JPH0719053B2 - Photosensitive composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a photosensitive composition which can be favorably used as a dye resistant layer of an organic color filter or the like.

[Conventional technology]

There are roughly two ways to install a color filter.

For example, a color separation organic color filter is directly manufactured on a solid-state image pickup device in which a photodetector and the like are provided on a silicon wafer (hereinafter referred to as "direct-attach type").

A solid-state image sensor and a color-separating organic color filter are individually manufactured, and the two are aligned with each other and bonded with an appropriate adhesive or the like (hereinafter referred to as "bonding type").

The photosensitive composition of the present invention is particularly useful when applied to a direct-attaching type color filter which is considered to be excellent in mass productivity.

When manufacturing a direct-attaching type color filter, the surface of the solid-state image pickup device is usually flattened, and a polymer layer (hereinafter referred to as a flattening layer) is applied to obtain a strain-free color filter. After that, provide a photosensitive material layer for forming the dyed layer on it, and then provide a patterned resist on the dyed layer and dye the exposed part of the dyed layer to form the dyed layer. The post resist is peeled off, and then the next dyed layer is formed in the same manner. (A method in which a single dyed layer is dyed separately into a plurality of dyed portions.) The dyed layer is exposed to a predetermined pattern, developed and dyed to form a dyed layer, and then a transparent dye resistant insulating layer And then the next dyed layer is formed thereon in the same manner.

The above method has a problem such as color bleeding at the boundary of each dyed portion, and the method is generally used.

In the color filter obtained by the above method,
The choice of dye resistant insulation layer is important.

The dye-resistant insulating layer serves as a dye-resistant layer of the dyed layer of the first color that has already been dyed when dyeing the second and subsequent colors.
It plays an important role in preventing color bleeding with time between the dyed layers of the finished color filter. Further, the dyeing resistant insulating layer is basically required to have good dyeing resistance, adhesion to the substrate and the dyeing layer, colorless transparency, development resistance, and coating property.

However, it is difficult to select one that satisfies all of these properties. That is, for example, as the layer to be dyed, a water-soluble photosensitive material such as a mixture of gelatin, casein, grey, polyvinyl alcohol, etc. and dichromate is usually used, and a water-soluble dye is used for dyeing. To be done. Therefore, as the dye-resistant insulating layer, a highly lipophilic one is required from the viewpoint of dyeing resistance, but when a highly hydrophilic one is required from the viewpoint of adhesiveness with the dyeing layer. This is because the contradictory properties are required.

[Problems to be solved by the invention]

In the case of a direct-attached color filter, it is directly connected to the color solid-state image sensor. Therefore, in order to extract an electric signal from the color solid-state image sensor, part of the dye-resistant insulating layer must be removed. The so-called bonding pad part and the like must be formed. For this reason, a photosensitive resin is used as the dye-resistant insulating layer of a direct-attached type color filter, and a desired pattern is exposed to light and developed.
The pad part etc. are formed. However, when forming a dye-resistant insulating layer using this photosensitive resin, a photosensitive resin capable of using visible light and near-ultraviolet light is used as an exposure light source for processing from the viewpoints of economy and operability. Since it absorbs visible light and near-ultraviolet light, it is colorless and transparent, and it must transmit visible light and near-ultraviolet light as completely as possible. It causes the drawbacks. Because of this, it is expensive
Moreover, polymethylmethacrylate or the like, which has poor productivity and can be processed only by electron beam exposure or the like, is used as the dye-resistant insulating layer, but it is still not satisfactory in various respects.

[Means for solving problems]

In order to eliminate the drawbacks of the conventional dyeing-resistant insulating layer as described above, the present inventors have conducted various studies and, by combining a specific polymer, dyeing resistance, adhesion to a substrate and a dyeing layer,
The present invention has been completed by finding a photosensitive resin which is excellent in colorless and transparent properties with respect to visible light and near-ultraviolet light and can be processed using visible light and near-ultraviolet light.

