JPS6018973A - Photoelectric conversion semiconductor device - Google Patents

Abstract

PURPOSE:To enhance the apparent value of the titled device by a method wherein, when a photoelectric conversion cell is brought into compound form on the substrate having a photoelectric conversion cell on the insulated surface, the disconnected wire between the adjoining cells is formed at 100mum or below, and the electrodes located at the upper part and the lower part of the adjoining cells are joined at the aperture located inside the non-single crystal semiconductor layer. CONSTITUTION:ITO 3 is vapor-deposited on a glass plate 2, a groove 16 of 20-50mum in width is provided using a YAG laser, and cell regions 11 and 13 and external connection terminals 8 and 9 are formed. Amorphous SixC1-x 4 having uniform pin structure is deposited, a penetrated hole 15 of 10-70muphi is provided on a layer 4 and a lower electrode 3 using a laser light (ITO+Al) 5 for the upper electrode is coated, and at the coupled part, the lower electrode 3 and the upper electrode 5 of the cell 11 are ohmic-contacted 17 on the side face of the electrode 3 using the penetrated hole 15, and they are series-connected. Then, a microscopic groove 19 is provided at the point approximately 50mum on the cell 13 side using a YAG laser, an electrode metal 5 and a part of a semiconductor layer 4 are removed, and an oxidizing process is performed, and an insulating material is formed. Lastly, Si resin is coated, and the semiconductor device is completed. According to this constitution, the effective area of the cell can be increased, and the isolated groove between cells can not be seen from the side of glass, thereby enabling to increase the commercial value of the semiconductor device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to combining photoelectric conversion elements or cells (hereinafter simply referred to as cells) on a substrate having an insulating surface.
The cutting line (opening groove) between adjacent cells is set to 100 μm or less, which is difficult to distinguish with the naked eye, and the purpose is to improve the visual commercial value of the device as a whole.

Therefore, in the present invention, a first electrode on a transparent substrate in a cell provided in an active region, a non-single crystal semiconductor that generates a photovoltaic force by light irradiation on this electrode, and a and the second electrode of approximately the same shape,
By adopting a structure with approximately the same arrangement (self-registration region), we can avoid a decrease in manufacturing yield due to deviations in alignment accuracy during compounding, and also because this self-registration region (hereinafter referred to as SG) is created by a scribing method using a laser beam. , 100μ or less (0.1mm) between each cell
(hereinafter) preferably 10 to 100μ.

Conventionally, PIN junctions, heterojunctions, or PINPINs...PIN junctions and multiple PINs have been made mainly of non-single crystal semiconductors, that is, non-single crystal silicon including amorphous silicon.
, an attempt was made to generate photovoltaic force by light irradiation using a bonding method in which PN junctions were stacked.

However, since the upper and lower electrodes of a semiconductor having such a junction are connected in series, the lower electrode of one cell must be electrically connected to the upper electrode of the adjacent cell, and each cell is electrically connected to each other. The necessary condition was that the system be isolated.

FIG. 1 shows a typical example of a conventional structure.

FIG. 1(A) shows a photoelectric conversion device (30) connected to a light-transmitting substrate (2).
) is a plan view seen from the back with the side facing downward.

In the drawing, it has an active region (14) that generates photovoltaic force upon irradiation with light, and an inactive region (15) that blinds the connecting portion (18) that connects each cell (1), (1'). 1st
The vertical cross-sectional views of A-λ and B-B' in Figure (A) are made to correspond (
As is clear from FIGS. B) and (C), in the conventional example, each cell (1),
(1') is a transparent conductive film (CTF) of the first electrode on the glass substrate (2), and (3) is separated between each cell. Further, the semiconductors (4) are connected to each other between each cell. Further, in the inactive region, the upper electrode of the cell (1) is connected to the lower electrode of the cell (1) by the connecting part (12), and this is repeated to connect the five cells to the external electrodes (8>, <
9) A series connection is made between the two. The number and size of these cells are determined by design specifications.

However, at first glance, this conventional structure appears to have a high manufacturing yield because there is only one semiconductor (4). However, in reality, three types of masks are used (a first mask for patterning the first conductive film, a second mask for forming a non-active region, and a third mask for patterning the second conductive film). However, since the first mask and the third mask are not of the self-line type, mask misalignment is likely to occur.

Due to this deviation (that is, a deviation of 1 to 3111 m is quite natural for a metal mask), the effective area of the cell is 20
A substantial reduction of ~40% was found. Furthermore, since a mask is used, the isolation region, which is the opening between the electrodes in the active region of FIG.
1 mm, for example, 0.5 mm, so when cell rjJ is 10 mm, if there is a deviation of 2 mm, the inside of the cell (15
) is 8mm, and during isolation (12) is 2.
5non, and the effective area decreases by nearly 20%.

