JP2800940B2 - Manufacturing method of color filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing a color filter used for color components in a color solid-state imaging device.

<Prior art and its problems> As a method of manufacturing a color filter used in a conventional color video camera or the like, a relief pattern-shaped resin layer is provided on a glass substrate, and the resin layer is dyed with a dye or the like to form a colored resin layer. An organic filter is generally formed by repeating the forming process a plurality of times for the number of colors required by the filter (this method is partially referred to as a relief dyeing method). As a photosensitive resin for forming a pattern, a resin obtained by adding a dichromate such as sodium dichromate, potassium dichromate or ammonium dichromate to natural proteins such as gelatin, casein, fish glue, and egg white is used. I have. These compositions are based on natural polymers,
It is difficult to obtain a uniform concentration or molecular weight distribution of functional groups such as amino groups involved in dyeing, and the photosensitive solution is easily decayed.
Poor adhesion of the obtained cured film to a support such as glass,
It has disadvantages such as using a chromium compound which is harmful to the human body as a photocuring agent.

In order to solve these drawbacks, a method using a synthetic resin has been devised, and a polymer having a basic group such as a tertiary amino group or a quaternary ammonium group is added with a diazo compound or an azide compound as a photocrosslinking agent. Added photosensitive resins have been proposed. (For example, JP-A-58-199342 and JP-A-59-155412) Alternatively, a method of introducing a photosensitive group into a polymer is also conceivable. There are difficulties in purification such as production of gel during polymerization and the like.

On the other hand, when a photocrosslinking agent is added to the polymer solution to form a photosensitive resin solution, a polymer having a basic property is used to impart dyeability with an acid dye. A bisazide compound is used as a photocrosslinking agent that has sufficient solubility in an organic solvent such as ethyl cellosolve used as a solvent, has sufficient practical sensitivity, and satisfies that resin coloring is small. Yes,
Among them, sodium 4,4'-diazidostilbene-2,2'-disulfonate is widely used. Using such a photosensitive resin obtained by adding a photocrosslinking agent to a synthetic resin,
As a method of forming a relief pattern, usually, a method of applying a photosensitive resin solution onto a glass substrate or a silicon wafer on which a solid-state imaging device is formed, drying the same, and then performing pattern exposure through a photomask and performing development Is used. A color filter used for color separation of a color solid-state imaging device has a relief pattern size of about several microns, and in order to obtain sufficient resolution, an alcohol or a cellosolve-based organic solvent is used as a developer. Often. However, sodium 4,4'-diazidostilbene-2,2'-disulfonate, which is usually used as a photocrosslinking agent, has a sulfonate ion in the molecule.
There is a problem that it is bonded to a basic group such as a quaternary ammonium ion in the polymer, and the solubility of an unexposed portion in a developer is reduced. Examples of bisazide compounds containing no sulfonic acid group include 4,4'-diazidochalcone and 2,6-bis (4'-azidobenzal) cyclohexanone, but their solubility in a polymer solution and photosensitivity are insufficient. And there is almost no practical use.

<Means for Solving the Problems> As a result of studying to solve these problems, the present inventors have found that they have sufficient solubility in a resin solvent, such as ethyl cellosolve, and a sulfone that reacts with a basic group of a polymer. Not having an acidic group such as an acid group, having sufficient light sensitivity,
The present inventors have found a photocrosslinking agent which satisfies such characteristics as not exhibiting coloring which is a problem in practical use, and has completed the present invention. That is, the present invention provides a method for producing a color filter in which a pattern to be dyed made of a photosensitive resin having a dyeing property is formed on a substrate, and this is dyed to form a colored layer. Having a polymer as a photosensitizer
A method for producing a color filter, comprising developing a bisazide compound having a “—SO ₂ NHR” group, particularly a compound having the following structure (a), and developing using an alcohol-based or cellosolve-based organic solvent as a developer. It is.

Here, R is C _n H _2n OH (n = 2 to 4), (N = 1 to 2, m = 1 to 2), C _n H _2n OC _m H _{2m + 1} (n = 2
4, m = 1~2), C n H 2n OC m H 2m OH (n = 2~4, m = 1~
2) or C _n H _{2n + 1} (n = 5 to 8) The photosensitive agent used in the present invention is easily soluble in an organic solvent used for a color filter resin such as ethyl cellosolve and has extremely wide operability. . Further, since it does not have an acidic group such as a sulfonic acid group, it does not react with a basic group in the resin, and the solubility of an unexposed portion in a developer does not decrease. Further, sufficient photocrosslinking occurs at 5 to 10% by weight of the resin, the strength of the dyeable resin film as a color filter can be maintained, and no coloring problem occurs.

Various polymers can be used as the polymer having a basic group used in the present invention, and are not particularly limited. Examples thereof include: (1) a cross-linkable monomer having a basic group and having affinity for an acid dye (b) 5 (2) 10 to 70% by weight of a hydrophilic monomer (c) other than (b), (3) a copolymer of 10 to 50% by weight of a hydrophobic monomer (d).

Examples of the crosslinkable monomer (b) include (N, N-dimethylamino) ethyl acrylate, (N, N-dimethylamino) ethyl methacrylate, (N, N-dimethylamino) ethyl acrylate, (N, N-dimethyl) (Amino) ethyl methacrylate (N, N-dimethylamino) propyl acrylamide, (N, N-dimethylamino) propyl methacrylamide, (N, N-dimethylamino) ethyl vinyl ether, (N, N-dimethylamino) propyl acrylate, ( N, N-dimethylamino) propyl methacrylate, and their methyl chloride salts, dimethyl sulfate,
P-Toluenesulfonic acid methyl salt, 2-hydroxy-3
-Methacryloyloxypropyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, and the like.

Examples of the hydrophilic monomer (c) include the following.

2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, acrylamide, methacrylamide, vinylpyrrolidone, N, N-dimethylacrylamide.

Examples of the hydrophobic monomer (d) include methyl methacrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, styrene, P-methylstyrene, butyl acrylate, and butyl methacrylate. These crosslinkable monomer (b), hydrophilic monomer (c), and hydrophobic monomer (d) can be polymerized by a conventionally known polymerization method, and a solution polymerization method is usually used.

In order to form a color filter using a photosensitive resin comprising the above copolymer, the above copolymer is dissolved in water, methyl cellosolve, ethyl cellosolve or the like, and then the bisazide compound is added to the resin in an amount of 5 to 10%. The weight is added and the copolymer concentration is usually adjusted to about 5 to 20% by weight.

Next, the above-mentioned photosensitive resin solution is applied on a glass substrate which has been washed and dried in advance, and dried in a dryer at 50 to 90 ° C., and the obtained photosensitive film is exposed to ultraviolet rays through a photomask and exposed to light. Allow the film to cure. Then methanol, ethanol,
An unexposed portion is dissolved and removed by methyl cellosolve or the like to obtain a relief pattern. Next, the relief pattern
After heat treatment at 120 to 180 ° C., it is immersed in a dye bath made of an acid dye to form a colored layer. The optimum heating temperature is determined according to the copolymer composition.

Further, after a transparent anti-staining layer is coated on the colored pattern, a second colored layer is formed through the same steps. This operation is repeated by the number of necessary coloring layers to obtain a color filter.

Further, the color filter manufactured according to the present invention can be directly formed on a silicon wafer on which a solid-state imaging device is formed by exactly the same method.

<Function> As described above, a pattern to be dyed is formed by a photosensitive resin obtained by adding the bisazide compound represented by the above (a) as a photosensitizer to a polymer having a chlorinated group, and the pattern is dyed and colored. In the method for producing a color filter as a layer, a reaction between a photosensitive agent and a basic group in a polymer does not occur, so that the solubility of an unexposed portion is reduced at the time of development, so that there is no undeveloped residue, and a stable relief is obtained. A pattern can be formed, and a color filter for a solid-state imaging device using a synthetic polymer instead of a natural protein can be manufactured. In addition, even if this is left for a long time before exposure, the developability does not decrease, and a stable color filter can be manufactured.

<Example 1> Monomers having the ratios shown in Table 1- (1) were polymerized using a usual solution polymerization method, and the resulting mixture was dropped and precipitated in ethyl acetate, purified, dried, and dried to obtain 10 g of the copolymer. Against ethyl cellosolve 9
0 g was added to obtain a resin solution. 1 g of the above bisazide compound (e) was dissolved in 100 g of the above resin solution to prepare a photosensitive resin solution.

The above-mentioned photosensitive resin liquid was spin-coated on a washed and dried glass substrate, and exposed and developed to form a relief pattern. As the developing solution, a solution consisting of 1.5 parts by weight of ethanol and 1 part by weight of 2-propanol was used. In this relief pattern, a line and space having a width of 2 μm could be resolved, the residual film ratio was 90% or more, and no film roughness was observed. In the developer, there was no significant change in developability between 1 and 2 parts by weight of ethanol with respect to 1 part by weight of 2-propanol. In addition, even if a photosensitive resin was coated on the substrate, dried, and left standing for 168 hours before exposure, there was no change in developability. After heating this relief pattern at 170 ° C. for 2 hours, it was immersed in a yellow dyeing solution having the following composition at 60 ° C. for 5 minutes, washed with water and dried to form a yellow colored layer.

