JPH02285675A - Solid-state image sensing device - Google Patents

Abstract

PURPOSE:To make flat hues and an intermediate layer, which are laminated on the upper part of a color filter layer, as a whole and to make it possible to dissolve the optical irregularity of a solid-state image sensing device by a method wherein the device is manufactured into a structure, wherein after an Al film is applied on some of a group of photodetectors on a substrate, a resin layer for filling a step is provided on a part, on which the Al film is not applied, and the color filter layer is laminated on the resin layer. CONSTITUTION:In a solid-state image sensing device of a structure, wherein an aluminum film 3 is applied on some of a group of photodetectors 2 on a substrate 1 and a filter layer 4 having a plurality of hues is laminated on the other photodetectors, after the above aluminum film 3 is applied, a resin layer 12 for filling a step is provided on a part, on which the film 3 is not applied, and a color filter layer 4 is laminated on the layer 12. For example, a frame-shaped aluminum film 3 is applied on some of a group of photodetectors 2 and prior to the formation of a color filter layer 4 having a plurality of hues on an inner side surrounded with the film 3, a transparent resin layer 12 is formed on the inner side surrounded with the film 3 to eliminate substantially a step between the film 3 and a substrate 1 in a region where the layer 4 is formed.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a solid-state image sensor in which a part of a group of light-receiving elements on a substrate is coated with an aluminum film, and 7J filter layers of a plurality of hues are laminated in stages on other groups of light-receiving elements. be.

[Prior art]

Generally, various structures are known for solid-state imaging devices that have an aluminum film on one part and a color filter layer on the other part, such as those shown in Figs. 3 and 4. It has a unique structure. In the figure, 1 is a silicon substrate cut into a predetermined size from a semiconductor wafer, for example, and a large number of light-receiving element groups 2 are installed on the substrate, and some of the light-receiving element groups have a predetermined thickness. A frame-shaped aluminum film 3 is coated, and color filter layers 4 of a plurality of hues are provided inside the aluminum film 3.The aluminum film 3 covers a part of the light receiving element group 2. This is applied to block light, and by looking at the potential difference between this light-shielded light-receiving element group and the light-receiving element group covered with the color filter layer 4, the color filter layer 4 is covered. It is designed to determine whether or not the light receiving element group has received light. Also, the color filter layer 4 is arranged in a shell as shown in FIG.
) to (D). That is, the aluminum film 3 is coated (Figure (A)).
In order to form the first layer of hue 5 on the substrate 1, gelatin is spin-coded (Figure B) and exposed using a predetermined pattern mask that exposes the portion to be left as the first layer of hue. When developed, a portion corresponding to the light receiving element remains (Figure (C)). The remaining portion is dyed, for example, red by a known dyeing means to form the hue of the first layer. Next, a transparent resin is spin-coded to form an intermediate layer 6, the surface is made substantially flat, and a second layer, hue 7, is formed in the same manner as described above.
D) Figure). The hue 7 of this M2 layer is green. Furthermore,
An intermediate layer 8 and a third layer of blue hue 9 are formed in the same manner as described above, and a surface layer 1o that also serves as protection is spin-coded on the surface thereof. Note that 11 is a plurality of electrodes provided on the substrate.

[Problem to be solved by the invention]

In the conventional example, since the aluminum layer 3 of a predetermined thickness is formed on the substrate, there is a step between it and the substrate 1, and when forming the hue 5 of the first layer, gelatin is spin-coded. , the thickness of the hue 5 corresponding to or adjacent to the stepped portion is significantly thicker than the other hue portions, and its cross-sectional shape becomes delta-shaped. The intermediate layer and the second layer Hue 7 which are sequentially laminated are similarly spin-coded, but since the cross-sectional shape of the first layer Hue 5 is delta-shaped, the cross-sectional shape of the first layer Hue 5 is a delta shape. Since they are laminated along the same direction, an inclination is unavoidable, and therefore the cross-sectional shape of the hue formed near the position where the aluminum film 3 is coated is deformed compared to the hue formed in the other central part.
The problem is that there is a difference in the refraction of light, which causes optical variations, resulting in a decrease in quality.

[Means to solve the problem]

As a specific means for solving the problems of the conventional example, the present invention provides a solid-state image device in which a part of a group of light-receiving elements on a substrate is coated with an aluminum film, and other light-receiving elements are laminated with filter layers of a plurality of hues. A solid, characterized in that after being coated with the aluminum film, a resin layer is provided to fill in the steps in the areas not covered with the aluminum film, and the color filter layer is laminated on the resin layer. By providing a resin layer to fill the steps, the hue and intermediate layers laminated on top of the resin layer become flat as a whole, and optical variations can be eliminated. .

【Example】

Next, the present invention will be explained in more detail with reference to illustrated embodiments. In order to facilitate understanding, the same parts as in the conventional example are given the same reference numerals, and the details thereof will be omitted. First, in FIG. 1, reference numeral 1 denotes a silicon substrate cut into a predetermined size from a semiconductor wafer, and a large number of light-receiving element groups 2 are provided on the substrate, and some of these light-receiving element groups have a predetermined thickness. The aluminum film 3 can be formed into various planar shapes such as a single character shape and an L shape, but the illustrated embodiment shows an example in which it is formed into a frame shape. be. Color filter layers 4 of a plurality of hues are provided inside surrounded by this aluminum membrane film 3. Prior to forming this color filter layer 4, a transparent resin layer 12 having approximately the same thickness is formed on the inside surrounded by the aluminum film 3, and in the area where the color filter layer 4 is to be formed, the aluminum film The feature of the present invention is that the step between the substrate 1 and the substrate 1 is substantially eliminated. That is, as shown in FIGS. 2(A) to 2(F), after a part of the optical element group 2 of the substrate 1 is coated with an aluminum film 3 of a predetermined thickness in the form of a frame, a photosensitive transparent film 3 is coated. The resin is spin-coded (Figure B), exposed using a pattern mask that exposes only the area where the color filter layer 4 will be formed, and then developed to coat the area where the color filter layer 4 will be formed with a transparent layer. A resin layer 12 is formed (Figure (C)). The transparent resin layer 12 thus formed has substantially the same thickness as the aluminum film 3. A color filter layer 4 is formed on top of this transparent resin layer 12. First, aluminum film 3 and transparent resin layer 1
In order to form the first layer of hue 7 on top of 2, gelatin is spin-coded (Figure D) and exposed using a predetermined pattern mask that exposes the portion to be left as the first layer of hue. When developed, a portion corresponding to the light-receiving element remains (Figure (E)). The remaining portion is dyed green using a known dyeing method to form the first layer, hue 7, and a transparent resin is spin-coded on top of it to form the intermediate layer 6, and the surface is made approximately flat. (Figure (F)). Next, a second layer of hue 5 is formed by the same means as described above. The hue 5 of this second layer is red. Furthermore, in the same manner as described above, an intermediate layer 8 and a third layer of blue hue 9 are sequentially laminated and formed, and a surface layer 10 that also serves as protection is spin-coded on the surface thereof. In this way, by forming the transparent resin layer 12 in the area where the color filter layer 4 is formed, the level difference between the aluminum film 3 and the substrate 1 is eliminated, and the hue and color are formed on the upper part of the transparent resin layer 12. By sequentially laminating the intermediate layers, the thickness of the hue formed particularly near the boundary portion of the aluminum film 3 becomes uniform throughout, and there is no large change in the refractive index of light passing through the hue. be. Incidentally, the thickness of the aluminum film 3 is 6000 to 110 mm.
The thickness before dyeing of the green and red hues of 7.5 is 10,000 to 13,000, and the thickness after dyeing is 15,000 to 16,000. Further, the blue hue 9 has a thickness of approximately 4000 mm before dyeing, and a thickness of approximately 6000 mm after dyeing. Furthermore, each intermediate layer 6.8
And the thickness of the surface layer 10 is ioooo~11000. [Effects of the Invention] As explained above, the solid-state image sensor according to the present invention is a solid-state image sensor in which a part of a group of light-receiving elements on a substrate is coated with an aluminum film, and other light-receiving elements are laminated with filter layers of a plurality of hues. The image sensor has a structure in which, after being coated with the aluminum film, a resin layer is provided to fill in a step in a portion not covered with the aluminum film, and the color filter layer is laminated on the resin layer. In particular, due to the structure in which a resin layer is provided to fill the step, the thickness of the hue formed close to the boundary part of the aluminum film among the hues laminated on top of the resin layer becomes uniform as a whole,
This eliminates large changes in the refractive index of light that passes through the hue, eliminates optical variations in the filter layer, stabilizes the quality of the product, and significantly improves performance, which is an excellent effect.

[Brief Description of the Drawings] Figure 1 is an enlarged sectional view showing the main parts of the solid-state image sensor according to the present invention, and Figures 2 (A) to (F) sequentially show the manufacturing process of the solid-state image sensor. FIG. 3 is a schematic front view of a conventional solid-state image sensor; FIG. 4 is an enlarged sectional view taken along line IV-IV in FIG. 3; FIG. Diagram (A)
-(D) are enlarged sectional views of main parts sequentially schematically showing the manufacturing process of the solid-state image sensor in the conventional example. 1... Substrate 2... Light receiving element group 3... Aluminum film 4... Color filter layer

Claims (2)

[Claims] (1) A solid-state image sensor in which a part of a group of light-receiving elements on a substrate is coated with an aluminum film, and other light-receiving elements are laminated with filter layers of a plurality of hues. 1. A solid-state image pickup device, characterized in that a resin layer is provided in a portion not covered with a film to fill in a step, and the color filter layer is laminated on the resin layer. (2) The solid-state image sensor according to claim 1, wherein the first filter layer among the filter layers of a plurality of hues is green.