JPH01117059A - Image sensor - Google Patents

Abstract

PURPOSE:To decrease capacitive coupling and leakage of current between discrete electrodes, by interposing a semiconductor, thin film between discrete electrodes arranged on an insulating substrate and a common electrode while covering interconnections of the discrete electrodes with said semiconductor thin film. CONSTITUTION:Following to washing an insulating substrate 1, a Cr or Al film is deposited all over the substrate 1 and is patterned by PEP to form discrete electrode 3s and a conductor electrode 25. Then a semiconductor thin film 21 is deposited by the plasma CVD process and slits are formed by PEP to separate the same between interconnections 7 of the discrete electrodes 3. Further, the semiconductor film 21 is patterned into predetermined configuations so as not to make contact with the conductor electrode 25. Subsequently, a transparent conductive film 23 is deposited and excessive parts thereof are removed along the ends of pixel electrodes 9 so as to prevent the image sensor from reading unrequired data.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to an image sensor, and more particularly to a contact type image sensor that can read image information etc. by being brought close to a document or the like.

(Conventional technology) Conventionally, image sensors that use a semiconductor thin film for the photosensitive part,
For example, the one described in Japanese Unexamined Patent Publication No. 100866/1986 is known.

As shown in FIG. 3, this image sensor has an insulating substrate 1
Individual electrodes 3 having pads 5, wiring portions 7, and pixel electrodes 9 are arranged in a line on top, and the individual electrodes 3 except for the pads 5 are covered with a semiconductor thin film 11. Problem) In the image sensor described above, if the transparent conductive film covers a portion of the individual electrode other than the pixel electrode, that portion also becomes the pixel electrode, and unneeded information is read. Therefore, it is necessary to remove the excess transparent conductive film by etching, but this may corrode the very fine individual electrode wiring portions. Therefore, process stability by protecting the wiring part,
Wiring parts are covered with a semiconductor thin film to improve environmental resistance during general use, but since the semiconductor thin film is also interposed between wiring parts, capacitive coupling and minute current leakage occur between adjacent wiring parts. exists.

Therefore, the separation of signal currents between the individual electrodes is incomplete, resulting in a problem of lowering the resolution of the image sensor.

The present invention has a simple configuration like conventional image sensors, has excellent process stability and environmental resistance, and improves resolution by minimizing capacitive coupling between adjacent individual electrodes and minute current leakage. The purpose is to provide an image sensor with improved performance.

[Structure of the invention]

(Means for solving the problem) A semiconductor thin film is interposed between the individual electrodes and a common electrode arranged on an insulating substrate, and the semiconductor thin film extends the wiring part of the individual electrodes along the individual electrodes except for the pads. Create a structure that covers the shape.

(Function) Since the wiring part of the individual electrodes is covered and protected by a semiconductor thin film, the device configured in this way has the same process stability and environmental resistance as conventional image sensors, and also has In addition, since the semiconductor thin film is separated between the wiring portions of adjacent individual electrodes, it is possible to minimize capacitive coupling and minute current leakage between adjacent individual electrodes, thereby improving resolution.

(Example) The present invention will be described below with reference to drawings showing embodiments.

FIG. 1 shows the configuration of an image sensor according to a first embodiment of the present invention, in which (a) is a plan view and (b) is an A-A
'This is a cross-sectional view. In FIG. 1, Cr is deposited on an insulating substrate 1.
Alternatively, a plurality of individual electrodes 3 formed of A4 or the like are arranged along the longitudinal direction of the insulating substrate 1, and the individual electrodes 3 are connected to the pixel electrode 9, the wiring section 7 for guiding image signals, and the driving integrated circuit element. It is composed of pads 5 for connection. Further, on the insulating substrate 1, a conductor electrode 25 is provided corresponding to the pixel electrode 9. B-5i on the individual electrode 3
:H.

Alternatively, a semiconductor thin film 21 made of a-5i: H/a SiC: H or the like and formed in a stripe shape is deposited to cover the area excluding the pad 5, and between the wiring parts 7 of the adjacent individual electrodes 3. It is separated into slit shapes and covers the individual electrodes along the wiring section 7. Further, a transparent conductive film 23 such as ITO is formed on the semiconductor thin film 21 and the conductive electrode 25.

Since the transparent conductive film 23 has a high electrical resistance, it is connected to an external circuit via a conductive electrode 25 having a low electrical resistance. In this embodiment, the transparent conductive film 23 and the conductive electrode 25 are collectively referred to as a common electrode 2f.

Next, an example of the manufacturing process will be briefly described. First, after cleaning the insulating substrate 1, a Cr or A2 film is deposited on the entire surface of the insulating substrate 1 by vapor deposition, and the film is patterned by PEP to form the individual electrodes 3 and the conductor electrodes 25. Next, a semiconductor thin film 21 is deposited by plasma CVD method, and PE
The wiring portions 7 of the individual electrodes are separated into slits by P, and further patterned into a predetermined shape so as not to contact the conductor electrodes 25.

Next, a transparent conductive film 23 is deposited, and the excess portion is removed by etching along the end of the pixel electrode 9 on the wiring portion 7 side so as not to read unnecessary information.

In the image sensor according to the present invention configured in this way, the individual electrodes 3 are connected to the semiconductor thin film 21 as in the conventional case.
Since it is coated with , the wiring portion 7 can be protected when the transparent conductive film 23 is etched, and environmental resistance such as corrosion resistance can also be ensured.

In addition to the embodiments described above, not only the wiring portion 7 of the individual electrode 3 but also the pixel electrode 9 may be covered with each individual electrode 3 in a manner that it is separated from the adjacent individual electrode. In this case, in terms of environmental resistance, the same effects as in the above embodiment can be obtained, and leakage between the electrodes of the negative layer can be reduced.

FIG. 2 shows the configuration of an image sensor according to a second embodiment of the present invention, in which (a) is a plan view and (b) is a sectional view taken along line BB'. In FIG. 2, a plurality of individual electrodes 3 consisting of pads 5 and wiring portions 7 arranged in a line and a common electrode 27 are formed on an insulating substrate 1, and a semiconductor thin film 21 is separated into slits from above. The individual electrode 3 and the common power 27
The film is deposited along the individual electrodes 3 with the pads 5 removed. In this case as well, as in the first embodiment, there is an effect of suppressing capacitive coupling between adjacent individual electrodes and minute current leakage, and an AQ of
When used, it has particularly excellent moisture resistance and environmental resistance.

In each of the embodiments described above, the wiring portion and the pad have different shapes, but the end portion of the wiring portion may be used as the pad as it is.

〔Effect of the invention〕

As detailed above, according to the image sensor of the present invention,
High resolution can be obtained by minimizing capacitive coupling between adjacent individual electrodes and microcurrent leakage while ensuring process stability and environmental resistance.

[Brief explanation of the drawing]

FIG. 1 shows an image sensor according to a first embodiment of the present invention, in which (a) is a plan view and (b) is a sectional view taken along the line AA';
FIG. 2 shows an image sensor according to a second embodiment of the present invention, in which (a) is a plan view and (b) is a sectional view taken along line B-B'. Further, FIG. 3 is a plan view showing a conventional image sensor. 1... Insulating substrate 11.21... Semiconductor thin film 3... Individual electrode 13.23... Transparent conductive film 5... Pad 15, 25... Conductor electrode 7... Wiring part 27. ...Common electrode 9
...Pixel electrode representative Patent attorney Nori Chika Yudo Kikuo Takehana S, Nozomi 1F (a)

Claims (1)

[Scope of Claims] An insulating substrate, an individual electrode having a plurality of pads and wiring portions arranged on the insulating substrate, a common electrode arranged on the insulating substrate, and a plurality of individual electrodes arranged on the insulating substrate. and a semiconductor film interposed between the common electrode and covering the individual electrode along the wiring part except for the pad part of the individual electrode.