JP2022156546A - Microlens forming composition, method for manufacturing microlens using composition, cured film, solid state image sensor and imaging device - Google Patents

Abstract

To provide a microlens forming composition that has few restrictions on the type of usable resins and causes few residues during image development.SOLUTION: A microlens forming composition contains (A) an unsaturated group-containing alkali-soluble resin, (B) a photopolymerizable monomer having at least one ethylenically unsaturated bond, (C) an epoxy compound having two or more epoxy groups, (D) a photopolymerization initiator, (E) an ultraviolet absorber, and (F) a solvent. The mass of the (F) ultraviolet absorber is 3 mass% or more and 20 mass% or less relative to the total mass of the solid content.SELECTED DRAWING: None

Description

The present invention relates to a composition for forming a microlens, a method for manufacturing a microlens using the composition, a cured film obtained by curing the composition, a solid-state imaging device having the microlens, and an imaging device.

Imaging devices such as digital cameras and camera-equipped mobile phones are equipped with solid-state imaging devices such as CCD (charge coupled device) image sensors and CMOS (complementary metal-oxide semiconductor) image sensors. The image sensor has fine condensing lenses (microlenses) for the purpose of improving the light condensing efficiency. In recent years, there has been a demand for higher pixel count, higher sensitivity, and miniaturization of the image sensor, and materials for microlenses that can meet these demands have been developed.

For example, Patent Document 1 discloses a resin composition used for forming a microlens pattern, containing an alkali-soluble resin having a glass transition temperature (Tg) of 70° C. or lower and a photosensitive agent. According to Patent Document 1, the above resin composition is said to be capable of forming a fine dot pattern even by heat flow at a low temperature (60 to 100° C.). Patent Literature 1 describes that the resin composition can form a microlens pattern by positive pattern formation in which the exposed portions are removed.

Further, Patent Document 2 discloses a siloxane resin composition containing a siloxane resin, metal-containing particles, and a polymerizable compound having an ethylenically unsaturated double bond. According to Patent Document 2, the siloxane resin composition maintains a high refractive index of the cured product of the siloxane resin composition by setting the ratio of Ti and Zr contained in the metal-containing particles to a specific range, while maintaining light resistance. It is said that it can improve the quality. Patent Document 2 describes that the siloxane resin composition can form a microlens pattern by negative pattern formation in which the unexposed areas are removed.

JP 2020-100793 A JP 2019-173016 A

As described in Patent Documents 1 and 2, both a resin composition capable of forming a positive pattern and a resin composition capable of forming a negative pattern are known as resin compositions for forming microlenses. ing.

However, according to the findings of the present inventors, the conventional resin compositions described in Patent Literature 1 and Patent Literature 2 have a problem that residues tend to be generated during development. Moreover, when the inter-lens distance is narrow, the microlenses may be connected to each other due to this residue. On the other hand, the resin composition for forming microlenses is also required to have good adhesion of the formed microlens pattern to the substrate.

The present invention has been made in view of these points, and a microlens-forming composition that can form a microlens pattern with less limitation on the resin that can be used, less residue during development, and good adhesion to a substrate. a microlens manufacturing method using the composition; a cured film obtained by curing the composition; a solid-state imaging device having the microlens; and an imaging device having the solid-state imaging device. .

A microlens-forming composition according to the present invention is a microlens-forming composition for forming a microlens pattern, wherein the microlens-forming composition comprises (A) an unsaturated group-containing alkali-soluble resin and , (B) a photopolymerizable monomer having at least one or more ethylenically unsaturated bonds, (C) an epoxy compound having two or more epoxy groups, (D) a photopolymerization initiator, and (E) ultraviolet absorption and (F) a solvent, and the content of the (E) ultraviolet absorber is 3% by mass or more and 20% by mass or less with respect to the total mass of the solid content.

The method for producing a microlens according to the present invention comprises a coating film layer forming step of applying the microlens-forming composition and drying it to form a coating film of the microlens-forming composition; An exposure step of irradiating a portion with radiation through a photomask, a developing step of developing the irradiated coating film and removing an unexposed portion, and heat-flowing the exposed portion after the development, and exposing and a heat flow step of heating and curing the portion while processing the portion into a microlens shape.

Another microlens manufacturing method according to the present invention includes a resin layer forming step of applying the microlens-forming composition, irradiating it with radiation, and curing it to form a resin layer of the microlens-forming composition. forming an etching resist layer on the surface of the resin layer; exposing a portion of the etching resist layer to radiation through a photomask; and developing the etching resist layer irradiated with the radiation. a heat flow step of heat-flowing the exposed portion after the development to process the exposed portion into a microlens shape; dry-etching the resin layer using the exposed portion after the heat flow as a mask layer; and a transfer step of transferring the shape of the mask layer to the resin layer.

Another microlens manufacturing method according to the present invention includes a coating film forming step of applying the microlens-forming composition onto a lens material layer and drying to form a coating film of the microlens-forming composition. And, an exposure step of irradiating a part of the coating film with radiation through a photomask, a developing step of developing the coating film irradiated with the radiation and removing an unexposed portion, and the coating film after the development A mask layer forming step of forming a mask layer having a microlens pattern by heat-flowing and heat curing the coating film while processing it into a microlens shape, and dry etching the lens material layer and the mask layer. and a transfer step of transferring the shape of the mask layer to the lens material layer.

The cured film according to the present invention is obtained by curing the microlens-forming composition.

A microlens according to the present invention comprises the cured film.

A solid-state imaging device according to the present invention includes the microlens described above.

An imaging device according to the present invention has the above-described solid-state imaging device.

According to the present invention, a composition for forming a microlens that has few limitations on resins that can be used and that hardly leaves residue during development, a method for producing a microlens using the composition, and a cured film obtained by curing the composition. , a solid-state imaging device having the microlens, and an imaging apparatus having the solid-state imaging device.

Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments. In addition, in this invention, when the first decimal place is 0 about content of each component, the notation after the decimal point may be abbreviate|omitted.

1. Microlens-forming composition The microlens-forming composition according to one embodiment of the present invention comprises (A) an unsaturated group-containing alkali-soluble resin and (B) a light having at least one or more ethylenically unsaturated bonds. It contains a polymerizable monomer, (C) an epoxy compound having two or more epoxy groups, (D) a photopolymerization initiator, (E) an ultraviolet absorber, and (F) a solvent.

In the following description, "(meth)acrylic acid" means both acrylic acid and methacrylic acid, "(meth)acrylate" means both acrylate and methacrylate, and "(meth)acryloyl" means both acryloyl and methacryloyl.

[(A) component]
Component (A) is an unsaturated group-containing alkali-soluble resin. By including the component (A), the microlens-forming composition can be made soluble in alkali development.

The unsaturated group-containing alkali-soluble resin as component (A) preferably has a polymerizable unsaturated group and an acidic group for developing alkali solubility in one molecule. It is more preferable to have both a carboxy group and a carboxy group. Any of the above resins can be widely used without any particular limitation.

From the viewpoint of enhancing the adhesion to the substrate, the component (A) is an unsaturated group-containing alkali-soluble resin represented by the following general formula (1) (hereinafter simply referred to as "general formula (1) Also referred to as "alkali-soluble resin").

In formula (1), Ar is each independently an aromatic hydrocarbon group having 6 to 14 carbon atoms, and part of the bonded hydrogen atoms are linear or branched alkyl groups having 1 to 10 carbon atoms. aryl or arylalkyl groups having 6 to 10 carbon atoms, cycloalkyl or cycloalkylalkyl groups having 3 to 10 carbon atoms, alkoxy groups having 1 to 5 carbon atoms, and halogen groups. may be substituted with a group. Each R ₁ is independently an alkylene group having 2 to 4 carbon atoms, and each l is independently a number of 0 to 3. Each G is independently a (meth)acryloyl group or a substituent represented by the following general formula (2) or (3), and Y is a tetravalent carboxylic acid residue. Z is each independently a hydrogen atom or a substituent represented by the following general formula (4), and at least one is a substituent represented by the following general formula (4). n is a number with an average value of 1-20.

In formulas (2) and (3), R ₂ is a hydrogen atom or a methyl group, R ₃ is a divalent alkylene group or alkylarylene group having 2 to 10 carbon atoms, and R ₄ has 2 carbon atoms. ∼20 divalent saturated or unsaturated hydrocarbon groups and p is a number from 0 to 10;

In formula (4), W is a divalent or trivalent carboxylic acid residue, and m is a number of 1 or 2.

Next, a method for producing the alkali-soluble resin represented by the general formula (1) will be described in detail.

First, an epoxy compound (a) having a bisarylfluorene skeleton having several oxyalkylene groups in one molecule, represented by the following general formula (5) (hereinafter simply referred to as "general formula (5) Epoxy compound (a)”) is reacted with either one or both of (meth)acrylic acid and a (meth)acrylic acid derivative represented by the following general formula (6) or the following general formula (7) , to obtain a diol compound containing a polymerizable unsaturated group. The bisarylfluorene skeleton is preferably a bisnaphtholfluorene skeleton or a bisphenolfluorene skeleton.

In formula (5), Ar is each independently an aromatic hydrocarbon group having 6 to 14 carbon atoms, and part of the bonded hydrogen atoms are alkyl groups having 1 to 10 carbon atoms, and substituted with a group selected from the group consisting of 6 to 10 aryl or arylalkyl groups, 3 to 10 carbon cycloalkyl or cycloalkylalkyl groups, 1 to 5 carbon alkoxy groups, and halogen groups; may have been Each R ₁ is independently an alkylene group having 2 to 4 carbon atoms, and each l is independently a number of 0 to 3.

