JPS593981A - Manufacture of thin film semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a thin film semiconductor device with less defect parts by removing failure parts by a method wherein defect parts contained in a thin film semiconductor layer are separated from a thin film semiconductor region which serves as a base. CONSTITUTION:An amorphous Si layer 2 having junctions such as P-I-N and P-N is formed to film on a conductive substrate 1 of a large area, and then a clear electrode film 3 is laminated. The large area amorphous Si film is separated into small area amorphous Si regions by means of a chemical or physical method. The electrical performance test for each amorphous Si solar battery separated is performed, and then only normal ones are so connected as to obtain a desired output. An electrode terminal 6 is laminated on each segment, collector wires 7 are adhered by utilizing spaces unnecessitated due to separation, and then the electrode terminal 6 formed on non-defective segment is connected to the collector wire 7. The electrode terminal 6 of a defective segment is not connected.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention describes a method for manufacturing a thin film semiconductor device.

In recent years, amorphous materials such as amorphous silicon,
2. Description of the Related Art Thin film semiconductor devices using microcrystalline or polycrystalline materials are being actively developed. In particular, solar cells are one type of semiconductor device having photoresponsiveness that utilizes this type of thin film semiconductor layer.

Unlike conventional semiconductor devices using single-crystal silicon, thin-film semiconductor devices allow semiconductor layers to be formed on a substrate using thin-film production techniques such as glow discharge and CVD, making it easy to obtain large-area devices. I'm starting to be able to do that. However, since the semiconductor layer is extremely thin, thin film semiconductor devices such as solar cells are often rejected due to trivial defects that occur in the surface condition of the substrate or in the process of forming the semiconductor layer. Particularly in semiconductor devices that require a large area, such as power solar cells, there is a problem in that the larger the area, the more the presence of defective parts will have a greater effect on performance, making the device less economical.

Figure 1 is a cross-sectional view of a conventionally developed Akylphus solar cell, in which a conductive film is coated on the surface of an insulating plate.
'! ! An amorphous silicon thin film 2 and a transparent electrode film 3 are sequentially laminated on a conductive substrate 1 made of non-woven steel or the like. The amorphous silicon thin film 2 is p-
Junctions such as n, p-1-n, etc. are formed, and when the light 4 is irradiated, a photovoltaic force is generated, and the substrate 1 and the transparent electrode film 3
Electricity can be extracted between the

Here, a solar cell 1 is constructed by laminating an amorphous silicon thin film 2 and a transparent electrode film 3 on the conductive substrate 1. In the actual cross-sectional structure, for example, defects 5-+9 on the substrate surface or defects 5-2 in the amorphous silicon thin film are often included, as shown in FIG. Such defective portions 5-1, 5-2 are electrically short-circuited, causing the photoelectromotive force generated by the incident light 4 to be unable to be extracted as output or causing a significant decrease in output.

Defects such as those mentioned above can be avoided using carefully selected substrates.
Even through a strictly controlled manufacturing process, it cannot be completely avoided.

However, as the recent trend is toward larger areas such as solar cells, which use large-area substrates in the same process, these defects only reduce performance. However, there are some that have a large impact in terms of cost.

The present invention has been made in view of the above-mentioned conventional problems, and by separating the defective portions included in the thin film semiconductor layer from the thin film semiconductor region serving as the base, the defective portions are removed and the thin film semiconductor with fewer defects is produced. A manufacturing method for obtaining the device is provided. Next, an amorphous silicon solar cell will be described in detail as an example.

In this example, as in the conventional method described above, an amorphous silicon layer 2 having p-1-n, p-n, etc. junctions is formed on a large-area conductive substrate 1, and then transparent electrodes are formed. Membranes 3 are laminated. The large-area amorphous silicon layer 2 deposited on the surface of the conductive substrate 10 is then segmented into small-area regions, and as shown in FIG. 2(a), the segmented solar cell is exposed to light. In the plan view when viewed from the perspective of a directional force, the shaded region' in the figure is a segmented solar cell region, and the gaps separating each small region are regions for separation.

FIGS. 2(b) and 2(c) are cross-sectional views corresponding to the above-mentioned FIG. 2(a). As a form of dividing the large-area amorphous silicon layer 2 into segments, the method shown in FIG. 2(b) is as follows.
As shown in FIG.
), there are cases where only the transparent electrode film 3 is removed. In the latter case, the amorphous silicon layer will remain, but since the amorphous silicon layer is an extremely thin film, the electric resistance in the in-plane direction is very large, so even if the amorphous silicon layer 2 remains, it is practically not adjacent to the amorphous silicon layer. The large-area solar cells are separated from the area covered by the transparent electrode film, and the large-area solar cells are segmented into small-area solar cells, which perform the same function as the former without the amorphous silicon layer.

The following method can be used to separate the large-area amorphous silicon film into small-area amorphous silicon regions.

1) After applying a resist agent to the areas where the amorphous silicon film is not to be removed, chemical treatment is performed to remove only the transparent electrode film 3 or the amorphous silicon film in the areas where the resist agent is not applied by etching, and then it becomes unnecessary. How to remove the resist agent.

2) After applying a chemical agent such as ink to the part where the amorphous silicon film or transparent electrode film needs to be removed, the entire amorphous silicon film or transparent electrode film is laminated, including on the chemical agent, and then chemical treatment is performed. A method of lifting off the portion of the amorphous silicon film or transparent electrode film that is to be removed together with the applied chemical agent.

3) A method of thermally removing the amorphous silicon film by irradiating the part of the amorphous silicon film to be removed with an electron beam, optical laser, or focused light beam.

4) A stone method in which the part of the amorphous silicon film to be removed is scratched with a sharp mechanical part.

5) Sprinkle water #* on the amorphous silicon film part you want to remove.
:Mechanical removal method by applying a jet stream.

Any separation process using chemical or physical methods described above is technically feasible.

Next, the plurality of solar cells separated into i-segments by the above method are electrically connected in order to extract output. That is, each separated small-area amorphous silicon solar cell is subjected to an electrical performance test, and each solar cell is determined to be normal or defective. Only the selected normal ones are connected in series and parallel to each other so that the desired total output can be derived. Electrical connections are made by laminating electrode terminals 6 on each segment shown in FIG.
The collector wire 7 shown in Figure (d) is pasted using the space that is no longer needed for separation. Based on the result of the above discrimination, the electrode terminals 6 formed on the good segments are connected to the collector wire 7, but the electrode terminals 6 of the defective segments are not connected to the collector wire 7. FIG. 2(d) shows a state 8-1.8-2 in which these connections are not made.

In the above-mentioned 4 repair ('jp), wires were selectively connected based on the results of discrimination between non-defective and defective products, but on the other hand, once all the separated small-area solar cells were connected in advance, It is also possible to form the connection part of a defective product by cutting it.

Although the above embodiments have been described using an amorphous silicon solar cell, the present invention can also be applied to a method of manufacturing a thin film semiconductor device in which a semiconductor device is manufactured by forming a semiconductor layer on a substrate using a thin film technique.

As described above, according to the present invention, since a large-area thin film semiconductor layer is separated into small-area regions, a semiconductor device can be constructed using normal regions except for defective regions containing defects. It is possible to eliminate waste and effectively utilize the semiconductor layer, and it is possible to obtain a thin film semiconductor device that is highly economical.

The present invention is particularly useful for large-area solar cells, and its contribution to cost reduction is significant.In general, according to the present invention, there is no noticeable difference in appearance between the defective segment and the non-defective segment. This also has the effect that, except for minute differences in the connection parts, there is little awareness of defective segments and the design is not compromised.

Furthermore, in addition to the above-mentioned method of segmenting a large-area thin film semiconductor layer into small areas and removing defective parts, if the defective part in the thin-film semiconductor layer can be identified in advance, it is possible to identify only the defective part, including the location and occupied area of the defect. It is also possible to separate it from the base thin film semiconductor layer and use the remaining normal semiconductor region regardless of the situation. Another advantageous effect is that the wiring described in the embodiment is no longer necessary.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the structure of a thin film semiconductor device, and Figure 2 (
a) to (d) are plan views and cross-sectional views showing embodiments of the method according to the invention; 1.'itE substrate 2. Amorphous silicon thin film 3. Transparent electrode film 4. Human radiation 5. Defect part 6 Electrode terminal 7 Collection electrode wire 8 Connection disconnection part

Claims (1)

[Claims] 1) p-1- on a substrate whose surface at least has conductivity;
A step of forming a thin film semiconductor layer with junctions such as n, p-n, etc., a step of separating the thin film semiconductor layer into a plurality of independent regions, and a step of separating the thin film semiconductor layer into a plurality of independent regions; A method for manufacturing a thin film semiconductor device, comprising a step of discriminating a normal thin film semiconductor region, and a step of electrically connecting the extracted normal thin film semiconductor regions to each other. is done by chemical methods such as chemical edge/removal, lino[off], etc.
3. Separation step of the thin film 1'' conductor layer: 1) A method for manufacturing a thin film semiconductor device as described in 1. Thermal methods such as light beams 4
) The separation of the thin film layer is carried out by a mechanical method such as scratching with a sharp machine, scratching with a sharp tool, or a jet stream. 5) The thin film semiconductor layer is separated by removing a part of the thin film semiconductor layer in the thickness direction. The method for manufacturing a thin film semiconductor device according to item 4. 6) The connection of the normal thin film semiconductor regions is selectively performed after discrimination of each separated thin film semiconductor region. Within the scope of claim 1 [method for manufacturing a thin film semiconductor device according to item 2].
% After connecting the thin film semiconductor area, do not cut the connection part of the thin film semiconductor area that corners the defective part! 1 B) A method for manufacturing a thin film semiconductor device as described in claim 1.