That is, the gist of the present invention is at least the following formula (I):
Having repeating units represented by (II) and (III), 10 to 85 mol% of repeating units (I), and repeating units (II)
10 to 70 mol%, repeating unit (III) 5 to 50 mol%
A photosensitive composition comprising a polymer comprising and a sensitizer.

(In the formula, R ¹ , R ³ and R ⁴ represent a hydrogen atom or a methyl group, R ² represents a C _{1 to} C ₆ alkyl group, R ⁵ represents a hydrogen atom or a phenyl group, and R ⁶ represents hydrogen. An atom, a phenyl group or a cyano group, R ⁷ represents a halogen atom, a nitro group or a methoxy group, and n represents an integer of 0 or 1 or 2.) The photosensitive composition of the present invention has the above formula (I ) To a polymer having a repeating unit represented by the formula (III) and a sensitizer.

The repeating unit (I) is an essential element for providing a polymer having high transparency and good coating property.
I) has a function of improving the adhesion of the polymer to the substrate and gelatin, and the repeating unit (III) is an essential element for imparting photosensitivity to the polymer.

Repeating unit (I) is 10 to 85 mol%, preferably 20 to 75 mol%, repeating unit (II) is 10 to 70 mol%, preferably
20-65 mol%, the repeating unit (III) is 5-50 mol%,
It is preferably used in the range of 8 to 40 mol%. If this range is deviated too much, the role of each unit mentioned above cannot be fully exerted.

In the present invention, when it is desired to make the polymer softer, a fourth repeating unit having a so-called soft segment is added, for example, as shown by the formula (IV). (In the formula, R ⁸ represents a hydrogen atom or a methyl group, and m is 1 to 5
(Representing an integer of) units can be included. The repeating unit (IV) is used in the range of 5 to 50 mol%.

The polymer of the present invention is a monomer which gives formula (I), ie an alkyl ester of acrylic acid or an alkyl ester of methacrylic acid, a monomer which gives formula (II), ie a monomer which gives acrylic acid or methacrylic acid and formula (III). , That is, 2-hydroxyethyl acrylate or 2-
A reaction product of hydroxyethyl methacrylate and cinnamic acid chloride or its derivative can be easily obtained by radical copolymerization according to a known method using a radical initiator such as azobisisobutyronitrile or benzoyl peroxide. You can Moreover, after radical-copolymerizing the monomer giving the formula (I) and the monomer giving the formula (II) with 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, May be reacted.

The polymer of the present invention has a composition of 3% in tetrahydrofuran (THF).
The intrinsic viscosity at 0 ° C is usually 0.1 to 3 dl / g, preferably 0.3
It is preferably in the range of to 2.5 dl / g, particularly preferably 0.4 to 1.5 dl / g. Various known sensitizers can be used. For example, anthrone, benzophenone, phenanthrene, Michler's ketone, 2-nitrofluorene, 5-nitroacenaphthene, chrysene, p-nitroaniline, 2-benzoylmethylene-3-methylnaphthothiazoline, 2-dibenzoylmethylene-3-methylnaphthothiazoline. , Benzyl, N-acetyl-4-nitro-
So-called triplet sensitizers such as 1-naphthylamine and anthraquinone are preferably used. As the amount of sensitizer,
0.1 to 20% by weight of polymer, preferably 0.5 to 10
Weight percent is used.

Usually, a solvent that dissolves both the polymer and the sensitizer, for example, ethyl cellosolve, a cellosolve solvent such as methyl cellosolve, an ester solvent such as butyl acetate, or dimethylformamide (DMF), dimethyl sulfoxide (DMSO), It is dissolved in a solvent such as N-methylpyrrolidone to serve as a photosensitive solution. The sensitizer itself often has a yellow color because of the sensitizer contained in it.However, a thin film is formed on the substrate by spin coating, casting, or the dip method, and visible light / near-ultraviolet light is used. If exposed and developed, the sensitizer can be easily washed out to obtain a colorless and transparent polymer layer.

Hereinafter, an example of a color filter using the photosensitive composition of the present invention will be described in more detail with reference to the drawings.

1 (a) to 1 (j) are explanatory views showing an example of a manufacturing process of a direct-attaching type color filter.

In the figure, 1 is a silicon wafer, 2 is a light detecting portion, 3 is a protective film, 4 is a flattening layer, 5 is a layer to be dyed, 6 is a mask, 7 is a dye resistant insulating layer, 8 is a bonding pad, and 9 is a pad. The dyed layer and 10 are surface layers, respectively.

In the case of a direct-attaching type color filter, the color filter is directly provided on the surface of the solid-state image pickup device, and the solid-state image pickup device as the base is, for example, a silicon wafer 1 as shown in FIG. 2 is provided, and a protective film 3 made of phosphorus glass, quartz or the like is provided on the upper surface thereof. Other than the above, the solid-state image sensor is provided with a scanning line, a light-shielding film, etc., but they are omitted in the drawing.

The color filter of the present invention is formed on the upper surface of the solid-state image pickup device as described above, and will be described in the order of steps.

First, the flattening layer 4 is coated on the protective film 3 of the solid-state image sensor to a thickness of about 0.2 to 2.0 μ. As the flattening layer, it is preferable to use the same one as the dyeing resistant insulating layer 7 described later. This layer flattens the surface of the photodetection portion, facilitates formation of the dyed layer 5, the dye-resistant insulating layer 7, and the like.
It is possible to reduce color stains and the like due to unevenness in thickness. Then, a predetermined bonding pad 8 and the like are processed on the flattening layer 4 {FIG. 1 (b)}.

The material of the flattening layer 4 and the method of processing the bonding pad 8 will be described later in detail together with the description of the dye-resistant insulating layer 7.

Then, on the flattening layer 4, gelatin, casein, grille,
A mixture of a water-soluble polymer such as albumin or a synthetic polymer such as polyvinyl alcohol and a dichromate such as ammonium dichromate is applied to form a photosensitive material layer for forming the dyed layer 5. {FIG. 1 (c)}.

The photosensitive material layer for constituting the dyed layer 5 is usually 0.
It is provided to be 1 to 2 μ.

Then, the photosensitive material layer for forming the dyed layer 5 is exposed through a mask 6 having a predetermined pattern {FIG. 1 (d)}. The photosensitive material for forming the layer to be dyed 5 is usually made to have photosensitivity in the range of 440 to 380 nm, and therefore, it is exposed by using a high pressure mercury lamp having a wavelength in such a region as a light source.

Then, it is developed with water to form a portion constituting the dyed layer 5 having a predetermined pattern {Fig. 1 (e)} and dyed with a first color dye having a predetermined spectral characteristic according to a known method. The dyed layer 5 is formed.

Then, a photosensitive resin composition for forming the dye-resistant insulating layer 7 is coated {FIG. 1 (f)}. In the present invention, in order to form the dye-resistant insulating layer 7, the above formula (I),
A composition of a copolymer having units represented by (II) and (III) and a sensitizer is applied on the dyed layer 5 formed thereon (FIG. 1 (f)), and a predetermined pattern, that is, Exposure is performed using a mask 6 having a pattern or the like in which the portion forming the bonding pad portion is light opaque {first
Figure (g)}. At the time of exposure, a high-pressure mercury lamp having a wavelength that the sensitizer has absorption may be used. In the exposed composition, the energy absorbed by the sensitizer is transferred to the cinnamoyl group in the polymer, and the cinnamoyl group in the excited state forms a cyclobutane ring with two molecules to cause crosslinking and insolubilization. .

