JP6515674B2 - Green photosensitive composition for solid-state imaging device and color filter using the same - Google Patents

Description

  The present invention relates to a green photosensitive composition for a solid-state imaging device and a color filter using the same.

  In a solid-state imaging device that reads a color image, for example, the incident light is separated into three colors of green, red and blue by passing it through the green, red and blue coloring layers of the color filter. The intensity is detected by the photoelectric conversion element included in each pixel. Thus, the solid-state imaging device outputs an image signal including color information from the photoelectric conversion element.

  In color filters of solid-state imaging devices, one pixel is generally arranged in a square. As the arrangement of each color, for example, green pixels are arranged in a checkered pattern, and red pixels and blue pixels are arranged not to share the same vertex in the same part in the remaining part.

  The color filter can be formed using photolithography. For example, a photosensitive composition containing a color pigment is applied onto a substrate, the coating film is pattern-exposed, and then the coating film is developed and the remaining coating film is baked. Thereby, a colored layer composed of a plurality of filter segments is obtained. Thus, the first colored layer is formed, and thereafter, the second and third colored layers are sequentially formed by the same method. When the pixel as shown in FIG. 1 is manufactured by such a manufacturing method, a green pixel having a large number of pixels is manufactured as the first colored layer.

JP, 2013-242554, A JP, 2009-244321, A

  In recent years, solid-state imaging devices consisting of CCD or CMOS imaging semiconductor elements are often used in digital cameras and video cameras, and mobile phones should be equipped with camera modules consisting of solid-state imaging devices and lens systems. It has come. For these applications, small-sized, light-weight, thin, and high-resolution solid-state imaging devices are further required. For example, in order to realize a resolution of up to 10 million pixels with a small solid-state imaging device, the size of each pixel has been miniaturized to 1 μm or less in each of the vertical and horizontal directions. When making the first green pixel by photolithography, it is necessary to make openings for forming red and blue pixels, but when the pixel size becomes 1 μm or less in each of the vertical and horizontal directions, the larger pixel size Even under the same manufacturing conditions as in the above, removal of the unexposed area in development can not be sufficiently performed, and a residue is likely to be generated.

  In addition, as the pixel size becomes smaller, thinning of the pixel is required. However, since the spectral characteristics require the same performance as before, it is necessary to increase the color pigment content. However, when the content of the color pigment is increased, the residue tends to be more easily generated.

  Furthermore, since the miniaturization of the pixel makes it easy to generate noise due to the roughness of the pixel surface, the pixel flatness is also required.

  In the conventionally known techniques, there are some in which measures for residue and film residue are taken in the formation of an opening pattern of several μm to several tens of μm (for example, see Patent Documents 1 and 2). However, at present, the residue in the pattern formation of the opening of 1 μm or less can not be dealt with.

  The present invention has been made in view of the above problems, and it is a green photosensitive composition for a solid-state imaging device having an extremely small amount of residue at the opening even in a fine pattern of 1 μm or less and having excellent pixel flatness. And it aims at providing a color filter using the same.

  The present invention is a green photosensitive composition for a solid-state imaging device comprising a pigment dispersion, a photopolymerizable monomer, a photopolymerization initiator and a solvent, wherein the pigment dispersion is a solid solution pigment of a green pigment and a yellow pigment, a dispersant And a solid solution pigment having a volume average particle size of 50 nm or less, and an acid value of the resin of 60 to 300 mg KOH / g, which is a green photosensitive composition for a solid-state imaging device.

  Also, the green pigment may be a halogenated phthalocyanine.

  The present invention is also a color filter having green pixels formed on a substrate using the green photosensitive composition for a solid-state imaging device.

  According to the present invention, a green photosensitive composition for a solid-state imaging device having extremely low residue in the opening and excellent in the flatness of pixels even in a fine pattern of 1 μm or less, and a color filter using the same are provided. It becomes possible.

