JPH0558585B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a photovoltaic exchange device using a non-single crystal semiconductor including an amorphous semiconductor that generates a photovoltaic force. A hole conductor that prevents the surface electrode and the back electrode from shorting or weakly leaking from each other due to the holes or pinholes (hereinafter referred to as pinholes) by filling the holes or pinholes that would otherwise occur. The present invention relates to a method for manufacturing a conversion device.

The present invention is characterized in that the insulator is an organic insulator, and pinholes where the upper and lower electrodes shoot or leak 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 and prevents the material from being shot between the upper and lower electrodes, which ultimately reduces the conversion efficiency of the photoelectric conversion device. This is to prevent the decline.

Conventionally, photoelectric conversion devices (hereinafter simply referred to as devices), that is, devices in which multiple elements are arranged on the same substrate and are integrated or hybridized, have been disclosed in, for example, Japanese Patent Application Laid-Open No. 55-4994, Japanese Patent Application Laid-Open No. 55-124274, and the present invention. Patent application 90097/90098/90099 filed by the inventor (Showa
54.7.16 application) etc. are known.

As a conventional invention, FIG. 1 shows a vertical cross-sectional view of a year-to-year conversion device made by a mask matching method.

In the drawing, a translucent substrate (e.g. glass plate) 1
Transparent conductive film (CTF) forming the first electrode on top
(abbreviated as ) 2 is selectively formed by an alignment process using a first metal mask. Furthermore, the semiconductor layer 3 is selectively formed in the same manner by an alignment process using a second metal mask. Furthermore, 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 portion 12 between the elements 11 and 31, and the connecting portion has one side surface 1 of the CTF.
6 is covered with the semiconductor layer 3, and the surface 14 of the other CTF is covered with the semiconductor layer 3.
so as not to be covered by the semiconductor layer 3. Furthermore, a first oxide electrode 37 and a second aluminum electrode 38
are electrically connected by contacts 14.
In this conventional example, the aluminum 4 reacts with the semiconductor 3, and the integrated photoelectric conversion device is heated to 150°C.
When left alone, the special product deteriorated in several tens of hours as shown by curve 25 in Figure 3. Therefore, the electrode was completely unsuitable for actual outdoor use.

Therefore, in order to improve such thermal reliability, a transparent conductive film such as ITO (indium tin oxide) is interposed under the aluminum electrode on the back side, ITO is provided on the semiconductor, and aluminum is further placed on top of it. A two-layer structure is known.

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

However, when this conductive film is formed, this light-transmitting conductive film has a strong tendency to wrap around, so if voids or pinholes are formed in a semiconductor in an undesirable manner, the light-transmitting conductive film will penetrate into the inside of the pinhole. Shooting or leakage occurred between the lower first electrode and the upper second electrode, making it impossible to put it into practical use.

For this reason, conventionally, in the formation of non-single crystal semiconductors, pinholes could only be put to practical use in small-area photoelectric conversion devices, such as 1 cm x 4 cm, where voids were difficult to exist, and 10 cm x 10 cm or more. Since these holes and pinholes always exist in large-area photoelectric conversion devices, it has been impossible to apply such a structure.

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

That is, by selectively filling only these pinholes with an insulator, the first electrode on the lower side and the second electrode on the upper side of the semiconductor can be connected even if a transparent conductive film with strong wraparound is used. It is an object of the present invention to prevent shots or leaks from occurring even when the parts are connected to each other, 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. 2A, a transparent substrate 1 such as a glass plate (for example, thickness 1.2 mm, length (left and right direction in the drawing)
10cm, width 10cm) was used. Furthermore, a transparent conductive film, such as ITO (1500Å) +
SnO ₂ (200-400 Å), ITO (1500 Å) + Sn ₃ N ₄ (500
Å) or a transparent conductive film whose main component is tin oxide or tin nitride added with a halogen element (1500~
2000Å) by vacuum evaporation method, LPCVD method, plasma
It was formed by a CVD method, a spray method, or a sputtering method.

Thereafter, a microcomputer was controlled to form patterning grooves 13 by irradiating the substrate with a YAG laser processing machine (wavelength: 1.06 μm or 0.53 μm) from the bottom or top of the substrate.

