JPS62144354A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To prevent the invasion of stray light to the surface of a photoelectric conversion element, and to improve the damp-proofing of a solid-state image pickup device by forming a polyimide layer as a passivation layer and shaping an amorphous silicon layer or an amorphous silicon carbide layer on the polyimide layer. CONSTITUTION:In a solid-state image pickup device in which a plurality of photoelectric conversion elements constituted of photoconductive thin-films 103 are arranged on a transparent insulating substrate 101, a polyimide layer 105 is formed as a passivation layer, and an amorphous silicon layer or an amorphous silicon carbide layer 106 is shaped onto the polyimide layer 105. Consequently,the scattering intensity of non-imaging beams can be attenuated, and the dispersion of outputs among a plurality of the photoelectric conversion elements can be reduced. The damp-proofing of the solid-state image pickup device is improved because moisture does not penetrate the amorphous silicon carbide layer, and the polyimide layer and the amorphous silicon layer are laminated one upon another, thus enhancing both damp-proofing and ion resistance.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a solid-state imaging device.

[Summary of the invention]

The present invention provides a substrate-side light incident type solid-state imaging device in which a plurality of photoelectric conversion elements made of photoconductive thin films are arranged on a transparent insulating substrate, in which a polyimide layer is formed as a passivation layer, and a polyimide layer is formed on the polyimide layer. By forming an amorphous silicon layer or an amorphous silicon carbide layer on the photoelectric conversion element surface, non-imaging light (stray light) incident on the photoelectric conversion element surface can be reduced and water and ions can be prevented from entering the element surface. This makes it possible to prevent this at the same time.

[Conventional technology]

Regarding conventional solid-state imaging devices, Proceedings of the 16th Annual Body Element Conference (1984) p. 560 Fig.

As shown in Figure 2, the passivation layer was only one layer of polyimide. (Figure 2) [Problems and objects to be solved by the invention] Many organic thin films such as polyimide are transparent. Therefore, when transparent polyimide is used as a passivation film, as shown in FIG. 6, a polyimide layer 305f! : Stray light 60 through
6 is incident on the photoelectric conversion element surface. As a result, output variations occur among the plurality of photoelectric conversion elements.

Additionally, although organic thin films such as polyimide generally do not allow ions to pass through, they are sensitive to moisture and lack moisture resistance.

For this reason, if a conventional solid-state imaging device is left in a high-temperature, high-humidity atmosphere, the leakage current of the photoelectric conversion element will increase due to lack of moisture resistance.

Conventional solid-state imaging devices have the above two problems. The present invention solves the above problems, and its purpose is to prevent stray light from entering the surface of a photoelectric conversion element and to improve the moisture resistance of a solid-state imaging device.

[Means for solving problems]

The solid-state imaging device of the present invention is a substrate-side light incident type solid-state imaging device in which a plurality of photoelectric conversion elements each made of a photoconductive thin film are arranged on a transparent insulating substrate, and a polyimide layer is formed as a passivation layer. A feature is that an amorphous silicon layer or an amorphous silicon carbide layer is formed on the polyimide layer.

〔Example〕

FIG. 1 shows a sectional view of the solid-state imaging device of the present invention.

101 is a transparent insulating substrate, 102 is a lower transparent electrode, 106
is an amorphous semiconductor layer, 104 is an upper electrode, and 102.10
3,104 form a photoelectric conversion element. 105 is a polyimide layer as a bathylene layer. 106 is amorphous silicon, amorphous silicon carbide, or a full stack of both.

The details will be explained below, following the steps.

(FIG. 4). First, a quartz substrate is used as a transparent insulating substrate 401, and an ITO film 402 as a lower transparent electrode is sputtered thereon and photo-etched. Next, the amorphous semiconductor N405-
It is formed by a 1z plasma CVD method and photoetched. Next, the Al-8i-(:'u layer 404i) of the upper electrode is sputtered and photoetched (FIG. 4-(a)).

On the element surface thus created, polyimide 405 as a passivation film is spin-coded and pad portions are patterned (FIG. 4-(b)).

Finally, amorphous (carbide) silicon 406 is formed on this polyimide layer by plasma CVD, and a pad portion is patterned (FIG. 4-(C)). Here, an amorphous silicon carbide layer of about 10oOA is formed on the polyimide layer,
On top of this, an amorphous silicon layer of about 1 μm was formed, and finally, 100 m of amorphous silicon carbide was again formed. That is,
It has a three-layer structure of a-8iz/a-8i/a-8iC.

In the solid-state imaging device of the present invention completed through the above-mentioned steps, since the intensity of the non-imaging light 507 is attenuated through the two layers of amorphous silicon, scattering of the non-imaging light is a cause. happen. Variations in output among a plurality of photoelectric conversion elements can be suppressed.

Furthermore, since the amorphous silicon layer does not allow moisture to pass through, the moisture resistance of the solid-state imaging device is improved. By stacking the polyimide layer and the amorphous silicon layer, both the wettability and the ionicity are improved.

Although a six-layer structure has been described above as an example of the structure of amorphous silicon, the structure is not limited to a three-layer structure. Since the amorphous (carbide) silicon layer is formed using the plasma CVD method, it is extremely easy to change the film structure to a single layer or multilayer structure, or to a different film thickness. Similar effects can be expected.

〔Effect of the invention〕

The solid-state imaging device of the present invention can attenuate the scattering intensity of non-imaging light by forming an amorphous silicon layer or an amorphous silicon carbide layer on the polyimide layer of the passivation layer, It was possible to reduce the output variation among a plurality of photoelectric conversion elements from the conventional ±4 inch to ±2%.

Furthermore, when a conventional solid-state imaging device is left in an environment with a temperature of 60% and a humidity of 90% for 20 hours, the dark output increases by about 30 mV, but with the solid-state imaging device of the present invention, the dark output does not increase under the same conditions. Moisture resistance was significantly improved.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a solid-state imaging device of the present invention, Fig. 2 is a sectional view of a conventional solid-state imaging device, and Fig. 5-mld 101...
...Transparent insulating substrate 102...Lower transparent electrode 106...Amorphous semiconductor layer 104...Upper electrode 105...Polyimide layer 106... ...Amorphous (carbide) silicon layer 201.
...Transparent insulating substrate 202...Lower transparent electrode 203...Amorphous semiconductor layer 204...Upper electrode 205...Polyimide layer 301... ...Transparent insulating substrate 302...Lower transparent electrode 305...Amorphous semiconductor layer 304...Upper electrode 305...Polyimide layer 306 ...Non-imaging optical path 401 ...Transparent insulating substrate 402 ...Lower transparent electrode 403 ...Amorphous semiconductor layer 404 ... Upper electrode 405 ... polyimide layer 406 ... amorphous (carbide) silicon Figure 2 Shiro Town 11α change 4L to II Koj complaint b1 elephant device tzeha 1 to 4t
Kagoi & Usu, Hikaru's poem 3rd figure 1'' 14th rest 4A shii s straight, 1μ road, knee 1 wato] Figure 4

Claims (1)

[Claims] In a solid-state imaging device in which a plurality of photoelectron conversion elements each made of a photoconductive thin film are arranged on a transparent insulating substrate, a polyimide layer is formed as a passivation layer, and an amorphous silicon layer or an amorphous silicon layer is formed on the polyimide layer. A solid-state imaging device characterized by forming a silicon carbide layer.