In formulas (6) and (7), R ₂ is a hydrogen atom or a methyl group, R ₃ is a divalent alkylene group or alkylarylene group having 2 to 10 carbon atoms, and R ₄ has 2 carbon atoms. ∼20 divalent saturated or unsaturated hydrocarbon groups and p is a number from 0 to 10;

A known method can be used for the reaction between the epoxy compound (a) represented by the general formula (5) and the (meth)acrylic acid or (meth)acrylic acid derivative. For example, Japanese Patent Laid-Open No. 4-355450 discloses a diol compound containing a polymerizable unsaturated group by using about 2 mol of (meth)acrylic acid per 1 mol of an epoxy compound having two epoxy groups. is obtained. In the present invention, the compound obtained by the above reaction is a diol (d) containing a polymerizable unsaturated group represented by the following general formula (8) (hereinafter simply referred to as "diol represented by general formula (8) ( d)”).

In formula (8), each Ar is independently an aromatic hydrocarbon group having 6 to 14 carbon atoms, and part of the bonded hydrogen atoms are alkyl groups having 1 to 10 carbon atoms, and substituted with a group selected from the group consisting of 6 to 10 aryl or arylalkyl groups, 3 to 10 carbon cycloalkyl or cycloalkylalkyl groups, 1 to 5 carbon alkoxy groups, and halogen groups; may have been Each G is independently a (meth)acryloyl group or a substituent represented by the following general formula (2) or (3), and each R ₁ independently has 2 to 4 carbon atoms. and each l is independently a number from 0 to 3.

In formulas (2) and (3), R ₂ is a hydrogen atom or a methyl group, R ₃ is a divalent alkylene group or alkylarylene group having 2 to 10 carbon atoms, and R ₄ has 2 carbon atoms. ∼20 divalent saturated or unsaturated hydrocarbon groups and p is a number from 0 to 10;

Synthesis of the diol (d) represented by the general formula (8), followed by reaction with a polyvalent carboxylic acid or its anhydride to produce an alkali-soluble resin represented by the general formula (1) is usually carried out in a solvent, optionally using a catalyst.

Examples of solvents include cellosolve solvents such as ethyl cellosolve acetate and butyl cellosolve acetate; high boiling point ether or ester solvents such as diglyme, ethyl carbitol acetate, butyl carbitol acetate and propylene glycol monomethyl ether acetate; Ketone solvents such as diisobutyl ketone and the like are included. Although there are no particular restrictions on the reaction conditions such as the solvent and catalyst used, it is preferable to use, as the reaction solvent, a solvent that does not have a hydroxyl group and has a boiling point higher than the reaction temperature.

Moreover, it is preferable to use a catalyst in the reaction between the epoxy group and the carboxy group or hydroxy group. For example, JP-A-9-325494 describes ammonium salts such as tetraethylammonium bromide and triethylbenzylammonium chloride, and phosphine catalysts such as triphenylphosphine and tris(2,6-dimethoxyphenyl)phosphine. .

Next, the diol (d) represented by the general formula (8), dicarboxylic acid or tricarboxylic acid or its acid anhydride (b), and tetracarboxylic acid or its acid dianhydride (c) are reacted. As a result, it is possible to obtain an alkali-soluble resin represented by the general formula (1), which has a polymerizable unsaturated group and an acidic group for exhibiting alkali-solubility in one molecule.

The acid component used for synthesizing the alkali-soluble resin represented by the above general formula (1) is a polyvalent diol (d) represented by the above general formula (8) capable of reacting with hydroxyl groups in the diol (d) molecule. As acid components, it is necessary to use a combination of dicarboxylic acid or tricarboxylic acid or their acid unihydride (b) and tetracarboxylic acid or their acid dianhydride (c). The carboxylic acid residue of the acid component may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. In addition, these carboxylic acid residues may contain a bond containing a heteroatom such as —O—, —S—, or a carbonyl group.

Examples of the dicarboxylic or tricarboxylic acids or their monoanhydrides (b) include chain hydrocarbon dicarboxylic or tricarboxylic acids, alicyclic hydrocarbon dicarboxylic or tricarboxylic acids, aromatic dicarboxylic or tricarboxylic acids, Or their acid monoanhydrides and the like are included.

Examples of said chain hydrocarbon dicarboxylic or tricarboxylic acids include succinic acid, acetylsuccinic acid, maleic acid, adipic acid, itaconic acid, azelaic acid, citralic acid, malonic acid, glutaric acid, citric acid, tartaric acid, oxoglutaric acid. , pimelic acid, sebacic acid, suberic acid, diglycolic acid, etc., and the above chain hydrocarbon dicarboxylic or tricarboxylic acids introduced with optional substituents.

Examples of the alicyclic hydrocarbon dicarboxylic acid or tricarboxylic acid include cyclobutanedicarboxylic acid, cyclopentanedicarboxylic acid, hexahydrophthalic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, norbornane dicarboxylic acid. Acids, chlorendic acid, hexahydrotrimellitic acid, etc., and the above-mentioned alicyclic hydrocarbon dicarboxylic acids or tricarboxylic acids into which optional substituents are introduced are included.

Examples of the aromatic dicarboxylic acid or tricarboxylic acid include acid monoanhydrides such as phthalic acid, isophthalic acid, trimellitic acid, 1,8-naphthalenedicarboxylic acid and 2,3-naphthalenedicarboxylic acid, and any Included are the above aromatic dicarboxylic acids or tricarboxylic acids into which substituents have been introduced.

Among the above dicarboxylic acids or tricarboxylic acids or their dianhydrides, succinic acid, itaconic acid, phthalic acid, trimellitic acid, tetrahydrophthalic acid, hexahydrotrimellitic acid, 1,8-naphthalenedicarboxylic acid, 2, 3-naphthalenedicarboxylic acid is preferred, and tetrahydrophthalic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid or their acid monoanhydrides are more preferred.

As the dicarboxylic acid or tricarboxylic acid or its acid anhydride (b), it is preferable to use an acid monoanhydride. The acid 1 anhydrides of dicarboxylic acids or tricarboxylic acids described above may be used alone or in combination of two or more thereof.

Examples of the tetracarboxylic acid or its dianhydride (c) include chain hydrocarbon tetracarboxylic acids, alicyclic hydrocarbon tetracarboxylic acids, aromatic tetracarboxylic acids, or acid dianhydrides thereof. etc. are included.

Examples of the above-mentioned chain hydrocarbon tetracarboxylic acids include butanetetracarboxylic acid, pentanetetracarboxylic acid, hexanetetracarboxylic acid, and the above-mentioned compounds into which substituents such as alicyclic hydrocarbon groups and unsaturated hydrocarbon groups have been introduced. Chain hydrocarbon tetracarboxylic acids and the like are included.

Examples of the alicyclic hydrocarbon tetracarboxylic acids include cyclobutanetetracarboxylic acid, cyclopentanetetracarboxylic acid, cyclohexanetetracarboxylic acid, cycloheptanetetracarboxylic acid, norbornanetetracarboxylic acid, and chain hydrocarbon groups. , and the above alicyclic tetracarboxylic acids into which a substituent such as an unsaturated hydrocarbon group is introduced.

Examples of aromatic tetracarboxylic acids include pyromellitic acid, benzophenonetetracarboxylic acid, biphenyltetracarboxylic acid, diphenylethertetracarboxylic acid, diphenylsulfonetetracarboxylic acid, and naphthalene-1,4,5,8-tetracarboxylic acid. , naphthalene-2,3,6,7-tetracarboxylic acid and the like.

Also, bis-trimellitic anhydride aryl esters can be used. The bis-trimellitic anhydride aryl esters are, for example, a group of compounds produced by the method described in International Publication No. 2010/074065, and are structurally aromatic diols (naphthalene diol, biphenol, terphenyl diol etc.) and two carboxyl groups of trimellitic anhydride are reacted to form an ester bond. These compounds are hereinafter referred to as bis-trimellitic anhydride esters of aromatic diols.

Among the above tetracarboxylic acids or their dianhydrides, biphenyltetracarboxylic acid, benzophenonetetracarboxylic acid, diphenylethertetracarboxylic acid, naphthalene-1,4,5,8-tetracarboxylic acid, naphthalene-2,3,6 ,7-tetracarboxylic acid is preferred, and biphenyltetracarboxylic acid, benzophenonetetracarboxylic acid, naphthalene-1,4,5,8-tetracarboxylic acid and naphthalene-2,3,6,7-tetracarboxylic acid are more preferred. Moreover, it is preferable to use an acid dianhydride as a tetracarboxylic acid or its acid dianhydride (c). Furthermore, bis-trimellitic anhydride of naphthalene diol can also be preferably used. The tetracarboxylic acid or its acid dianhydride and the bis-trimellitic anhydride ester of the aromatic diol may be used singly or in combination of two or more thereof.

The method for reacting the diol (d) represented by the general formula (8) with the acid components (b) and (c) is not particularly limited, and known methods can be employed. For example, JP-A-9-325494 describes a method of reacting epoxy (meth)acrylate and tetracarboxylic dianhydride at a reaction temperature of 90 to 140°C.

Here, diol (d) containing a polymerizable unsaturated group, dicarboxylic acid or tricarboxylic acid or their acid unihydride (b), tetracarboxylic dianhydride ( It is preferable to carry out the reaction so that the molar ratio with c) is (d):(b):(c)=1.0:0.01-1.0:0.2-1.0.

