JPH0831583B2 - Method for forming color layers of multiple colors for solid-state imaging device - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a color layer on each corresponding light receiving part when manufacturing a color solid-state imaging device.

[Prior art]

Generally, when manufacturing a color solid-state imaging device, a pattern mask is used to form a color layer in each light receiving portion, and as a pattern mask alignment means, for example, the method shown in FIG. 4 is used. Has been done. In the figure, reference numeral 1 is a substrate of a solid-state image sensor, which substrate is made of a fragile material such as silicon or glass, and a large number of light receiving portions 2 are formed on the upper surface thereof, and a plurality of alignments for alignment are provided. Mark 3 is given. Then, a color resist layer 4 is formed on the substrate 1, and when the color resist layer is exposed and developed corresponding to the light receiving portion 2, it is necessary to accurately align the color resist layer with a pattern mask 5. . For that purpose, the alignment is performed using the alignment mark 3 as a reference, and an optical system detecting means 7 is used to detect the reference alignment mark 3. The detection means 7 of this optical system is the transmission part 6 of the pattern mask 5.
Through the illumination of the alignment mark 3,
That is, epi-illumination is applied, the position is searched, and alignment is performed.

[Problems to be Solved by the Invention]

However, when the epi-illumination by the detecting means 7 is dyed in green and the color resist layer 4 is dyed in red, for example, the green spectrum of the epi-illumination is the curve of (a) shown in FIG. 5 (A). This is the range, and the red spectrum of the color resist layer 4 becomes the curve (B) shown in FIG. 5 (B). Therefore, when the alignment mark 3 is observed by epi-illumination through the red color resist layer 4 to attempt alignment, the illumination light is attenuated in the overlapping region (hatched portion) of the two spectra due to the difference in the spectra. This means that the alignment mark 3 can be observed only within the range of the curve of the spectrum (c) of the reflected light shown in FIG. 5 (C). Therefore, under the constant observation illumination in the conventional example, depending on the type of color resist, the observation illumination is significantly attenuated and the visibility of the alignment mark is poor, and it is the actual situation that the alignment cannot be performed sufficiently. There is a problem that must be solved to improve the visibility of and to perform accurate alignment.

[Means for Solving the Problems]

As a specific means for solving the problems of the conventional example, the present invention provides a substrate of a solid-state imaging device having a large number of light receiving parts and a plurality of alignment marks with a pre-colored color resist layer. A pattern mask is overlaid on the resist layer, and irradiation light is radiated from the pattern mask to observe the reflected light from the alignment mark to align the pattern mask, and then the color resist layer is exposed and developed to correspond to the light receiving portion. In the method of forming a color layer of a plurality of colors for a solid-state image pickup device, in which the step of forming a color layer is repeated for each color of the color resist layer, the same color as that of the color resist layer is provided as the illumination light. By using the emission color of, since the spectrum is almost the same, the attenuation of reflected light is eliminated and the visibility of the alignment mark is improved. That.