FIG. 2 is a pixel layout diagram showing a color filter of the embodiment.

  Hereinafter, the present invention will be described in more detail by way of embodiments, but the present invention is not limited to these embodiments.

  The green photosensitive composition which concerns on this embodiment contains a pigment dispersion, a photopolymerizable monomer, a photoinitiator, and a solvent.

  The photopolymerizable monomer is a compound which can be polymerized by an active radical, an acid or the like generated from a photopolymerization initiator by being irradiated with light. For example, compounds having a polymerizable carbon-carbon unsaturated bond can be mentioned.

  The photopolymerizable monomer is preferably a trifunctional or higher polyfunctional photopolymerizable compound. Examples of trifunctional or higher polyfunctional photopolymerizable compounds include pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, etc. Can be mentioned.

  The photopolymerizable monomers may be used alone or in combination of two or more. The content thereof is preferably 1 to 50 parts by mass, and more preferably 5 to 30 parts by mass with respect to 100 parts by mass of the solid content of the photosensitive composition. When the photopolymerizable monomer is less than 1 part by mass, curing of the film does not occur sufficiently, and when it exceeds 50 parts by mass, a residue on development tends to be generated.

  An acetophenone type compound can be used as a photoinitiator. Examples of acetophenone compounds include diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one and 2-hydroxy-2-methyl-1-phenylpropan-1-one. , Benzyldimethyl ketal, 2-hydroxy-2-methyl-1- [4- (2-hydroxyethoxy) phenyl] propan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1- [ Oligomers of 4- (1-methylvinyl) phenyl] propan-1-one and the like can be mentioned. Preferably, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one and the like can be mentioned.

  Further, the photopolymerization initiator may be used in combination with a plurality of acetophenone and other photopolymerization initiators. As photopolymerization initiators other than the acetophenone type, active radical generators, sensitizers, acid generators and the like that generate active radicals by being irradiated with light may be mentioned. Examples of the active radical generator include benzoin compounds, benzophenone compounds, thioxanthone compounds, and triazine compounds.

  Examples of the benzoin compound which is an active radical generator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether and the like.

  Examples of benzophenone compounds which are active radical generating agents include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3 ', 4,4'-tetra. (T-butylperoxycarbonyl) benzophenone, 2,4,6-trimethyl benzophenone and the like.

  Examples of thioxanthone compounds that are active radical generating agents include 2-isopropyl thioxanthone, 4-isopropyl thioxanthone, 2,4-diethyl thioxanthone, 2,4-dichloro thioxanthone, 1-chloro-4-propoxy thioxanthone, etc. .

  Examples of triazine compounds which are active radical generating agents include 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine and 2,4-bis (trichloromethyl). -6- (4-Methoxynaphthyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxystyryl) -1,3,5-triazine, 2,4-bis (Trichloromethyl) -6- [2- (5-methylfuran-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (furan-2) -Yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (4-diethylamino-2-methylphenyl) ethenyl] -1,3,5-triazine, 2,4-bi Etc. (trichloromethyl) -6- [2- (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine.

  As an active radical generator, for example, 2,4,6-trimethylbenzoyldiphenyl phosphine oxide, 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'- It is also possible to use biimidazole, 10-butyl-2-chloroacridone, 2-ethylanthraquinone, benzyl, 9,10-phenanthrenequinone, camphorquinone, methyl phenylglyoxylate, titanocene compounds and the like.

  As an acid generator, for example, 4-hydroxyphenyldimethylsulfonium p-toluenesulfonate, 4-hydroxyphenyldimethylsulfonium hexafluoroantimonate, 4-acetoxyphenyldimethylsulfonium p-toluenesulfonate, 4-acetoxyphenyl methyl. Onium salts such as benzyl sulfonium hexafluoroantimonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium hexafluoroantimonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium hexafluoroantimonate, and nitrobenzyl tosylates Benzoin tosylates can be mentioned.

  Further, among the compounds described above as the active radical generator, there are also compounds which generate an acid simultaneously with the active radical. For example, a triazine type photoinitiator is used not only as an active radical generator but also as an acid generator.

  The content of the photopolymerization initiator is preferably 0.1 to 30 parts by mass, and more preferably 0.5 to 15 parts by mass with respect to 100 parts by mass of the solid content of the photosensitive composition. When the content of the photopolymerization initiator is less than 0.1 parts by mass, the film formation can not be performed because the sensitivity at the time of exposure is insufficient.

  Examples of the solvent used in the present invention include ethers, aromatic hydrocarbons, ketones, alcohols, esters, and amides.

  As ethers, for example, tetrahydrofuran, tetrahydropyran, 1,4-dioxane, 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, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dipropyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate Methyl cellosolve acetate, ethyl cellosolve acetate, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol methyl ether acetate, methoxybutyl acetate, methoxy pentyl acetate, anisole, phenetole, and the like methyl anisole.

  Moreover, as aromatic hydrocarbons, benzene, toluene, xylene, mesitylene etc. are mentioned, for example.

  Examples of ketones include acetone, 2-butanone, 2-heptanone, 3-heptanone, 4-heptanone, 4-methyl-2-pentanone, cyclohexanone and the like.

  Examples of alcohols include methanol, ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, glycerin and the like.

  Examples of esters include ethyl acetate, n-butyl acetate, isobutyl acetate, amyl formate, isoamyl acetate, isobutyl acetate, butyl propionate, isopropyl butyrate, ethyl butyrate, butyl butyrate, alkyl esters, methyl lactate, ethyl lactate Methyl oxyacetate, ethyl oxyacetate, butyl oxyacetate, methyl methoxyacetate, ethyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, methyl 3-oxypropionate, ethyl 3-hydroxypropionate, 3-methoxy Methyl propionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 2-oxypropionate, ethyl 2-hydroxypropionate, propyl 2-oxypropionate, 2-metho Methyl cypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, methyl 2-oxy-2-methylpropionate, 2-oxy-2- Ethyl methyl propionate, methyl 2-methoxy-2-methyl propionate, ethyl 2-ethoxy 2-methyl propionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, 2-oxobutane Methyl acid, ethyl 2-oxobutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, γ-butyrolactone and the like can be mentioned.

  Examples of the amides include N, N-dimethylformamide, N, N-dimethylacetamide and the like.

  Examples of other solvents include, for example, N-methyl pyrrolidone, dimethyl sulfoxide and the like.

  Among the above-mentioned solvents, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, ethyl cellosolve acetate, ethyl carbitol acetate, butyl carbitol acetate, 2-heptanone, cyclohexanone, ethyl lactate, butyl acetate, methyl 3-methoxypropionate, 3- Methyl ethoxypropionate, ethyl 3-ethoxypropionate and the like are preferably used.

  The solvents may be used alone or in combination of two or more. 30-95 mass parts is preferable among 100 mass parts, and, as for content of the solvent in a photosensitive composition, 60-90 mass parts is more preferable. If it is less than 30 parts by mass, it will be difficult to obtain flatness by the coat, and if it exceeds 95 parts by mass, a coat having a sufficient film thickness can not be obtained.

  Next, the pigment dispersion is described. The pigment dispersion according to this embodiment comprises a solid solution pigment of a green pigment and a yellow pigment, a dispersant, and a resin.

  Pigments applied to the green photosensitive composition include green pigments and yellow pigments. The green pigment is preferably a halogenated phthalocyanine, and among the 16 substitutable hydrogen atoms in the phthalocyanine ring, one having 8 to 16 substitution is preferable, and one having 12 to 16 substitution is preferable. Is more preferred. As a halogen atom substituted to a phthalocyanine ring, a bromine atom, a chlorine atom, a fluorine atom, and an iodine atom are mentioned, A bromine atom or a chlorine atom is more preferable, and a bromine atom is still more preferable. Further, the halogen atoms to be substituted may be all the same or different. Examples of these pigments include C.I. I. Pigment Green 7, 36, 58.