For this reason, it has been strongly recommended that the combination of upper and lower electrodes be made into a self-registration region in order to improve its efficiency.

Furthermore, in the conventional example shown in FIG.
5) is provided, and this non-active region covers two parts of the entire substrate.
It accounts for 0-30%. For this reason, process efficiency decreases, and it is not possible to reduce manufacturing costs.

For this reason, it is extremely important to create a photoelectric conversion device that does not have non-active regions.

The present invention has been made to achieve this object. That is, in the present invention, only the opening grooves (1J5 to 70μ) for separating the plurality of first electrodes can be seen from the light irradiation surface side. Further, area (15) in FIG. 1(A)
There are no inactive regions such as , and the connecting portions constitute the isolation regions of each cell. In addition, since it is a maskless process that uses a laser scribe (hereinafter simply referred to as LS), the first groove is laminated on a TV monitor, and optical patterning is performed at a predetermined position using the groove as a reference. So-called computer
It is now possible to use the aided self-registration method.

Further, a contact between the first electrode of the first cell and the second electrode of the second cell is provided inside the semiconductor of the substrate (in the center in FIG. 2), and is connected to a transparent conductive film. The effective sheet resistance can be made extremely small. As a result, since the connecting portion was not provided outside the cell, it was possible to significantly improve the efficiency of its effective area.

Furthermore, instead of creating an open trench with a structure in which this contact cuts all the semiconductor between adjacent cells, the open trench (10
By discontinuously providing one or more grooves (up to 60μφ), the presence of these grooves can be seen with the naked eye from the glass surface side, and the scribe line does not become an eyesore on the product. It has the characteristics of

In addition, since the contact is an open hole, all the sides around the hole can form a connecting part between the first electrode and the second electrode, reducing the contact resistance in this part to 1Ω or less. I was able to do that.

The present invention has many such features, and details thereof will be described below with reference to the drawings.

FIG. 2 shows the manufacturing process and apparatus of the photoelectric conversion device of the present invention.

In the drawings, a substrate (eg, glass) having an insulating surface is used as the substrate. This drawing shows a case where four cells are connected in series. That is, the photoelectric conversion device of the present invention uses a larger substrate of 20 cm x 60 cm, which has 10 to 500 active regions (14) on the same substrate.

In each cell, a first conductive film was formed over the entire surface of the base. Furthermore, this conductive film is shaped into a predetermined shape using a laser (here, 1.06
YAG with a wavelength of μ or 0.53μ, or 0.48
The first open groove (16
) was formed. Then, a cell region (11), <13) and an electrode part for external connection (8>, <9'') were formed.The diameter of this laser beam is generally 30 to 50μ (3μ is also possible from a structural standpoint). However, considering the yield, a relatively long focal length of 30μ was used), so the inside of the first open groove was set to 10 to 70μ, preferably 20 to 50μ.

A plan view of FIG. 2(A) and a longitudinal sectional view taken along line AA' are shown. In (A-1), the first transparent conductive film (CT
A first electrode (3) was formed on the substrate (2).

This CTP is formed by stacking ITO (indium oxide containing 10% or less of tin oxide) or tin oxide in a single layer or in multiple layers. Generally, it is formed to a thickness of 500 to 2,500 layers using a well-known electron beam evaporation method.

Next, as shown in FIG.
6) A uniform film thickness is formed on all the upper surfaces. Furthermore, a vertical cross-sectional view of 13-B and CC' in FIG.
, (B-2).

This semiconductor (4) is, for example, 5ixC+-4 (0< x
< 1 In general, the P type with x = 0.7 to 0.8) is about 1
A semiconductor whose main component is silicon to which hydrogen or a halogen element is added is added to a thickness of 0.4 to 0.00 mm.
6μ thick and further N-type microcrystalline silicon or N
5ixC+-x (0< x < IX ~0.
9) as a main component of the semiconductor PIN junction structure.

Of course, this is P (SixC1-< x =0.7~
0.8 ) I (St)-N (μC3i)-P
(SixC,, x =0.7~0.8) 1(Si
xGe+-qx=0.6~0.8)-N(#
It may also be a tandem structure of PINPIN structure such as C5i).

