JPH0743517A - Color solid state image pickup device and production thereof - Google Patents

Abstract

PURPOSE:To make a color filter a thin film and to prevent deterioration of sensitivity and mixture of color due to oblique light by forming a light-shading film layer of an acrylic resin on a solid state image pickup element, forming a dyed layer of an acrylic resin directly on this light-shading film layer. CONSTITUTION:A flattened resin layer 1 of a transparent polymer resin is applied by thickness required for flattening the surface on the surfaceof the element. A light-shading film layer 7 is formed on the flattened resin layer 1 above the CCD part 6 so as not to cover the photodiode part 2. Dyed layers 3, 4, 5 are made of acrylic resin. The light-shading film layer 7 is formed on the flattened resin layer 1 above the photodiode part 2. The dyed layers 3, 4, 5 are formed in contact with the upper part of the light-shading film layer 7 and in adjacent to each other. Even when the thickness of the light-shading film layer 7 is reduced within the range of extent in which the light-shading effect of the film is not deteriorated, flatness of the dyed layers 3, 4, 5 is not lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color solid-state image pickup device and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, miniaturization of solid-state image pickup devices has progressed, and a reduction in pixel area has caused a problem of reduction in sensitivity. In order to improve the sensitivity, it is necessary to optimize the microlens and thin the filter so that the microlens can easily collect light.

A conventional color solid-state image pickup device has a structure as shown in the sectional view of FIG. In order to flatten the surface of the element, a flattening resin layer 1 made of a transparent polymer resin is applied to flatten a desired film thickness. A dyeing base layer having photosensitivity is applied as the light-shielding film layer 7, and then the dyeing base layer is formed into a predetermined pattern on the CCD section 6 by using a photolithography technique and dyed with a black dye. Next, the color loss prevention layer 8 made of a transparent polymer resin material is applied on the light shielding film layer 7 to flatten the light shielding film. The same dyed base layer used to form the light-shielding film layer 7 is formed into a predetermined pattern by using a photolithography technique. The patterned dye base layer is dyed with a dye to form the dye layer 5. The dyeing layer 5 is treated so as to prevent color mixture and color loss during subsequent dyeing of the dyeing layer. The same steps as described above are repeated, and the dyed base layer is dyed sequentially with the dyes of yellow and cyan to form the dyed layer 3 and the dyed layer 4.

[0004]

However, in the above-described conventional structure and manufacturing method of the color solid-state image pickup device, since the color loss preventing layer 8 is applied on the light shielding film layer 7, the filter film thickness becomes thick. There was a problem that it would end up. Further, when the oblique light 9 is incident, the light of the dyeing layer adjacent to the photodiode part 2 may be mixed and color mixing may occur.

In the above conventional color filter manufacturing method, in order to completely prevent color mixture and color loss, the fixing time is set sufficiently by the treatment with a fixing solution, and the fixing temperature is set to be higher than the dyeing temperature thereafter. I had to do it. As a result, the fixing solution stains the dyeing layer more than necessary, and the dyeing layer swells. Therefore, there is a problem that the thinning of the filter is hindered and the filter becomes brittle.

In this case, when the fixing solution is heated to a high temperature, the decomposition of the aqueous solution of tannic acid, which is a component of the fixing solution, is accelerated, the fixing effect is not maintained, and the usable period is shortened.

In view of the above problems, it is an object of the present invention to provide a color solid-state imaging device in which the color loss prevention layer on the light-shielding film layer is omitted and a manufacturing method thereof.

In view of the above problems, it is an object of the present invention to reduce the temperature of the fixing solution in the fixing process and reduce the fixing time while preventing color mixture.

[0009]

In order to achieve the above-mentioned object, a color solid-state image pickup device of the present invention comprises a light-shielding film layer made of an acrylic resin formed on a substrate on which a solid-state image pickup element is formed, and the light-shielding film. It is provided with a dyeing layer directly made of acrylic resin on the membrane layer.

In addition, when a dyeing layer is formed on the substrate on which the solid-state image pickup device is formed by using an acrylic resin, when the dyeing layer having a high dyeing temperature is formed and the dyeing temperature is the same, the size of the dye molecule becomes large. Form from a small dyed layer.

Further, a step of dyeing and fixing black on the acrylic resin on the substrate on which the solid-state image pickup device is formed,
A step of dyeing and fixing a dye base layer on the main surface of the substrate.

[0012]

In the present invention, since the flattening resin layer on the light shielding film layer can be omitted, the color filter can be thinned.

Further, in the present invention, since the temperature of the fixing solution can be lowered and the fixing time can be shortened, the swelling of the color filter can be suppressed and the usable period of the fixing solution can be extended.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the color solid-state image pickup device of the present invention will be described.