For example, when using an acid dianhydride (b) or an acid dianhydride (c), the amount of acid component relative to the diol (d) containing a polymerizable unsaturated group [(b)/2+(c)] It is preferable to carry out the reaction so that the molar ratio of [(d)/[(b)/2+(c)]] is 0.5 to 1.0. Here, when the molar ratio is 0.5 or more, the content of the unreacted acid anhydride can be suppressed from becoming excessive, so the stability over time of the alkali-soluble resin composition can be enhanced. Further, when the molar ratio is 1.0 or less, it is possible to suppress the content of the diol containing an unreacted polymerizable unsaturated group from becoming excessive, so that the stability of the alkali-soluble resin composition over time can be improved. can be enhanced. In addition, for the purpose of adjusting the acid value and molecular weight of the alkali-soluble resin represented by the general formula (1), the molar ratio of each component (b), (c) and (d) is arbitrarily within the above range. can be changed.

In the present invention, the content of the alkali-soluble resin represented by the general formula (1), which is the component (A), is preferably 10% by mass or more and 90% by mass or less with respect to the total mass of the solid content. More preferably, the content is not less than 80% by mass and not more than 80% by mass. When the content of the component (A) is 10% by mass or more, even if the pattern is fine, the development adhesion is excellent and peeling of the pattern can be suppressed, and when the content is 90% by mass or less , exhibits good photocurability, is excellent in contrast between exposed and unexposed areas during development, and can provide sufficient photolithographic properties.

The acid value of the alkali-soluble resin represented by the general formula (1) is preferably 50 mgKOH/g or more and 200 mgKOH/g, more preferably 60 mgKOH/g or more and 150 mgKOH/g or less. When the acid value is 50 mgKOH/g or more, residues are less likely to remain during alkali development, and when it is 200 mgKOH/g or less, the penetration of the alkali developer does not become too fast, so peeling development can be suppressed. can be done. The acid value can be determined by titration with a 1/10 N-KOH aqueous solution using a potentiometric titrator "COM-1600" (manufactured by Hiranuma Sangyo Co., Ltd.).

Further, the weight average molecular weight (Mw) of the alkali-soluble resin represented by the general formula (1) is preferably 1000 or more and 40000 or less, more preferably 1500 or more and 30000 or less, and 2000 or more and 15000 or less. is more preferred. When the weight-average molecular weight (Mw) is 1000 or more, pattern peeling from the substrate can be suppressed even for fine patterns. Further, when the weight average molecular weight (Mw) is 40,000 or less, the solubility of the unexposed portion in an alkaline developer is improved, and the generation of residue can be suppressed. The weight average molecular weight (Mw) can be determined by, for example, gel permeation chromatography (GPC) "HLC-8220GPC" (manufactured by Tosoh Corporation).

Further, another example of resins preferable as component (A) includes resins that are copolymers of (meth)acrylic acid, (meth)acrylic acid esters, etc., and have (meth)acryloyl groups and carboxy groups. be Examples of the resin include a copolymer obtained by copolymerizing (meth)acrylic acid esters containing glycidyl (meth)acrylate in a solvent, reacting (meth)acrylic acid, and finally dicarboxylic acid. Alternatively, an unsaturated group-containing alkali-soluble resin obtained by reacting an anhydride of tricarboxylic acid is included. The copolymer, shown in JP-A-2014-111722, hydroxyl groups at both ends derived from diester glycerol esterified with (meth) acrylic acid 20 to 90 mol% of repeating units, and together with this A copolymer composed of 10 to 80 mol% of repeating units derived from one or more polymerizable unsaturated compounds, having a number average molecular weight (Mn) of 2000 to 20000 and an acid value of 35 to 120 mgKOH/g. , And shown in JP 2018-141968, a unit derived from a (meth) acrylic acid ester compound, a unit having a (meth) acryloyl group and a di- or tricarboxylic acid residue, weight average An unsaturated group-containing alkali-soluble resin, which is a polymer having a molecular weight (Mw) of 3000 to 50000 and an acid value of 30 to 200 mgKOH/g, can be referred to.

In addition, about unsaturated group containing alkali-soluble resin of (A) component, you may use only 1 type individually, and may use 2 or more types together.

Next, the components (B) to (G) contained in the microlens-forming composition according to one embodiment of the present invention will be described.

[(B) component]
Component (B) is a photopolymerizable monomer having at least one ethylenically unsaturated bond. By containing the component (B), the exposure sensitivity and developability can be improved.

Examples of component (B) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, Triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol di(meth)acrylate ) acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, glycerol (meth)acrylate Acrylate, glycerol di(meth)acrylate, glycerol tri(meth)acrylate, sorbitol penta(meth)acrylate, sorbitol hexa(meth)acrylate, phosphazene alkylene oxide-modified hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth) (Meth)acrylic acid esters such as acrylates, dendrimer-type polyfunctional acrylates, and the like are included. These photopolymerizable monomers may be used alone or in combination of two or more.

The content of component (B) is preferably 1 part by mass or more and 200 parts by mass or less, more preferably 4 parts by mass or more and 100 parts by mass or less, and 10 parts by mass or more and 70 parts by mass or less per 100 parts by mass of component (A). is more preferred. When the content of component (B) is 1 part by mass or more with respect to 100 parts by mass of component (A), the effect of improving exposure sensitivity and developability by component (B) is sufficiently exhibited. Further, when the content of component (B) is 200 parts by mass or less per 100 parts by mass of component (A), the concentration of acidic functional groups is sufficiently high, and good solubility in an alkaline developer in the exposed area is obtained. From what is obtained, a desired pattern can be formed.

[(C) component]
Component (C) is an epoxy compound having two or more epoxy groups. By including the component (C), a sufficient cross-linked structure can be formed, so that the chemical resistance can be improved.

Examples of component (C) include bisphenol A-type epoxy compounds, bisphenol F-type epoxy compounds, bisphenol fluorene-type epoxy compounds, bisnaphtholfluorene-type epoxy compounds, diphenylfluorene-type epoxy compounds, phenol novolac-type epoxy compounds, and cresol novolac-type epoxy compounds. compounds, phenol aralkyl-type epoxy compounds, phenol novolac compounds containing a naphthalene skeleton (for example, NC-7000L: manufactured by Nippon Kayaku Co., Ltd.), biphenyl-type epoxy compounds (for example, jERYX4000: manufactured by Mitsubishi Chemical Corporation, "jER" is the same company registered trademark), naphthol aralkyl-type epoxy compound, trisphenolmethane-type epoxy compound (e.g., EPPN-501H: manufactured by Nippon Kayaku Co., Ltd.), tetrakisphenolethane-type epoxy compound, polyhydric alcohol glycidyl ether, polyhydric carboxylic acid a copolymer of a monomer having a (meth)acrylic group containing glycidyl (meth)acrylate as a unit, represented by a copolymer of methacrylic acid and glycidyl methacrylate, 3′,4′-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate (e.g., Celoxide 2021P: manufactured by Daicel Corporation, "Celoxide" is a registered trademark of the same company), butanetetracarboxylic acid tetra(3,4-epoxycyclohexylmethyl)-modified ε-caprolactone (e.g., Epolead GT401: manufactured by Daicel Corporation, "Epolead" is a registered trademark of the same company), an epoxy compound having an epoxycyclohexyl group (e.g., HiREM-1: manufactured by Shikoku Kasei Co., Ltd.), a polyfunctional epoxy compound having a dicyclopentadiene skeleton (for example, HP7200 series: manufactured by DIC Corporation), 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (for example, EHPE3150: Daicel Corporation) manufactured by Nippon Soda Co., Ltd.), epoxidized polybutadiene (eg, NISSO-PBJP-100: manufactured by Nippon Soda Co., Ltd., “NISSO-PB” is a registered trademark of the same company), epoxy compounds having a silicone skeleton, and the like. In addition, these compounds may use only the compound of 1 type, and may use 2 or more types together.

Among the components (C), bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol fluorene type epoxy compounds, bisnaphtholfluorene type epoxy compounds, phenol novolac type epoxy compounds, cresol novolac type epoxy compounds, and biphenyl type epoxy compounds. is preferred, and a biphenyl-type epoxy compound is more preferred. By using a biphenyl-type epoxy compound, it is possible to achieve both the mechanical strength and chemical resistance of the cured product that meet the required properties and the patterning properties of the microlens-forming composition during photocuring. The degree of freedom in designing the forming composition can be increased.

The epoxy equivalent of the epoxy compound of component (C) is preferably 100 g/eq or more and 300 g/eq or less, more preferably 100 g/eq or more and 250 g/eq or less. Further, the number average molecular weight (Mn) of the (C) component epoxy compound is preferably 100 or more and 5,000 or less. When the epoxy equivalent is 100 g/eq or more and the number average molecular weight (Mn) of the epoxy compound is 100 or more, a cured film having good solvent resistance can be obtained, and the epoxy equivalent is 300 g/eq or less, When the number average molecular weight (Mn) is 5,000 or less, sufficient alkali resistance can be maintained even when an alkaline chemical solution is used in the post-process.

The epoxy equivalent of the epoxy compound of component (C) can be determined by titration with a 1/10 N-perchloric acid solution using a potentiometric titrator "COM-1600" (manufactured by Hiranuma Sangyo Co., Ltd.). Further, the number average molecular weight (Mn) of the epoxy compound can be determined by, for example, the above gel permeation chromatography (GPC) "HLC-8220GPC" (manufactured by Tosoh Corporation).