  As a yellow pigment, any pigment may be used as long as it forms a solid solution with a green pigment. For example, C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 24, 31, 32, 34, 36, 36: 1, 40, 42, 43, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 126, 127, 128, 129, 139, 147, 150, 151, 152, 153, 154, 155, 156, 161, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, 182, 185, 187, 188, 19 Yellow pigments such as 3, 194, 198, 199, 213, 214 can be used.

  40-90 mass parts is preferable with respect to 100 mass parts of solid content of a pigment dispersion, and, as for the usage-amount of a solid solution pigment, 50-80 mass parts is more preferable. If the amount is less than 40 parts by mass, the concentration as the coloring component is insufficient, and if it exceeds 90 parts by mass, sufficient dispersion can not be achieved.

  A solid solution pigment of a green pigment and a yellow pigment is prepared by dissolving both the green pigment and the yellow pigment in a good solvent to make a pigment solution and depositing in a poor solvent. As the good solvent, an acid or an alkali is used. For example, as the acid, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, and chromic acid, and citric acid And organic acids such as acetic acid, lactic acid, butyric acid, formic acid, oxalic acid, amino acids, ascorbic acid, and para-toluenesulfonic acid. As the alkali, hydroxides of alkali metals (sodium hydroxide, potassium hydroxide, etc.), hydroxides of alkali earth metals (calcium hydroxide, etc.), organic bases (diazabicycloundecene, tetrabutylammonium hydroxide) , Tetramethyl ammonium hydroxide, sodium methoxide and the like).

  An acid or an alkali may be used alone, or a plurality of solvents may be used in combination as the good solvent used for preparation of the solid solution pigment. In addition, water, an alcohol solvent, an aprotic polar solvent, or the like may be used in combination as a solvent for dissolving the acid or alkali or enhancing the solubility of the pigment. Specifically, examples of alcohol solvents include methanol, ethanol, 2-propanol, 1-methoxy-2-propanol and the like, and examples of polar solvents include acetonitrile, N, N-dimethylformamide, N, N-dimethyl Examples include acetamide, dimethyl sulfoxide, sulfolane, N-methyl-2-pyrrolidinone and the like.

  As the poor solvent, any solvent can be used as long as it is uniformly mixed with the good solvent and the pigment is sufficiently precipitated. The solubility of the pigment in the poor solvent is desirably 0.01 parts by mass or less of the pigment to 100 parts by mass of the poor solvent. Examples of poor solvents include water, alcohol solvents, ketone solvents, ester solvents, aprotic polar solvents and the like. Specifically, acetone, methyl ethyl ketone, cyclohexanone etc. are mentioned as a ketone system solvent. Examples of ester solvents include ethyl acetate, butyl acetate, ethyl lactate, 1-methoxy-2-propyl acetate and the like.

  The same solvents as those described for the good solvent and the poor solvent may be used, but if the acid or alkali is reduced, the solubility of the pigment is lowered, and if the pigment can be precipitated, the same solvent is used for the good solvent and the poor solvent. You may

  The volume average particle size of the solid solution pigment is preferably 50 nm or less, and more preferably 30 nm or less. When the volume average particle size exceeds 50 nm, the flatness of the pixel to be patterned is deteriorated.

  The method for producing the solid solution pigment is not particularly limited, but in order to produce a solid solution pigment with high size uniformity, it is preferable to carry out mixing of the pigment solution and the poor solvent as quickly as possible. Any of the conventionally known devices used for stirring, mixing, dispersion, crystallization such as an internal circulation type stirring device, an external circulation type stirring device, a flow rate and an ion concentration control device can be applied as a mixing method. Alternatively, the pigment solution may be mixed into the continuously flowing poor solvent. As a method of injecting the pigment solution into the poor solvent, any of the conventionally known liquid injection methods can be used, but it is injected from the liquid of the poor solvent or from above as a jet from a nozzle such as a syringe, needle or tube. Is preferred. In addition, in order to inject in a short time, it is also possible to inject from a plurality of nozzles.