Then, by developing with a suitable developing solution such as ethyl cellosolve, methyl ethyl ketone, or a mixture of these with benzyl alcohol or N-methylpyrrolidone, the unexposed portions corresponding to the bonding pad portions are eluted. The dye-resistant insulating layer 7 (filter portion) which has been processed and has the sensitizer dissolved by development is obtained, and the dye-resistant insulating layer 7 becomes colorless and transparent {FIG. 1 (h)}. Even when the present photosensitive composition is used for the flattening layer 4, the transparent flattening layer 4 processed by the bonding pad 8 and the like can be obtained by the same operation.

Then, a photosensitive substance for forming a dyed layer is provided on the dye resistant insulating layer 7 in the same manner as described above, and exposed and developed to form a dyed layer portion having a predetermined pattern. Then, the second dyed layer 9 is formed by dyeing with a second color dye having a predetermined spectral characteristic {FIG. 1 (i)}.

Such an operation may be repeated to form another layer to be dyed through the dye-resistant insulating layer.

As the layer to be dyed, three types of three primary color systems of red, green and blue may be used, or three types of complementary color systems of cyan, green and yellow may be used. At this time, for example, the second yellow dyed layer may be formed so as to partially overlap the first cyan dyed layer, and the third color green color may be obtained at the overlapped portion.

Usually, a surface layer 10 is provided on the uppermost layer to be dyed in order to smooth the surface or protect the dyed layer.

The surface layer 10 is required to have strength, transparency, adhesion to the intermediate layer and the dyeing layer, and workability such as a bonding pad portion, and any material that satisfies the requirements may be used.
You may use the photosensitive composition mentioned above.

The surface layer 10 is usually provided so as to have a film thickness of 0.1 to 2 .mu.m, and is exposed and developed to perform a predetermined bonding pad or the like {FIG. 1 (j)}.

As described above, the color filter of the present invention can be obtained. However, the flattening layer or the dyeing resistant insulating layer of the color filter of the present invention has complete dyeing resistance, and the adhesiveness with the substrate or the dyeing layer. Is good and therefore a clear image can be obtained.

In the present invention, the above-mentioned special photosensitive composition is used as the flattening layer and / or the dye-resistant insulating layer, but in the present invention, at least one layer comprising the above-mentioned photosensitive composition is provided, and the other is Other resin layers or the like may be used and may be appropriately selected and determined according to the application. However, in view of the physical properties of the photosensitive composition, it is preferable to use it as a dye-resistant insulating layer rather than a flattening layer. Other photosensitive resins include polyglycidyl methacrylate, polymethyl methacrylate,
Various materials such as polymethyl isopropenyl ketone, methyl methacrylamide, polyhexafluorobutyl methacrylate, and polybutene-1-sulfone can be used.

〔Example〕

 The present invention will be described in more detail with reference to the following examples.

Synthesis Example 1 14.0 g of methyl methacrylate, 10.35 g of methacrylic acid, 15.6 g of cinnamoyloxyethyl methacrylate and 15.05 g of carbitol acrylate were dissolved in 400 ml of dioxane, and degassed sufficiently with nitrogen gas. While maintaining the reaction system in a nitrogen atmosphere, heat the mixture to 80 ° C to obtain benzoyl peroxide 1
6.4 mg was added, and the mixture was reacted at 80 ° C for 15 hours. After the reaction, the reaction mixture was added dropwise to 1350 ml of n-hexane to precipitate a polymer, and the precipitated polymer was again added with 200 m of methyl ethyl ketone.
It was dissolved in l, dropped into 600 ml of n-hexane and reprecipitated,
It was dried in a vacuum dryer.

Yield 23.7 g ηsp / c = 0.52 (in THF, 30 ° C. c = 0.20 g / dl) Synthesis Example 2 Methyl methacrylate 5.0 g, methacrylic acid 2.58 g, and cinnamoyloxyethyl methacrylate 5.2 g were dissolved in dimethyl sulfoxide 25 ml, and nitrogen was added. Bubbling and deaerating. Then, the reaction solution is heated to 48 ° C., 0.6 g of azobisisobutyronitrile is added, and the mixture is reacted in a nitrogen atmosphere at 48 ° C. for 8 hours. After the reaction, the reaction solution was poured into 300 ml of water to isolate the polymer, and the isolated polymer was dissolved in 40 ml of THF and 120 ml.
Was added dropwise to n-hexane for reprecipitation and purification.

