JPS6180105A - Direct forming method of color filter - Google Patents

Abstract

PURPOSE:To obtain an image having a good color separation and to prevent a color mixing by coating a writing part with a black metal film after a vapor deposition of Al, and then by continuously etching to form two layers wiring pattern. CONSTITUTION:The wiring part is coated with a Cr film 6 after vapor-depositing an Al film 2 suitable for an electrode. Two layers film composed of the Al film and the Cr film is continuously etched via a photomask processing whereby the Al wiring part 2 always exists under the Cr film 6. As a reflection light in an exposure for forming a color layer 3 is absorbed by the Cr film 6, a formation of an abnormal pattern is prevented, and a desired pattern is formed. According to the titled method, for formation of the abnormal pattern in a color filter is completely prevented, and the color filter suitable for the solid- state image pickup element is directly formed by only coating the black metal film 6 on the Al vapor-deposited film 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for directly forming a color filter for a solid-state image sensor.

(Structure of conventional example and its problems) In recent years, solid-state image sensors have begun to be widely used for consumer and industrial purposes, and the applications of color solid-state image sensors are about to expand. There are two methods for forming color filters used in solid-state imaging devices: an adhesive method and a direct formation method, which are suitable for mass production and can utilize semiconductor processing technology. Since then, the direct formation method has become mainstream. Currently, various methods for directly forming color filters are being studied to develop techniques for forming finer patterns.

FIG. 1 shows a cross section of a solid-state image sensor with a color filter manufactured by a conventional direct forming method. In the figure, l indicates a semiconductor wafer, and 2 indicates an aluminum wiring part of the solid-state image sensor device.

3 shows a color layer of a directly formed color filter. 4
5 indicates a separation layer that separates the color layers of the color filter, and 5 indicates a photodiode.

The color filter color layers on each photodiode of the solid-state imaging device must not overlap irregularly. However, when actually forming a color filter, the shape of each turn may be different from that of the mask due to the influence of reflection from the aluminum surface. In particular, the boundaries between each color layer of a color filter are often provided on aluminum, and as shown in 3 in FIG. 1, the color layer portions protrude from the aluminum due to the influence of reflected light. Since this extra color layer enters the adjacent photodiode section 5, it affects the spectral characteristics of the color solid-state image sensor and induces fatal defects.

(Object of the Invention) The present invention provides a method for directly forming a color filter that eliminates the above-mentioned drawbacks and has good color separation and no color mixture.

(Structure of the Invention) In order to achieve this object, the method of directly forming a color filter of the present invention involves coating with a black metal film after the aluminum vapor deposition process, and forming two-layer wiring/guts by continuous etching. This method attempts to absorb all the light reflected by the aluminum wiring section, which makes it possible to form a color filter pattern on the mask pattern.

(Description of Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a cross-sectional view showing an example of a color solid-state image sensor manufactured by the direct formation method according to the present invention, in which 1 is a semiconductor layer, 2 is an aluminum wiring part, 3 is a color layer of a color filter, and 4 is a color solid-state image sensor made by a direct forming method according to the present invention. 5 is a separation layer of a color layer of a color filter, 5 is a photodiode, and 6 is a chromium film pattern as a black metal film according to the present invention.

The manufacturing method involves first depositing an aluminum film for electrodes, and then depositing a chromium film thereon. The two-layer film of chromium and aluminum is
After going through a photomanuk process, it is continuously etched. At this time, the aluminum wiring portion always exists under the chromium film. Therefore, during exposure to form the color layer 3, the reflected component is absorbed by the chromium [6], so pattern abnormalities can be prevented and a designed pattern can be formed.

Note that in this embodiment, a chromium film is used as an example of a black metal film, but other black metal materials may be used instead of the chromium film.

As described above, the method of directly forming a color filter for solid-state imaging devices according to the present invention can completely prevent abnormal patterns on the color filter by simply adding a black metal film on the aluminum vapor-deposited film, and The practical effects of direct formation of color filters for image sensors are significant.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a solid-state image sensor with a color filter made by a conventional direct forming method, and FIG. 2 is a sectional view of a solid-state image sensor with a color filter made by a direct forming method according to the present invention. ■...Semiconductor wafer, 2...Aluminum wiring part, 3...
- Color layer of color filter, 4... Separation layer of color filter, 5... Photodiode, 6... Chrome film pattern as a black metal pattern.

Claims (1)

[Claims] A method for directly forming a color filter, which comprises coating an aluminum vapor-deposited film for an electrode of a solid-state image sensor with a black metal, and forming a two-layer wiring pattern by continuous etching.