  The solid solution pigment obtained by the above method can be easily separated by centrifugation or filtration. The organic pigment may be used as a slurry containing a solvent, but if necessary, it may be finely divided by a drying method such as spray drying, centrifugal drying, filtration drying, vacuum drying or lyophilization. It can also be used as a powder.

  As the dispersant, for example, as an acrylic dispersant, Disperbyk (registered trademark)-2000, Disperbyk-2001, BYK (registered trademark)-LPN 6919, BYK-LPN 21116, BYK-LPN 21324 (all, manufactured by Big Chemie Co., Ltd.), urethane based dispersion Agents, Disperbyk-161, Disperbyk-162, Disperbyk-165, Disperbyk-167, Disperbyk-170, Disperbyk-182 (above, made by BIC Chemie Co., Ltd.), Solsperse (registered trademark) 76500 (made by Lubrisol Co., Ltd.), polyethylene Solsperse 24000 (manufactured by Lublisol Co., Ltd.) as an imine-based dispersant, Azispar (registered trademark) PB 821, Azispar P as a polyester-based dispersant 822, AJISPER PB880, mention may be made of Ajisper PB881 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), and the like.

  The amount of the dispersant used is preferably 2 to 50 parts by mass, and more preferably 5 to 40 parts by mass with respect to 100 parts by mass of the solid content of the pigment dispersion. In the range of less than 2 parts by mass or more than 50 parts by mass, sufficient dispersion can not be provided.

  As the resin, alkyl acrylate or alkyl methacrylate such as acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, cyclic cyclohexyl acrylate or methacrylate, hydroxyethyl acrylate or methacrylate, styrene or the like The thing synthesize | combined using about 3-5 types of monomers out of can be used.

  The acid value of the resin is preferably 60 to 300 mg KOH / g, and more preferably 80 to 250 mg KOH / g. If the acid value is less than 60 mg KOH / g, the solubility in development is insufficient and residue tends to remain, and if it exceeds 300 mg KOH / g, pattern peeling is likely to occur, making it difficult to produce a color filter.

  The amount of the resin used is preferably 2 to 50 parts by mass, and more preferably 5 to 40 parts by mass with respect to 100 parts by mass of the solid content of the pigment dispersion. If the amount is less than 2 parts by mass or more than 50 parts by mass, sufficient dispersion can not be achieved. In addition, you may stir and mix resin at the time of preparation of a photosensitive composition as needed. At this time, the types of resin used for the pigment dispersion and the resin used for the photosensitive composition are not limited.

  The pigment dispersion may be prepared by any method, for example, a dispersing machine such as a sand mill, bead mill, ball mill, dissolver or the like, or an ultrasonic dispersing machine is preferably used.

  The use amount of the pigment dispersion is preferably 40 to 95 parts by mass, and more preferably 50 to 85 parts by mass with respect to 100 parts by mass of the solid content of the photosensitive composition. When the amount is less than 40 parts by mass, the concentration as a coloring component is insufficient, and when the amount is more than 95 parts by mass, formation of pixels becomes difficult.

  According to a green photosensitive composition for a solid-state imaging device and a color filter using the same according to the present embodiment, the pigment dispersion comprises a solid solution pigment of a green pigment and a yellow pigment, a dispersant, and an acid value of 60 to With a resin of 300 mg KOH / g and a volume average particle diameter of the solid solution pigment of 50 nm or less, even in a fine pattern of 1 μm or less, the residue at the opening is extremely small, pattern peeling hardly occurs, and It is possible to improve the flatness of the pixel.

  Hereinafter, specific examples of the present invention will be described. In Examples and Comparative Examples, "part" means "part by mass".

