JPH01149459A - Solid-state color image pickup element - Google Patents

Abstract

PURPOSE:To augment a color filter in its resolution feature by a method wherein a flattened layer is caused to contain a yellow dye in a solidstate color image pickup element wherein photoelectric conversion-capable photodetecting sections are provided on a semiconductor substrate and color filters are located through the intermediary of a flattening layer at photodetecting spots corresponding to the photodetecting sections. CONSTITUTION:A color mixing preventing layer 6 is formed on a flattened layer 5 containing a yellow dye built on an aluminum light-stopping film 4. Formed together with the color mixing preventing layer 6 on the flattened layer 5 are a magenta dye layer 7, a cyanine dye layer 8, and a yellow dye layer 9. The yellow dye for the flattened layer 5 is so selected as to absorb 'g' rays (436nm) emitted by a stepper light source and to transmit far ultraviolet rays (250nm). This choice prevents random reflection that may otherwise be caused by the aluminum light-stopping layer 5 in a color filter patterning process. Far ultraviolet rays are applied to prevent the exposure time from being too long in the formation of through-holes in the flattened layer 5. A transparent high-polymer resin film is used for the flattening layer 5 and for the color mixing prevent layer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color solid-state image sensor, and more particularly to a color solid-state image sensor with reduced color unevenness and improved color reproducibility.

[Conventional technology]

In general, a color solid-state image sensor separates light incident through a camera optical system into red, blue, green, or their complementary colors, and extracts the color signal as an electrical signal.

Conventionally, this type of color solid-state imaging device has a structure as shown in the plan view of FIG. 2 and the AA/cross-sectional view of FIG. 3. As shown in FIG. 3, the solid-state image sensing device has a light-receiving section 2 that performs photoelectric conversion of incident metal on the surface of a semiconductor substrate 1.
An aluminum light-shielding film 4 is provided on the light-receiving portion 2 via an interlayer film 3 to define an aperture corresponding to the amount of incident light.

On top of that is a color mixture prevention layer 6 (
The magenta dyeing layer 7t is patterned into a predetermined shape and dyed through a transparent polymer resin film such as PMMA, PGMA, or GCM. As the chromosomal matrix of this dyeing layer 7, a protein such as gelatin or casein glue, or a water-soluble resist obtained by adding dichromate to polyvinyl alcohol is used. Further, a cyan dyed layer 8 is provided via a color mixture prevention layer 6, a yellow dyed layer 9 is similarly provided via a color mixture prevention layer 6, and the uppermost layer also has a color mixture prevention layer 6.

In this solid-state imaging device, a magenta dye layer 7 (Mg), a cyan dye layer 8 (Cy), and a yellow dye layer 9 (Ye) are arranged in a fixed pattern as shown in the plan view of FIG.

[Problem that the invention seeks to solve]

In the above-mentioned conventional color solid-state image sensor, the color filter is patterned on the aluminum light-shielding film 4 through the color mixture prevention film 6, so that light is diffusely reflected during exposure and the reflected light affects other cells. ! This has the disadvantage that it produces whisker-like images on other cells, resulting in poor resolution. Therefore, there is a drawback that color unevenness occurs on the imaging screen and color reproducibility deteriorates.

An object of the present invention is to eliminate such drawbacks, improve the resolution of color filters, reduce color unevenness as a result, and provide a color solid-state image sensor that has completely improved color reproducibility.

[Means to solve all problems]

The structure of the present invention is a color solid-state image sensor in which a light-receiving section having a photoelectric conversion function is provided on a semiconductor substrate, and a color filter is arranged at a light-receiving position corresponding to the light-receiving section through a smooth layer. It is characterized by including.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a partial cross-sectional view of an embodiment of the present invention, showing a portion corresponding to FIG. 3. FIG. This embodiment is different from that shown in FIG. 3 in that the color mixture prevention layer 6 on the aluminum light-shielding film 4 shown in FIG. 3 is replaced with a smooth layer 5 containing yellow dye. Therefore, on this smooth layer 5, there is a magenta dyed layer 7.
A cyan dyed layer 8 and a yellow dyed layer 9 are formed together with a color mixture prevention layer 6.

The yellow dye used in the smooth layer 5 containing yellow dye on the aluminum light-shielding film 4 absorbs the G-line (436 nm), which is the wavelength of the light source of the stepper, and
50 nm) is used. For this reason,
Diffuse reflection from the aluminum light-shielding film 4 can be suppressed when patterning the color filter, and deep ultraviolet rays are used when forming through-holes in the smooth layer 5, so problems such as a long exposure time do not occur. Note that the same transparent polymer resin film as the color mixture prevention layer 6 is used for the smooth layer 5 containing yellow dye.

〔Effect of the invention〕

As explained above, the present invention has the smooth layer 5 containing yellow dye on the top of the aluminum light-shielding film 4, which reduces diffuse reflection caused by aluminum during patterning of the color filter formed on top of the smooth layer 5, and improves resolution. This has the effect of improving color quality, eliminating whiskers, reducing color unevenness, and improving color reproducibility.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a color solid-state image sensor according to an embodiment of the present invention, FIG. 2 is a plan view of an example of a conventional color solid-state image sensor, and FIG. 3 is a cross-sectional view taken along line A-A in FIG. be. 1... Semiconductor substrate, 2... Light receiving section, 3
......Interlayer film, 4...Aluminum light shielding film, 5...Smooth layer, 6...Color mixture prevention layer, 7...Magenta dyeing Layer 8...Cyan dyed layer, 9...Yellow dyed layer. Agent Patent Attorney Uchi Hara Sound Most 1 Quotation 2 B Figure 3

Claims (2)

[Claims] (1) A light receiving section having a photoelectric conversion function on a semiconductor substrate,
A color solid-state image sensor in which a color filter is disposed at a light-receiving position corresponding to the light-receiving portion through a smooth layer, wherein the smooth layer contains a yellow dye. (2) The color solid-state imaging device according to claim 1, wherein the yellow dye has light absorption in the near ultraviolet region and almost no light absorption in the far ultraviolet region.