JPS6269566A - Manufacture of photoelectric conversion device - Google Patents

Abstract

PURPOSE:To prevent short circuits or leakage related to upper and lower electrodes of a semiconductor, by forming a light sensitive organic resin on the semiconductor, which includes vacant holes or pinholes in the inside, projecting light so as to harden the organic resin, and removing unnecessary resin. CONSTITUTION:Flakes are attached to a semiconductor when a film is formed. When the film is removed, many vacant holes 6 and pinholes 6' are present unwillingly. Therefore, the photoresist of a light sensitive organic resin is applied on the semiconductor as a coat. The resist is impregnated into the pinholes 6' and the like. Ultraviolet rays are projected on the resist side. The organic resin filled in the pinholes and the like among said light sensitive organic resin is hardened. Thereafter, the entire body is rinsed. Post baking is performed, and the organic resin 7 and 7' are chemically stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a photoelectric conversion device using a non-single crystal semiconductor including an amorphous semiconductor that generates photovoltaic force.
When forming a non-single crystal semiconductor, holes or pinholes that are inadvertently formed in the semiconductor are filled with an insulator, and the holes or pinholes (hereinafter referred to as pinholes) where the front and back electrodes are formed are filled with an insulator. This invention relates to a method of manufacturing a photoelectric conversion device that prevents short-circuiting or weak leakage from occurring due to the above.

The present invention is characterized in that the insulator is an organic insulator, and pinholes where the upper and lower electrodes are shorted or leaked are selectively filled without using any photomask.

During long-term use of this photoelectric conversion device, the material of the back electrode gradually impregnates inside the semiconductor through the pinholes, preventing short circuits between electrodes with high voltages above and below, and ultimately improving the conversion efficiency of the photoelectric conversion device. This prevents a decrease in

Conventionally, a photoelectric conversion device (hereinafter simply referred to as a device), that is, a device in which a plurality of elements are arranged on the same substrate and integrated or hybridized, is disclosed in, for example, Japanese Patent Laid-Open No. 55-4994. Japanese Patent Application Laid-Open No. 55-124274 and Japanese Patent Application No. 54-90097/90098/90099 filed by the present inventor (filed on July 16, 1982) are also known.

As a conventional invention, FIG. 1 shows a vertical cross-sectional view of a photoelectric conversion device manufactured by a mask alignment method.

In the drawing, a transparent conductive film (abbreviated as CTF) (2) constituting the first electrode is selected on a transparent substrate (for example, a glass plate) (1) by an alignment process using a first metal mask. to form. Further, a semiconductor layer (3) is selectively formed in the same manner by an alignment process using a second metal mask. Further, a second electrode (4) made of aluminum is provided by an alignment process using a third metal mask.

In FIG. 1, there is a connecting part (12) between the elements (11) and (31), and in the connecting part, one side surface (16) of the CTF is covered with a semiconductor layer (3), and the other CTF is covered with a semiconductor layer (3). Avoid covering the surface (14) with the semiconductor layer (3). Further, the first oxide electrode (37) and the second aluminum electrode (38) are electrically connected through a contact (14).

In this conventional example, aluminum (4) reacts with semiconductor (3), and when this integrated photoelectric conversion device is left at 150°C, its characteristics change to several tens of degrees as shown in curve (25) in Figure 3. It has deteriorated over time. Therefore, the electrode was completely unsuitable for actual outdoor use.

Therefore, in order to improve such thermal reliability, a light-transmitting conductive film such as ITO is coated under the aluminum electrode on the back surface.
A two-layer structure is known in which ITO (indium tin oxide) is provided on a semiconductor, and aluminum is further provided on top of the ITO.

With such a structure, thermal reliability can be significantly improved because ITO can prevent aluminum from reacting with the semiconductor.

However, when forming this conductive film, this light-transmitting conductive film has a strong tendency to attract foreign particles, so if voids or pinholes are formed in the semiconductor, they may get inside the pinholes. However, a short circuit or a leak occurred between the first electrode on the lower side and the second electrode on the upper side, making it impossible to put it into practical use.

For this reason, conventionally in the formation of this non-single crystal semiconductor,
It can only be put to practical use in photoelectric conversion devices with a small area, such as 1 cm x 4 cm, where pinholes are difficult to exist, and photoelectric conversion devices with a large area of 10 cm x 10 cm or more always have holes or pinholes. Therefore, it was impossible to apply such a structure.

The present invention provides extremely effective means for industrially solving these problems.

In other words, by selectively filling only these pinholes with an insulating material, the first electrode on the lower side and the second electrode on the upper side of the semiconductor can be connected even if the transparent conductive film has strong dust. The purpose of the present invention is to prevent short-circuiting or leakage even when used, and examples thereof will be shown below.

Example 1 FIG. 2 is a longitudinal sectional view showing the manufacturing process of the present invention.

In FIG. 2 (8), a transparent substrate (1), for example, a glass plate (for example, thickness 1,2+wm, length 10 cm in the left-right direction in the drawing, width 10 cm) was used. Furthermore, a light-transmitting conductive film, for example, ITO (1
500 people) +5nOz (200-400 people),
ITO (1,500 people) + 5n3Na (500 people) or a transparent conductive film (1,500 to 2,000 people) whose main component is tin oxide or tin nitride added with a halogen element is prepared by vacuum evaporation, LPCVD, plasma CVD, It was formed by a spray method or a sputter method.

After that, the microcomputer is controlled to irradiate the substrate with a YAG laser processing machine (wavelength 1.06μ or 0.53μ) from the bottom or top of the substrate for patterning (1
3) was formed.

The opening formed by patterning had a width of about 50 μm and a length of 10 cm, and the width of each element (31) and (11) was 10 to 20 mm. The CTF (2) constituting the first electrode was thus cut and separated to form open grooves.

Thereafter, a non-single-crystal semiconductor layer having a PN or PIN junction is formed on this '-plane to a thickness of 0.2 to 1.0μ, typically 0.5 to 0.7μ, by plasma CVD or photoCVD. formed. A typical example is a P-type semiconductor (SixCt
-x x=50~1508 1-1 type amorphous or semi-amorphous silicon semiconductor (0.4~0.9μ)
- A non-single crystal semiconductor having one PIN junction made of a semiconductor having N-type microcrystals (200 to 500).

Or P-type semiconductor (SixCt-x) I-type amorphous silicon semiconductor - N-type silicon semiconductor - P-type 5i
xC+-X semiconductor-■ type 5ixGe+-x (x=0.5
) - Tandem type PINPIN made of N-type silicon semiconductor (300 to 1000 people)...A PIN junction semiconductor may be used.

Such a non-single crystal semiconductor layer (3) was formed to have a uniform thickness over the entire surface.

However, this semiconductor has flakes (snowflakes) during film formation.
Pores (6
), a large number of pinholes (6') are undesirably present. As many as 2 to 4 of these may be observed per 10 fields of view using a microscope with a magnification of 100 times.

Therefore, by the method of the present invention, this pinhole etc. (6)
, (6") was selectively filled with insulating material. The process is shown below.

After forming the semiconductor shown in FIG. 2(^), a photosensitive organic resin was coated on the semiconductor. At this time, care was taken to ensure that the organic resin sufficiently impregnated into the pinholes and the like. As the photosensitive organic resin, a positive type photoresist such as Kano PR-800 sold by Tokyo Ohka Co., Ltd. was used. This photosensitive organic resin is applied to the entire surface of the semiconductor using a spinner, coater or spray method.
Form to a thickness of 1 to 5 μm. At this time, it is important to reduce the amount of photosensitive organic resin formed on the back side of the semiconductor so that pinholes and the like can be more fully filled.

For example, when using a spinner, rotate the resist at 50° rpm.
Coating was carried out under conditions of 5 seconds and 200 rpm for 30 seconds.

Furthermore, this coated organic resin film is pre-baked (85°C).
, 40 hours). Furthermore, as a development process, ultraviolet light (wavelength 300-400r+m) is applied from this resist side (
17) to immobilize the organic resin filled in the pinholes, etc. of this photosensitive organic resin, and further exposed to light to unimmobilize the organic resin on the semiconductor surface. This condition is that when using 0FPR-800, the ultraviolet light is 6mW/
am” for 5 seconds, and then a predetermined developing process was performed.

Furthermore, the whole was rinsed (with pure water for 10 minutes) by a known method. Then there is a pinhole (6).