  Solid solution pigments of photosensitive compositions used in Examples and Comparative Examples were prepared as follows.

<Preparation of solid solution pigment 1>
0.7 parts of a green pigment Pigment Green 58 (PG 58) and 0.3 parts of a yellow pigment Pigment Yellow 139 (PY 139), 19.8 parts of a 25% aqueous solution of tetramethylammonium hydroxide (TMAH), and dimethyl sulfoxide (DMSO) 79. It was dissolved in a mixture with 2 parts. The pigment solution was introduced into 2000 parts of stirred 0.05 mol / L hydrochloric acid with a microsyringe to precipitate a solid solution pigment. The precipitated pigment was subjected to suction filtration, water washing and vacuum drying to obtain a dry pigment, whereby a solid solution pigment 1 was obtained.

<Preparation of solid solution pigment 2>
A solid solution pigment 2 was obtained in the same manner as the solid solution pigment 1 except that 0.6 parts of Pigment Green 58 (PG 58) as a green pigment and 0.4 parts of Pigment Yellow 150 (PY 150) as a yellow pigment were used.

<Preparation of solid solution pigment 3>
0.6 parts of Pigment Green 36 (PG 36) as a green pigment and 0.4 parts of Pigment Yellow 139 (PY 139) as a yellow pigment were dissolved in a mixture of 70 parts of 96% concentrated sulfuric acid and 29 parts of 60% fuming sulfuric acid . The pigment solution was introduced into 2000 parts of a stirred 0.1 mol / L aqueous sodium hydroxide solution through a microsyringe to precipitate a solid solution pigment. The precipitated pigment was subjected to suction filtration, water washing and vacuum drying to obtain a dry pigment, and solid solution pigment 3 was obtained.

<Preparation of solid solution pigment 4>
0.7 part of Pigment Green 58 (PG 58) and 0.3 part of Pigment Yellow 139 (PY 139) were dissolved in a mixed solution of 19.8 parts of a 25% aqueous solution of TMAH and 79.2 parts of DMSO. The pigment solution was introduced into 500 parts of pure water while stirring, using a microsyringe. Thereafter, 500 parts of 0.2 mol / L hydrochloric acid was added to precipitate a solid solution pigment. The precipitated pigment was subjected to suction filtration, water washing and vacuum drying to obtain a dry pigment, whereby a solid solution pigment 4 was obtained.

<Preparation of Mixed Pigment 1>
0.7 part of Pigment Green 58 (PG 58) was dissolved in a mixed solution of 19.8 parts of a 25% aqueous solution of TMAH and 79.2 parts of DMSO. The pigment solution was introduced into 2000 parts of stirred 0.05 mol / L hydrochloric acid with a microsyringe to precipitate a pigment. The precipitated pigment was subjected to suction filtration, water washing and vacuum drying to obtain a dry pigment. Further, 0.3 part of Pigment Yellow 139 (PY139) was dissolved in a mixed solution of 19.8 parts of a 25% aqueous solution of TMAH and 79.2 parts of DMSO. The pigment solution was introduced into 2000 parts of stirred 0.05 mol / L hydrochloric acid with a microsyringe to precipitate a pigment. The precipitated pigment was subjected to suction filtration, water washing and vacuum drying to obtain a dry pigment. These dry pigments were mixed to obtain a mixed pigment 1.

  The resin of the photosensitive composition used by the Example and the comparative example was synthesize | combined as follows.