The open groove formed by patterning has a width of approximately
The length was 10 cm, and the width of each element 31, 11 was 10 to 20 mm. In this way, the CTF 2 constituting the first electrode was cut and separated to form an open groove. Thereafter, a non-single crystal semiconductor layer having a PN or PIN junction was formed on the upper surface by plasma CVD or optical CVD to a thickness of 0.2 to 1.0 μm, typically 0.5 to 0.7 μm. A typical example of this is a P-type semiconductor (SixC _1- x
x = 50 to 150 Å) - I-type amorphous or semi-amorphous silicon semiconductor (0.4 to 0.9 μ) - N-type semiconductor having microcrystals (200 to 500 Å) 1
This is a non-single crystal semiconductor with two PIN junctions.

Or, P-type semiconductor (SixC _1- x) - I-type amorphous silicon semiconductor - N-type silicon semiconductor - P
Type SixC _1- x semiconductor − Type I SixGe _1-X (x=0.5) −N
A tandem type PINPI made of type silicon semiconductor (300 to 1000 Å)...A PIN junction semiconductor may also be used.

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

However, many voids 6 and pinholes 6' are undesirably present in this semiconductor due to reasons such as flakes (snowflakes) adhering to the film during film formation and detaching after the film is formed. As many as 2 to 4 of these can be observed per 10 fields of view using a 100x microscope.

Therefore, the pinholes 6, 6' were selectively filled with an insulator by the method of the present invention. The work is shown below.

After forming the semiconductor shown in FIG. 2A, 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, etc. This photosensitive organic resin is a photoresist sold by Tokyo Ohka Co., Ltd.
A positive type photoresist such as OFPR-800 was used. Apply this photosensitive organic resin to the entire surface of this semiconductor using a spinner, coater or spray method.
Form to a thickness of 5μ. At this time, it is important to use less photosensitive organic resin than the photosensitive organic resin formed on the back side of the semiconductor to more fully fill pinholes and the like. For example, a spinner was used to apply the resist at 500 rpm for 5 seconds and 2000 rpm for 30 seconds. Furthermore, the applied organic resin film was prebaked (85°C, 40 hours). Furthermore, as a development process, ultraviolet holes (wavelengths from 300 to
400 nm) 17 was irradiated to immobilize the organic resin filled in pinholes, etc. of this photosensitive organic resin, and further exposed to light to unimmobilize the organic resin on the semiconductor surface. When OFPR-800 was used, the ultraviolet aperture was set at 6 mW/cm ² for 5 seconds, and a predetermined development process was performed.

After that, the whole was rinsed (with pure water for 10 minutes) by a known method. Then 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 organic resins 7 and 7' filled inside the exposed pinholes. Then, as shown in FIG. 2B, only the pinholes 6, 6' can be selectively filled with organic resin insulators 7, 7'.

The upper surface of this insulator can be filled to approximately coincide with the upper surface of the semiconductor or to a lesser extent (due to volume contraction during post-curing, etc.).

Furthermore, as a next step, as shown in FIG. 2B, 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.

Thus, by forming the second groove 18, the side surfaces 8 and 9 of the first electrode were exposed. The side surface 9 of this second groove may be on the left side of the side surface 16 of the first electrode 37', and as an extreme example, as shown in the drawing, the side surface 9 of the second groove may be inside the first electrode 37. Good too. Further, this patterning can be carried out either by exposing the side surface 8 as shown in FIG. 1B or by exposing the surface of the first electrode (as shown in FIG. 14) without patterning the conductive film 2. good.

In FIG. 2, as shown in FIG. 2C, a two-layer conductive film 4 was formed on the upper surface of the substrate, and an opening groove 20 for cutting and separation in the third laser scribing method was further provided.