Yield 3.64g (28.5%) ηsp / c = 0.85 (30 ° C in THF, c =
0.20 g / dl) Examples 1 and 2 1.2 g of the polymer of Synthesis Example 1 or 2 and 36 mg of 2-dibenzoylmethylene-3-methylnaphthothiazoline were dissolved in ethyl cellosolve to make the total 10 g, and a 0.2 μm Millipore filter was used. To obtain a photosensitive solution. 2 inch φ
It was applied on a 0.5 mm thick Rampax glass substrate by spin coating (5000 rpm) to a thickness of 0.5 μ. The sensitivity, resolution, dyeing resistance, transparency, and adhesiveness were evaluated by the following methods.

(1) Sensitivity: No. 2 stepper blot manufactured by Kodak Co., Ltd. was used, and a mask aligner MA-10 manufactured by Mikasa Co., Ltd. was used. After exposure, development was performed for 1 minute with ethyl cellosolve. The film thickness of each obtained step was measured with a film thickness meter α-step manufactured by Tencor Co., Ltd. to prepare a sensitivity curve, and the sensitivity was determined by having an irradiation energy amount giving a residual film rate of 80%.

(2) Resolving power …… An image obtained after exposure and development was performed using an optical microscope (X500) in the same manner as in the case of sensitivity evaluation using a resolution test chart manufactured by Totopan Co., Ltd. and a mask aligner MA-10 manufactured by Mikasa Co., Ltd. The resolution was defined as the width of the smallest line and space that was observed and resolved.

(3) Transparency: Mikasa's Mask Aligner MA-1
The whole surface was exposed using 0, and after development, the spectral transmittance at 380 to 780 nm was determined using a spectrophotometer 228 manufactured by Hitachi, Ltd.

(4) Dyeing resistance: The same substrate as that for which transparency was evaluated was dyed yellow or cyan under the same conditions as those for a color filter to be followed, and the spectral transmittance was evaluated in the same manner as when transparency was evaluated after rinsing. I asked.

(5) Adhesion ... Adhesive tape (cellophane tape) was adhered well by finger pressure, and the adhesiveness to glass was evaluated by peeling the adhesive tape. Further, a dyed layer of gelatin was formed on the upper surface of the flattening layer in the same manner as in Example, and the adhesive strength was evaluated with the adhesive tape as in the above. The evaluation criteria are as follows.

◯: No peeling at all ×: Peeling seen even in part Example 3 A photosensitive composition prepared in the same manner as in Example 1 was spin-coated on a solid-state imaging device substrate consisting of a large number of photodetection sections and a drive circuit for driving them so as to have a film thickness of 2 μm. Thus, a resin layer for forming the flattening layer was formed. The applied resin layer was yellowish. A mask aligner MA10 type (manufactured by Mikasa Co., Ltd.) equipped with a high-pressure mercury lamp is used through a mask having a predetermined pattern such as a bonding pad on the resin layer forming this flattening layer.
20 ° C after exposure with an energy amount of 800 mm / cm ³
And developed for 1 minute with ethyl cellosolve. The yellowing disappeared and the transparent flattening layer thus obtained, which had been subjected to processing such as bonding and pad portions, was a transparent layer.

Then, an aqueous solution of gelatin monochromate ammonium (10: 2, weight ratio) was applied on the flattening layer by spin coating to a film thickness of 1 μm to form a photosensitive material layer for forming a layer to be dyed. . The light-sensitive material layer forming this layer to be dyed was exposed through a mask having a predetermined pattern using the same apparatus as above with an energy amount of 200 millijure / cm ³ , and then developed with water at 45 ° C. for 1 minute. Then
The gelatin film was cured by heating at 120 ° C for 15 minutes.

