JPH02280385A - Contact sensor and manufacture thereof - Google Patents

Abstract

PURPOSE:To enable the title sensor to be cleaned with acid prior to formation of a photoelectric conversion layer and hence eliminate interlayer short-circuiting between the photoelectric conversion layer and a transparent conduction layer provided on the upper portion of the sensor by employing an acid-resistant material as a first conductor layer upon providing a plurality of strip-shaped separate electrodes as the first conduction layer on a high resistance glass substrate. CONSTITUTION:A plurality of strip-shaped electrodes 2 are formed in parallel to each other on a high resistance glass substrate 1. Highly acid-resistant Cr is available for the electrodes 2, on one ends of which electrodes a photoelectric conversion layer 4 is mounted lying across those electrodes and covered with a transparent conductor layer 5. On the other ends a bonding pad 6 is mounted, and outside the strip-shaped electrodes 2 a common electrode 7 as a U-shaped second conductor layer is formed in parallel to the electrodes 2. The electrodes 2 as a first conductor film are formed only with Cr. Accordingly, acid-washing prior to the formation of the photoelectric conversion layer 4 is assured, whereby any film defect upon the film formation is reduced to prevent the photoelectric conversion layer 4 from being short-circuited with the transparent conductor layer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a contact sensor used in an input section of an image reading device, and a method of manufacturing the same.

(Prior Art) In recent years, contact sensors have been used in input sections of image reading devices such as facsimiles and OCR devices.

Such a contact sensor is made up of a large number of photoelectric conversion elements arranged in a line, and irradiates light from a light source with approximately the same length as the contact sensor onto a document placed close to the contact sensor. The image information of the original is read by receiving reflected light from the original into each of the photoelectric conversion elements described above and photoelectrically converting it.

Hereinafter, a conventional contact sensor will be explained with reference to FIG. 5.

In FIG. 5, in the contact sensor, individual electrodes (2) and bonding pads (2) each made of a first conductive film made of a metal such as Cr/i are arranged on an insulating substrate (ω) made of glass or the like. Moreover, on this insulating substrate ■, a-5
A photoelectric conversion layer (a) such as i is deposited on the pixel component portion of the individual electrode.

A transparent conductive layer 0 such as T, 00, etc. is deposited.

Next, a method for manufacturing the contact sensor shown in FIG. 5 will be described.

This will be explained with reference to FIGS. 6(a) to 6(f).

First, as shown in FIG. 6(a), a Cr metal layer 02,000 and a metal layer 1p such as AQ are deposited by vapor deposition or the like on an insulating substrate ω made of glass or the like. Next, Fig. 6(b)(C)
Pattern formation is performed by photoetching as shown in FIG. Thereafter, a photoelectric conversion layer (A) 2 such as a-5i is deposited on this pattern by P-CVD (Fig. 6(d)).
) L, forming a pattern using dry etching (
Figure 6(e)). Furthermore, 1. After depositing a transparent electrode layer (59,800 layers) of T, O, etc. by sputtering technology, a pattern is formed by photoetching or partial sputtering (FIG. 6(f)). The contact sensor shown in FIG. 5 is obtained.

Next, we will discuss the problems with conventional contact sensors.

First, since the first conductor layer is formed of Cr/AI2 or the like, if a strong treatment such as acid cleaning is performed before the photoelectric conversion film is deposited, AQ will dissolve and it cannot be used as a process. As a result, dirt such as organic matter on the individual electrodes such as Cr cannot be completely removed, and defects are likely to occur in the photoelectric conversion layer (a) formed thereon, so the first conductor layer Many interlayer short-circuit defects occur in film (2).

Further, in the common electrode portion, since the first conductive layer (2) and the transparent conductive layer 0 are in contact with each other, the transparent conductive layer (2) must be deposited after patterning the photoelectric conversion layer (4).

However, when the photoresist on the photoelectric conversion layer (a) is subjected to dry etching, it becomes difficult to peel off, so the resist remains at the interface between the photoelectric conversion layer and the transparent conductive layer on the pixel component, resulting in a short service life and low sensitivity. This may cause defects such as

Furthermore, the step of the photoelectric conversion layer (a) 2- is replaced with a thin transparent conductive layer 0.
Since 800 people covered it, breaks may occur in the transparent conductive film N0 at the end of the photoelectric conversion layer (a).

In addition, when etching the transparent conductive film 0, the first conductor layers (2 and 2) are protected only with photoresist. However, the etching solution for the transparent conductive layer 2 also protects the first conductor layers It has the property of dissolving quickly, and a slight resist defect may cause the already formed first conductor layer■,■
Problems such as open defects occurred in the wiring patterns were observed.