The content of component (C) is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 3 parts by mass or more and 20 parts by mass or less, based on the total mass of the solid content. By setting the content of the epoxy compound as component (C) to 1 part by mass or more, the chemical resistance can be further enhanced. can sufficiently ensure the adhesion of the

[(D) component]
(D) A component is a photoinitiator. By including the component (D), the reaction of the portion irradiated with light proceeds sufficiently, and the solubility of the cured portion during development is reduced to form a desired fine pattern.

Examples of component (D) include 2-[4-(methylthio)benzoyl]-2-(4-morpholinyl)propane, 2-(o-chlorophenyl)-4,5-phenylbiimidazole, 2-(o- chlorophenyl)-4,5-di(m-methoxyphenyl)biimidazole, 2-(o-fluorophenyl)-4,5-diphenylbiimidazole, 2-(o-methoxyphenyl)-4,5-diphenylbiimidazole , 2,4,5-triarylbiimidazole, 2,2′-bis(2-chlorophenyl)-4,4′,5,5′-tetraphenyl-1,2-biimidazole and other biimidazole compounds ; 2-trichloromethyl-5-styryl-1,3,4-oxadiazole, 2-trichloromethyl-5-(p-cyanostyryl)-1,3,4-oxadiazole, 2-trichloromethyl-5 Halomethylthiazole compounds such as -(p-methoxystyryl)-1,3,4-oxadiazole; 2,4,6-tris(trichloromethyl)-1,3,5-triazine, 2-methyl-4 ,6-bis(trichloromethyl)-1,3,5-triazine, 2-phenyl-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-chlorophenyl)-4,6 -bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxynaphthyl) -4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3 ,4,5-trimethoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methylthiostyryl)-4,6-bis(trichloromethyl)-1,3 Halomethyl-s-triazine compounds such as ,5-triazine; 1,2-octanedione, 1-[4-(phenylthio)phenyl]-,2-(O-benzoyloxime) (Irgacure OXE01, manufactured by BASF Japan) , “Irgacure” is a registered trademark of the same company), 1-(4-phenylsulfanylphenyl)butane-1,2-dione-2-oxime-O-benzoate, 1-(4-methylsulfanylphenyl)butane-1 , 2-dione-2-oxime-O-acetate, 1-(4-methylsulfanylphenyl)butan-1-one oxime- O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-bicycloheptyl-1-one oxime-O-acetate, 1-[9-ethyl-6-( 2-methylbenzoyl)-9H-carbazol-3-yl]-adamantylmethan-1-one oxime-O-benzoate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl ]-adamantylmethan-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-tetrahydrofuranylmethan-1-one oxime-O-benzoate , 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-tetrahydrofuranylmethan-1-one oxime-O-acetate, 1-[9-ethyl-6-(2- methylbenzoyl)-9H-carbazol-3-yl]-thiophenylmethan-1-one oxime-O-benzoate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl] -thiophenylmethan-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-morphonylmethan-1-one oxime-O-benzo Art, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-morphonylmethan-1-one oxime-O-acetate, 1-[9-ethyl-6-( 2-methylbenzoyl)-9H-carbazol-3-yl]-ethane-1-one oxime-O-bicycloheptanecarboxylate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3- yl]-ethane-1-one oxime-O-tricyclodecanecarboxylate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethane-1-one oxime-O -adamantanecarboxylate, 1-[4-(phenylsulfanyl)phenyl]octane-1,2-dione 2-O-benzoyloxime, 1-[9-ethyl-6-(2-methylbenzoyl)carbazole-3 -yl]ethanone-O-acetyloxime, (2-methylphenyl)(7-nitro-9,9-dipropyl-9H-fluoren-2-yl)-acetyloxime, ethanone, 1-[7-(2 -methylbenzoyl)-9,9-dipropyl-9H-fluoren-2-yl]-1-(o-acetyloxime), ethanone, 1-(-9,9-dibutyl-7-nitro-9H-fluorene-2 -yl)-1-O-acetyloxime, ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) (Irgacure OXE02 ) and other O-acyloxime compounds; benzyl dimethyl ketal; anthraquinones such as 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, and 2,3-diphenylanthraquinone; azobisisobutyronitrile, benzoyl Organic peroxides such as peroxides and cumene peroxide are included. In addition, these photoinitiators may be used individually by 1 type, and may use 2 or more types together.

The content of component (D) is preferably 0.1 parts by mass or more and 30 parts by mass or less, and 0.3 parts by mass or more based on 100 parts by mass of the total amount of components (A) and (B). It is more preferably 20 parts by mass or less. When the content of the component (D) is 0.1 parts by weight or more, the photopolymerization can be sufficiently progressed particularly on the upper surface of the composition (the radiation irradiation side). Further, when the content of the component (D) is 30 parts by weight or less, the curing reaction hardly progresses to the deep part of the coating film, and it becomes easy to form a lens shape by heat flow.

[(E) component]
(E) Component is an ultraviolet absorber. When forming a negative pattern, the composition may be cured at the interface with the substrate even in areas not irradiated with radiation due to the radiation spreading along the interface after reaching the substrate interface. . As a result, it is thought that the cured resin spreads along the substrate interface, and this spread resin becomes a residual. On the other hand, the ultraviolet absorber absorbs the irradiated radiation and suppresses the spread of excess radiation along the substrate interface. Therefore, it is considered that the microlens-forming composition containing an ultraviolet absorber can suppress the generation of a residue that is peculiar to negative pattern formation. In addition, it is thought that by suppressing the residue, it is possible to suppress the connection between the microlenses that occurs when the inter-lens distance is small.

The ultraviolet absorber is preferably a compound having an absorption peak in the wavelength range of 250 to 400 nm, more preferably a compound that efficiently absorbs light with a wavelength of 365 nm.

Examples of component (E) include benzotriazole compounds, benzophenone compounds, triazine compounds, salicylic acid compounds, benzoate compounds, cinnamic acid derivatives, naphthalene derivatives, anthracene and its derivatives, dinaphthalene compounds, phenanthroline compounds, and the like. In addition, these ultraviolet absorbers may be used individually by 1 type, and may use 2 or more types together.

In the present invention, the ultraviolet absorber is preferably selected from the group consisting of benzotriazole compounds, benzophenone compounds and triazine compounds. These UV absorbers efficiently absorb the energy of radiation (e.g., UV rays), suppress the spread of excess radiation along the interface of the substrate, and reduce the formation of residue at pattern edges after development. can.

Examples of benzotriazole compounds include 2-(2′-hydroxy-5′-methylphenyl)benzotriazole, 2-(2′-hydroxy-5′-t-butylphenyl)benzotriazole, 2-(2′- Hydroxy-3′,5′-di-t-butylphenyl)benzotriazole, 2-(2′-hydroxy-3′-t-butyl-5′-methylphenyl)-5-chlorobenzotriazole, 2-(2 '-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole, 2- (2′-Hydroxy-4′-octoxyphenyl)benzotriazole, 2-{2′-hydroxy-3′-(3″,4″,5″,6″-tetrahydrophthalimidomethyl)-5 '-methylphenyl}benzotriazole, C7-C9-alkyl-3-[3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]propion ether, etc. included.

Examples of benzophenone compounds include 4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy -4-methoxy-5-sulfobenzophenone trihydrate, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, sodium 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone , hydroxide dodecyl benzophenone, and the like.

Examples of triazine compounds include 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-isooctyloxyphenyl)-1,3,5-triazine, 2-[4( (2-hydroxy-3-dodecyloxypropyl)-oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-( (2-hydroxy-3-tridecyloxypropyl)-oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2, 4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine and the like.

Moreover, you may use a commercial item as said ultraviolet absorber. Examples of commercial products include Tinuvin PS, 99-2, 326, 384-2, 900, 928, 1130 ("Tinuvin" manufactured by BASF is a registered trademark of the same company), Adekastab LA-24, 29, 31G, 32, 36 (manufactured by ADEKA Co., Ltd., "ADEKA STAB" is a registered trademark of the same company) and other benzotriazole compounds, UVINUL3049 and 3050 (manufactured by BASF, "UVINUL" is a registered trademark of the same company), benzophenone compounds such as ADEKA STAB 1413, Tinuvin400, 405, 460, Adekastab LA-46, and triazine compounds such as F70.

In the present invention, the UV absorber as the component (E) is preferably a compound having a photosensitive functional group, more preferably a benzotriazole compound, a benzophenone compound, or a triazine compound. From the viewpoint of enhancing the reactivity with the components (A) and (B), the photosensitive functional group is preferably an ethylenically unsaturated group. Examples of the ethylenically unsaturated groups include acryloyl groups, methacryloyl groups, vinyl groups, allyl groups, styrenyl groups, and the like. Among these, an acryloyl group and a methacryloyl group, which are highly reactive with components (A) and (B), are preferred. By using an ultraviolet absorber having an ethylenically unsaturated group, the photosensitive reactive group of the ultraviolet absorber reacts with the unsaturated group-containing alkali-soluble resin or photopolymerizable monomer, and the ultraviolet absorber is incorporated into the resin. can be taken in. As a result, from the viewpoint of reducing thermal damage to the substrate, for example, even when the composition is cured at a low temperature such as 140 ° C., the UV absorber is suppressed from exuding into the solvent and cured. It can improve the chemical resistance of the object. In addition, it is possible to suppress coloration due to deposition of the ultraviolet absorber, sublimation during baking, and the like.