Non-immobilized organic resin other than the organic resin film fixed within (6゛) can be dissolved away. That is, all the organic resin on the semiconductor (3) can be removed. Furthermore, post-baking (150° C. for 1 hour) was performed to chemically stabilize the ammonium resin (T), (7') filled inside the exposed pinhole. Then, as shown in FIG. 2(B), only the pinholes (6) and (6°) portions can be selectively filled with the organic resin insulators (7) and (7').

The upper surface of this insulator can be filled so that it is approximately equal to or slightly smaller than the upper surface of the semiconductor (due to volume contraction during boss curing, etc.).

Furthermore, as a next step, as shown in FIG. 2(B), a second open groove (18) was formed to the left of the first open groove (13) by a second laser scribing process. This laser scribing was performed by irradiating the substrate (1) from above.

Thus, the side surfaces (8) and (9) of the first electrode were exposed by forming the second open groove (18). The side surface (9) of this second open groove may be on the left side of the side surface (16) of the first electrode (37°); as an extreme example, as shown in the drawing, the side surface (9) of the first electrode (37 ). Furthermore, this patterning can be carried out without exposing the side surface (8) as shown in FIG. 1(B) or without patterning the conductive film (2). (such as) may be exposed.

In FIG. 2, a two-layer conductive film (4) for the back electrode is further formed on this top surface as shown in FIG. Groove (2
0) was established.

This second electrode has a transparent conductive film (23) of 300 to 1
400 people For example, ITO (indium tin oxide) + I
n203 (indium oxide), SnO□ (tin oxide)
, ITN (indium tin nitride) (a mixture of indium nitride and tin nitride) was used to form the first layer. Furthermore, a metal film (24) of aluminum, chromium, silver, a single layer of aluminum (300 to 5000) or a double layer of aluminum and nickel was formed on the top surface. For example, the two-layer conductive film (4) was made of ITO (23) with a thickness of 1050 and aluminum (24) with a thickness of 1000. This ITO and aluminum promote reflection of incident light (10) from the front side of the substrate (1) on the back electrode, and
This is for effectively photoelectrically converting long wavelength light of 00 nm. This is also because the ITO prevents aluminum and semiconductor from reacting with each other as in the prior art, causing a decrease in reliability. These were formed using a sputtering method, an electron beam evaporation method, or a plasma CVD method at a temperature of 300° C. or lower so as not to deteriorate the semiconductor layer.

In order to be in close contact with the N-type semiconductor on the back surface, a conductive film made of a translucent indium compound (ITO or ITN) containing indium oxide, indium nitride, or a mixture thereof as a main component was preferable. On the other hand, if the semiconductor on the back side is a P-type semiconductor, tin oxide (SnOz)-tin nitride (snsN
4) A light-transmitting conductive film whose main component is antimony nitride (SbN) or a tin compound of a mixture thereof is excellent in terms of long-term reliability and high efficiency.

The light-transmitting conductive film (23) is brought into close contact with the conductive film oxide or nitride (2) and (8) constituting the lower first electrode at the contact I-(8). Then, this becomes an oxide or nitride (37)-oxide or nitride (23) contact (8), and as shown in the conventionally known structure (FIG. 1), one side is not metal. Therefore, even in a temperature test of 150° C., there is no deterioration and the reaction does not proceed.

Thus, as shown in FIG. 2(C), a plurality of elements (3
We were able to create a photoelectric conversion device in which 1) and (11) were connected in series at the connecting part (12).

FIG. 2(D) shows an attempt to further complete the present invention as a photoelectric conversion device. That is, a silicon nitride film (
21) was formed to a thickness of 500 to 2000 people. Furthermore, an external lead terminal (5) is provided, and these are made of organic resin (22
) was filled.

Thus, when the irradiation light (10) is irradiated with AMI (100 mW/cm") on a photoelectric conversion device panel integrated with a substrate (10 cm x IOC, l) as in this example, the open circuit voltage curve is 12.315 V. It was possible to provide an output with a factor of 0.599 and a conversion efficiency of 8.33χ.

However, if the exact same steps are used but only the step of filling the organic resin of the present invention shown in FIG. 2(B) is omitted, only the following conversion efficiency can be obtained. That is, Sample 1 Sample 2 Open circuit voltage 11.49V 3.02V Fill factor 0.471 0.316 Short circuit current 53.7
m8 54.201 Conversion efficiency 4.43χ
0.75χ From these results, it can be seen how effective it is to fill the pinholes of the present invention with organic resin.

Example 2 FIG. 3 is a longitudinal sectional view showing another manufacturing process of the present invention.

In FIG. 3 (8), a non-light-transmitting substrate has an insulating surface in which an inorganic insulating film (41) such as a heat-resistant organic resin or enamel is formed on a conductive stainless steel foil (40) with a thickness of 10 to 100 μm. was used. Furthermore, a conductive film for the lower electrode is applied over the entire surface of these two surfaces, for example, chromium (200), aluminum (1500) + 5nOz (200 to 40).
0 people), aluminum (1500 people) + 5nJt (5
00 people) or a transparent conductive film whose main component is tin oxide or tin nitride added with a halogen element (1500~2
000 people) by vacuum evaporation method, LPCVD method, plasma CVD method
It was formed by D method, spray method, or sputtering method.

Thereafter, under the control of a microcomputer, irradiation was performed using a YAG laser processing machine (wavelength: 1.06μ or 0.53μ) to form patterning grooves (13).

The opening formed by patterning has a width of about 50 μm and a length of 10 cm, and the width of each element (31), (1, 1) is 10”□20nv+.The conductive film ( 2) was cut and separated to form an opening.After this, this two sides were subjected to plasma CVD or photoCVD.
A non-single crystal semiconductor layer having a PN or PIN junction was formed to a thickness of 0.2 to 1.0 μm, typically 0.5 to 0.7 μm, by method D. A typical example is an N-type semiconductor (200~
500 people) - I-type amorphous or semi-amorphous silicon semiconductor (0.4-0.9 μ) - P-type semiconductor (
A non-single-crystal semiconductor having one NIP junction was made of a semiconductor formed by gradually laminating SinC+-x (X=50 to 150 people).

or N-type semiconductor (300-1000 people) - ■ type 5ix
Ge + - * (0 <
Type amorphous Si semiconductor-P type 5ixC,-, (0<
X<1) A tandem type NIPNIP consisting of semiconductors (50 to 200 people)...A NIP junction semiconductor may be used.

The non-single crystal semiconductor layer (3) was formed to have a uniform thickness over the entire surface and to have a flat or uneven texture structure.

However, this semiconductor has flakes (snowflakes) during film formation.
Pores (6
), many pinholes (6゛) are present unintentionally. In some cases, as many as 2 to 4 of them can be observed per 10 fields of view using a microscope with a magnification of 100 to 1000 times.

For this reason, the present invention is directed to pinholes (6), (6”), etc.
The insulation material was selectively filled. The work is shown below.

After forming the semiconductor shown in FIG. 3 (8), this semiconductor was coated with a photosensitive organic resin. At this time, care was taken to ensure that the organic resin sufficiently impregnated into the pinholes and the like. As the photosensitive organic resin, a positive type photoresist such as OFl'R-800 sold by Tokyo Ohka Co., Ltd. was used. After that, the same treatment as in Example 1 was performed.

Thus, as shown in Figure 3(B), the pinhole (6)
, organic resin insulator (7) is selectively applied only to the portion (6').

(7゛) can be filled.

Furthermore, as a next step, as shown in FIG. 3(B), a second open groove (18) was formed to the left of the first open groove (13) by a second laser scribing step. This laser scribing was performed by irradiating the substrate (1) from above.

The formation of the second opening (18) thus exposed the side surfaces (8) and (9) of the first electrode. The side surface (9) of this second open groove may be on the left side of the side surface (16) of the first electrode (37'); as an extreme example, as shown in the drawing, the side surface (9) of the first electrode (37') ). Furthermore, this patterning can be carried out without exposing the side surface (8) as shown in FIG. 1(B) or without patterning the conductive film (2). (such as) may be exposed.

Thereafter, a second electrode was formed using a transparent conductive film using a metal mask. That is, this second electrode is a transparent conductive film (
23) for 300 to 1,400 people, such as ITO (indium tin oxide), InzOs (indium oxide).

It was formed from Snow (tin oxide) and ITN (indium tin nitride) (a mixture of indium nitride and tin nitride).

These are designed to prevent a conductive film from being formed in the open groove (20).
A metal mask is placed on the semiconductor shown in FIG. 3(B) in advance, and then a transparent conductive layer is formed using a sputtering method, an electron beam evaporation method, or a plasma CVD method at a temperature of 300° C. or less without deteriorating the semiconductor layer. A film was formed.

Thus, as shown in FIG. 3(C), a plurality of elements (3
We were able to create a photoelectric conversion device in which 1) and (11) were connected in series at the connecting part (12).

FIG. 3(D) shows an attempt to further complete the present invention as a photoelectric conversion device. That is, polyimide,
Organic resins such as polyamide, kapton or epoxy (2
2) was filled.

Thus, when the irradiation light (10) is irradiated with 8 Ml (100 mW/cm") from a photoelectric conversion device panel integrated with a substrate (10 cm x 10 cm) as in this example, the open circuit voltage is 11.30 V, and the fill factor is 11.30 V. It was possible to provide an output of 0.626 short circuit current 79.4 mA, current density 17.31 mA/cm", and conversion efficiency 8.16x.

However, if the exact same steps are used but only the step of filling the organic resin of the present invention shown in FIG. 3(B) is omitted, only the following conversion efficiency can be obtained. That is, open circuit voltage 6.
54V Fill factor: 0.368 Short-circuit current: 75.69mA Conversion efficiency: 3.48χ These show how effective it is to fill the pinholes of the present invention with organic resin.

Figure 4 shows the reliability test of the present invention and the conventional example.
, conditions of high temperature storage in the atmosphere).

The curve (25) in FIG. 4 is the conventionally known configuration shown in FIG. 1, in which the back electrode has a structure in which aluminum is in close contact with the semiconductor, and the connection portion is a tin oxide-aluminum contact method. .

In this structure, aluminum oxide is formed at the contact portion, and the aluminum itself also reacts with the N-type semiconductor. As a result, it drops to less than 50% of its initial value in just a few hours.

Further, the curve (26) is the reliability characteristic of the photoelectric conversion device having the structure of Example 1. This is a case where a two-layer film of ITO and aluminum is used as the back electrode. In this case, the contact was an oxide (tin oxide)-oxide (ITO) contact, and the reliability of the contact portion was excellent.

Curve (27) shows the structure of the photoelectric conversion device of Example 2, and similar to Example 1, good reliability characteristics were obtained.

More importantly, by filling the pinholes of the present invention with an insulator, there is little variation among samples of photoelectric conversion devices in the initial state, and the manufacturing yield is high. For example, even if 10 pieces of 10CIl are made, the σ (dispersion) can be obtained as 0.27.

The organic resin mold (22) is covered for fixing the extraction electrode (5), and this panel is, for example, 40 cm
20cm, 60cm x 40cm or 120cm
x40cm packaged with 6 pieces, 2 pieces or 1 piece aluminum sash frame, 120cm x 40cm NE
It is possible to provide DO standard panels.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a conventional photoelectric conversion device. FIGS. 2 and 3 are longitudinal sectional views showing the manufacturing process of the photoelectric conversion device of the present invention. FIG. 4 shows an example of reliability characteristics of photoelectric conversion devices of the present invention and a conventional example.

Claims (1)

[Claims] 1. A step of forming a first electrode on a substrate having an insulating surface, a step of forming a non-single crystal semiconductor having holes or pinholes on the electrode, and a step of forming a non-single crystal semiconductor having holes or pinholes on the electrode; a step of forming a photosensitive organic resin on the semiconductor including the inside of the pinhole; a step of irradiating light from the photosensitive organic resin side to fix the organic resin filled in the hole or pinhole; and fixing. The pores or pinholes of the semiconductor are filled with an induced resin insulator by the steps of removing unused organic resin and forming a second electrode on the semiconductor. Method for manufacturing a photoelectric conversion device. 2. In claim 1, the organic resin formed on the semiconductor surface is non-immobilized by light irradiation, and the organic resin filled in the cavity or pinhole is immobilized by the organic resin. 1. A method for producing a photoelectric conversion device, characterized in that a photoelectric conversion device is irradiated with light. 3. The method for manufacturing a photoelectric conversion device according to claim 1, wherein the second electrode is a transparent conductive film or a metal film is formed on the conductive film.