by mass).

[0084] Example 3 70.0 g (21.0 g as solids) of copolymer A-2 obtained in Synthesis Example 2 as 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, and 6.6 g of propylene glycol monomethyl ether and 23.8 g of propylene glycol monomethyl ether acetate as solvents were blended to obtain a homogeneous solution. The solution was then filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solids concentration 29% by mass).

[0085] Example 4 70.0 g (21.0 g as solids) of copolymer A-3 obtained in Synthesis Example 3 as 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, and 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. The solution was then filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solids concentration 17% by mass).

[0086] Example 5 70.0 g (21.0 g as solids) of copolymer A-3 obtained in Synthesis Example 3 as component (A), 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, and 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. The solution was then filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solids concentration 15% by mass).

[0087] Example 6 84.0 g (25.2 g as solids) of copolymer A-3 obtained in Synthesis Example 3 as component (A), 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, and 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. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solids concentration 17% by mass).

[0088] Comparative Example 1: 70.0 g (21.0 g as solids) of copolymer A-4 obtained in Synthesis Example 4, which does not correspond 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, and 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. The solution was then filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solids concentration 28% by mass).

[0089] Comparative Example 2: 60.0 g (21.0 g as solids) of copolymer A-5 obtained in Synthesis Example 5, which does not correspond 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, and 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. The solution was then filtered using a polyethylene microfilter with a pore size of 0.10 μm to obtain a positive photosensitive resin composition (solids concentration 32% by mass).

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

[0091] [Evaluation of Patterning Properties] Each of the positive photosensitive resin compositions prepared in Examples 1 to 6 and Comparative Examples 1 and 2 was applied to a silicon wafer using a spin coater and prebaked on a hot plate at 80°C for 90 seconds to form a resin film having a thickness shown in Table 2. Next, the resin film was subjected to a first exposure using an i-line stepper (NSR-2205i12D, NA = 0.63, manufactured by Nikon Corporation) through a predetermined mask at an exposure dose shown in Table 2. Here, as the mask, a mask forming a 4 μm × 4 μm square dot pattern / 4 μm space was used for the 4 μm-thick resin film (Examples 1 to 3 and Comparative Examples 1 and 2), and a mask forming a 1 μm × 1 μm square dot pattern / 1 μm space was used for the 1 μm-thick resin film (Examples 4 to 6). Thereafter, within 10 minutes of the first exposure, development was performed using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH). A 4 μm × 4 μm square dot pattern was formed for the 4 μm thick resin film, and a 1 μm × 1 μm square dot pattern was formed for the 1 μm thick resin film. The formed square dot patterns were observed at 5000x magnification using a scanning electron microscope. If the resin film residue was clearly visible in the spaces between adjacent square dot patterns, the patterning ability was evaluated as "×", and if the resin film residue was not visible, the patterning ability was evaluated as "○". The evaluation results are shown in Table 2.

[0092]

[0093] [Lens Shape Evaluation] Using the positive photosensitive resin compositions prepared in Examples 1 to 6 and Comparative Examples 1 and 2, a 4 μm x 4 μm square dot pattern was formed on a silicon wafer for a 4 μm-thick resin film, and a 1 μm x 1 μm square dot pattern was formed for a 1 μm-thick resin film, according to the procedure described in [Patterning Property Evaluation] above. Subsequently, the square dot pattern was baked on a hot plate for 5 minutes at the reflow temperature shown in Table 2. Furthermore, using the i-line stepper, 500 mJ / cm was applied to the entire surface of the square dot pattern. ２After the second exposure, the pattern was baked on a hot plate for 10 minutes at the post-bake temperature shown in Table 2 to produce a microlens. Furthermore, the entire surface of a 1 μm×1 μm square dot pattern formed using the positive photosensitive resin composition prepared in Example 4 was exposed to 500 mJ / cm 2 using the i-line stepper without being baked at the reflow temperature (the reflow temperature is shown as "none" in Table 2). ２ After the second exposure, the microlenses were fabricated by baking on a hot plate for 10 minutes at the post-bake temperature shown in Table 2. The microlenses fabricated were rated as "□" if they had a square prism or a truncated square pyramid shape, and "◯" if they had a spherical or hemispherical shape. The evaluation results are shown in Table 2.

[0094] [Evaluation of Chemical Resistance] The positive photosensitive resin compositions prepared in Examples 1 to 6 and Comparative Examples 1 and 2 were each applied to a silicon wafer using a spin coater, and prebaked on a hot plate at 80°C for 90 seconds to form a resin film having a thickness shown in Table 2. Next, the entire surface of the resin film was irradiated with 500 mJ / cm using the i-line stepper. ２ After exposure to light, the wafer was baked on a hot plate for 10 minutes at the post-bake temperature listed in Table 2 to form a cured film. The silicon wafer on which the cured film was formed was immersed for 5 minutes at 23°C in propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, and a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH). The thickness of the cured film was measured before and after immersion, and the change in thickness before and after immersion was calculated. If the film thickness increased or decreased by 10% or more compared to the film thickness before immersion for even one of the solvents used for the immersion, the chemical resistance was evaluated as "×." If the film thickness increased or decreased by less than 10% for all solvents, the chemical resistance was 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 to a quartz substrate using a spin coater, and prebaked on a hot plate at 80°C for 90 seconds to form a resin film having a thickness shown in Table 2. Next, the entire surface of the resin film was irradiated with 500 mJ / cm using the i-line stepper. ２ After exposure to light at 1000 K, the substrate was baked on a hot plate for 10 minutes at the post-bake temperature shown in Table 2 to form a cured film. The quartz substrate on which the cured film was formed was measured for transmittance at a wavelength of 400 nm using an ultraviolet-visible spectrophotometer UV-2550 (manufactured by Shimadzu Corporation). When the transmittance at a wavelength of 400 nm was less than 90%, the transparency was evaluated as "×", and when it was 90% or higher, the transparency was 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, cured films were formed on quartz substrates according to the procedure described in the [Transparency evaluation] above. The quartz substrates on which the cured films were formed were heated in an oven at 100°C for 1,000 hours, and then the transmittance at a wavelength of 400 nm was measured using the UV-visible spectrophotometer. When the transmittance at a wavelength of 400 nm increased or decreased by 5% or more compared to the transmittance before heating for 1,000 hours, the evaluation was "x", and when the increase or decrease in transmittance was less than 5%, the evaluation was "o". The evaluation results are shown in Table 2.

[0097] <THS Test> Using the positive photosensitive resin compositions prepared in Examples 1 to 6, cured films were formed on quartz substrates according to the procedure described in the "Transparency Evaluation" section above. The quartz substrates on which the cured films were formed were stored for 1,000 hours in a thermo-hygrostat chamber whose interior was maintained at 85°C and a relative humidity of 85%, and then the transmittance at a wavelength of 400 nm was measured using the UV-visible spectrophotometer. When the transmittance at a wavelength of 400 nm increased or decreased by 5% or more compared to the transmittance before storage for 1,000 hours, the result was evaluated as "X", and when the increase or decrease in transmittance was less than 5%, the result was evaluated as "O". The evaluation results are shown in Table 2.

[0098] <Xenon Arc Test> Using the positive photosensitive resin compositions prepared in Examples 1 to 6, cured films were formed on quartz substrates according to the procedure described in the above [Transparency Evaluation]. A cut filter (L38, manufactured by Shibuya Optical Co., Ltd.) was attached to the quartz substrate on which the cured film had been formed, and the film was exposed to 25,000,000 lx·h in a xenon arc tester (Q-SUNXe-1, manufactured by Q-Lab Co., Ltd.). The transmittance at a wavelength of 400 nm was then measured using the above UV-visible spectrophotometer. When the transmittance increased or decreased by 5% or more compared to the transmittance at a wavelength of 400 nm before exposure using the xenon arc tester, the film was evaluated as "x", and when the increase or decrease in transmittance was less than 5%, the film was evaluated as "○".

[0099] The results in Table 2 demonstrate that by using the positive photosensitive resin composition of the present invention, positive patterning is possible without leaving any residue, and that microlenses having a truncated or hemispherical shape can be formed even in a low-temperature process at 130°C or less, and that these microlenses have excellent transparency, chemical resistance, and long-term reliability.

Claims

1. A positive photosensitive resin composition comprising the following component (A), component (B), component (C), and a solvent: Component (A): (a1) a monomer represented by the following formula (1), (a2) a monomer containing an epoxy ring, and (a3) ​​a copolymer of a monomer containing a hydroxyl group having an acid dissociation constant pKa of 14 or more, the copolymer not containing a carboxyl group or a carboxylic anhydride group. Component (B): quinone diazide compound Component (C): Photoacid generator 【Chemistry 1】 (In the formula, 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 (a2) monomer containing an epoxy ring is a monomer represented by the following formula (2), and the (a3) ​​monomer containing a hydroxy group having an acid dissociation constant pKa of 14 or more is a monomer represented by the following formula (2): The positive photosensitive resin composition according to claim 1 , wherein the monomer is represented by the formula (3): 【Chemistry 2】 (In the formula, R ０ each independently represents a hydrogen atom or a methyl group; R ３ represents a divalent organic group represented by the following formula (I), R ４ represents a monovalent organic group represented by the following formula (4) or the following formula (5), R ５ represents a monovalent organic group represented by the following formula (I'): 【Chemistry 3】 (In the formula, c represents an integer of 0 to 3, d represents an integer of 1 to 3, e each independently represents an integer of 2 to 6, * represents a bond to the alkenyl group of the monomer represented by formula (2) or formula (3), and · represents a bond to the monovalent organic group represented by formula (4) or formula (5).)

3. 2. 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): 【Chemistry 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. 【Chemistry 5】

4. 2. The positive photosensitive resin composition according to claim 1, wherein the component (A) has a weight average molecular weight in terms of polystyrene of 5,000 to 30,000.

5. 2. 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): 【Chemistry 6】 (In the formula, R ６ represents a hydrocarbon group or a perfluoroalkyl group having 1 to 10 carbon atoms; R ７ represents a linear alkyl or alkoxy group having 1 to 8 carbon atoms, or a branched alkyl 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): Multifunctional epoxy compound

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

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

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. 10. A method for producing a microlens, comprising: a coating step of coating a substrate with the positive photosensitive resin composition according to claim 1 to form a resin film; a first exposure step of exposing at least a portion of the resin film to light 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 less after the second exposure step.

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

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

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