When forming the light shielding film, the color filter is directly formed on the solid-state image pickup device, which will be described with reference to FIG.

A flattening resin layer 1 made of a transparent polymer resin is applied on the surface of the element to a desired thickness for flattening. The light-shielding film layer 7 is formed on the flattening resin layer 1 above the CCD section 6 so as not to cover the photodiode section 2. The dye layers 3, 4, and 5 are made of acrylic resin. The light shielding film layer 7 is formed on the flattening resin layer 1 and on the photodiode portion 2. Also, each dyeing layer 3,
4, 5 are formed adjacent to each other in contact with the upper portion of the light shielding film layer 7. By reducing the thickness of the light-shielding film layer 7 to such an extent that the light-shielding effect does not deteriorate, the coating flatness of the dyeing layers 3, 4, 5 is not impaired.

In this embodiment, by omitting the color loss prevention layer 8 formed of the transparent polymer resin layer on the light-shielding film layer 7, the filter film thickness can be reduced and the sensitivity reduction due to the reduction of the element area can be prevented. it can. Further, by omitting the color loss prevention layer 8 on the light shielding film layer 7, it is possible to prevent the light of the dyeing layer adjacent to the photodiode part 2 from being mixed in when the oblique light 9 enters.
Color mixing can be prevented.

A second embodiment of the method of manufacturing a color solid-state image pickup device of the present invention will be described.

The formation of the color filter directly on the solid-state image pickup device will be described with reference to the sectional process drawing of FIG.

First, in order to flatten the surface of the device, a flattening resin layer 1 made of a transparent polymer resin is applied and flattened (FIG. 2A). A dyeing base layer made of an acrylic resin having photosensitivity is applied, and then the dyeing base layer is applied to the photodiode portion 2 by using a photolithography technique.
A predetermined dyeing layer 3 is formed on the above, and dyeing is carried out using a yellow dye whose dye molecule is the next largest cyan, which is used in a later step. Dyeing temperature 70 ℃, concentration 0.1-0.5%,
It is immersed in a dyeing solution adjusted to pH 3 to 7 for 5 to 30 minutes, and then washed sufficiently with water. Fixing, which is performed to prevent the yellow dye from coming off and color mixture with the dye used in the subsequent step, is immersed in an aqueous tannic acid solution having a concentration of 2% at a temperature of 40 ° C. for 1 to 3 minutes, washed with water, and then heated at a temperature of 40. ℃, concentration 2%
Soak in the tartar stone for 1-3 minutes and wash with water (Fig. 2
(B)). By performing the fixing process for forming the dyeing layer 3, the fixing liquid is coated on the surface of the dyeing layer 3.
At this time, a small hole is opened in the layer coated with this fixing solution. Since this hole is smaller than the size of the yellow dye molecule, it is possible to prevent the dye from falling out and color mixing. Next, as in the case of FIG. 2B, the dyeing layer 4 is formed of an acrylic resin, and dyeing is performed with a dye molecule of yellow or a cyan dye larger than magenta used in a later step. Dyeing temperature 70 ℃, density 0.1-0.5
%, PH 3 to 7 is immersed in a dyeing solution adjusted to 5 to 30 minutes, and then sufficiently washed with water. Fixing, which is performed to prevent the cyan dye from coming off and color mixture with a dye used in a subsequent step, is immersed in a tannic acid aqueous solution having a concentration of 2% at a temperature of 40 ° C. for 1 to 3 minutes, washed with water, and then heated at a temperature of 40. ℃, concentration 2%
Soak in the tartar stone for 1-3 minutes and wash with water (Fig. 2
(C)). Since cyan dyeing is performed at 70 ° C., the yellow dyeing layer 3 also temporarily expands due to heat. Accordingly, the small holes of the coating on the surface of the yellow dyeing layer 3 due to the fixing solution also expand, and color mixing easily occurs. However, since the size of the cyan dye molecule is larger than this hole, the cyan dye does not enter the yellow dyeing layer 3 to cause color mixing. Further, similarly to FIG. 2B, the dyeing layer 5 is formed of an acrylic resin, and dyeing is performed using a magenta dye whose dye molecule is smaller than yellow or cyan. Dyeing at temperature 4
It is immersed in a dyeing solution adjusted to 0 ° C., a concentration of 0.01 to 0.1% and a pH of 3 to 7 for 5 to 30 minutes, and then sufficiently washed with water. The size of the magenta dye molecule is smaller than that of the yellow and cyan dye molecules (FIG. 2D). However, since magenta dyeing is performed at 40 ° C., expansion of the yellow dyeing layer 3 and the cyan dyeing layer 4 is small. Therefore, the small holes coated with the fixing solution on the surface of the yellow dye layer 3 and the cyan dye layer 4 do not expand so much. Since the hole is sufficiently smaller than the size of the magenta dyeing molecule, the magenta dye does not enter the yellow dyeing layer 3 and the cyan dyeing layer 4 to cause color mixing.

In this embodiment, the temperature of the fixing solution is lowered from 70 ° C., which is the same as the dyeing temperature, to 40 ° C., and the fixing time is shortened from 5 minutes to 1 to 3 minutes. The penetration of the fixer into the dyeing layer depends on the temperature and time as shown in FIG. By forming from a dyeing layer with a high dyeing temperature and a dyeing layer with a small dye molecule size when the dyeing temperature is the same, it is possible to prevent color mixture of each dyeing layer and suppress swelling of the dyeing layer. I can. Since the temperature of the fixing liquid is lowered in this way, the life of the fixing liquid is extended and the fixing time can be shortened, so that the throughput can be improved.

A third embodiment of the method of manufacturing a color solid-state image pickup device of the present invention will be described.

The formation of the color filter directly on the solid-state image pickup device will be described with reference to the sectional process drawing of FIG.

First, in order to flatten the surface of the element, a flattening resin layer 1 made of a transparent polymer resin is applied and flattened (FIG. 4A). A dye base layer made of an acrylic resin having photosensitivity is applied, and then this dye base layer is formed by photolithography technique on the CCD section 6 to form a predetermined light-shielding film layer 7 so that dye molecules are Dye with the next largest black dye, cyan, used in a later step. Dyeing temperature 70 ℃, concentration 0.1 ~ 0.5%, pH 3 ~
It is immersed in the dyeing solution adjusted to 7 for 5 to 30 minutes, and then sufficiently washed with water. Fixing performed to prevent the black dye from coming off and color mixture with the dye used in the subsequent step is performed with a tannic acid aqueous solution having a temperature of 40 ° C. and a concentration of 2% by 1 to 3 times.
After immersing for 1 minute and rinsing with water, it is immersed in tartar with a temperature of 40 ° C. and a concentration of 2% for 1 to 3 minutes and then rinsing with water (FIG. 4B). By performing the fixing process for forming the light shielding film layer 7, the fixing liquid is coated on the surface of the light shielding film layer 7. At this time, a small hole is opened in the layer coated with this fixing solution. Since this hole is smaller than the size of the black dye molecule, it is possible to prevent the dye from falling out and color mixing. Similar to FIG. 4B, the dyeing layer 3 is formed on the photodiode part 2 with an acrylic resin, and the dye molecules are smaller than black or cyan used in the later step and magenta used in the later step. Dye with the larger yellow dye.

The dyeing is carried out at a temperature of 70 ° C., a density of 0.1 to 0.5%,
It is immersed in a dyeing solution adjusted to pH 3 to 7 for 5 to 30 minutes, and then washed sufficiently with water. Fixing, which is performed to prevent the yellow dye from coming off and color mixture with the dye used in the subsequent step, is immersed in an aqueous tannic acid solution having a concentration of 2% at a temperature of 40 ° C. for 1 to 3 minutes, washed with water, and then heated at a temperature of 40. ℃, concentration 2%
Soak in the tartar for 1-3 minutes and wash with water (Fig. 4
(C)). Since the yellow dyeing is performed at 70 ° C., the black light shielding film layer 7 is also temporarily expanded by heat. Accordingly, the small holes of the coating of the fixing liquid on the surface of the black light-shielding film layer 7 also expand and the color mixing easily occurs. Since the size of the yellow dye molecule is smaller than the size of the black dye molecule, if the fixing temperature is 70 ° C., it enters the black light-shielding film layer 7 through the small hole of the coating, and the wavelength 40
At 0 nm, the transmittance decreases by about 5%, causing color mixing. However, since the black dyeing layer is a light-shielding film layer, there is no problem in use unless the colors are lost even if the colors are mixed. Similar to FIG. 4B, the dyeing layer 4 is formed of an acrylic resin, and dyeing is performed using a dye whose dye molecule is black, yellow, or cyan which is larger than magenta used in a later step. Dyeing is carried out by immersing in a dyeing solution adjusted to a temperature of 70 ° C., a concentration of 0.1 to 0.5% and a pH of 3 to 7 for 5 to 30 minutes, and then sufficiently washing with water. Fixing, which is performed to prevent the cyan dye from coming off and color mixture with a dye used in a subsequent step, is immersed in a tannic acid aqueous solution having a concentration of 2% at a temperature of 40 ° C. for 1 to 3 minutes, washed with water, and then heated at a temperature of 40. It is soaked in tartar of 2% concentration for 1 to 3 minutes and washed with water (FIG. 4 (d)). Since cyan dyeing is performed at 70 ° C., the yellow dyeing layer 3 also temporarily expands due to heat. Accordingly, the small holes of the coating on the surface of the yellow dyeing layer 3 due to the fixing solution also expand, and color mixing easily occurs. However, since the size of the cyan dye molecule is larger than this hole, the cyan dye does not enter the yellow dyeing layer 3 to cause color mixing. Similar to FIG. 4B, the dyeing layer 5 is formed of an acrylic resin, and dyeing is performed using a magenta dye whose dye molecule is smaller than yellow or cyan.
Dyeing temperature 40 ℃, concentration 0.01-0.1%, pH 3-7
It is immersed for 5 to 30 minutes in the dyeing solution prepared as described above, and then sufficiently washed with water (FIG. 4 (e)). The size of the magenta dye molecule is smaller than that of the yellow-cyan dye molecule. However, since magenta dyeing is performed at 40 ° C., expansion of the yellow dyeing layer 3 and the cyan dyeing layer 4 is small. Therefore, the small holes coated with the fixing solution on the surface of the yellow dye layer 3 and the cyan dye layer 4 do not expand so much. Since the hole is sufficiently smaller than the size of the magenta dye molecule, the yellow dye layer 3 and the cyan dye layer 4
No magenta dye is mixed in and no color mixing occurs.