Examples of benzotriazole, benzophenone and triazine compounds having ethylenically unsaturated groups include 2-[2-hydroxy-5-(methacryloyloxyethyl)phenyl]-2H-benzotriazole and the like.

Examples of commercially available UV absorbers include RUVA-93 (manufactured by Otsuka Chemical Co., Ltd.).

The content of component (E) is 3% by mass or more and 20% by mass or less, preferably 4% by mass or more and 20% by mass or less, and 6% by mass or more and 18% by mass or less based on the total mass of the solid content. is more preferable. By setting the content of component (E) to 3% by mass or more, it is possible to reduce the amount of radiation that spreads along the interface between the substrates and reduce the generation of residues at pattern edges after development. By setting the content of the component (E) to 20% by mass or less, the reaction in the portion irradiated with the radiation can proceed sufficiently, so that the microlens-forming composition can be sufficiently cured. .

[(F) component]
(F) Component is a solvent. By including component (F), it is possible to obtain a liquid microlens-forming composition containing components (A) to (E) and (G) described above.

Examples of solvents include alcohols such as methanol, ethanol, n-propanol, isopropanol, ethylene glycol, propylene glycol, 3-methoxy-1-butanol, ethylene glycol monobutyl ether, 3-hydroxy-2-butanone, diacetone alcohol. , α- or β-terpineol and other terpenes, acetone, methyl ethyl ketone, cyclohexanone, N-methyl-2-pyrrolidone and other ketones, toluene, xylene, tetramethylbenzene and other aromatic hydrocarbons, methyl cellosolve, ethyl cellosolve , methyl carbitol, ethyl carbitol, butyl carbitol, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol ethers such as glycol monoethyl ether, ethyl acetate, butyl acetate, ethyl lactate, 3-methoxybutyl acetate, 3-methoxy-3-butyl acetate, 3-methoxy-3-methyl-1-butyl acetate, cellosolve acetate, Esters such as ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and the like are included.

The content of component (F) is preferably 40% by mass or more and 80% by mass or less with respect to the total mass of the microlens-forming composition. When the content of the component (F) is 40% by mass or more, the viscosity of the microlens-forming composition can be easily applied onto the substrate. An excellent coating film can be obtained.

[(G) component]
The (G) component is a sensitizer. By including the component (G), the curing reaction by the photopolymerization initiator (D) can be controlled with higher accuracy.

Examples of component (G) include triethanolamine, triisopropanolamine, benzophenone, 4,4′-bisdimethylaminobenzophenone (Michler ketone), 4-phenylbenzophenone, 4,4′-dichlorobenzophenone, hydroxybenzophenone, 4,4′-dichlorobenzophenone, Benzophenones such as 4′-diethylaminobenzophenone; acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p-tert-butylacetophenone, benzyldimethylketal, etc. acetophenones; benzoin ethers such as benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-dimethylaminoethyl benzoic acid, 4-dimethylamino ethyl benzoate, 4-dimethylamino benzoic acid (n-butoxy) ethyl, isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 4-benzoyl-4'-methyl-diphenylsulfide, acrylated benzophenone, Benzophenones such as 3,3′,4,4′-tetra(t-butylperoxycarbonyl)benzophenone, 3,3′-dimethyl-4-methoxybenzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2 - Thioxanthone series such as isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 4,4'-bisdiethylamino Aminobenzophenone series such as benzophenone, 10-butyl-2-chloroacridone, 2-ethylanthraquinone, 9,10-phenanthrenequinone, camphorquinone and the like are included. In addition, these sensitizers may be used individually by 1 type, and may use 2 or more types together.

The content of component (G) is preferably 0.5 parts by mass or more and 200 parts by mass or less, more preferably 1 part by mass or more and 100 parts by mass or less with respect to a total of 100 parts by mass of component (D). When the content of component (G) is 0.5 parts by mass or more, the photopolymerization initiator can be sufficiently activated by light irradiation, and when it is 200 parts by mass or less, the photopolymerization initiator It is possible to control the curing reaction by more accurately.

[Other ingredients]
The microlens-forming composition of the present invention may optionally contain a curing agent, a curing accelerator, a thermal polymerization inhibitor, an antioxidant, a chain transfer agent, a plasticizer, a filler, a leveling agent, an antifoaming agent, and an interface. Additives such as activators, coupling agents, and viscosity modifiers can be added.

Examples of curing agents include amine-based compounds, polycarboxylic acid-based compounds, phenolic resins, amino resins, dicyandiamide, Lewis acid complex compounds, and the like, which contribute to curing of epoxy resins.

Examples of curing accelerators include tertiary amines, quaternary ammonium salts, tertiary phosphines, quaternary phosphonium salts, borate esters, Lewis acids, organometallic compounds, imidazoles, etc., which contribute to accelerating the curing of epoxy resins. be

Examples of thermal polymerization inhibitors and antioxidants include hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, phenothiazine, hindered phenolic compounds and the like.

Examples of chain transfer agents include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, β-mercaptopropionic acid, 2-ethylhexyl-3-mercaptopropionate, n-octyl-3-mercapto propionate, methoxybutyl-3-mercaptopropionate, stearyl-3-mercaptopropionate, trimethylolpropane tris(3-mercaptopropionate), tris-[(3-mercaptopropionyloxy)-ethyl]- isocyanurate, pentaerythritol tetrakis (3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptopropionate), tetraethylene glycol bis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate) acid), 3,3′-thiodipropionic acid, dithiodipropionic acid, thiol compounds such as laurylthiopropionic acid, and the like.

Examples of plasticizers include dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, and the like. Examples of fillers include glass fibers, silica, mica, alumina, and the like.

Examples of antifoaming agents and leveling agents include silicone-based, fluorine-based, and acrylic-based compounds.

Examples of surfactants include fluorine-based surfactants, silicone-based surfactants, and the like.

Examples of coupling agents include 3-(glycidyloxy)propyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, and the like.

The microlens-forming composition of the present invention can be obtained by mixing the components (A) to (G) and optional other components and heating the mixture.

2. Method for Producing Composition for Microlenses The methods (1) to (3) for producing the composition for microlenses are described below.

[Microlens manufacturing method (1)]
A method for producing a microlens composition according to an embodiment of the present invention includes (i) applying the microlens-forming composition described above and drying to form a coating film of the microlens-forming composition. (ii) an exposure step of irradiating a portion of the coating film with radiation through a photomask; and (iii) a developing step of developing the irradiated coating film and removing the unexposed portion. and (iv) heat-flowing the exposed portion after development to heat-cure the exposed portion while processing the exposed portion into a microlens shape. Each step will be described below.

[Coating film layer forming step]
The coating film layer forming step is a step of applying the microlens-forming composition described above onto a substrate and drying it to form a coating film layer.

A well-known thing can be used for the said base material. Examples of substrates include glass substrates, silicon wafers, plastic substrates, and substrates having colored resists, overcoats, antireflection films, and various metal thin films formed thereon. Examples of plastic substrates include resin substrates made of plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and polyimide. The substrate may be provided with a light-receiving element such as a photodiode, a light-emitting element such as an organic light-emitting element, a dye-containing element such as a color filter, and the like.

A known coating method can be used as a coating method for the microlens-forming composition. Examples of the coating method include a method using a known solution dipping method, a spray method, a roller coater, a land coater, a slit coater or a spinner. By these methods, the microlens-forming composition can be applied to a desired thickness.

A known drying method can be used for drying the microlens-forming composition applied by the above-described method. The drying method can be carried out by heating with an oven, a hot air blower, a hot plate, an infrared heater, etc., vacuum drying, or a combination thereof. The heating temperature and heating time for the resin film can be appropriately selected according to the solvent to be used. The heating temperature and heating time are preferably 80 to 120° C. and 1 to 10 minutes, for example.

[Exposure process]
The exposure step is a step of irradiating a portion of the coating film layer with radiation through a photomask to photocure a portion of the coating film (microlens-forming composition).

A known photomask can be used as the photomask. Examples of photomasks include multi-tone masks such as halftone masks and graytone masks. A gray-tone mask has a light-shielding portion and a diffraction grating formed on a translucent substrate. In the diffraction grating, the intervals between light transmission regions such as slits, dots, and meshes are intervals equal to or less than the resolution limit of light used for exposure, and this configuration controls the transmittance of light. A halftone mask has a light-shielding portion and a semi-transmissive portion formed on a light-transmitting substrate. Transmittance of light used for exposure is controlled by the semi-transmissive portion.

Examples of irradiated radiation include visible light, ultraviolet light, deep ultraviolet light, electron beams, X-rays, and the like. Among the above radiations, ultraviolet rays are preferred. Moreover, a known exposure device (ultra-high pressure mercury lamp, high pressure mercury lamp, metal halide lamp, far ultraviolet lamp, etc.) can be used as a device for irradiating radiation. Moreover, the wavelength of the radiation to be irradiated is preferably 250 nm or more and 400 nm or less. The exposure dose of radiation is preferably 25 mJ/cm ² or more and 3000 mJ/cm ² or less, more preferably 50 mJ/cm ² or more and 2000 mJ/cm ² or less.

[Development process]
The development step is a step of alkali-developing the coating film irradiated with radiation to remove the coating film in the unexposed areas.

Examples of coating film development methods include shower development, spray development, dip development, and puddle development. The above developing method can be carried out using a commercially available developing machine, an ultrasonic cleaning machine, or the like.