This second electrode has a transparent conductive film 23 of 300~
1400Å e.g. ITO (indium tin oxide),
In ₂ O ₃ (indium oxide), SnO ₂ (tin oxide),
The first layer was formed with ITN (indium tin nitride) (a mixture of indium nitride and tin nitride). Furthermore, the top surface is made of aluminum, chrome,
A metal film 24 was formed as a single layer film of silver or aluminum (300 to 5000 Å) or a double film of aluminum and nickel. Later ITO23 is 1050Å,
The aluminum 24 was made into a two-layer conductive film 4 with a thickness of 1000 Å. This ITO and aluminum promote reflection of incident light 10 from the front side of the substrate 1 on the back electrode,
This is for effectively photoelectrically converting long wavelength light of 600 to 800 nm. Moreover, the ITO prevents aluminum and semiconductor from reacting with each other and causing a decrease in reliability as in the conventional example. These are sputtering method, electron beam evaporation method or plasma CVD method.
300℃ to avoid deteriorating the semiconductor layer.
Formed at the following temperatures:

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 is preferable. On the other hand, if the semiconductor on the back side is a P-type semiconductor, a transparent conductive film whose main component is a tin compound of tin oxide (SnO ₂ ), tin nitride (Sn ₃ N ₄ ), antimony nitride (SbN), or a mixture thereof is used. 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 forming the lower first electrode at the contact 8 . This results in an oxide or nitride 37 - oxide or nitride 23 contact 8, one of which is not metal, as shown in the conventionally known structure (FIG. 1). For this reason,
Even in a temperature test of 150℃, there was no deterioration or reaction progress.

In this way, as shown in FIG. 2C, a photoelectric conversion device in which a plurality of elements 31 and 11 were connected in series through the connecting portion 12 could be manufactured.

FIG. 2D shows an attempt to further complete the present invention as a photoelectric conversion device. That is, a silicon nitride film 21 was formed as a passivation film to a thickness of 500 to 2000 Å by a photo-CVD method or a plasma vapor phase method. Further, external lead terminals 5 were provided, and these were filled with an organic resin 22 such as polyimide, polyamide, Kapton, or epoxy.

Thus, when irradiation light 10 is irradiated with AM1 (100 mW/cm ² ) on a photoelectric conversion device panel integrated with a substrate (10 cm x 10 cm) as in this example, open circuit voltage is 12.315 V, fill factor is 0.599, and short circuit current is 77.89 mA. It was possible to provide an output with a current density of 16.974 (mA/cm ² ) and a conversion efficiency of 8.33%.

However, if the same steps are used but only the step of filling the organic resin of the present invention shown in FIG. 2B is omitted, only the following conversion efficiency can be obtained. That is, Sample 1 Sample 2 Open voltage 11.49V 3.02V Fill factor 0.471 0.316 Short circuit current 53.7mA 54.20mA Conversion efficiency 4.43% 0.75% These show 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. 3A, a non-light-transmitting substrate having an insulating surface in which an inorganic insulating film 41 such as a heat-resistant organic resin or enamel was formed on a conductive stainless steel foil 40 having a thickness of 10 to 100 μm was used. Furthermore, a conductive film for the lower electrode is applied over the entire upper surface, such as chromium (200 Å), aluminum (1500 Å) + SnO ₂ (200 Å).
~400Å), aluminum (1500Å) + Sn ₃ N ₄
(500 Å) or a transparent conductive film (1500 to 2000 Å) mainly composed of tin oxide or tin nitride doped with a halogen element is formed by vacuum evaporation, LPCVD, plasma CVD, spraying, or sputtering. Ta.

After this, control the microcomputer and YAG
Irradiation was performed using a laser processing machine (wavelength: 1.06μ or 0.53μ) to form patterning grooves 13.

The open groove formed by patterning has a width of approximately
The length was 10 cm, and the width of each element 31, 11 was 10 to 20 mm. The conductive film 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 was formed on the upper surface by plasma CVD or optical CVD to a thickness of 0.2 to 1.0 μm, typically 0.5 to 0.7 μm. A typical example is an N-type semiconductor (200 to 500
Å) - I-type amorphous or semi-amorphous silicon semiconductor (0.4~0.9μ) - P-type semiconductor (SinC _1-X X = 50~150Å) It was made into a crystalline semiconductor.

or N-type semiconductor (300-1000Å) - I-type
SixGe _1-X (0<X<1) Amorphous semiconductor-P
Type SixC _1- x semiconductor - N type silicon reaction pair - I type amorphous Si semiconductor - P type SixC _1-X (0<X<1)
Tandem type made of semiconductor (50-200Å)
NIPNIP...A NIP junction semiconductor may also 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, many voids 6 and pinholes 6' are undesirably present in this semiconductor due to reasons such as flakes (snowflakes) adhering to the film during film formation and detaching after the film is formed. The number can be seen under a microscope with a magnification of 100 to 1000 times.
As many as 2 to 4 individuals may be observed per 10 visual fields.

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

After forming the semiconductor shown in FIG. 3A, 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, etc. This photosensitive organic resin is a photoresist sold by Tokyo Ohka Co., Ltd.
A positive photoresist such as OFPR-800 was used.
After that, the same treatment as in Example 1 was performed.

Thus, as shown in FIG. 3B, the organic resin insulator 7, is selectively applied only to the pinholes 6, 6'.
7' can be filled.

Furthermore, as a next step, as shown in FIG. 3B, 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.

Thus, by forming the second groove 18, the side surfaces 8 and 9 of the first electrode were exposed. The side surface 9 of this second groove may be on the left side of the side surface 16 of the first electrode 37', and as an extreme example, as shown in the drawing, the side surface 9 of the second groove may be inside the first electrode 37. Good too. Furthermore, this patterning can expose the surface of the first electrode (as shown in FIG. 14) without patterning the conductive film 2, even if it exposes the side surface 8 as shown in FIG. 1B. Good too.

Thereafter, a second electrode was formed using a transparent conductive film using a metal mask. That is, this second electrode is made of a transparent conductive film 23 with a thickness of 300 to 1400 Å, such as ITO (indium tin oxide), In ₂ O ₃ (indium oxide), SnO ₂ (tin oxide), ITN (indium tin nitride). (a mixture of indium nitride and tin nitride).

In order to prevent the formation of a conductive film in the grooves 20, a metal mask is placed on the semiconductor shown in FIG. A transparent conductive film was formed at a temperature of 300°C or lower, which does not cause deterioration.

In this way, as shown in FIG. 3C, a photoelectric conversion device in which a plurality of elements 31, 11 were connected in series at the connecting portion 12 could be manufactured.

FIG. 3D shows an attempt to further complete the present invention as a photoelectric conversion device. That is, these were filled with an organic resin 22 such as polyimide, polyamide, Kapton, or epoxy.

Thus, when AM1 (100 mW/cm ² ) is irradiated on a photoelectric conversion device panel integrated with a substrate (10 cm x 10 cm) as in this example for irradiation light 10, the following will be obtained: Open circuit voltage 11.30 V Fill factor 0.626 Short circuit current 79.4 It was possible to provide an output with a mA current density of 17.31 mA/cm ² and a conversion efficiency of 8.16%.

However, if the same steps are used but only the step of filling the organic resin of the present invention shown in FIG. 3B is omitted, only the following conversion efficiency can be obtained. That is, open voltage 6.54V fill factor 0.368 short circuit current 75.69mA conversion efficiency 3.48% These show how effective it is to fill the pinholes of the present invention with organic resin.

FIG. 4 compares the reliability test (150° C., high temperature storage condition in the atmosphere) between the present invention and the conventional example.

The curve 25 in FIG.
The configuration shown in the figure is such that the back electrode has a structure in which aluminum is in close contact with the semiconductor, and the connecting portion is of the tin oxide-aluminum contact type.
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, the value can drop to less than 50% of the initial value with just a few numbers.

Further, a 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 represents 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 you make 10 pieces of 10cm□, you can get a σ (dispersion) of 0.27.

The organic resin mold 22 is covered for fixing the extraction electrode 5, and this panel is, for example, 40cm×
20cm, 60cm x 40cm or 120cm x 40cm, 2 pieces
It is possible to install a NEDO standard panel of 120cm x 40cm by packaging it with a single or single aluminum sash frame.

[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)

[Scope of 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 in which holes or pinholes are present on the electrode, and a step of forming a first electrode on the substrate having an insulating surface. A step of forming a positive photoresist photosensitive organic resin on the semiconductor including the inside of the pinhole, and irradiating light from the photosensitive organic resin side to remove the organic resin filled in the void or pinhole. Filling the voids or pinholes of the semiconductor with an organic resin insulator by including a fixing step, a step of removing unfixed organic resin, and a step of forming a second electrode on the semiconductor. A method for manufacturing a photoelectric conversion device characterized by: 2. 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.