In this embodiment, by omitting the color loss prevention layer 8 formed of the transparent polymer resin layer on the light-shielding film layer 7, the filter film thickness can be reduced and the sensitivity reduction due to the reduction of the element area can be prevented. it can. Further, by omitting the color loss prevention layer 8 on the light shielding film layer 7, it is possible to prevent the light of the dyeing layer adjacent to the photodiode part 2 from being mixed in when the oblique light 9 enters.
Color mixing can be prevented.

[0027]

According to the present invention, when a light-shielding film layer is formed, a light-shielding film layer made of an acrylic resin is provided on the solid-state image sensor, and a dyeing layer made of an acrylic resin is directly provided on the light-shielding film layer. Can make the color filter thin,
It is possible to realize an excellent color solid-state imaging device capable of preventing a decrease in sensitivity and color mixture due to oblique light.

When a dyeing layer is formed using an acrylic resin, it is formed from a dyeing layer having a high dyeing temperature, and when the dyeing temperature is the same, it is formed from a dyeing layer having a small dye molecule size. Since the temperature of the fixer can be lowered and the fixing time can be shortened for processing, it is possible to realize an excellent color solid-state image sensor capable of suppressing the swelling of the color filter and extending the usable period of the fixer. .

Further, when the light shielding film layer is formed, black is dyed and fixed on the acrylic resin on the solid-state image pickup device,
Since the subsequent steps of dyeing and fixing the dyed base layer make it possible to omit the color loss prevention layer on the light-shielding film layer, the color filter can be made thinner, and sensitivity deterioration and color mixing due to oblique light can be prevented. It is possible to realize an excellent color solid-state imaging device that can be realized.

[Brief description of drawings]

FIG. 1 is a sectional view of a solid-state image sensor according to a first embodiment of the present invention.

2A to 2C are cross-sectional views in order of the processes of a solid-state imaging device according to the second embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between a swelling amount and a fixing condition.

FIG. 4 is a sectional view in order of steps of a solid-state imaging device according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a conventional solid-state image sensor.

[Explanation of symbols]

 1 flattening resin layer on element surface 2 photodiode part 3, 4, 5 dyeing layer 6 CCD part 7 light-shielding film layer 8 color loss prevention layer 9 oblique light

Claims (3)

[Claims] 1. A light-shielding film layer made of an acrylic resin formed on a substrate on which a solid-state imaging device is formed, and a dyeing layer made of an acrylic resin directly on the light-shielding film layer. Color solid-state imaging device. 2. When forming a dyeing layer using an acrylic resin on a substrate on which a solid-state imaging device is formed, the dyeing layer having a high dyeing temperature is formed, and when the dyeing temperature is the same, the size of the dye molecule is A method for manufacturing a color solid-state imaging device, which is characterized by forming from a small dyed layer. 3. A step of dyeing and fixing black on an acrylic resin on a substrate on which a solid-state image sensor is formed, and a step of dyeing and fixing a dye base layer on the main surface of the substrate. A method of manufacturing a color solid-state imaging device having a feature.