JPH0360154A - Solid-state color image sensing device - Google Patents

Abstract

PURPOSE:To eliminate failures that a part of a color filter to be formed on a light shielding film is missed or invades other cells by forming on an aluminum light shielding film a coat which absorbs electromagnetic wave of the wave length of an exposure light source used at the time of patterning photosensitive resist. CONSTITUTION:On a semiconductor substrate 1 on which a photo detecting part 2 is formed, an aluminum light shielding film 4 optically shielding the part except said part 2 is formed via a passivation film 3, thereby forming a solid-state image sensing element. A polymer resin film 5 containing yellow dye absorbing the wavelength of mercury lamp light is spin-coated and thermoset. At the time of patterning dyed layers 8, 9, ultraviolet rays of the mercury lamp is absorbed by the polymer resin film 5, and not reflected by the aluminum light shielding film 4, so that the dyed layers 8, 9 are precisely patterned.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color solid-state image sensor, and particularly to a color solid-state image sensor in which a color filter layer is directly formed on a chip.

[Prior Art] Generally, a color solid-state image sensor separates the light incident through the optical system of a camera into red, blue, green, or their complementary colors, and extracts the color video signal as an electrical signal. be.

Conventionally, as this type of color solid-state image sensor, one having a cross-sectional structure shown in FIG. 2 has been adopted.

This solid-state image sensor has a light receiving section 2 that photoelectrically converts incident light within the surface area of a semiconductor substrate 1, and an aperture for the incident light is formed on the semiconductor substrate 1 through a passivation film 3 on the light receiving section 2. An aluminum light-shielding film 4 is provided.

Then, on top of this, a cyan dyed layer 8 patterned into a predetermined shape and dyed is placed through a color mixture prevention layer 7 (for example, a transparent polymer resin film such as PGMA, PMMA, GCM, etc.) for smoothing the substrate surface. Further, a yellow dyeing layer 9 is formed on top of the yellow dyeing layer 9 with a color mixture prevention layer 7 interposed therebetween.
It has a structure in which the uppermost layer also has a color mixture prevention layer 7. The dyed layer 8.9 is obtained by dyeing using a protein such as gelatin, casein, glue, or a water-soluble resist prepared by adding dichromate to polyvinyl alcohol as a chromosomal matrix.

[Problems to be Solved by the Invention] In the conventional color solid-state image sensor described above, the color filter is patterned on the aluminum light shielding film 4 via the color mixture prevention film, so the water-soluble resist causes diffuse reflection of light during exposure. receive. For this reason, accurate patterning is not possible with water-soluble resists, so in conventional dyed layers, patterns that extend into other cells may be formed or necessary patterns may be missing. In that case, color unevenness occurs and color reproducibility deteriorates.

[Means for Solving the Problems] The color solid-state image sensing device of the present invention is one in which a transparent polymer resin film and a color filter layer are laminated on a semiconductor substrate on which a plurality of photoelectric conversion regions are formed. An aluminum light-shielding film having holes on the photoelectric conversion region and a coating that absorbs ultraviolet rays or electromagnetic waves having a specific wavelength below are formed between the semiconductor substrate and the transparent polymer resin film.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 (f>) is a sectional view showing an embodiment of the present invention. In the figure, parts common to the conventional example of FIG. 2 are given the same reference symbols. This embodiment The difference from the conventional example shown in FIG.
5 is formed.

This color solid-state image sensor is formed through the steps shown in FIGS. 1(a) to 1(e). That is, first, an aluminum light-shielding film 4 is formed on the semiconductor substrate 1 in which the light-receiving part 2 is formed in its surface area, via a passivation film 3, to block light except for the light-receiving part, thereby constructing a solid-state image sensor.
Figure 1 (a)] 0th order, 43 which is the wavelength of mercury lamp light
PG containing yellow dye that absorbs wavelengths around 6 nm
A polymer resin film 5 such as MA is spin-coated to a thickness of 1 μm and thermally cured by baking at 120°C [Figure 1 (b)].Next, dichromium is applied to natural proteins such as gelatin. A water-soluble resist 6 to which an acid salt has been added is spin-coated to a thickness of 2 μm, exposed with a mercury lamp, and developed to form a pattern on the aluminum light-shielding film 4 [Figure 1 (C)] ), Next, ashing is performed using a resist removing means such as oxygen plasma or ozone, and the polymer resin film containing the yellow dye on the light receiving area is removed using the water-soluble resist as a mask [Figure 1 (d)). Next, the water-soluble resist is removed with an alkaline aqueous solution such as potassium hydroxide.
Figure 1(e)).

Next, a transparent polymer resin film such as PGMA is formed to a thickness of about 1 μm to flatten the substrate surface, and then a water-soluble resist such as gelatin is spin-coated to a thickness of 1 μm. A lamp is used to form a pattern at a predetermined position on the light-receiving part.The cyan dyeing layer 8 is formed by dyeing using a cyan dyeing solution heated to 50°C.Next,
A transparent polymer resin film is formed to a thickness of about 1 μm, a yellow dyeing layer 9 is formed in the same manner as the cyan dyeing layer, and a transparent polymer resin is formed on the top. ) Obtain the element shown.

In the above process, when patterning the dyeing layer 8.9, the ultraviolet rays from the mercury lamp are absorbed by the polymer resin Jul (5) and are not reflected by the aluminum shielding layer 11i4, so that the dyeing layer 8.9 can be patterned accurately. Ru.

Note that the wavelength of the electromagnetic waves absorbed by the polymer resin film 5 should be determined depending on the exposure means used.

[Effects of the Invention] As explained above, the present invention has a coating formed on an aluminum light-shielding film that absorbs electromagnetic waves at the wavelength of the exposure light source used when patterning a photosensitive resist. According to the invention, defects such as parts of the color filter formed on the light-shielding film missing or protruding onto other cells are eliminated. Therefore, according to the invention, there is no color unevenness and brown color reproducibility is achieved. A good color solid-state image sensor can be provided.

[Brief explanation of drawings]

FIG. 1(f) is a sectional view showing one embodiment of the present invention.
1(a) to 1(e) are cross-sectional views of a chip for explaining the manufacturing process thereof, and FIG. 2 is a cross-sectional view showing a conventional example. 1... Semiconductor substrate, 2... Light receiving section, 3...
・Passivation film, 4... Aluminum light-shielding film, 5... Polymer resin film containing yellow dyeing 4, 6
... Water-soluble resist, 7... Color mixing prevention layer,
8...Cyan dyed layer, 9...Yellow dyed layer.

Claims (1)

[Claims] a semiconductor substrate in which a plurality of photoelectric conversion regions are formed in a surface region; an aluminum light-shielding film having openings on the plurality of photoelectric conversion regions formed on the semiconductor substrate via an insulating film; and the aluminum A coating that absorbs electromagnetic waves of specific wavelengths such as ultraviolet rays or lower is formed on the light-shielding film, and a color filter layer is formed on top of the coating to cover a predetermined photoelectric conversion area via a transparent polymer resin film. A color solid-state image sensor.