Soak for 1 minute at 75 ℃ in an approximately 0.1% aqueous solution of "Kayanol N5G" (manufactured by Nippon Kayaku Co., Ltd.) {Kayanol is a trade name of Nippon Kayaku Co., Ltd.} adjusted to pH 4 with acetic acid. Dyeing treatment was performed to form a layer to be dyed.

Next, a photosensitive composition having the same composition as that of the planarizing layer is formed to a film thickness of 0.5.
Spin coating is applied so that the thickness becomes μ, and exposure and development are performed in the same way as in the case of the flattening layer to make it transparent and bonding.
A dye-resistant insulating layer having a pad portion and the like processed was formed.

Then, a gelatin monochromate ammonium layer was formed on the dye-resistant insulating layer in the same manner as described above, exposed and developed in the same manner as described above, and the pH was adjusted to 4 with acetic acid, "Diacron Turkis Blue GF". "(Made by Mitsubishi Kasei Co., Ltd.)
About {Diacron is a registered trademark of Mitsubishi Kasei Co., Ltd.}
A dyed layer was formed by dyeing with a 0.3% aqueous solution at 75 ° C. for 1 minute.

Then, the same photosensitive composition as the flattening layer was applied as a protective film by spin coating so as to have a film thickness of 0.5 μ, exposed under the same conditions as above, and developed and bonded.
A solid color image pickup device was obtained in which a transparent surface layer on which a pad portion or the like was processed was formed and a color filter was directly attached.

[Effects of the Invention] As described above, according to the composition of the present invention, the dyeing resistance is excellent, the adhesiveness between the substrate and the dyed layer, the visible and the near-ultraviolet colorless transparency are good, and the visible light and the near-ultraviolet rays are A light ray can be used to form a processable dye resistant insulation layer.

[Brief description of drawings]

1 (a) to 1 (j) are explanatory views showing an example of a manufacturing process of a direct-attaching type color filter. In the figure, 1 is a silicon wafer, 2 is a light detecting portion, 3 is a protective film, 4 is a flattening layer, 5 is a layer to be dyed, 6 is a mask, 7 is a dye resistant insulating layer, 8 is a bonding pad, and 9 is a pad. The layer to be dyed, 10 represents the surface layer, respectively.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-47-34794 (JP, A) JP-A-50-6404 (JP, A) JP-A-55-40416 (JP, A) JP-A-47- 32815 (JP, A) Japanese Patent Sho 49-28122 (JP, B1)

Claims (2)

[Claims] 1. At least a repeating unit represented by the following formulas (I), (II) and (III), wherein the repeating unit (I) is 10 to 85 mol% and the repeating unit (II) is 10 A photosensitive composition comprising a sensitizer and a polymer containing 70 to 70 mol% of repeating unit (III) and 5 to 50 mol% of repeating unit (III). (In the formula, R ¹ , R ³ and R ⁴ represent a hydrogen atom or a methyl group, R ² represents a C _{1 to} C ₆ alkyl group, R ⁵ represents a hydrogen atom or a phenyl group, and R ⁶ represents hydrogen. Represents an atom, a phenyl group or a cyano group, R ⁷ represents a halogen atom, a nitro group or a methoxy group, and n represents an integer of 0, 1 or 2.) 2. The photosensitive composition according to claim 1, wherein the polymer further has a repeating unit represented by the following formula (IV), the repeating unit (I) is 10 to 80 mol%, and the repeating unit ( A photosensitive composition comprising a polymer containing 10 to 70 mol% of II), 5 to 50 mol% of repeating units (III) and 5 to 50 mol% of repeating units (IV). (In the formula, R ⁸ represents a hydrogen atom or a methyl group, and m is 1 to 5
Represents the integer of