<Synthesis of Resin 1>
A reaction vessel is charged with 370 parts of cyclohexanone, heated to 80 ° C. while injecting nitrogen gas into the vessel, 38 parts of methacrylic acid (MAA), 6 parts of 2-hydroxyethyl methacrylate (2-HEMA), benzyl methacrylate at the same temperature (BzMA) 21 parts, n-butyl methacrylate (n-BMA) 16 parts, paracumylphenol ethylene oxide modified acrylate (Toagosei Co., Ltd. product: Alonics M110) 21 parts, 2, 2'-azobisisobutyronitrile 0 The polymerization reaction was carried out by dropping 4 parts of the mixture over 2 hours. After completion of the dropwise addition, the reaction is further carried out at 80 ° C. for 3 hours, then 0.2 parts of azobisisobutyronitrile dissolved in 10 parts of cyclohexanone is added, and the reaction is continued at 80 ° C. for 1 hour A solution was obtained. After this resin solution is cooled to room temperature, about 2 g is sampled and dried by heating at 180 ° C. for 20 minutes to measure the non-volatile content, and cyclohexanone is added to the previously synthesized resin solution so that the non-volatile content is 20% by mass. A solution of Resin 1 was prepared by addition. The resin acid value determined by acid value reduction titration using a potassium hydroxide (KOH) aqueous solution was 230 mg KOH / g.

<Synthesis of Resin 2>
The synthesis and adjustment of non-volatile components were carried out in the same manner as Resin 1 except that 28 parts of MAA, 8.5 parts of 2-HEMA, 23 parts of BzMA, 18 parts of n-BMA and 23 parts of Alonix M110 were changed. , Resin 2 was obtained. The resin acid value determined by acid value reduction titration using a potassium hydroxide (KOH) aqueous solution was 160 mg KOH / g.

<Synthesis of Resin 3>
Synthesis and adjustment of non-volatile components in the same manner as Resin 1 except that MAA was changed to 54 parts, 2-HEMA to 4 parts, BzMA to 16 parts, n-BMA to 10 parts, and Alonics M110 to 16 parts. I got three. The resin acid value determined by acid value reduction titration using a potassium hydroxide (KOH) aqueous solution was 350 mg KOH / g.

Example 1
14 parts of solid solution pigment 1, 6.5 parts of Disperbyk-2001 (manufactured by Bick Chemie Japan, 46% solid content) as a dispersant, 15 parts of resin 1 and 64.5 parts of propylene glycol monomethyl ether acetate (PGMEA) Mixed. This mixture was dispersed by a sand mill for 8 hours using a glass bead having a diameter of 0.1 mm, and then filtered through a 5 μm filter to prepare a pigment dispersion. The particle diameter of the obtained dispersion was measured with a particle size distribution analyzer (manufactured by Nikkiso Co., Ltd .: Nanotrac (registered trademark) UPA-EX 150).

  Next, 47.5 parts of the above pigment dispersion, 1 part of A-TMPT (manufactured by Shin-Nakamura Chemical Co., Ltd.) as a monomer, 0.4 parts of Irgacure 907 (manufactured by BASF Japan Ltd.) as an initiator, a resin 5.5 parts of 1 and 45.6 parts of PGMEA as a solvent were mixed with stirring, and filtered through a 5 μm filter to prepare a green photosensitive composition.

Next, the green photosensitive composition was applied onto a silicon wafer with a planarizing film, and was heated on a hot plate at 100 ° C. for 1 minute as pre-baking. Next, using an i-line stepper (Canon Co., Ltd .: FPA-5510iZ), perform exposure at a focal length of −0.6 μm and an exposure dose of 5000 J / m ² through a mask having a square pixel pattern of 0.8 μm square. went. The coated film after exposure was developed for 1 minute with an organic alkaline developer (manufactured by ADEKA: OD-260C), then washed with water for 1 minute, and dried by spin drying. After drying, heat treatment was performed on a hot plate at 230 ° C. for 4 minutes to obtain green pixels according to Example 1.

<Residue evaluation>
The pixels were photographed at 50,000 × using a scanning electron microscope (SEM), and evaluated according to the amount of residue in the unexposed area according to the following criteria.
;: No residue in the unexposed area ○: some residue in the unexposed area but no problem with no problem ×: there is a residue in the unexposed area and there is a practical problem

<Surface roughness evaluation>
The surface roughness Ra of the pixel was measured by AFM. According to the value of surface roughness, the following criteria evaluated.
;: The surface roughness value is small ○: The surface roughness value is somewhat large, but there is no problem value ×; The surface roughness value is large and there is a practical problem

Example 2
A pigment dispersion, a photosensitive composition, and a green pixel were produced in the same manner as in Example 1 except that the pigment was changed to solid solution pigment 2.