Examples of developers suitable for development include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, diethylamino ethanol, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5.4.0]- Examples include aqueous solutions of alkalis (basic compounds) such as 7-undecene and 1,5-diazabicyclo[4.3.0]-5-nonane. The development conditions vary depending on the microlens-forming composition, but are preferably carried out at a temperature of 20 to 30° C. for 10 to 120 seconds.

[Heat flow process]
The heat flow step is a step of heat-curing the exposed portion (coating film) after development by heat-flowing and melt-flowing the exposed portion while processing the exposed portion into a microlens shape.

The method of heat-flowing the exposed area after development can be carried out by a known method (heating with an oven, hot air blower, hot plate, infrared heater, etc., vacuum drying, or a combination thereof). The heat flow temperature is not particularly limited as long as it is a temperature at which the coating film melts and flows. The temperature of the heat flow is preferably 140-250° C. for 10-120 minutes, more preferably 180-230° C. for 30-90 minutes.

By using the microlens-forming composition of the present invention, even if microlens pattern formation is performed by a negative photolithography method such as the production method (1), the spread of radiation along the substrate interface is suppressed. As a result, the residue at the end of the pattern after development is reduced, so that the microlenses are prevented from being connected to each other, and a better shaped microlens pattern can be formed.

[Microlens manufacturing method (2)]
The microlens-forming composition of the present invention can sufficiently exhibit the effect of suppressing the formation of residues in the above production method (1), but is also suitable for forming microlenses by the following production methods (2) and (3). can be used for

A method for producing a microlens composition according to an embodiment of the present invention includes (i) applying the microlens-forming composition, irradiating it with radiation, and curing it to obtain a resin of the microlens-forming composition. (ii) forming an etching resist layer on the surface of the resin layer; (iii) exposing a portion of the etching resist layer to radiation through a photomask; (iv) a development step of developing the etching resist layer irradiated with radiation; (v) a heat flow step of processing the exposed portion into a microlens shape by heat-flowing the exposed portion after development; a transfer step of dry-etching the resin layer using the exposed portion after the flow as a mask layer and transferring the shape of the mask layer to the resin layer.

[Resin layer forming step]
The resin layer forming step is a step of applying the microlens-forming composition to the substrate surface, irradiating radiation, and drying to form a resin layer of the microlens-forming composition. In the above process, before the microlens-forming composition is applied, the unevenness of the base material surface is filled by applying a transparent resin by spin coating and flattened. Then, after the microlens-forming composition is applied to the flattened surface of the substrate, it is irradiated with radiation (for example, ultraviolet rays) and thermally cured to form a resin layer. The method of applying the composition for forming a microlens, the method of irradiating the applied composition for forming a microlens, and the method of irradiating the composition can be performed in the same manner as the method used in the production method (1) described above. can. The heat curing may be performed by a normal method for heat curing (post-baking) a composition containing an alkali-soluble resin and an epoxy resin.

[Step of forming an etching resist layer]
The step of forming an etching resist layer is a step of forming an etching resist layer on the surface of the resin layer.

The components of the etching resist are not particularly limited as long as the shape can be transferred to the resin layer as a mask layer in the transfer step described later. The etching resist may be a positive resist or a negative resist. Moreover, a well-known method can be used for the method of forming an etching resist layer on the surface of a resin layer.

[Exposure process]
The exposure step is a step of irradiating a portion of the etching resist layer with radiation through a photomask and photocuring a portion of the etching resist layer. The method of exposing the etching resist layer is the same as the method used in the manufacturing method (1) described above, and conditions such as temperature can be appropriately changed according to the type of etching resist.

[Development process]
The developing step is a step of alkali developing the etching resist layer irradiated with radiation. The exposed portion is removed when the etching resist is of a positive type, and the exposed portion is removed when the etching resist is of a negative type. The method of alkali development may be appropriately selected from known methods according to the type of etching resist.

[Heat flow process]
The heat flow step is a step of heat-flowing the exposed portions of the etching resist layer after development to melt flow the exposed portions of the etching resist layer into a microlens shape. The heat flow process can be performed by the same method as used in the above-described manufacturing method (1), with conditions such as temperature appropriately changed in accordance with the type of etching resist.

[Transfer process]
The transfer step is a step of dry-etching the resin layer using the exposed portion of the etching resist layer after heat flow as a mask layer to transfer the shape of the mask layer to the resin layer.

A known method can be used for the dry etching. Examples of dry etching methods include plasma etching, ion etching, reactive ion etching, sputter etching, and the like. A known device can be used for dry etching. Examples of gases that can be used for dry etching include fluorine-based gases such as CHF ₃ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ and SF ₆ , chlorine-based gases such as Cl ₂ and BCl ₃ , and O ₂ . , O ₃ and other oxygen-based gases, H ₂ , NH ₃ , CO, CO ₂ , CH ₄ , C ₂ H ₂ , C ₂ H ₄ , C ₂ H ₆ , C ₃ H ₄ , C ₃ H ₆ , C ₃ Reducing gases such as H ₈ , HF, HI, HBr, HCl, NO, NH ₃ and BCl ₃ and inert gases such as He, N ₂ and Ar are included. These gases can be mixed and used.

[Microlens manufacturing method (3)]
A method for producing a microlens composition according to an embodiment of the present invention includes (i) applying the microlens-forming composition onto a lens material layer and drying to form a coating film of the microlens-forming composition. (ii) an exposure step of irradiating a portion of the coating film with radiation through a photomask; and (iii) developing the irradiated coating film to remove the unexposed portion. and (iv) a mask layer forming step of forming a mask layer having a microlens pattern by heat-flowing the developed coating film and heating and curing the coating film while processing the coating film into a microlens shape. and (v) dry etching the lens material layer and the mask layer to transfer the shape of the coating layer to the lens material layer.

[Coating film forming process]
The coating film forming step is a step of applying the microlens-forming composition onto the lens material layer and drying to form a coating film of the microlens-forming composition. At this time, the surface of the lens material layer is flattened by the same method as described in the microlens manufacturing method (2). The method of applying the microlens-forming composition and the method of drying the applied microlens-forming composition can be performed in the same manner as the method used in the production method (1) described above.

The lens material layer may be a layer made of a known lens material.

[Exposure process and development process]
The above (ii) exposure step and (iii) development step can be performed by the same method as described in the microlens manufacturing method (1).

[Mask layer forming step]
The mask layer forming step is a step of heat-flowing and melt-flowing the coating film after development, heating and curing the coating film while processing the coating film into a microlens shape, and forming a mask layer having a microlens pattern. . The heat flow of the coating film can be performed by a method similar to that used in the production method (1) described above.

[Transfer process]
The transfer step can be performed by a dry etching method similar to that used in the manufacturing method (2) described above.

By using the composition for forming a microlens of the present invention, even in a method using the composition for forming a microlens as a resist material like the production method (3), the interface between the lens layer and the etching resist layer Spreading of radiation along the edge of the resist pattern is suppressed, and generation of residue at the edge of the resist pattern can be suppressed. Therefore, by using the cured product of the microlens-forming composition of the present invention as a mask, the lens layer can be etched with high precision, and a microlens pattern with a better shape can be formed.

3. Solid-State Imaging Device The solid-state imaging device of the present invention has the microlenses described above. Since the solid-state imaging device of the present invention has the above-described microlenses, it is possible to increase the number of pixels and increase the sensitivity.

4. Imaging Device The imaging device of the present invention has the solid-state imaging device described above. Since the imaging apparatus of the present invention has the solid-state imaging device described above, it is possible to obtain high-quality images.

EXAMPLES Hereinafter, embodiments of the present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited to these.

First, synthesis examples of the unsaturated group-containing alkali-soluble resin as the component (A) will be described. Unless otherwise specified, the resins in these synthesis examples were evaluated as follows.

Note that when the same model of measuring equipment is used, the name of the equipment manufacturer is omitted from the second position. Further, the glass substrates used in the examples are all subjected to the same treatment. Moreover, when the first decimal place of the content of each component is 0, the notation after the decimal point may be omitted.

[Solid content concentration]
The solid content concentration is the weight [W ₁ (g)] obtained by impregnating a glass filter [weight: W ₀ (g)] with 1 g of the resin solution obtained in Synthesis Example, and after heating at 160 ° C. for 2 hours. It was determined by the following formula using the weight [W ₂ (g)] of .
Solid content concentration (% by weight) = 100 × (W ₂ - W ₀ )/(W ₁ - W ₀ )

[Epoxy equivalent]
After dissolving the resin solution in dioxane, add an acetic acid solution of tetraethylammonium bromide, and titrate with a 1/10 N-perchloric acid solution using a potentiometric titrator "COM-1600" (manufactured by Hiranuma Sangyo Co., Ltd.). rice field.

[Acid value]
The acid value was obtained by dissolving the resin solution in dioxane and titrating it with a 1/10 N-KOH aqueous solution using a potentiometric titrator "COM-1600" (manufactured by Hiranuma Sangyo Co., Ltd.).

[Molecular weight]
The molecular weight is determined by gel permeation chromatography (GPC) "HLC-8220GPC" (manufactured by Tosoh Corporation, solvent: tetrahydrofuran, column: TSKgelSuper H-2000 (2) + TSKgelSuper H-3000 (1) + TSKgelSuper H-4000 ( 1 piece) + TSKgelSuper H-5000 (1 piece) (manufactured by Tosoh Corporation), temperature: 40 ° C., speed: 0.6 ml / min), standard polystyrene (manufactured by Tosoh Corporation, PS-oligomer kit) conversion A weight average molecular weight (Mw) was obtained as a value.