【Example】

Next, the method of the present invention will be described in detail with reference to the illustrated explanatory drawings. To facilitate understanding, the same parts as those in the conventional example will be described with the same reference numerals. In FIGS. 1 and 2, on a substrate 1 of a solid-state image sensor formed of a fragile material such as silicon or glass, a plurality of light receiving portions 2 are formed in an aligned state on the upper surface thereof, and the light receiving portions are formed. Alignment mark 3 for alignment at a position off
Are provided in plural. On the substrate 1 having such a structure, color layers of three primary colors are sequentially formed in an appropriate arrangement corresponding to the light receiving section 2, and a color image pickup device is formed. The alignment mark 3 is required to form the color layer corresponding to the light receiving portion 2. That is, the first color resist layer 4 on the substrate 1
Is formed, and when the color resist layer is exposed and developed corresponding to the light receiving portion 2, accurate alignment is performed using the pattern mask 5. In this case, the overall alignment is performed with the alignment mark 3 as a reference, and the optical system detecting means 7 is used to detect the reference alignment mark 3, and this optical system detection is performed. The means 7 is the transmission part 6 of the pattern mask 5.
Through this, the alignment mark 3 is irradiated with epi-illumination, and as shown in FIG. 2, its position is searched and the alignment is performed. If the color resist layer 4 for the first color is dyed red and exposed and developed, for example, the color resist layer 4 must be removed from all parts other than the light receiving portion 2 corresponding to the red color layer. . Therefore, the pattern of the pattern mask 5 must exactly match the pattern of the solid-state image sensor. Therefore, the position of the alignment mark 3 is searched by the detecting means 7 to perform the alignment, but the alignment mark 3 must be clearly visible in the search and the alignment. Therefore, it was discovered that the visibility is remarkably improved by matching the illumination color of the epi-illumination from the detection means 7, that is, the illumination color of the observation illumination with the color of the dyeing of the color resist layer 4. That is, when the color resist layer 4 is dyed red,
When the illumination light of the epi-illumination from the detection means 7 is changed to red, the spectrum of the red illumination light becomes as shown by the curve (d) as shown in FIG. 3 (A), which is shown in FIG. (B)
Looking at the figure, the curve is approximately similar to the curve (b) of the spectrum of the color resist layer 4 dyed in the similar color red. Therefore, since the spectra of both are substantially the same, as shown in FIG. 3 (C), the illumination light of the epi-illumination is reflected with almost no attenuation, and the reflected light spectrum curve (e) The alignment mark 3 can be visually recognized in the range, and the search and the alignment work can be accurately and easily performed. In addition, dyeing of the color resist layer is another color,
For example, if the color is green, the illumination light is changed to green, and if the color is blue, the visibility of the alignment mark is improved similarly to the above. Therefore, the color of the illumination light may be changed depending on the pattern mask used.

【The invention's effect】

As described above, according to the method of forming a color layer of a plurality of colors in the solid-state image sensor according to the present invention, the substrate of the solid-state image sensor having a large number of light receiving parts and a plurality of alignment marks is pre-colored. Providing a color resist layer, overlaying a pattern mask on this color resist layer, irradiating with irradiation light, observing the reflected light from the alignment mark to align the pattern mask, and then exposing and developing the color resist layer. Then, the step of forming the color layer corresponding to the light receiving portion is repeated for each color of the color resist layer, and in the method of forming the color layers of a plurality of colors for the solid-state imaging device, the illumination light is the Since the luminescent color similar to this color is used according to the color, the alignment mark is searched and aligned by the detecting means. In the above, by using the emission color of the same system as the dyeing of the color resist layer as the observation illumination light of the detecting means, when the alignment mark is seen through the colored color resist layer, the spectrum is almost the same, so that the transmission and The attenuation of the reflected light is eliminated, the visibility of the alignment mark is improved, and the excellent effect that accurate alignment can be easily performed is achieved.

[Brief description of drawings]

FIG. 1 is an explanatory view for searching an alignment mark in the present invention, FIG. 2 is a plan view of an alignment mark portion searched by the method, and FIGS. 3 (A) to 3 (C).
FIG. 4 is a spectrum graph for supporting the theory of the present invention, FIG. 4 is an explanatory view showing the alignment method in the conventional example, and FIGS. 5 (A) to (C) show the actual conditions of the search in the conventional example. It is a graph of a spectrum. 1 ... Substrate, 2 ... Light receiving part 3 ... Alignment mark 4 ... Color resist layer 5 ... Pattern mask, 6 ... Transmission part 7 ... Optical system detecting means

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsumi Yamamoto 1-5-1 Taito, Taito-ku, Tokyo Within Toppan Printing Co., Ltd. (56) References JP-A-59-104162 (JP, A) 54-99577 (JP, U)

Claims (1)

[Claims] 1. A colored resist layer, which is colored in advance, is provided on a substrate of a solid-state imaging device having a large number of light receiving parts and a plurality of alignment marks, and a pattern mask is superposed on the colored resist layer, The step of irradiating the irradiation light and observing the reflected light from the alignment mark to align the pattern mask, and then exposing and developing the color resist layer to form the color layer corresponding to the light receiving part is performed. A method of forming a color layer of a plurality of colors for a solid-state image sensor, which is repeated for each color, characterized in that, as the illumination light, an emission color of a similar color to the color of the provided color resist layer is used. A method for forming color layers of a plurality of colors on a solid-state image sensor.