Next, after coating a photosensitive resin FVR (trade name, manufactured by Fuji Pharmaceutical Co., Ltd.), and forming an anti-dye layer, magenta,
A cyan colored layer was formed in the same procedure to obtain a color filter. Magenta and cyan were dyed with a dye solution having the following composition.

Yellow: Suminol Milling Yellow 4G (Sumitomo Chemical Co., Ltd.) 0.5% aqueous solution at 60 ° C. for 5 minutes Magenta: Kayanol Milling Let 3BW (Nippon Kayaku Co., Ltd.) 0.5% aqueous solution at 60 ° C. for 5 minutes Cyan: Diamira Turkey Blue G (manufactured by Mitsubishi Kasei Co., Ltd.) 0.5% aqueous solution dyed at 60 ° C. for 5 minutes <Example 2> Using the monomers in the ratios shown in Table 1- (2), A photosensitive resin solution was obtained in the same procedure. As the azide compound, the following bis azide compound (f) was used.

After undercoating was performed using a FVR on the silicon wafer on which the solid-state imaging device was formed, a photosensitive resin solution was applied, exposed, and developed to obtain a relief pattern. After heating this at 170 ° C for 2 hours, Daiwa Green CFT
The product was dyed with a 1% solution (trade name, manufactured by Daiwa Kasei Co., Ltd.) at 73 ° C. for 15 minutes to form a green colored layer.

Thereafter, the same operation as in Example 1 was performed to sequentially form red and blue colored layers, thereby obtaining a color filter. The dyeing conditions for each colored layer are as follows.

Red: Daiwa Red CFT (trade name, manufactured by Daiwa Kasei Co., Ltd.) 1% solution dyed at 65 ° C. for 5 minutes Blue: Daiwa Blue CFT (trade name, manufactured by Daiwa Kasei Co., Ltd.) 0.5% solution dyed at 65 ° C. for 5 minutes <Example 3> ~ 5> 1 g of each of the bisazide compounds shown in Table 2 was dissolved in 100 g of the resin liquid used in Example 1 to obtain a photosensitive resin solution. Thereafter, the same operation as in Example 1 was performed to form a relief pattern, which was dyed to obtain a colored layer. In each case, good results similar to those of Example 1 such as developability and resolution were obtained.

<Comparative Example> In 100 g of the resin liquid used in Example 1, 0.5 g of the following bis azide compound (g) was dissolved as a photosensitive agent to prepare a photosensitive resin solution.

Using this photosensitive resin solution, the same operation as in Example 1 was performed to form a relief pattern. This photosensitive resin layer has a ratio of ethanol to 2-propanol as a developing solution.
Must be strictly adjusted to 1.5 parts by weight to 1 part by weight,
When the amount of ethanol was large, wrinkles and peeling occurred in the relief pattern, and when the amount of ethanol was small, residual development occurred. Further, when left for 24 hours or more before the exposure after coating, the developability was remarkably deteriorated, undeveloped residues occurred, and a satisfactory relief pattern was not obtained.

<Effect of the Invention> According to the color filter manufacturing method of the present invention, a color filter is prepared by using a photosensitive resin obtained by adding a bisazide compound represented by the above (a) to a polymer having a basic group as a photosensitive agent. The instability of the developing property at the time of forming the relief pattern, which is the most important step in the production of, is eliminated, and a stable relief pattern without developing residue can be formed. Further, even if the photosensitive resin is applied on the substrate and left for a long time before exposure, no undeveloped portion remains after development. Therefore, it is possible to solve the problem of poor storage stability of the photosensitive resin and the deterioration with time of the solid-state imaging device caused by the mixture of impurities, which are problems when a conventional natural protein is used.

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-74946 (JP, A) JP-A-63-32542 (JP, A)

Claims (1)

(57) [Claims] 1. A method for manufacturing a color filter, comprising forming a pattern to be dyed made of a photosensitive resin having a dyeing property on a substrate and dyeing the pattern to form an adhesive layer, wherein the photosensitive resin has a basic group. A method for producing a color filter, comprising adding a bisazide compound having the following structure (a) as a photosensitive agent to a polymer, and developing the polymer using an alcohol-based or cellosolve-based organic solvent. Here, R is C _n H _2n OH (n = 2 to 4), C _n H _2n CH (O
H) C _m H _2m (n = 1 to 2, m = 1 to 2), C _n H _2n OC _m H
_{2m11 (n = 2~4, m =} 1~2), C n H 2n OC m H 2m OH
(N = 2 to 4, m = 1 to 2) or C _n H _2n11 (n =
5-8)