JPS6030173A - Color solid-state image pickup element - Google Patents

Abstract

PURPOSE:To improve positioning precision, to enhance resolution, and to enable to form a color solid-state image pickup element in a fine pattern by a method wherein color filter layers and photoelectric conversion parts are formed in a selfaligning construction. CONSTITUTION:The pattern of photoelectric conversion parts 1 is formed on a semiconductor substrate 5, aluminum is evaporated on the whole surface interposing an insulating film 6 between them, optically shielding aluminum electrodes 4 are left using a photo resist film 9, and casein layers 10 to be used for filter layers are formed on the whole surface. The photo resist layer 9 is removed, dyeing is performed selectively using a photo resist film 11, and color dyed layers 8 are formed. Dyeing is repeated to form a color dyed layer 7. Because the device is formed in a selfaligning construction using the photo resist film 9 used at electrodes 4 formation time also at dyed layers 7, 8 formation time, positioning can be attained automatically, and widths of the electrodes 4 can be made small.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color homogeneous imaging device with high resolution.

In general, unlike conventional color image pickup tubes, color solid-state fj# and Tsuka devices require accurate relative alignment of the photoelectric conversion section formed on the semiconductor substrate and the color filter. If this positional accuracy is poor, color shift will occur.

This causes problems such as color mixing. On the other hand, even in recent color solid-state imaging devices, the water absorption of higher resolution is strong.

With advances in semiconductor technology, fine patterning has become possible. Along with this fine patterning, precision in the relative position of the photoelectric conversion section and the power filter is also required.

Next, a conventional color solid-state image sensor will be explained.

FIG. 1 shows a partial plan view of a color solid-state image sensor using a conventional charge-coupled device. This color solid-state image sensor includes a photoelectric conversion section 1 and a shift register 2 that transfers signal charges.
and a transfer section 3 that transfers the charges generated in the photoelectric conversion section 1 to the shift register 2, forming one pixel, and these pixels are arranged in a matrix. Here, predetermined color filters (7, 8) are arranged on each photoelectric conversion unit 1 as an image sensor for force 2-. In this figure, G(
Green) shows an example of the most commonly used green checkerboard arrangement in which B (blue) and R (red) are arranged symmetrically in the G gap.

The shaded area outside the photoelectric conversion section 1 in this figure is an aluminum (AA) electrode 4 for a light shield.

FIG. 2 shows a sectional view taken along the dashed line AA' in FIG. In this image sensor, a photoelectric conversion section 1 is first formed on the surface of a semiconductor substrate 5, and a green (G) color filter layer 7 and a red (R) color filter layer 8 are formed with an insulating film 6 interposed therebetween. The patterns of these G and R color filter layers 7.8 are aligned with respect to the light shielding At electrode 4. In this case, the color filter layer 8 is formed on the shielding electrode 4, and the color filter layer 7 is further formed on this color filter layer 8, so that the alignment accuracy deteriorates. That is, in this structure.

The pattern alignment of the mascara filter layer 8 is carried out.
This alignment becomes difficult due to unevenness on the semiconductor substrate 5. Next, the filter layer 70 and 1 are all aligned, but in this case, since the unevenness of the filter layer 8 is also added, the accuracy becomes significantly worse.

The distance between the end of the filter layer (7, 8) and the other photoelectric conversion part l in this alignment depends on the thickness of the filter layer (7, 8), but excludes all influences such as refraction of t. 1 μm for
A certain amount of leeway is required. Considering these points, in the current structure, the width of the light shield electrode 4 is at least 4 to 5 mm.
The center must be about μm. However, in future color high-resolution solid-state imaging devices, 1l-1, fine patterning is required, so the width of the shield electrode 4 is 1 to 2μ.
It is thought that approximately 100 m will be required.

An object of the present invention is to provide a color solid-state image pickup device that can meet such demands, has good alignment accuracy, and has a fine pattern with high resolution.

The structure of the present invention is such that a plurality of pixels each consisting of a pair of a photoelectric conversion section and a charge transfer section that transfers charges generated in the photoelectric conversion section are arranged in a matrix on a semiconductor substrate, and each of the photoelectric conversion sections The color solid-state image sensing device is provided with a color filter layer on which a predetermined wavelength is completely transmitted, each of which is characterized in that the color filter layer and the photoelectric conversion part have a self-aligned structure.

The present invention will be explained in detail below with reference to the drawings.

FIGS. 3(a) to 3(f) are cross-sectional views showing the steps of manufacturing the sidetone according to the present invention. FIG. 3(a) is a cross-sectional view before formation of a light shielding electrode in the manufacturing process of a solid-state imaging device, in which a pattern of a photoelectric conversion section 1 is formed on a semiconductor substrate 5, and an insulating film 6 is formed on this. Indicates the condition. next,
Aluminum (At) is deposited on the entire surface, and the entire photoresist film 9 is used to selectively remove the photoelectric conversion part 1, leaving the light shielding aluminum electrode 4 (FIG. 3(b)).
. Next, when the casein layer 10 used as a filter layer is formed on the entire surface (FIG. 3(C)), the level difference between the photoelectric conversion part 1 and the optical shield layer is largely separated, or the photoresist layer 9 and the optical A thin layer remains on the side of the aluminum shield.

Next, when the photoresist layer 9 is removed, the casein on the photoresist is also removed at the same time, so that casein is formed only in the photoelectric conversion region 1 where it is needed (Fig. 3(d)
)). Next, using 11 photoresist films, selective dyeing is performed to form the entire color dyeing layer 8 (FIG. 3(e)).

Thereafter, color dyeing layers 7.8 are formed by repeating the required number of dyeings, and the imaging device is completed.

Here, since the dyed casein in the present invention is self-aligned with the photoelectric conversion part, color mixing due to light refraction and rotation by the conventional dyed layer on the aluminum for the light shield does not occur. do not have. In the present invention, since the self-aligning structure used when forming the entire dyed layer (7, 8) of the photoresist film 9 when forming the electrodes 4 is applied, automatic alignment is possible.
Therefore, it is fully applicable to the case where the width of the light shielding electrode 4 is 1 μm.

Although the present invention has been described above using a charge-coupled device as an example, it is also possible to use an MO8 type sensor.

The present invention provides light 't(1
! .

The present invention is characterized in that the conversion portion and the color dyeing layer are formed in self-alignment, and is applicable to all color solid-state imaging devices having such a structure.

[Brief explanation of the drawing]

Fig. 1 is a partial plan view of a color solid-state image sensor, Fig. 2 is a sectional view taken along the line AA' in Fig. 1, and Fig. 3 (al to (f)).
1A and 1B are cross-sectional views showing an example of the present invention in the order of manufacturing steps. In the figure, 1: light weight conversion section, 2: charge transfer register section. 3...Transfer gate section, 4...
Light shield odoresist film, 10... casein layer. Agent Patent Attorney Uchihara iL /'” 'l:: □
``'・ゞ、'' ノ゛・、−１: District 7, Figure 2

Claims (1)

[Scope of Claims] One pixel consisting of a pair of a photoelectric conversion section and a charge transfer section that transfers charges generated in the photoelectric conversion section is arranged in a matrix on a semiconductor substrate, and on each of the photoelectric conversion sections In a color solid-state image sensor in which color filters each transmitting a predetermined wavelength are provided. A color solid-state image sensor, wherein the Cassie filter layer and the photoelectric conversion section have a self-aligned structure.