JPH01108767A - Contact type image sensor - Google Patents

Abstract

PURPOSE:To improve the efficiency wherein a reflected light from a manuscript arrives at an image sensor element, by arranging an uneven structure to scatter a manuscript reading light, on a substrate or a light transmitting conducting film of a window to transmit the manuscript reading light, which is adjacent to the inside or the outside of the image sensor element and formed on a conducting film. CONSTITUTION:On a transparent glass substrate 2, an SnO2 film, as a light transmitting conducting film part 3, is formed. As a first laser processing, the film 3 is separated, and a groove 13 is formed by using excimer laser light. Thereon an NIN type semicon ductor film is formed as a photoelectric conversion semiconductor part 4. On the upper surface of the semiconductor part, a molybdenum electrode 5 is formed. As a second laser processing, a groove 14 is dug as far as the glass substrate, by irradiat ing laser light in almost similar manner to the groove 13. Then, on an element, a path window 8 for manuscript reading light is formed by laser processing. At this time, the frequency of laser irradiation is about 1.5 times that of the second laser processing. Therefore, the laser processed groove reaches about midway of the light transmitting conducting film 3, and a recessed part 16 is formed at the same time. By this recessed part 18, the light is scattered, and arrives at elements 16, 17 on both sides of the window, with high efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to the structure of a contact type image sensor used in image scanners, facsimiles, and the like.

(b) Conventional technology Close-contact image sensors are generally classified into the following two structures.One is between the sensor 0ω and the original (1);
This type of device uses a 1-magnification imaging lens θD, for example, as shown in FIG. The reflected light is imaged one-to-one on the sensor surface Om and read. Using this method has the disadvantage that the use of the lens OD increases the size of the image sensor device and increases cost.

The second type is a complete contact type image sensor that does not use a lens between the sensor θω and the document (1).

As shown in FIG. 3, this type of device conventionally uses photolithography technology to provide a light entrance window (8) inside the element (00), and the original (1) is in close contact with the transparent protective film.
) is used to read patterns. An image sensor with this structure does not require an optical system, does not take up space, and has a small number of parts (manufacturing cost can be reduced).

However, this type of image sensor uses the original reading light (
7) does not spread beyond the inside of the passing window (8), causing a problem in that it is difficult for the reflected light (9) from the original to reach the element efficiently.

In particular, as the number of elements per 1 mm increases in order to increase the resolution of image sensors, the width of this passing window (8) will become narrower, and the efficiency with which reflected light (9) will reach will become worse. There was a problem where the

(C) Structure of the Invention The present invention solves the above-mentioned problems. Therefore, in the present invention, a close contact film having a transparent conductive film, a semiconductor film having a photoelectric conversion function, and a conductive film having a light-shielding property on a transparent substrate is provided. In the type image sensor, irregularities for scattering the original reading light are provided on the substrate of the original reading light passing window or the transparent conductive film provided on the conductive film adjacent to the inside or outside of the image sensor element. This is a close-contact image sensor with the following characteristics.

In other words, an uneven shape is formed on the substrate or the transparent conductive film portion of the light passing window (8), and the uneven portion allows the document reading light (7
) to increase the efficiency with which the reflected light (9) from the original reaches the image sensor element.

Further, laser processing can be used to create the device of the present invention, and by using this laser light, at least the light-shielding conductive film portion and the photoelectric conversion semiconductor portion are removed to form a window through which original reading light passes.

At this time, the depth of the removed area can be adjusted by arbitrarily changing the output of the laser beam or the number of times the laser beam is irradiated.

In addition, since the processing uses laser light, Figures 4 (A) to (C)
) As shown in ), it is now possible to provide the reading light passing window (8) at any position with respect to the image sensor element 0ω, which allows more flexibility in the design of the image sensor device. Ta.

The present invention will be explained below with reference to Examples.

[Example 1] FIGS. 1A to 1D show a method for manufacturing an image sensor of the present invention.

A transparent glass substrate (2) is used as the substrate, and a SnO□ film of 0.5 to 0.6 μ-
A film is formed by a known CVD method to a thickness of .

First, as the first laser processing, KrF excimer laser light is used to process S n O! Membrane (3) has a width of 125 μm and an interval of 5
01111, and the length is 100tI11, and the groove side is formed.

On this upper surface, a NIN type amorphous silicon semiconductor is formed to a thickness of about 0.7 .mu.m as a charge conversion semiconductor section (4) by a known plasma CVD method.

The film forming conditions are shown below.

N-type layer Raw material gas PH3/5iHi O,5χ
5SCCMSiH4100χ 11005CC Pressure 0.1Torr High frequency power 13.56MHz 20W Substrate temperature
250°C ■Type layer Raw material gas SiHm 100χ 11
005CCOther conditions were the same as for the N-type layer.A molybdenum electrode (5) of approximately 0.2μ was deposited on the upper surface of the semiconductor portion thus formed by a known sputtering method.
l form.

Next, as a second laser processing step, a similar laser beam is irradiated to approximately the same position as the first laser processing groove side to form a groove 04) having a width of 10 μm up to the glass substrate.

Next, in this embodiment, a passage window (8) for document reading light is provided on the image sensor element by laser processing.

The number of times of laser light irradiation at this time was 1.5 times the number of times of irradiation in the second laser processing step. Therefore, the laser-processed groove is formed using a transparent conductive film (3) that is the base of the NIN type semiconductor (4).
). Therefore, the recess 08) is formed at the same time.

Although this passing window (8) has a width of 50 μm and is linear, it is not limited to this shape, and may have a circular shape as shown in FIG. 4(A). However, in this embodiment In the case of , the beam shape of the laser beam used is 10 μm wide,
Since it has an ultra-flat shape with a length of 100 mm, productivity would have been better if it was processed in a straight line.

Furthermore, the position of the passing window (8) does not need to be on the image sensor element (it only needs to be adjacent to it; that is, the fourth
As shown in Figures (A) to (C), the light (7) passing through the passage window (8) is reflected by the original (1) and the reflected light (9) reaches the image sensor element. Good to have.

Further, in the case of this embodiment, in order to form the passage window (8), the laser-processed groove does not need to stop on the SnO film (3), and may be provided up to the substrate (2).

Finally, a light-shielding epoxy resin (6) for light-shielding the multilayer wiring and the a-3t side surface O0 is printed by screen printing.

In this case, a printed pattern is used in which the grooves (8) are not completely shielded from light. As a result, light incident from the epoxy resin side enters the original (1) through the window (8) SnO and glass, and the reflected light is absorbed by the elements θ and 06) on both sides of the window, corresponding to the reflected light from the original. It can provide bright and dark electrical output.

In particular, due to the recesses 08) provided in the SnO, the light is scattered and reaches the elements 06), 07) on both sides of the window with higher efficiency.

[Example 2] This example corresponds to an element having the structure shown in FIG. 5(A).

In producing an element with this structure, all the same steps as in Example 1 were used up to the second laser step.

In the laser processing to open the next passing window (8), SnO
□Up to the upper semiconductor part (4) was removed to provide a window.

Next, light was irradiated from the molybdenum electrode side using a known laser or photo-CVD method, and a convex portion 09) was provided with a 5ift film on the substrate at a position corresponding to the passage window (8).

This convex portion is not limited to Sin or a film, but any material that transmits light can be used.

[Example 3] This example corresponds to the structure shown in Figure 5 (B).

In this case, the manufacturing method shown in Example 1 is the same up to the second laser processing step.

However, this second laser-processed groove side reaches the glass substrate (2) and the glass substrate (2) is dug to form a recess 0 mark.

In this embodiment, this laser-processed groove ■ is used as a light passage window (8).

(d) Effects With the configuration of the present invention, reflected light from the original can reach the image sensor element more efficiently, making it possible to put a high-resolution image sensor into practical use.

Further, the image sensor of the present invention has a feature that no physical force is applied to the element because the original always comes into contact with the substrate.

Furthermore, when laser processing is used, there is a degree of freedom in which the position of the document reading light passage window can be arbitrarily varied.

[Brief explanation of the drawing]

FIG. 1 shows a process diagram of the method of the invention. FIG. 2 and FIG. 3 show schematic diagrams of conventional devices. FIG. 4 and FIG. 5 show examples of application of the method of the invention. 1... Manuscript 2... Board 3.5・Electrode part 4...Semiconductor section 8... Passing window

Claims (1)

[Scope of Claims] 1. In a contact image sensor having a transparent conductive film, a semiconductor film having a photoelectric conversion function, and a conductive film having a light-shielding property on a transparent substrate, adjacent to the inside or outside of the image sensor element. A contact image sensor characterized in that a substrate of an original reading light passing window provided on a conductive film or a transparent conductive film is provided with irregularities for scattering original reading light. 2. A contact image sensor according to claim 1, characterized in that a concave portion is provided in the passage window portion of the substrate or the transparent conductive film on the document reading light irradiation side. 3. A contact type image sensor according to claim 1, characterized in that a convex portion is provided in the passage window portion of the document side surface of the substrate.