JP2911041B2 - Manufacturing method of color filter - Google Patents

Description

The present invention relates to a method of manufacturing a color filter for a solid-state imaging device.

[Conventional technology]

The layer to be dyed of the color filter for a solid-state imaging device is coated with a dyeing substrate composed of gelatin, casein, glue, polyvinyl alcohol, etc. and a dichromate, and selectively exposed and developed to form a pattern. The pattern-formed product is formed by immersing it in a dyeing solution together with the substrate. Here, gelatin, casein, glue, polyvinyl alcohol, etc. used as the staining substrate have differences in coating unevenness properties, photosensitivity, resolution, dyeing properties, etc., and it is difficult to select the best one. One type is selected mainly with respect to coating unevenness characteristics and resolution.

For example, after dyeing the first dyed layer, the dye is fixed and the dyed layer is fixed with an aqueous solution of tannic acid, an aqueous solution of antimony potassium tartrate, an aqueous solution of formaldehyde, etc., and the color mixture during the dyeing of the dyed layer is performed. It is known to prevent color loss.

Alternatively, it is also known that after the first dyed layer is dyed, an intermediate protective film is formed with a synthetic resin to prevent color mixing and color omission during subsequent dyed layer dyeing.

Alternatively, it is also known that after the first dyed layer is dyed, color mixing and color omission at the time of dyeing the dyed layer are prevented by combining the above two methods.

It is also known to prevent color mixing and color omission in subsequent dyeing layer selection in the second and subsequent dyeing layers, similarly to the first dyeing layer.

[Problem to be solved by the present invention]

In the above-described conventional technique, in the method of preventing color mixing and color loss using a tannic acid aqueous solution or the like, if the subsequent dyeing is performed at a high temperature, color mixing and color loss cannot be completely prevented, and a specific wavelength region cannot be prevented. In this case, there is a problem that color mixing and color omission occur.

In addition, if the prevention of color mixing and color loss with a tannic acid aqueous solution or the like is carried out under strong conditions, the transmittance is reduced and color loss occurs in the process of preventing color mixing and color loss, and this amount is unstable. is there.

Also, in the case where color mixing and color omission are prevented by an intermediate protective film made of synthetic resin, similarly to the case of tannic acid aqueous solution,
When the subsequent dyeing is carried out at a high temperature, there is a problem that color mixing and color omission cannot be completely prevented.

[Means for solving the problem]

In order to solve the above problems, the ratio of color mixing was investigated. As shown in FIG. 1, it was found that the degree of color mixing at the time of dyeing depends on the dyeing temperature and dyeing time and is more affected by the dyeing temperature. .

For example, when comparing casein and gelatin, although slightly different depending on the dye, when dyed at the same temperature, gelatin can be dyed 5 to 10 times faster than casein,
Gelatin 10-20 compared to casein when the time is equal
It can be dyed at a low temperature.

Therefore, when color mixing occurs in the dyed layer formed before the second dyed layer at the time of dyeing after the second dyed layer, the above-described problem is caused by forming a new dyed layer with a dye substrate having high dyeability and dyeing at a low temperature. It has been found that the present invention can be solved, and the present invention has been completed.

The present invention, by changing the staining substrate by the staining layer,
The purpose is to prevent color mixing and color omission during dyeing, and to manufacture a color filter having a target spectral distribution. That is, the dyeing substrate is changed to a highly dyeable one in a dyeing process in which color mixing and color loss easily occur, and dyeing is performed at a low temperature.
Prevents color loss.

 The present invention will be described in more detail below.

For example, suppose that the first dyed layer undergoes color mixing and color omission as shown in FIG. 3 during the dyeing of the second dyed layer. In FIG. 3, reference numeral 5 denotes a spectral distribution before color mixing and color loss, and reference numeral 6 denotes a spectral distribution after color mixing and color loss.

Therefore, even if the coating unevenness characteristics and the resolution are sacrificed to some extent, the second dyed layer is dyed at a low temperature using a dye substrate having a high dyeability, so that color mixing and color loss as shown in FIG. Can be prevented.

Next, the present invention will be described more specifically with reference to the drawings.

 FIG. 4 shows a color filter on the solid-state imaging device.

First, the photoelectric conversion unit 11 is provided on the solid-state imaging device substrate 10.
A flattening film 13 is applied thereon, selectively exposed, developed, and then cured by heating or the like. The flattening film 13 can be formed of a synthetic resin transparent to visible light.

Thereafter, a first dyed layer 14 (red layer) forming a flat color filter is applied on the flattening film 13. This first
The dye layer 14 is formed by applying a dye substrate, performing selective exposure and development to form a pattern, and then dipping the pattern together with the substrate in a red dye solution. After dyeing the pattern, the dye is fixed and the dyed layer is fixed with an aqueous solution of tannic acid, an aqueous solution of antimony potassium tartrate, an aqueous solution of formaldehyde, etc., so as to avoid color mixing and color loss.

Further, after forming the first dyed layer 14, the same steps as the formation of the first dyed layer 14 are repeated by changing the type of the dyeing solution, so that the second dyed layer 15 (green layer) and the third dyed layer 16 are formed. (Blue layer). Through the above steps, color filters of three primary colors are formed.

The protective film 17 is formed on the above filter. This is for protecting the photoelectric conversion unit 11 and the staining layers 14 and 1516, and is made of a synthetic resin that is transparent to visible light in the same manner as the flattening film 13.

Here, for example, when casein is employed as a color substrate for the dyed layers 14, 15, and 16, all colors are mixed in the second dyed layer (green layer) when the third dyed layer (blue layer) is dyed as shown in FIG. Can be seen.

Therefore, by changing the staining substrate of the third staining layer from casein to highly stainable gelatin, the staining conditions were changed to 65 ° C., 5 ° C.
From 50 minutes to 50 ° C. for 5 minutes, a target spectral distribution as shown in FIG. 5 can be obtained.

As in the above example, by changing the dyeing substrate to a dyeing layer having a higher dyeing property, color mixing and color omission can be prevented.

Example 1 In forming a color filter on a solid-state imaging device, the following red, green, and blue dyed layers were sequentially formed.

First staining layer: Red: After staining with casein as a dyeing substrate, the dyeing solution was treated at 80 ° C. for 5 minutes.

Second dyeing layer: green: dyed with the following dyeing solution using casein as a dyeing substrate, and then treated at 70 ° C. for 5 minutes.

Third dyed layer: blue: Dyeing was performed with the following dyeing solution using gelatin as a dyeing base material, followed by treatment at 50 ° C. for 5 minutes.

The processing temperature was lowered to 50 ° C. by using gelatin as the dye base of the third dye layer, and color mixing of the first and second dye layers could be prevented.

Example 2 In forming a color filter, cyan and yellow dyed layers were sequentially formed.

First dyeing layer: Cyan: Casein was used as a dyeing substrate, and dyed with the following dyeing solution, followed by treatment at 70 ° C. for 10 minutes.

Second stained layer: yellow: Dyeing was performed with the following staining solution using gelatin as a staining base material, and then treated at 60 ° C. for 5 minutes.

By using gelatin as the dye base of the second dye layer, the processing temperature could be lowered and color mixing could be prevented.

〔The invention's effect〕

According to the present invention, a color filter having an ideal spectral distribution can be manufactured by preventing color mixture and color omission.

[Brief description of the drawings]

FIG. 1 is an example of a decrease in peak value due to color mixing. FIG. 2 shows a spectral distribution of a color filter according to the present manufacturing method. FIG. 3 shows a spectral distribution of a conventional color filter. FIG. 4 is an example of a solid-state imaging device and a color filter formed on the solid-state imaging device. FIG. 5 is an example of a spectral distribution of a color filter according to the present manufacturing method. FIG. 6 is an example of the spectral distribution of a conventional color filter. 1 ... peak value of transmittance at dyeing temperature 50 ° C 2 ... peak value of transmittance at dyeing temperature 60 ° C 3 ... peak value of transmittance at dyeing temperature 70 ° C 4 ... dyeing temperature Peak value of transmittance at 80 ° C. 5 Spectral distribution before color mixture and color loss 6 Spectral distribution after color mixture and color loss 7 Target value of short wavelength half value 8 Long wavelength half value Target value 9: Target value of peak value 10: Solid-state imaging device substrate 11: Photoelectric conversion unit 12: Aluminum electrode 13: Flattening film 14: First staining layer (red layer) 15: Second Dyeing layer (green layer) 16: Third dyeing layer (blue layer) 17: Protective film.

Claims (1)

(57) [Claims] In a method of manufacturing a color filter formed on a solid-state imaging device, an n-th dye substrate of a color filter has higher dyeability and is dyed at a lower temperature than an (n-1) th dye substrate. A method for manufacturing a color filter, comprising: