JPS6240784A - Manufacture of photodiode - Google Patents

Abstract

PURPOSE:To accurately and readily manufacture a photodiode by using a photosensitive organic insulating film for an interlayer insulating film, and by forming a contact hole by making an exposure to ultraviolet rays with an amorphous silicon film pattern as a mask for self-alignment with the pattern and the hole. CONSTITUTION:A lower electrode 11 is formed by a transparent SnO2, ITO on a glass substrate 10, and an amorphous silicon film pattern 12 is formed in the prescribed shape thereon. Then, a photosensitive organic resin is coated on the entire surface, baked to form a photosensitive organic insulating film 13, and an ultraviolet ray is then exposed from the substrate 10 side. As a result, since the amorphous silicon absorbs the ultraviolet ray, the ray is emitted only to the other portion to be cured. Then, when it is developed, the film 13 on the film 12 is removed to form a contacting hole 14, and an upper electrode 15 is eventually fored in the hole 14.

Description

[Detailed Description of the Invention] [Summary] A method for manufacturing a photodiode, in which a photosensitive organic insulating film is used as an interlayer insulating film between a lower electrode and an upper electrode that sandwich amorphous silicon, and this is applied to the lower electrode side. After exposing the amorphous silicon to ultraviolet light and removing the photosensitive organic insulating film on the amorphous silicon to form a contact hole, an upper electrode is formed to accurately align the amorphous silicon film pattern and the contact hole. becomes easier.

[Industrial application field]

The present invention relates to a method of manufacturing a photodiode used as a component of an image sensor or the like.

[Conventional technology]

FIG. 2 is a diagram showing an example of a conventional method for manufacturing a photodiode. To explain with a diagram, first, a transparent lower electrode 2 using 5nOz or the like and an amorphous silicon film pattern 3 are formed on a glass substrate 1 as shown in Figure A, and then a photosensitive organic insulating film 4 is formed on the entire surface as shown in Figure B. After coating, a contact hole 6 is formed by exposure using a mask 5 as shown in Fig. C, and finally an upper electrode 7 is formed as shown in Fig. E.

A voltage is applied between the upper electrode 7 and the lower electrode 2, and when light is incident from the glass substrate l side, the lower '1t
The barrier between i2 and the amorphous silicon film pattern 3 is excited, and a current flows between the upper and lower electrodes 2.7, acting as a photodiode.

[Problem that the invention seeks to solve]

The conventional manufacturing method described above has a drawback in that the contact hole 6 is likely to be misaligned due to mask alignment in the step shown in FIG. Especially in a large-area group Fi<230, for example, where many photodiodes are arranged, such as in an image sensor.
Mask alignment in cases such as X 60 +n ) is increasingly difficult.

The present invention was created in view of these points, and an object of the present invention is to provide a method for manufacturing a photodiode that allows easy mask alignment.

[Means for solving problems]

Therefore, in the present invention, there are a step of forming a transparent lower electrode 11 and an amorphous silicon film pattern 12 on the glass substrate 10, a step of coating the entire surface with a photosensitive organic insulating film 13, and a step of forming an amorphous silicon film pattern 12 from the glass substrate 10 side. Photosensitive organic insulating film 13 using silicon film pattern 12 as a mask
The method is characterized by comprising a step of exposing the photosensitive organic insulating film 13 to ultraviolet light, a step of developing the photosensitive organic insulating film 13 to form a contact hole 14, and a step of forming an upper electrode 15 in the contact hole 14.

[For production]

By using a photosensitive organic insulating film as the glabella insulating film and exposing it to ultraviolet light using the amorphous silicon film pattern as a mask to form a contact hole, the amorphous silicon film pattern and the contact hole can be self-aligned, making it possible to accurately and easily It becomes possible to manufacture diodes.

〔Example〕

FIG. 1 is a diagram for explaining the present invention in detail, and a
-e is a diagram showing the process.

In this embodiment, first, as shown in FIG. 1a, a glass substrate 10
Lower electrode 1 is placed on top using transparent SnO□, ITO, etc.
An amorphous silicon film pattern 12 is formed thereon in a predetermined shape. Next, as shown in FIG. 1, a photosensitive organic resin (for example, Photonice, manufactured by Toshi Co., Ltd.) is coated on the entire surface and betatized at 90° C. to form a photosensitive organic insulating film 13. Next, as shown in FIG. 1C, the glass substrate IO side is exposed to ultraviolet light. As a result, since amorphous silicon absorbs ultraviolet rays, only other parts are exposed to ultraviolet rays and are cured. Next, when this is developed, the photosensitive organic insulating film 13 on the amorphous silicon film pattern 12 is removed and a contact hole 14 is formed, as shown in FIG. 1d. Finally, as shown in FIG. 1e, an upper electrode 15 is formed in the contact hole 14.

According to this embodiment, there is no need to align the amorphous silicon film pattern and the mask as in the prior art, and since the contact hole is self-aligned using the amorphous silicon film pattern as a mask, accurate alignment can be achieved.

Therefore, accurate pattern formation is possible even on a large-area substrate such as an image sensor. Further, since an exposure device is not required for exposure and only a mercury lamp is required, costs can be reduced.

〔Effect of the invention〕

As described above, according to the present invention, a photodiode can be manufactured accurately and easily using an extremely simple method, and is extremely useful in practice.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the present invention in detail, and FIG. 2 is a diagram for explaining an example of a conventional method for manufacturing a photodiode. In FIG. 1, 10 is a glass substrate, 11 is a lower electrode, 12 is an amorphous silicon film pattern, 13 is a photosensitive organic insulating film, 14 is a contact hole, and 15 is an upper electrode.

Claims (1)

[Claims] 1. (a) A transparent lower electrode (10) on a glass substrate (10).
1) and a step of forming an amorphous silicon film pattern (12), (b) a step of applying a photosensitive organic insulating film (13) on the entire surface, (c) a step of forming an amorphous silicon film pattern (12) from the glass substrate (10) side. 12) as a mask and a photosensitive organic insulating film (
(d) forming a contact hole (14) by developing the photosensitive organic insulating film (13); (e) forming an upper electrode (15) in the contact hole (14); A method for manufacturing a photodiode, comprising the steps of: