JPH03280576A - Manufacture of color solid-state image sensing device - Google Patents

Abstract

PURPOSE:To form a thin film color filter and simplify the structure, by providing a dye-base layer as an isolated independent unit. CONSTITUTION:Transparent polymer resin 3 is spread on a semiconductor substrate 1 on which a solid-state image sensing device is formed, and the element surface is flattened. Photosensitized material such as gelatin, casein, glue and PVA whose viscosity is adjusted is spread on the surface, and dye-base layers 7 are formed by exposure, development, and rinsing process, in the isolated independent state where adjacent layers do not come into contact with each other. Then by using positive type transparent resin 8 as a resist mask, windows are opened only at necessary portions, and dyeing is performed by using magenta dye. Thus a magenta color filter 4 is formed. The similar process is repeated by changing the dye.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a color solid-state imaging device, in which a color filter for color separation is directly formed on a semiconductor substrate on which a solid-state imaging device is formed.

2. Description of the Related Art In recent years, as a method for colorizing a solid-state image sensor, a method of directly forming a color filter on the solid-state image sensor has become mainstream. A method of manufacturing a conventional color solid-state imaging device will be described with reference to the drawings. Figure 2 (a)-(g
) is a diagram showing a conventional method for manufacturing a color solid-state imaging device in order of steps. In the figure, 1 is a semiconductor substrate on which a solid-state image sensor is formed, 2 is a light receiving section, 3 is a transparent polymer resin, and 4 is a semiconductor substrate on which a solid-state image sensor is formed.
5 indicates a magenta color filter, 5 a yellow color filter, and 6 a cyan color filter.

A method of manufacturing the color solid-state imaging device configured as described above will be described below.

First, in FIG. 2(a), a transparent polymer resin 3 is applied onto a semiconductor substrate l on which a solid-state image pickup device is formed, and the surface of the device is flattened. Next, a photosensitive and viscosity-adjusted material such as gelatin, casein, grue, or PVA is applied, and the desired pattern is formed by exposure, development, and rinsing, and then dyed with magenta dye.
A magenta color filter 4 is formed as shown in FIG. 4(b). In order to prevent color mixing in the next dyeing step, the intermediate layer 31 is formed by applying the transparent polymer resin used to flatten the surface of the element, as shown in FIG. 3(C).

Thereafter, by changing the dye and performing the same steps as in Figures (b) and (c), a magenta color filter 4. Yellow color filter 5. Second intermediate layer 32. Each color filter of the cyan color filter 6 is formed, and finally, the same transparent polymer resin as that used for flattening the element surface and for the intermediate layer is formed as a surface protective film 33, as shown in FIG. A color solid-state imaging device as shown is used.

In the above conventional method, for example, when forming magenta, yellow, and cyan color filters, magenta,
It is necessary to form yellow and cyan dyed base layers,
Accordingly, at least two interlayer films are required to prevent color mixture.

With this configuration, not only does the total thickness of the color filter layer become thicker, but also the dyed base layer of each color has a structure with different levels in the height direction, so depending on the pattern size and the thickness of the interlayer, light may leak and reach the light receiving area. This may adversely affect image quality such as flicker.

In order to prevent the light that has passed through each color filter from entering the adjacent light-receiving section and causing problems such as color mixing, the color filters 4, 5, and 6 of each color are arranged so that they do not overlap each other as shown in Figure 3. There is a proposal to form an aluminum light shielding film 13 at a position in the optical path of light passing through the gap between adjacent color filters to block reflection of light (see Japanese Utility Model Application Publication No. 1-100461). .

Problems to be Solved by the Invention However, with an aluminum light-shielding film that reflects light, the reflected light from the light-shielding film enters an adjacent filter, and the light is further reflected at the interface between the color filter and other layers and enters the light receiving section. This may cause light contamination.

When the total thickness of the filter layer becomes thicker, the distance between the light receiving part and the corresponding filter increases (this means that the problem of light passing through the filter entering the adjacent light receiving part and causing color mixing can no longer be solved). There wasn't.

The present invention solves the above-mentioned conventional problems, and aims to provide a method for manufacturing a color solid-state imaging device equipped with a color filter that is thinner than the conventional one and prevents light from mixing between adjacent pixels. .

Means for Solving the Problems In order to achieve the above object, the present invention coats a dyed base material on a semiconductor substrate on which a solid-state image sensor is formed, and forms a separate and independent dyed base pattern corresponding to each pixel. The manufacturing method includes the steps of selectively dyeing a dyed base pattern using a resist mask, and forming a light-absorbing layer between color filters having various spectral characteristics.

Function The present invention employs the above-described method in which the dyed base layer is separated and independent, so that it is possible to form a color filter without color mixture between adjacent filter pixels.
In addition, since a light-absorbing layer is provided between the inserted color filters, the light that has passed through the filters does not enter the adjacent light-receiving area, and color solid-state imaging can prevent problems such as color mixing and flickering. equipment can be provided.

EXAMPLE Hereinafter, an example of the present invention will be explained with reference to the drawings. In FIGS. molecular resin,
4 is a magenta color filter, 5 is a yellow color filter, 6 is a cyan color filter, 7 is a dyed base layer,
8 is positive transparent resin, 9 is green color filter, 1
0 is an exposure mask, 11 is a deep ultraviolet light, and 12 is a light absorption layer.

A method of manufacturing a color solid-state imaging device having the above configuration will be described below.

First, in FIG. 1(a), a transparent polymer resin 3 is applied onto a semiconductor substrate 1 on which a solid-state image pickup device is formed, and the surface of the device is flattened. Next is gelatin and casein, which have been made photosensitive and have their viscosity adjusted.

A dyed base layer 7 is formed by applying a material such as GREEU or PVA, exposing it to light, developing it, and rinsing it so that it is separated and independent so that adjacent layers do not come into contact with each other, as shown in FIG. 3(b). Subsequently, using the positive type transparent resin 8 as a resist mask, windows are opened only at necessary locations and dyed with magenta dye, thereby forming a magenta color filter 4 as shown in FIG. 2C. Figures (d) to (') below show how the same process is repeated with different dyes.Magenta color filter 4.Yellow color filter 5.Cyan color filter 6.Green color filter Figure 9 (K) shows the state in which the color filter surface has been flattened by applying positive type transparent resin 8 after the formation of color filter 9 has been completed.
Using an exposure mask 10, far ultraviolet light 11 is irradiated only between the color filters. The state after development and rinsing treatment is shown in FIG. 2(i). Subsequently, using the same material used to form the dyed base layer 7, coating, exposure, development, and rinsing were performed, followed by dyeing with black dye to form the light absorption layer 12, as shown in Figure (j). It is. Then, in FIG. 6(k), a transparent polymer resin 3 is applied to protect the surface of the color filter, and the formation of the color filter is completed.

In this example, dyeing was performed in the order of magenta, yellow, cyan, and green, but it goes without saying that the dyeing order may be changed.

Effects of the Invention As is clear from the above embodiments, according to the present invention, a group of color filters without color mixing between adjacent filter pixels can be formed in a multilayer dyed base layer, and the color filter can be made thinner, This makes it possible to simplify the structure. In addition, since a black light absorption layer made of gelatin or the like is provided between each color filter, it does not reflect light like a conventional aluminum film, and the light that has passed through the color filter enters the adjacent light receiving area. It is possible to completely prevent the occurrence of negative effects such as flicker, and to provide a color solid-state imaging device with excellent image quality.Furthermore, conventional aluminum reflective films are usually formed by vapor deposition in a vacuum. However, since the present invention forms a black absorbing film by applying gelatin, an expensive vapor deposition apparatus is not required.

[Brief explanation of drawings]

FIGS. 1(a) to 2(a) are process cross-sectional views showing a method for manufacturing a color solid-state imaging device according to an embodiment of the present invention, and FIG. 2(a)
) to (g) are process sectional views showing a conventional method of manufacturing a color solid-state imaging device, and FIG. 3 is a sectional view of a main part of a color solid-state imaging device showing another example of the conventional method. l... Semiconductor substrate, 2... Light receiving section, 4
...Magenta color filter, 5.Old...Yellow color filter, 6..Cyan color filter, 7..Dyeing base layer, 9..Green color Filter, 12... Light absorption layer.

Claims (1)

[Claims] In a method of manufacturing a color solid-state imaging device in which an organic color filter consisting of a plurality of color groups is formed on a semiconductor substrate,
forming separate and independent dyed base layers at locations corresponding to each pixel of the dyed base layer constituting the organic color filter so that adjacent pixels do not come into contact with each other;
By repeating the step of coloring the separately formed dyed base layer with a color corresponding to each pixel pattern, a color filter having a plurality of spectral characteristics is formed in one layer, and then each of the separately formed spectral characteristics A method for manufacturing a color solid-state imaging device in which a light absorption layer is formed between color filters having characteristics.