The abbreviations used in Synthesis Examples are as follows.
BPFE: bisphenol fluorene type epoxy resin (an epoxy resin in which Ar represented by the general formula (1) is a benzene ring and l is 0, epoxy equivalent 256 g/eq)
BNFE: bisnaphtholfluorene type epoxy resin (an epoxy resin in which Ar represented by the general formula (1) is a naphthalene ring and l is 0, epoxy equivalent 281 g/eq)
BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride THPA: 1,2,3,6-tetrahydrophthalic anhydride TPP: triphenylphosphine AA: acrylic acid PGMEA: propylene glycol monomethyl ether acetate DCPMA: Dicyclopentanyl methacrylate GMA: Glycidyl methacrylate St: Styrene AIBN: Azobisisobutyronitrile TDMAMP: Trisdimethylaminomethylphenol HQ: Hydroquinone SA: Succinic anhydride TEA: Triethylamine

[Synthesis Example 1]
BPFE (50.00 g, 0.10 mol), AA (14.07 g, 0.20 mol), TPP (0.26 g), and PGMEA (40.00 g) were placed in a 250 mL four-neck flask equipped with a reflux condenser. The mixture was charged and stirred at 100-105° C. for 12 hours to obtain a reaction product. After that, PGMEA (25.00 g) was added to the reaction product to adjust the solid content to 50% by mass.

Next, BPDA (14.37 g, 0.05 mol) and THPA (7.43 g, 0.05 mol) were added to the resulting reaction product and stirred at 115 to 120° C. for 6 hours to obtain an unsaturated group-containing alkali-soluble resin. A resin solution of (A)-1 was obtained. The resin solution had a solid content concentration of 57.0% by mass, an acid value (in terms of solid content) of 96 mgKOH/g, and an Mw of 3,600 by GPC analysis.

[Synthesis Example 2]
BPFE (50.00 g, 0.10 mol), AA (14.07 g, 0.20 mol), TPP (0.26 g), and PGMEA (40.00 g) were placed in a 250 mL four-neck flask equipped with a reflux condenser. The mixture was charged and stirred at 100-105° C. for 12 hours to obtain a reaction product. After that, PGMEA (25.00 g) was added to the reaction product to adjust the solid content to 50% by mass.

Next, BPDA (10.06 g, 0.03 mol) and THPA (11.89 g, 0.08 mol) were added to the resulting reaction product, stirred at 115 to 120° C. for 6 hours, and the polymerizable unsaturated group-containing alkali A resin solution of soluble resin (A)-2 was obtained. The resin solution had a solid content concentration of 57.0% by mass, an acid value (in terms of solid content) of 98 mgKOH/g, and an Mw of 2,300 by GPC analysis.

[Synthesis Example 3]
BPFE (50.00 g, 0.10 mol), AA (14.07 g, 0.20 mol), TPP (0.26 g), and PGMEA (40.00 g) were placed in a 250 mL four-neck flask equipped with a reflux condenser. The mixture was charged and stirred at 100-105° C. for 12 hours to obtain a reaction product. After that, PGMEA (25.00 g) was added to the reaction product to adjust the solid content to 50% by mass.

Next, BPDA (19.25 g, 0.07 mol) and THPA (0.30 g, 0.002 mol) were added to the resulting reaction product, stirred at 115 to 120° C. for 6 hours, and the polymerizable unsaturated group-containing alkali A resin solution of soluble resin (A)-3 was obtained. The solid content concentration of the resin solution was 56.3% by mass, the acid value (in terms of solid content) was 97 mgKOH/g, and the Mw by GPC analysis was 4,700.

[Synthesis Example 4]
BNFE (50.00 g, 0.09 mol), AA (12.82 g, 0.20 mol), TPP (0.23 g), and PGMEA (40.00 g) were placed in a 250 mL four-neck flask equipped with a reflux condenser. The mixture was charged and stirred at 100-105° C. for 12 hours to obtain a reaction product. After that, PGMEA (25.00 g) was added to the reaction product to adjust the solid content to 50% by mass.

Next, BPDA (13.09 g, 0.04 mol) and THPA (6.77 g, 0.04 mol) were added to the resulting reaction product and stirred at 115 to 120° C. for 6 hours to obtain an unsaturated group-containing alkali-soluble resin. A resin solution of (A)-4 was obtained. The solid content concentration of the resin solution was 56.1% by mass, the acid value (in terms of solid content) was 91 mgKOH/g, and the Mw by GPC analysis was 3,500.

[Synthesis Example 5]
PGMEA (300 g) was placed in a 1 L four-necked flask equipped with a reflux condenser, and the inside of the flask system was replaced with nitrogen, and then the temperature was raised to 120°C. A mixture of AIBN (10 g) dissolved in a monomer mixture (DCPMA (77.1 g, 0.35 mol), GMA (49.8 g, 0.35 mol), and St (31.2 g, 0.30 mol)) was dropped into the flask. It was added dropwise from the funnel over 2 hours and further stirred at 120° C. for 2 hours to obtain a copolymer solution.

Then, after replacing the inside of the flask system with air, AA (24.0 g, 95% of glycidyl groups), TDMAMP (0.8 g) and HQ (0.15 g) were added to the obtained copolymer solution, The mixture was stirred at 120° C. for 6 hours to obtain a polymerizable unsaturated group-containing copolymer solution. SA (30.0 g, 90% of the number of moles of AA added) and TEA (0.5 g) were added to the obtained polymerizable unsaturated group-containing copolymer solution and reacted at 120 ° C. for 4 hours to obtain a polymerizable unsaturated group. A resin solution of group-containing alkali-soluble copolymer resin solution (A)-5 was obtained. The solid content concentration of the resin solution was 46.0% by mass, the acid value (in terms of solid content) was 76 mgKOH/g, and the Mw by GPC analysis was 5,300.

Microlens-forming compositions of Examples 1 to 11 and Comparative Examples 1 to 3 were prepared in the amounts shown in Table 1 (unit: % by mass). The ingredients used in Tables 1 and 2 are as follows.

(Unsaturated group-containing alkali-soluble resin)
(A)-1: Resin solution obtained in Synthesis Example 1 (solid content concentration 57.0% by mass)
(A)-2: Resin solution obtained in Synthesis Example 2 (solid content concentration 57.0% by mass)
(A)-3: Resin solution obtained in Synthesis Example 3 (solid content concentration 56.3% by mass)
(A)-4: Resin solution obtained in Synthesis Example 4 (solid content concentration 56.1% by mass)
(A)-5: Resin solution obtained in Synthesis Example 5 (solid content concentration 46.0% by mass)

(Photopolymerizable monomer)
(B): Dipentaerythritol penta/hexaacrylate mixture (KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd., "KAYARAD" is a registered trademark of the company)

(epoxy compound)
(C): Biphenyl-type epoxy resin (jER YX4000, manufactured by Mitsubishi Chemical Corporation, "jER" is a registered trademark of the same company, epoxy equivalent 180 to 192 g/eq)

(Photoinitiator)
(D)-1: Omnirad 907 (manufactured by IGM Resins, B.V., "Omnirad" is a registered trademark of the company)
(D)-2: Irgacure OXE-01 (manufactured by BASF, "Irgacure" is a registered trademark of the company)

(Ultraviolet absorber)
(E)-1: Tinuvin 384-2 (manufactured by BASF Japan, solid content concentration 95% by mass, "Tinuvin" is a registered trademark of the company)
(E)-2: Tinuvin 400 (solid content concentration 85% by mass)
(E)-3: Adekastab 1413 (manufactured by ADEKA Co., Ltd., "Adekastab" is a registered trademark of the company)
(E)-4: RUVA-93 (manufactured by Otsuka Chemical Co., Ltd.)

(solvent)
(F): Propylene glycol monomethyl ether acetate (PGMEA)

(sensitizer)
(G): Michler Ketone

[evaluation]
The cured films obtained by curing the microlens-forming compositions of Examples 1 to 11 and Comparative Examples 1 to 3 shown in Tables 1 and 2 were evaluated as follows.

(Preparation of substrate with cured film for refractive index measurement)
The microlens-forming composition shown in Tables 1 and 2 was applied to a 5-inch substrate (silicon wafer) using a spin coater so that the film thickness after heat curing was 1.0 μm, and then a hot plate was applied. A dried film was prepared by pre-baking at 100° C. for 5 minutes. Next, the dried film was irradiated with ultraviolet rays of 500 mJ/cm ² with an ultra-high pressure mercury lamp (wavelength 365 nm, illuminance 30 mW/cm ² ) to perform a photocuring reaction (exposure). C. for 30 minutes for main curing (post-baking) to obtain a substrate with a cured film for refractive index measurement.

[Refractive index evaluation]
Using an ellipsometer (manufactured by JA Woollam), the refractive index at a wavelength of 633 nm of the substrate with the cured film after the main curing was measured.

(Preparation of substrate with cured film for transmittance measurement)
The microlens-forming composition shown in Tables 1 and 2 was applied to a 125 mm×125 mm glass substrate “#1737” (manufactured by Corning Incorporated) (hereinafter referred to as “glass substrate”) so that the film thickness after heat curing was 1.5 mm. It was coated using a spin coater so as to have a thickness of 0 μm, and prebaked at 100° C. for 5 minutes using a hot plate to prepare a dry film. Next, the dried film was irradiated with ultraviolet rays of 300 mJ/cm ² with an ultra-high pressure mercury lamp (wavelength 365 nm, illuminance 30 mW/cm ² ) to perform a photocuring reaction (exposure). C. for 30 minutes to obtain a cured film-attached substrate for transmittance measurement.