[Example 3]
A pigment dispersion, a photosensitive composition, and a green pixel were produced in the same manner as in Example 1 except that the pigment was changed to solid solution pigment 3.

Example 4
A pigment dispersion, a photosensitive composition, and a green pixel were produced in the same manner as in Example 1 except that the resin used in the pigment dispersion and the photosensitive composition was changed to the resin 2.

[Example 5]
In Example 1, the composition ratio of the pigment dispersion was changed to 25.7 parts of a solid solution pigment, 7.6 parts of a dispersant, 18 parts of a resin, and 48.7 parts of a solvent, and a photosensitive composition. The pigment dispersion and the photosensitive composition were the same as in Example 1 except that the composition ratio of the pigment dispersion was changed to 50.3 parts and the solvent was changed to 48.3 parts, and the resin was not stirred and mixed. A green pixel according to Example 5 was produced.

[Example 6]
A pigment dispersion, a photosensitive composition, and a green pixel were produced in the same manner as in Example 5 except that the pigment was changed to the solid solution pigment 2.

Comparative Example 1
A pigment dispersion, a photosensitive composition, and a green pixel were produced in the same manner as in Example 1 except that the resin was changed to the resin 3.

Comparative Example 2
A pigment dispersion, a photosensitive composition, and a green pixel were produced in the same manner as in Example 1 except that the pigment was changed to the solid solution pigment 4.

Comparative Example 3
A pigment dispersion, a photosensitive composition, and green pixels were produced in the same manner as in Example 1 except that the pigment was changed to Mixed Pigment 1.

  Table 1 shows the results of the volume average particle size, the residue evaluation, and the surface roughness evaluation of the pigment dispersion.

(Evaluation results)
From the results shown in Table 1, it can be confirmed that the green pixels according to Examples 1 to 6 have extremely low residues in the development of the opening and excellent pixel flatness even in a fine pattern of 1 μm or less The

  On the other hand, in the green pixel of Comparative Example 1, the resin 3 having a resin acid value of 350 mg KOH / g was used. Therefore, the flatness of the green pixel was poor and there was a practically problematic level. In addition, since the green pixel according to Comparative Example 2 uses a pigment dispersion having a volume average particle diameter of 71 nm, there is a residue in the unexposed area, and the flatness is also poor, which is a level at which there is a practical problem. The Moreover, since the green pigment which concerns on the comparative example 3 used the mixed pigment 1, there is a residue in an unexposed part and it was a level which has a problem practically.

  The green photosensitive composition of the present invention can be used as a material for forming a color filter for a solid-state imaging device because the residue of the opening during development is extremely small even in a fine pattern of 1 μm or less and the flatness of the pixel is excellent. .

1: Color filter 11 for solid-state imaging device 11 green pixel 12 red pixel 13 blue pixel

Claims (3)

What is claimed is: 1. A green photosensitive composition for a solid-state imaging device comprising a pigment dispersion, a photopolymerizable monomer, a photopolymerization initiator and a solvent,
The pigment dispersion comprises a solid solution pigment of a green pigment and a yellow pigment, a dispersant, and a resin,
The volume average particle size of the solid solution pigment is 50 nm or less,
The green photosensitive composition for a solid-state imaging device, wherein the acid value of the resin is 60 to 300 mg KOH / g.   The green photosensitive composition for a solid-state imaging device according to claim 1, wherein the green pigment is a halogenated phthalocyanine pigment.   The color filter which has a green pixel formed on the board | substrate using the green photosensitive composition for solid-state imaging devices of Claim 1 or 2.

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