(Problems to be Solved by the Invention) As described above, in the conventional contact sensor, there have been problems such as interlayer short-circuits and resist residue in the pixel portion, oven wiring leads, and step breaks in the transparent conductive layer.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a contact sensor with a long life and high sensitivity at a high yield.

[Structure of the invention]

(Means for solving problem i1) In order to achieve the above-mentioned problem, the contact sensor of the present invention has the following features:
a high-resistance base, a first conductor layer disposed on the high-resistance base, and a photoelectric conversion layer disposed on the high-resistance base and at least a portion of the first conductor layer; A device comprising a transparent conductor layer disposed on the photoelectric conversion layer and a second conductor layer disposed on the transparent conductor layer, the first conductor layer being made of an acid-resistant material. It is.

The manufacturing method includes a first step of forming a first conductor layer made of an acid-resistant material on a high-resistance substrate, and a step of forming a first conductor layer on the high-resistance substrate and at least a portion of the first conductor layer. a second step of forming a photoelectric conversion layer on the photoelectric conversion layer, a third step of forming a transparent conductor layer on this photoelectric conversion layer, and a fourth step of forming a second conductor layer on this transparent conductor layer. It is characterized by having the following.

Furthermore, in other manufacturing methods, the first
a first step of forming a conductor layer, a second step of forming a photoelectric conversion layer on this high-resistance substrate and at least a portion of this first conductor layer, and a second step of forming a photoelectric conversion layer on this high-resistance substrate and on at least a portion of this first conductor layer. a third step of forming a transparent conductor layer on the transparent conductor layer, and forming a second conductor layer on the transparent conductor layer using a lift-off technique;
and a fourth step of correcting the disconnected portion of the first conductor layer.

(Function) In order to have the above-mentioned structure, since the present invention uses an acid-resistant substance for the first conductor layer, it is possible to perform acid cleaning and remove stains before depositing the photoelectric conversion layer. This makes it possible to prevent interlayer short circuits between the transparent conductor layer and the first conductor layer, thereby improving characteristics and reliability.

Furthermore, in the present invention, the pixels and leads are formed using an acid-resistant substance in the first conductor layer, and the common electrode and the bonding pad are formed in the second conductor layer after forming the transparent conductor layer. , it is possible to improve characteristics and reliability.

(Example) Examples of the present invention will be described below.

In FIG. 1(a) and FIG. 1(b), the contact sensor has an individual electrode made of Cr on a glass substrate, and a photoelectric conversion layer made of a-3i arranged on this pixel component (
B) and I placed on this photoelectric conversion layer (4).

T, 0. It basically consists of a transparent conductor layer 0 consisting of. Of this transparent conductor layer 0, Ti
A bonding pad (0) is arranged on the common electrode (2) formed by sequentially laminating /Al2 and on the individual electrode (2).

Next, referring to FIGS. 2(a) to 2(f), the first
A method of manufacturing the contact sensor shown in FIG. 1(a) and FIG. 1(b) will be described.

First, as shown in Fig. 2(a), a C
Deposit r(12). Next, pixels of individual electrodes and wiring leads are formed by PEP using a photosensitive resist resin. (Fig. 2(b)) After that, on this pixel etc., a photoelectric conversion layer 0 consisting of a-3i is applied by CVD method.
A film is deposited on the entire surface to a thickness of p, and then a transparent conductor layer (2) consisting of 1, T, and O is deposited by sputtering technique. (FIG. 2(C)) Next, this transparent conductor layer 0 is formed into a predetermined shape by wet etching (PEP) using acid, and the photoelectric conversion layer (a) is formed into a predetermined shape by dry etching (PEP). (Figure 2(d)) On top of this, Ti/
A film of Al2 with a thickness of 14 mm is sequentially deposited by sputtering technique. (Figure 2(e)) Finally.

A common electrode and a bonding pad are formed using PEP to obtain the contact sensor shown in FIGS. 1(a) and 1(b). (Fig. 2(f)) At this time, the alignment between the lead made of Cr and the bonding pad made of Ti/Al2 is as shown in Fig. 3(a) to Fig. 3(e). The configuration is such that the tolerance range is wide.

In the above embodiment, since the first conductor film is made only of acid-resistant Cr(12), the photoelectric conversion layer (4
) Acid cleaning can be performed before film deposition, and stains such as organic substances on glass (1) and Cr (12) can be thoroughly removed. As a result, film defects in the photoelectric conversion layer (A) that occur when the photoelectric conversion layer (A) is deposited on dirt are eliminated, and short-circuiting between the eyebrows between Cr(12) and the transparent conductor layer (■) can be prevented. .

In addition, the common electrode is made of a transparent conductor layer ■ and a Ti/Al layer on top of it.
2 (16), it is possible to continuously deposit the photoelectric conversion layer (4) and the transparent conductor layer (2), and chemicals such as resist do not come into contact with the photoelectric conversion layer (M)/transparent conductor layer interface in the pixel area. In addition to improving the characteristics, defects in the transparent conductor layer and corrosion due to moisture can be prevented.

Furthermore, dry etching of the photoelectric conversion layer changes the resist surface and makes it difficult to remove it, but in the above example, the resist in the pixel area during PEP of the photoelectric conversion layer (a-3i) is on the photoelectric conversion layer (a-3i). Since it is coated on the transparent conductive electrode (1, T, O,), which has a weaker adhesion than the resist, the resist can be easily peeled off, workability is improved, and defects caused by residual resist can be prevented.

Conventionally, the photoelectric conversion layer has two thicknesses (a-3i) (a).
4-light conductor (1, T, O,
) ■ Because of the coverage (L/), step breaks may occur at the edges, but with the structure of the above example, the coverage can be achieved with a single thickness of Ti/Al2 (16). Therefore, step breakage can be prevented.

In addition, since there is a photoelectric conversion layer (a-5i) on the entire surface during etching of the transparent conductor (1, T, O,) to protect the Cr lead, even if there is a resist defect, the transparent conductor (I) can be etched.

T, 0. ) There is no risk of the Cr lead being dissolved by the etching solution, and lead open can be prevented. Furthermore, since the resist only needs to be applied on the transparent conductor (1, T, O,) (5), workability is improved.

Similarly, when etching the photoelectric conversion layer (a-3L) (4).

In the past, even small resist defects caused damage to the photoelectric conversion layer (a-5
i) (4) is etched to form Cr(12) and transparent conductor (1,T.

However, in the above example, during etching of the photoelectric conversion layer (a-3i) (a), the photoelectric conversion layer (a-Si) (4) on the pixel was formed using a transparent conductor (4). 1.T.
O, ) (c), even if there are resist defects, the transparent conductor 0. Photoelectric conversion layer (a-5
i) @) is not etched. Therefore, it is possible to prevent short-circuit between the eyebrows.

Furthermore, since there is a PEP with two fine patterns of Cr (12) and Ti/AN (16), if you try to form a bonding pad and lead of the same shape and overlap them as in the past, you will have to use a small photo mask. Pad short may occur due to misalignment.

Therefore, in the above embodiment, lead (
As shown in e), by widening the allowable range of mask alignment, workability can be improved and pad short-circuit defects can be prevented.

As a result, Cr(12) and transparent conductor (1,T,O,)
Improved yield by preventing various defects such as interlayer shorts in 051, open Cr leads, remaining resist on pixels, broken bonding pad shorts in photoelectric conversion layer (a-3L) (4) steps, etc.Resist peeling , improved workability in resist coating and mask alignment, and better contact at the photoelectric conversion layer (a-3i)/transparent conductive film (1, T, O,) interface by avoiding contact with water and chemicals. It has the effect of becoming.

Next, other embodiments of the manufacturing method of the present invention will be described. This will be explained below with reference to FIGS. 4(a) to 4(g).

Vapor deposition of Cr(12) on the glass substrate (Fig. 4 Ca)'
)I. Individual electrodes are formed by photo-etching using a photosensitive resist resin (Fig. 4 (b)). Here, short-circuit points in the wiring leads are detected by electrical inspection and short-circuit correction is performed. , CV a-3i (14)
A film is deposited on the entire surface by step D, and then step 1. Depositing T, O, (15) by sputtering, 1. T, O, (15) are patterned by partial sputtering or full-surface sputtering followed by photoetching (FIG. 4(e)).

Next, a-5i (14) is formed by photoetching (FIG. 4(d)). At this stage, open locations of the wiring leads are detected by electrical inspection. Then, a Cr/Al2 (26) pattern is formed on it by lift-off, and at this time, the open portions are also corrected at the same time.

First, the common electrode and bonding pad portions are exposed using a negative pattern photomask, and then the open repair portion is spot exposed. Developed to Cr/1 (
26), the resist corresponding to the portion where it is desired to be deposited is removed (FIG. 4(e)). Cr/AQ (26) is deposited on top of it by sputtering (Fig. 4 (f)), and unnecessary parts of the resist (17) and Cr/AQ (26) are removed (Fig. 4 (g)). ).

By using the above-described method of manufacturing a contact sensor, there is no need to predict and correct a portion where an open is likely to occur before forming a lead electrode by laminating conventional Cr/AQ and etching it into the shape of the lead electrode. That is, since the open correction is performed after confirming that an open has occurred after etching Cr, it is possible to prevent the lead open from occurring due to a prediction error.

Also, there is no need to make more corrections than necessary. and,
Since open correction is performed during the formation of the top layer film, it is possible to deal with any open that may occur during the process, and almost no open will occur in the process after open correction. Further C
r, photoelectric conversion layer (a-3i), and transparent conductor layer (1,
Since T, O, ) have already been formed, open points can be detected by electrical inspection. Therefore, it is possible to prevent the occurrence of open circuits due to oversight, and the number of man-hours can be greatly reduced compared to the conventional method in which detection was performed manually using a microscope. Furthermore, this open correction method does not require any skill, and there is no need to worry about increasing the number of short corrections.

Moreover, since the photoelectric conversion layer (a-3i) is a pattern of only Cr before being deposited, cleaning with acid is possible, and short-circuit between the eyebrows between Cr and the transparent conductor layer (1, T, O,) can be prevented. Furthermore, after the Aff film is deposited, a buttering beam lift-off is used and no resist is applied to the A12 surface, so the surface is not contaminated, and since the AQ film is deposited on the top layer,
There is no exposure to high temperatures and surface oxidation does not progress easily.

Therefore, the bonding performance of the wire connecting the IC and the sensor board is improved.

Finally, if the second conductor layer is patterned by photo-etching, there is a risk that Cr in the first conductor layer will be dissolved during Cr etching if Cr/AQ is used, but if lift-off is used, the Cr in the first conductor layer Cr/i can be used as the second conductor layer.

Note that the reason why the second conductor layer is not made of a single layer of L but is made of Cr/AQ is to increase the adhesion strength with the first conductor layer.

As a result, yields are improved by making accurate open corrections in the final process, workability is improved by introducing electrical inspection, and yield and reliability are improved by increasing the adhesive strength of the i-surface. have an effect.

In the method of manufacturing the contact sensor shown in FIGS. 4(a) to 4(g), the first conductor layer may or may not be made of an acid-resistant material.

〔Effect of the invention〕

By employing the above-described configuration, it is possible to improve the characteristics and reliability of the contact sensor, and to obtain the contact sensor with good workability and high yield.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are schematic diagrams showing embodiments of the contact sensor of the present invention, and FIGS. 2(a) to 2(f)
3(a) to 3(e) illustrate the manufacturing method shown in FIGS. 2(a) to 2(f). 4(a) to 4(g) are simplified process diagrams showing an example of another manufacturing method of the contact sensor of the present invention, and FIG. 5(a) and 5(g) are simplified diagrams showing the effects. b) is a schematic diagram of a conventional contact sensor, and FIGS. 6(a) to 6(f) are simplified process diagrams showing a method of manufacturing a conventional contact sensor. ■...Glass substrate (high resistance base) ■...Individual electrode (first conductor layer) (A)...Photoelectric conversion layer ■...Transparent conductor layer■
...Common electrode (second conductor layer) Agent Patent attorney Norihiro Ken Yudo Takehana Kikuo (α) (b) Figure (C) Figure

Claims (4)

[Claims] (1) A high-resistance base and a first conductor layer disposed on the high-resistance base. a photoelectric conversion layer disposed on the high-resistance substrate and on at least a portion of the first conductor layer; a transparent conductor layer disposed on the photoelectric conversion layer; and a transparent conductor layer disposed on the transparent conductor layer. a second conductor layer, wherein the first conductor layer is made of an acid-resistant material. (2) a first step of forming a first conductor layer made of an acid-resistant material on a high-resistance substrate; and a photoelectric conversion process on the high-resistance substrate and at least a portion of the first conductor layer A second step of forming a layer, a third step of forming a transparent conductor layer on this photoelectric conversion layer, and a fourth step of forming a second conductor layer on this transparent conductor layer. A method of manufacturing a contact sensor, characterized by: (3) a first step of forming a first conductor layer on the high-resistance substrate; and a step of forming a photoelectric conversion layer on the high-resistance substrate and at least a portion of the first conductor layer. a third step of forming a transparent conductor layer on this photoelectric conversion layer; and a third step of forming a second conductor layer on this transparent conductor layer using a lift-off technique; A method of manufacturing a contact sensor, comprising: a fourth step of correcting a disconnection point of the contact sensor. (4) In the method for manufacturing a contact sensor according to claim 3, the first step is a step of forming a first conductor layer made of an acid-resistant material on the high-resistance substrate. A method for manufacturing a contact sensor.