JPH01143585A - Color solid-state image pickup element - Google Patents

Abstract

PURPOSE:To prevent damage to step, crack or exfoliation of a color decomposition filter layer by making a lower face with the color decomposition filter provided thereupon flat in advance. CONSTITUTION:A storage region 11 is formed highest, a non-photodetector 15 of a photodetecting region 12 is higher and a scribe section 13 and a photodetector 14 of the photodetection region 12 are formed lowest. A photosensing transparent resin layer 21 is formed to the entire face in the solid-state image pickup element as above. In this state, if the part of the storage region 11 is not made flat, the photosensitive transparent resin layer 22 is formed to the entire face. If the flatness is not enough, a smoothing layer is formed again onto the entire face. The color decomposition filter is formed on the solid-state image pickup element made flat in this way. Thus, damage to step, crack or exfoliation of the color decomposition filter are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a color solid-state imaging device in which a color separation filter is directly attached to the solid-state imaging device.

<Prior art> The surface of a solid-state image sensor has an accumulation region 11 as shown in FIG.
, the light receiving area 12 and the scribe portion 13 have different heights. Also, in the light receiving area 12, the light receiving part 14 and the non-light receiving part 1
5, the heights are different.

For this reason, conventionally, as shown in Japanese Unexamined Patent Publication No. 56-10982, a transparent film was formed to fill the recesses on the light-receiving section and a color separation filter was directly provided, thereby cutting off the color separation filter layer. , to prevent cracking and peeling.

In addition, the manufacturing method for this color separation filter is to spin-coat a water-soluble photosensitive resin with excellent dyeability and flatten it, then pre-baking it, exposing it to a mask in a pattern, developing it, and then dyeing it. . Naturally, this process was repeated for the number of colors in the color separation filter.

<Problems to be Solved by the Invention> However, the level difference that has been solved by the above technique is only in the light receiving section. Therefore, a level difference still exists between the light receiving section and the outside of the light receiving section area. Therefore, cracks, breakage, and peeling phenomena occur in that part. Furthermore, since white portions are formed in some areas, uneven coating occurs when the photosensitive resin is spin-coated. The thickness of this photosensitive resin causes density unevenness in the dyed recolor separation filter, resulting in color unevenness during imaging.

Means for Solving the Problems> In order to solve the above-mentioned problems, the lower surface on which the color separation filter is to be provided is flattened in advance. This means that not only the light receiving region jJl is flattened, but the entire area including the scribe portion and the accumulation region is flattened. Of course, if there is only one step, it is sufficient to perform the resin agglomeration only once, but it is difficult to provide two types of layer thickness when forming the resin twice. Therefore, it is common to perform resin formation two or more times. At this time, the resin forming method may be a method in which resin is formed on the deep low part in the -th time by the difference thickness between the deep low part and the shallow low part, and then resin is formed on the entire low part by the thickness of the shallow low part. However, the deep low part and the shallow low part may be formed separately. Also, in this case, the lower level was set to the second floor, but it may be the third floor or higher.

<Function> In the color solid ↑ image element of the present invention, the lower surface of the color separation filter is flat, and therefore the color separation layer is also formed flat. This flat property has the effect of preventing cranking, breakage, and peeling. Also,
The color unevenness of color separation filters formed by photolithography depends on the thickness of the photosensitive resin before dyeing, and the thickness of this photosensitive resin is influenced by spin coating. The influence of this spin coating depends on the flatness of the object to be coated, that is, the bottom surface of the color separation filter.

<Example><Example1> An example of the present invention will be described in detail using a concave surface. FIG. 1 is a partial sectional view showing an embodiment of the present invention before forming a color separation filter. Figure 2 shows
It is a partial sectional view before forming the photosensitive transparent resin layer for the second time. FIG. 3 is a partial sectional view before forming the same photosensitive transparent resin layer.

In this solid-state image sensor, the accumulation region 11 is formed to be the highest, and the non-light receiving portion 15 of the light receiving region 12 is the second highest. On the other hand, the scribe section 13 and the light receiving section 14 of the light receiving region 12 are formed at the lowest level. This condition is shown in the cross-sectional view of FIG. A photosensitive transparent resin is formed on the entire surface of such a solid-state image sensor.

Next, after pre-baking, a mask is placed on top of this, excluding only the light-receiving part 14 and scribe part 13, and by exposing, developing, and post-baking, the first layer of photosensitive resin is Form layer 21. Next, a photosensitive transparent resin is again formed on the entire surface. Next, after pre-baking, a mask is placed on the accumulation region 11 from above, exposed and developed, and post-baked to form a solid with a second photosensitive resin layer 22 as shown in FIG. Obtain an image sensor. If flattening is still insufficient even after this, another smoothing layer is formed over the entire surface, but this may not be necessary. Then, a photosensitive resin with good dyeability is spin-coated on top of this to form it uniformly.
After prebaking, parts other than the pixel areas are masked and developed to form a color separation filter. This process is repeated for the number of colors.

<Example 2> Another example of the present invention will be explained. Figure 4 shows
FIG. 5 is a partial cross-sectional view showing a state before forming a color separation filter in one embodiment of the present invention, and FIG. 5 is a partial cross-sectional view before forming a second photosensitive transparent resin layer. FIG. 6 is a partial sectional view before forming the same photosensitive transparent resin layer.

In this solid-state image sensor, the pad portion 16 is formed particularly high, and this portion is higher than the other portions. Furthermore, almost the entire surface except for the scribe section 13, pad section 16, and light receiving section 14 has the same height. Furthermore, the scribe section 13 and the light receiving section 14 are lower than the others. This condition is shown in FIG. A photosensitive transparent resin is formed on the entire surface of such a solid-state image sensor. Next, after pre-baking, a mask with a pattern excluding the light-receiving area 14 and scribe area 13 is used to expose, develop, and post-bake to obtain the photosensitivity of the first layer as shown in Figure 5. A transparent resin layer 23 is provided. Next, after forming a photosensitive transparent resin on the entire surface, the second layer is formed as shown in Figure 4 by forming a photosensitive transparent resin, then masking with a pattern only for the pad area, exposing, developing, and post-baking. A solid-state imaging device provided with a photosensitive resin layer 24 is obtained. On such a solid-state image sensor, a color separation filter is formed by the same method as in the first embodiment.

<Effects of the Invention> According to the present invention, the conventional problems of cranking, breakage, and peeling of color separation filters have been significantly reduced. Additionally, the thickness of the color separation filter became uniform, and the spectral characteristics also became uniform.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of a solid-state image sensor before forming a color separation filter showing an embodiment of the present invention, and FIG. 2 is a partial cross-sectional view before forming a second photosensitive resin layer. FIG. 3 is a partial sectional view before forming the photosensitive resin layer. FIG. 4 is a partial cross-sectional view of a solid-state image sensor before forming a color separation filter in another example, and FIG. 5 is a partial cross-sectional view before forming the same second photosensitive resin layer. FIG. 6 is a partial cross-sectional view before forming a photosensitive resin layer. 11... Accumulation area 12... Light receiving area 13...
・Scribe part 14... Light-receiving part 15... Non-light-receiving part 16... Pad part 21. 23...-layer photosensitive transparent resin 22. 24... Second layer photosensitive transparent resin Kazuo Suzuki, Representative of Toppan Printing Co., Ltd. 14 〕5 Figure 1 Figure 2! Figure 3 Figure 6

Claims (1)

[Claims] 1) A color solid-state imaging device characterized in that a color separation filter is provided on a flat surface whose entire surface is flattened by applying a photosensitive transparent resin to the unevenness on the solid-state imaging device.