[Transmittance evaluation]
Using an ultraviolet-visible-infrared spectrophotometer "UH4150" (manufactured by Hitachi High-Tech Science Co., Ltd.), the transmittance at a wavelength of 400 nm of the substrate with the cured film after the main curing was measured.

(Preparation of substrate with cured film for pattern adhesion and pattern edge residue evaluation)
The microlens-forming compositions shown in Tables 1 and 2 were applied onto a glass substrate of 125 mm×125 mm using a spin coater so that the film thickness after heat curing treatment would be 2.0 μm, and a hot plate was applied. A dried film was prepared by pre-baking at 100° C. for 5 minutes. Next, the dried film was irradiated with ultraviolet rays of 300 mJ/cm ² from an ultra-high pressure mercury lamp (wavelength 365 nm, illuminance 30 mW/cm ² ) for photocuring reaction (exposure).

Next, the exposed dry film (exposed film) was developed with a 0.8% TMAH (tetramethylammonium hydroxide) developer at 23° C. at a shower pressure of 1 kgf/cm ² for a development time (break time) at which the pattern begins to appear. = BT), followed by washing with water spray of 5 kgf/cm ² to remove the unexposed portions of the exposed film, thereby obtaining a dot pattern of 5 µm in diameter on the glass substrate. Finally, the obtained dot pattern was subjected to main curing (post-baking) at 230° C. for 30 minutes using a hot air dryer to obtain a substrate with a cured film for pattern adhesion and pattern edge residue evaluation. .

[Evaluation of pattern adhesion]
(Evaluation method)
The dot pattern (cured film) with a diameter of 5 μm on the substrate was observed with an optical microscope for the presence or absence of peeling of the dot pattern. In addition, △ or more was taken as the pass.

(Evaluation criteria)
○: Peeling is not confirmed in the dot pattern △: Peeling is confirmed in part of the dot pattern ×: All of the dot pattern is peeled off

[Residue Evaluation at Pattern Edge]
(Evaluation method)
The dot pattern (cured film) with a diameter of 5 μm on the substrate was observed with a scanning electron microscope (SEM) for the presence or absence of residues at the edges of the dot pattern. In addition, △ or more was taken as the pass.

(Evaluation criteria)
○: Residue is not observed at the edge of the pattern △: Residue is observed at part of the edge of the pattern ×: Residue at the edge of the pattern is conspicuous

(Preparation of substrate with cured film for chemical resistance evaluation)
Each of the microlens-forming compositions shown in Tables 1 and 2 was applied onto a glass substrate using a spin coater so that the film thickness after heat curing was 2.0 μm, and heated at 100° C. using a hot plate. A dry film was produced by pre-baking for 5 minutes. Next, the dried film was irradiated with ultraviolet rays of 300 mJ/cm ² with an ultra-high pressure mercury lamp (wavelength 365 nm, illuminance 30 mW/cm ² ) to perform a photo-curing reaction (exposure). C. for 1 hour or 230.degree. C. for 30 minutes to obtain a substrate with a cured film for chemical resistance evaluation.

[Solvent resistance evaluation]
(Evaluation method)
The film thickness (L1) of the cured film after main curing (post-baking) and the film thickness (L2) of the cured film after immersion in acetone for 10 minutes, washing, and drying were measured using a stylus method. It was measured using a shape measuring device "P-17" (manufactured by KLA-Tencor Co., Ltd.), and the residual film ratio (%) was calculated from the following formula. In addition, △ or more was taken as the pass.
Remaining film rate (%) = L2/L1 x 100

(Evaluation criteria)
○: Remaining film rate is 90% or more △: Remaining film rate is 80% or more and less than 90% ×: Remaining film rate is less than 80%

The above evaluation results are shown in Tables 3 and 4.

As shown in Examples 1 to 11, it was found that a cured film having a high refractive index and a high transmittance can be formed by using the microlens-forming resin composition of the present invention.

As shown in Examples 1 to 11, it was found that by using a resin composition containing an ultraviolet absorber, it was possible to suppress the generation of residue peculiar to negative pattern formation. This is because the ultraviolet absorber absorbs the irradiated radiation and suppresses the spread of excess radiation along the substrate interface, and the composition at the interface with the substrate at the site where the radiation is not irradiated. It is thought that this is for suppressing the hardening of .

Further, as shown in Examples 4 to 11, by using an ultraviolet absorber having an ethylenically unsaturated group, the exudation of the ultraviolet absorber into the solvent is suppressed, and the chemical resistance of the cured product is increased. I found that it can be done. It is believed that this is because the photosensitive reactive group of the UV absorber reacts with the unsaturated group-containing alkali-soluble resin or the photopolymerizable monomer to incorporate the UV absorber into the resin.

INDUSTRIAL APPLICABILITY The microlens-forming resin composition of the present invention can be used for solid-state imaging devices that require high pixel count and high sensitivity.

Claims (13)

A microlens-forming composition for forming a microlens pattern,
(A) an unsaturated group-containing alkali-soluble resin;
(B) a photopolymerizable monomer having at least one or more ethylenically unsaturated bonds;
(C) an epoxy compound having two or more epoxy groups;
(D) a photoinitiator;
(E) an ultraviolet absorber;
(F) a solvent;
including
A composition for forming a microlens, wherein the content of the ultraviolet absorber (E) is 3% by mass or more and 20% by mass or less with respect to the total mass of the solid content. 2. The microlens-forming composition according to claim 1, wherein (A) the unsaturated group-containing alkali-soluble resin is a resin represented by the following general formula (1).

(In formula (1), Ar is each independently an aromatic hydrocarbon group having 6 to 14 carbon atoms, and some of the bonded hydrogen atoms are linear or branched chains having 1 to 10 carbon atoms. from the group consisting of an alkyl group, an aryl or arylalkyl group having 6 to 10 carbon atoms, a cycloalkyl or cycloalkylalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and a halogen group; may be substituted with selected groups, each R ₁ is independently an alkylene group having 2 to 4 carbon atoms, each l is independently a number of 0 to 3, and each G is independently is a (meth)acryloyl group, a substituent represented by the following general formula (2) or the following general formula (3), Y is a tetravalent carboxylic acid residue, Z is each independently a hydrogen atom or a substituent represented by the following general formula (4), one or more of which is a substituent represented by the following general formula (4). n is a number with an average value of 1 to 20.)

(In formulas (2) and (3), R ₂ is a hydrogen atom or a methyl group, R ₃ is a divalent alkylene group or alkylarylene group having 2 to 10 carbon atoms, and R ₄ is a 2 to 20 divalent saturated or unsaturated hydrocarbon groups, and p is a number from 0 to 10.)

(In formula (4), W is a divalent or trivalent carboxylic acid residue, and m is a number of 1 or 2.) 3. The microlens-forming composition according to claim 1, wherein the (E) ultraviolet absorber is selected from the group consisting of benzotriazole compounds, benzophenone compounds and triazine compounds. 4. The microlens-forming composition according to claim 1, wherein the (E) ultraviolet absorber has an ethylenically unsaturated group. The unsaturated group-containing alkali-soluble resin (A) has a weight average molecular weight of 1000 or more and 40000 or less and an acid value of 50 mgKOH/g or more and 200 mgKOH/g or less, according to any one of claims 1 to 4. Microlens-forming composition. 6. The microlens-forming composition according to any one of claims 1 to 5, comprising a sensitizer as component (G). a coating film layer forming step of applying the microlens-forming composition according to any one of claims 1 to 6 and drying to form a coating film of the microlens-forming composition;
An exposure step of irradiating a part of the coating film with radiation through a photomask;
A developing step of developing the coating film irradiated with the radiation and removing an unexposed portion;
A heat flow step of heat-curing the exposed portion after the development by heat-flowing the exposed portion while processing the exposed portion into a microlens shape;
A method of manufacturing a microlens, comprising: a resin layer forming step of applying the microlens-forming composition according to any one of claims 1 to 6, irradiating it with radiation, and curing it to form a resin layer of the microlens-forming composition;
forming an etching resist layer on the surface of the resin layer;
an exposure step of irradiating a portion of the etching resist layer with radiation through a photomask;
a developing step of developing the etching resist layer irradiated with the radiation;
a heat flow step of heat-flowing the exposed portion after the development to process the exposed portion into a microlens shape;
a transfer step of dry-etching the resin layer using the exposed portion after the heat flow as a mask layer to transfer the shape of the mask layer to the resin layer;
A method of manufacturing a microlens, comprising: a coating film forming step of applying the microlens-forming composition according to any one of claims 1 to 6 onto the lens material layer and drying to form a coating film of the microlens-forming composition; ,
An exposure step of irradiating a part of the coating film with radiation through a photomask;
A developing step of developing the coating film irradiated with the radiation and removing an unexposed portion;
a mask layer forming step of forming a mask layer having a microlens pattern by heat-flowing the developed coating film and heating and curing the coating film while processing the coating film into a microlens shape;
a transfer step of dry-etching the lens material layer and the mask layer to transfer the shape of the mask layer to the lens material layer;
A method of manufacturing a microlens, comprising: A cured film obtained by curing the microlens-forming composition according to any one of claims 1 to 6. A microlens comprising the cured film according to claim 10 . A solid-state imaging device comprising the microlens according to claim 11 . An imaging device comprising the solid-state imaging device according to claim 12 .