JPS60263565A - Long-sized one-dimensional sensor - Google Patents

Abstract

PURPOSE:To make dispersion in sensor area for each picture element small and to prevent destruction of a photoelectric conversion film by constituting a title sensor so that a beltlike common electrode is not opposed to corner parts of plural individual electrodes and not using the corner parts of individual electrode as sensors. CONSTITUTION:An Al film is formed on a glss substrate 1 by electron beam vapor deposition to a thickness of 3,000Angstrom . A sensor section and its electrode pattern are formed by photolithography to obtain a lower individual electrode 2. The longitudinal width W of the electrode 2 is made to 1.5 times lateral width D. A film of hydrogenated amorphous silicon is formed by a glow discharge process to form a photoconductive conversion film 3. Further, a beltlike common electrode 4, narrower than the width W of a lower individual electrode, is provided in beltlike form not to oppose to right above the corner part of the lower individual electrode 2. By such constitution, the part that does not oppose to the common electrode 4 of the lower individual electrode 2 does not work as a sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Technical Field The present invention relates to a sandwich-type long-dimensional image sensor in which a charge conversion membrane is sandwiched between upper and lower electrodes.

1 Conventional Techniques 1 One-dimensional image sensors are known as document reading elements for facsimile machines, intelligent copying machines, and the like. Conventionally, this type of light receiving sensor uses a one-dimensional solid-state image device (COD or MOS type) to obtain a corresponding image information signal by subjecting an original image to slit exposure and reducing the image.

This -dimensional solid-state image device is manufactured using IC technology and is approximately 30 mm in size, so an optical system with a long optical path must be used to guide the reflected light from the original to the light receiving section. , it becomes difficult to downsize the device. Furthermore, such devices require complex adjustments of the optical system, and
Problems such as a decrease in the amount of light at the periphery of the screen and deterioration in resolution also arise.

In order to improve these problems, a so-called long-dimensional image sensor has been devised, which uses an element button with the same length as the width of the document and closely focuses an image using a fiber lens array. FIG. 3 is a plan view of a conventional sandwich type long-dimensional sensor, and FIG. 4 is a cross-sectional view taken along the line AA' in FIG. 3.

This conventional sensor structure has the following two problems.

(1) In patterning the lower individual electrodes 2 on the glass substrate 1, there is a problem of undercuts during electrode etching, and the undercuts are particularly severe at the four corners a of each lower individual electrode 2. Therefore, the lower individual electrode 2
This causes variations in the pattern dimensions, which causes variations in the sensor area for each pixel, which causes a large change in the sensor output. In each figure, 3 is a charge conversion membrane, and 4 is a strip-shaped common electrode.

(2) When voltage is applied, the electric field concentrates at the four corners a of the lower individual electrode 2, and the charge conversion film 3 is likely to be destroyed.

[Objective of the Invention 1] The present invention was made in order to eliminate various problems of conventional long one-dimensional image sensors, and to prevent dielectric breakdown of the photoelectric conversion film due to concentration of electric field at the electrode end of each pixel. It is an object of the present invention to provide a long-dimensional image sensor that prevents the above problems and reduces output variations of each sensor.

[Configuration of the Invention] In the present invention, in a long-dimensional image sensor,
The strip-shaped common electrode is configured so that it does not face the corners of the plurality of individual electrodes, and the corners of the individual electrodes are used as sensors.
This makes it possible to reduce variations in sensor area for each pixel, and to avoid destruction of the photoelectric conversion film due to electric field concentration of the individual electrodes.

[Embodiment] A plan view of a sensor structure according to an embodiment of the present invention is shown in FIG. 1, and a sectional view taken along the line A-A' is shown in FIG. The lower individual electrodes 2 are formed in a vertically long rectangular shape and are arranged at appropriate intervals in the horizontal direction. A photoelectric conversion film 3 made of an amorphous or polycrystalline semiconductor is formed on the lower individual electrode 2 . Furthermore, a band-shaped common electrode 4 is provided above the common electrode 4, which is narrower than the width W of the lower individual electrode and is provided in a band-like manner so as not to face directly above the corner of the lower individual electrode.

Next, a specific example of the above embodiment will be described. Glass substrate 1
On top of this, AI is deposited to a thickness of approximately 3000 nm by electron beam evaporation. Subsequently, an electrode pattern for the sensor section and its leads is formed using 7-otolithography to form the lower individual electrodes 2. At this time, the lower individual electrode 2 has a vertical width W approximately 1.5 times the horizontal width, and is made into a vertically long rectangle. When producing a sensor with a linearity of 8 pieces/age, the vertical width of the sensor part is 150 μm and the horizontal width is 10 μm (1 μm eave).

Next, in order to form the photoconductive conversion film 3, hydrogenated amorphous silicon is deposited to a thickness of about 1 μm by a glow discharge method.

Subsequently, ITO (In2O2-3
nO2 (5%)) by RF sputtering, approximately 10
A thin film was formed to a thickness of 0.00 mm, and a strip-shaped common electrode pattern with a width of 100 μm was formed directly above the center of the lower individual electrode 2 using 7 otolithography.

By the above method, the long-dimensional image sensor of the present invention can be formed.

With the above configuration, only the part of the lower individual electrode 2 that faces the common electrode 4 acts as a sensor, and the part that does not face does not act as a sensor.

In addition, the individual electrodes are transparent electrodes, and the upper common electrode is a metal electrode (A
A similar effect was obtained even in the case of the structure in which the light is incident from the glass substrate side.

[Effect 1] By employing the configuration described above, the present invention can achieve the following effects.

By not using the corners of individual electrodes as sensors, even if there is an undercut at the corner, the sensor area is not affected, and the variation in sensor output can be reduced from 20% to 50% or less.

By not using the corners of the lower individual electrodes as sensors, electric field concentration at the corners is alleviated, and dielectric breakdown of the charge conversion film is eliminated.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the long-dimensional sensor of the present invention, FIG. 2 is a sectional view taken along the line A-A' in FIG. 1, and FIG. 3 is a plan view of a conventional long-dimensional sensor. Figure 4 is A of Figure 3.
-A' line sectional view. 1... Glass substrate, 2... Lower individual electrode, 3...
Charging conversion membrane, 4... strip-shaped common electrode. Patent Applicant: Sharp Co., Ltd. Agent Patent Attorneys: Ao-Haku and 2 others Figure 1 Figure 2 Figure 3 Δ Figure 4

Claims (1)

[Claims] (1) It has a sandwich-type electrode structure formed at both ends of the upper and lower parts of the photoconductive layer, with the electrode on one side being a strip-shaped common electrode for multiple pixels, and the electrode on the other side being formed for each pixel. In a long-dimensional sensor consisting of individual electrodes in which at least one of the individual electrodes and the strip-shaped common electrode is a transparent electrode, the strip-shaped common electrode does not face a corner that is an end of the individual electrode. A long-dimensional sensor characterized by: