JPS59161863A - Manufacture of reader element for continuous thin film manuscript - Google Patents

Abstract

PURPOSE:To contrive the uniformity of the characteristics of each photoelectric conversion part by a method wherein the lower electrode, a hydrogenated amorphous Si film, and an insulation layer are successively formed on a substrate, and then a window serving as a photo receiving part is formed in this insulation layer. CONSTITUTION:The lower electrode SE2 is formed on the surface of the insulation substrate 1. Next, the hydrogenated amorphous Si film 2 is so formed as to cover the photo signal lead-out part of the electrode SE2. Then, an Si nitride film 4 is formed on the substrate 1 whereon the film 2 is formed. The window serving as the photo receiving part is formed by removing the film 4 on said lead-out part. The upper photo transmitting electrode 3 is so formed as to cover the photo receiving region. Thereby, the titled element wherein the characteristic of each photoelectric conversion part is uniform can be manufactured.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a long thin film document reading element.

Recently, long thin film document reading elements have been used in image reading devices and image information processing devices such as facsimile machines.

Figures 1 and 2 show this long thin film document reading element, with Figure 1 being a plan view, and Figure 2 showing A-h in Figure 1.
A cross-sectional view along 'g is shown.

In FIGS. 1 and 2, a plurality of light range conversion units LE*
, LEz , LEs , .=, LEn are lower electrodes 5EIp arranged in parallel at appropriate intervals on the insulating substrate 1
A hydrogenated amorphous silicon film 2 as a photoconductor formed overlapping one end of S'Et t SEs p ・"e SEn, and an upper transparent film formed on the hydrogenated amorphous silicon film 2. It is composed of a photosensitive electrode 3.

The part that functions as the above-mentioned photoelectric conversion unit (hereinafter referred to as
(referred to as the light receiving part)Ll = Lx -Ls -...
.

Ln is the lower electrode 8E1-SEt-SEn,
・”.

This is the area where SEn and the upper translucent quadrupole 3 intersect. In addition, the lower electrode 8E1, SEz −SEg −・
..., the light receiving part Ll g L2 p of SEn
L3 e "', the lower part of Ln (...hereinafter referred to as the original signal extraction part) LS+ eLSt tLSs *
An optical signal is taken out to the outside via -yLSn.

In addition, the operation of the long thin film document reading element is, for example, by applying a bias voltage of an appropriate magnitude to the photoelectric conversion unit LE shown in FIG. When irradiated, electrons and holes are generated in the light receiving part L2, and the electrons and holes move toward the lower electrode SE and the upper transparent electrode 3, respectively, thereby increasing the intensity of the irradiated light. A photocurrent of a magnitude corresponding to the current flows. Similar operations are performed for other photoelectric conversion units.

Next, a method for manufacturing the long thin film original reading element shown in FIGS. 1 and 2 will be explained using the manufacturing process diagram shown in FIG. 3.

(1) First step: A conductor layer is formed over the entire surface of the insulating substrate 1, and the lower electrode SE1 is formed into an appropriate shape and size by photolithography and photoetching.
t SEt t SEse ... t SEn is formed (see FIG. 3(a)).

(2nd step, lower part' polarization S kl g S E2 g sk
g # river? Lay hydrogenated amorphous silicon on one end of S E n to an appropriate thickness, for example, plasma C.
An amorphous silicon film 2 is deposited and hydrogenated to a thickness of 1 μm using a VD method or the like (see FIG. 3(b)).

(3) Third step A metal mask (not shown) having an appropriately shaped opening is provided on the substrate 1 on which the hydrogenated amorphous silicon film 2 is formed, and plasma CVD, reactive vacuum evaporation,
Alternatively, the upper transparent electrode 3 is formed by a method such as a single-reactive sputtering method (see FIG. 3(e)).

In addition, the light receiving part Lt tLs tLs t""tL
It is necessary that n has the same size, but even if the position of the metal mask when forming the upper transparent electrode 3 is shifted, the light receiving portion Lt t Lx e Lm t...,
The lower electrode SE,
.

SE,,SEa,...@b Optical signal extraction part LS1 *LS2 yLss p"" of Er1,
The width of the portion other than LSn is made as narrow as possible (see FIG. 1).

By the way, in order to improve the resolution (resolving power) of a long thin film original reading element, it is conceivable to increase the arrangement density of photoelectric conversion parts. If the arrangement density of the charging conversion section to be formed is doubled, the size of the light receiving section will be reduced to about 1/4,
It becomes difficult to align the metal mask when forming the upper transparent electrode, and it becomes necessary to fabricate the upper transparent electrode by photolithography and etching.

However, as the array density of the photoelectric conversion section increases, the width of the upper transparent electrode becomes narrower, for example, at an array density of 16 electrodes/mm, it becomes less than 50 pm, and the length of the upper transparent electrode becomes relatively long. . Therefore, when a bias voltage is applied to each photoelectric conversion section, there is a problem in that some photoelectric conversion sections are not applied with a desired bias voltage due to the resistance of the upper transparent electrode.

In addition, as the arrangement density of the photoelectric conversion section increases, the portion of the lower electrode other than the original signal extraction portion becomes narrower, which increases the possibility of wire breakage.The present invention was made in view of the above-mentioned circumstances. It is an object of the present invention to provide a method for manufacturing a long thin film original reading element that facilitates the manufacture of a long thin film original reading element and has uniform characteristics.

Therefore, in the present invention, after forming a lower electrode and a hydrogenated amorphous silicon film on a substrate, an insulating layer is formed on the hydrogenated amorphous silicon film, and a window that becomes a light receiving part is formed in the insulating layer. , and further filtered to form an upper transparent electrode.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 4 shows a manufacturing process diagram of a long thin film original reading element to which the method for manufacturing a long thin film original reading element according to the present invention is applied, and for convenience of explanation, FIGS. The same symbols as those used in Figure 3 are used.

The manufacturing process will be sequentially explained below.

(1) First step: A chromium film is deposited on the surface of the insulating substrate 1 to a thickness of approximately 3000 Å, and photolithography and etching are performed to form the lower electrode S bl p S K 2 2S”
s e ''' y S E n is formed (see FIG. 4(a)).

(2) The lower part of the second step is polar SEt −SEt , SEs −−, S
Optical signal extraction part LS1 of En) LSt *LS
ss..., hydrogenated amorphous silicon is deposited to a thickness of about 1000 OA so as to cover LSn to form a hydrogenated amorphous silicon film 2 (see Fig. 4).
b)).

(3) Third step A silicon nitride group 4 is formed by plasma CVD on the substrate 1 on which the hydrogenated amorphous silicon film 2 is formed (see FIG. 4(e)).

(4) Fourth step: Photolithography and etching are performed on the silicon nitride film 4 to form the original signal extraction portion LS1 pL.
st tLrss , -. The silicon nitride film 4 on LSn is removed to form a window that will become a light receiving part (Fig. m4 (
d)). The substrate l at the end of this fourth step
A plan view of the is shown in FIG. As shown in FIG. 5, each original signal extraction portion LS, LS.

The sizes of tls3, . . . , LSn are the same, and this can be done by the photolithography 8 and etching described above.

3. In this embodiment, the silicon nitride film 4 is used as an insulating layer, but the silicon nitride film 4 is not limited to this, and for example, PSGC! Materials such as silicon oxide (J-doped silicon oxide), silicon oxynitride, and polyimide may also be used.

(5) Fifth process source signal extraction part LSs - LSt - LSs,
....

Hydrogenated amorphous silicon film 2 on LSn, that is, light-receiving region Lr* p Lx y 'Lrs
ITO is deposited to a thickness of about 200 OA so as to cover the portions t..., Ln (windows for forming the light receiving section) to form the upper transparent electrode 3 (see FIG. 4(e)). ).

The performance of the long thin film document reading element manufactured as described above was found to be uniform in characteristics of each light '1 converting section compared to when tabulated by the conventional method.

Further, FIG. 6 shows another embodiment to which the method of manufacturing a long thin film document reading element according to the present invention is applied. Figure 6(a) shows
FIG. 6(b) is a plan view of the long thin film original reading element corresponding to the end of the third step in the above-mentioned embodiment, and FIG. A sectional view taken along line B' is shown.

In this embodiment, the lower electrode S El y S K! is arranged so as to increase the arrangement density of the photoelectric conversion parts. *SE
l e..., SEn are arranged in a staggered manner, an insulating substrate 1, a hydrogenated amorphous silicon film 2
, the upper transparent electrode 3 is formed in the same manner as in the previous embodiment. Conventionally, the upper translucent electrode 3 had to have a width of dt, but according to the present invention, the optical signal extraction part LSI
v LS2 y LSD y ・= p L S n
, the width d t/ can be set to any value.

Further, FIG. 7 shows another embodiment of the present invention, in which the seventh factor (a
) # and FIG. 7(b) also show a plan view of a long thin film original reading element corresponding to the fourth step of the above-mentioned embodiment. In this embodiment, FIG. 7(a) and FIG. As shown in (b), the lower polarization SE1, SE, BE formed on the substrate 1
@ , ・=, 8En optical signal extraction part LS1 g L
All the parts other than StgLbat-"gLSn are covered with a silicon nitride film 4, especially as shown in FIG. 7(b).
In the case of , the lower four poles SE□, SF,, SE,.

. . ., since the step of SEn is eliminated, the probability of occurrence of a photoelectric conversion section with poor characteristics becomes smaller.

Note that by forming an insulating layer such as a silicon film for use in the long thin film document reading element, it is possible to manufacture an element that is stable against thermal stress.

As explained above, according to the present invention, hydrogenated amorphous silicon and ITO may be deposited on the original signal extraction portion of the lower electrode, and the hydrogenated amorphous silicon film and the upper light-transmitting electrode may be deposited using a mask. can be formed. In particular, it is not necessary to narrow the width of the upper transparent electrode, and the characteristics of each photoelectric conversion section can be made uniform by the resistance of the upper transparent electrode.

In addition, since the lower electrode is covered with an insulating layer except for the original signal extraction part, there is no need to reduce its width, which prevents disconnection, and also prevents mechanical contact when forming the hydrogenated amorphous silicon film and the upper transparent electrode Can be preserved from wear and tear.

[Brief explanation of drawings]

FIG. 1 is a plan view of a conventional long thin film document reading element, FIG. 2 is a sectional view taken along the line AA' in FIG. 1, and FIG. 3 is a manufacturing process of a conventional long thin film document reading element. 4 is a manufacturing process diagram of a long thin film original reading element to which the manufacturing method of a long thin film original reading element according to the present invention is applied, and FIG. 5 is a third step of the manufacturing process diagram shown in FIG. 4. Plan view of the element at the end, No. 6
7 and 7 show plan views of other embodiments of the present invention (such as long thin film document reading elements). 1... Insulating substrate, 2... Hydrogenated amorphous silicon film, 3... - Upper transparent electrode, 4... silicon nitride film, SEX, SE,, SE8. SEn... lower electrode. Fig. 1 Fig. 2 Fig. 3

Claims (1)

[Claims] (υ lower part 4&, hydrogenated amorphous silicon film,
and a method for manufacturing a long thin film document reading element having a laminated structure of an upper translucent electrode, including forming the lower electrode pattern and the hydrogenated amorphous silicon film on the hydrogenated amorphous silicon film. 1. A method of manufacturing a long thin film original reading element, comprising depositing an insulating layer and forming a hole to serve as a light receiving portion in the insulating layer. (2) The long insulating layer is made of one material selected from PSG (phosphorus-doped silicon oxide), silicone, silicon oxynitride, and polyimide. A method for manufacturing a thin film document reading element.