Next, the pattern shown in FIG. 2(C) was formed. Figure 2 (C
) is a longitudinal cross-sectional view corresponding to D-D' and E-E' of (C-1
>, shown in (C-2). As is clear from this drawing, in the connecting portion (12), the first electrode (3) of the cell (13) and the second electrode (5) of the cell (11) make ohmic contact with each other through the second open groove ( 15). In particular, the contact I-(17) in the connection part (12) is achieved on the side surface of the first electrode created by the second opening (15) and has a so-called side contact structure. In other words, it is sufficient for the two cells to have a second open electrode contact with a diameter of only 10 to 70 μΦ, and the material constituting the second electrode is electrically connected in series to this portion in close contact. As is clear from the longitudinal cross-sectional view of (C-1), the second electrode (5) is merely formed on the semiconductor (4). This second electrode was formed by forming ITO to a thickness of 100 to 1,300, for example, 1,050, and further forming a metal whose main component was aluminum to a thickness of 500 to 2,000. Of course, if reliability is not important, ITO may be removed. Moreover, ITO alone was sufficient for this electrode.

In order to improve the characteristics by utilizing the reflectivity of the back electrode, the above-mentioned ITO÷AI or ITO+Ag was preferable.

After this, the laser star live (19
) was carried out. This is a YAG laser (wavelength 1.06μ, 0
．． After forming the second conductive film of 53μ), while monitoring the first open groove on a TV monitor,
An open groove was made at a position on the 00μ second cell side (13). The average output of the laser beam is 0.3 to 0.5, the beam diameter is 30 to 50 μφ, and the beam scanning speed is 1 to 10 m.
/min Generally, the speed was set at 3 m/min.

The trench (19) was formed by removing at least a portion of the underlying semiconductor of the second conductive film and oxidizing it to form an insulator.

As is clear from this drawing, the first electrode (3), the semiconductor (4), and the second electrode (5) are arranged on a transparent substrate (2) having an insulating surface with a diameter of 10 to 100 μm, preferably 20 to 20 μm. 5
The scribe lines (16) having a diameter of 0 μ are provided in approximately the same shape and in the same arrangement.

In FIG. 2(C), organic resin (22
) For example, silicone, epoxy or polyimide from 1 to
It is completed by coating it to a thickness of 20μ.

As a result, as is clear from this drawing, this photoelectric conversion device is
Instead of making a single x5cm photoelectric conversion device on the same size glass substrate, we can create a 20cm x 20cm or 20cm x 60cm or 40cm x 40cm photoelectric conversion device.
It has become possible to fabricate multiple photoelectric conversion devices on a large glass substrate at once. And finally these 1
It can be divided into individual photoelectric conversion devices using a glass cutter.

To this end, instead of creating an active region and a non-active region as conventionally known, all are essentially active regions and a first electrode, a semiconductor and a second electrode are formed on the substrate. It is possible to simply form a homogeneous film, and the structure of the present invention having a connecting portion therein is extremely superior in efficiency (number of good products that can be produced with the same substrate).

Of course, a large number (100 to 100
Even in the conventional example shown in FIG. 1, it is not impossible to produce o photoelectric conversion device substrates and finally divide them. However, in such cases, precision of alignment of the mask substrate is required,
Furthermore, since it is extremely difficult for the mask to lift off from the substrate, conventional methods have their own limitations.

Furthermore, as is clear from Fig. 2 <C>, the effective area of the cell is all but a very small part of the 10 to 300 μm of the connecting part (12), and the effective area is more than 90%. The structure of the present invention was significantly superior to 80% of the conventional example.

In the pattern of a photoelectric conversion device for a calculator as shown in FIG. 2, the grooves and holes are only in the Y direction or spots, and multiple patterning is not required. For this reason, instead of using mask-specific screening printing methods, which originally feature complex pattern creation and areal patterns,
The conventional method of forming grooves or holes as in the present invention actually improves the effective area and speed of laser light penetration (improving productivity).
Excellent.

Taking these things into consideration, it has been found that the present invention has the following major features.

That is, the present invention makes it possible to adopt a method [1] in which a large number of photoelectric conversion devices are simultaneously fabricated on a large-area substrate, and one photoelectric conversion device is fabricated on each substrate by dividing the photoelectric conversion devices. Therefore, it is possible to manufacture the device at a price of 1/3 to 115 times lower than that of the conventional method. [2] Since the first groove, second hole, and third groove are self-registered and controlled by a computer, the effective area of the cell is large, and each cell made of the same hatch is There is little variation between photoelectric conversion devices [3] The manufacturing yield is high because it is a maskless process [4] The inside of the scribe line of the first groove for isolation between each cell is extremely small, 10 to 50μ, and The second opening is also very small, 10 to 50 μφ, and the third opening is not visible at all from the glass surface side. As a result, it can be confirmed with the naked eye that vibrisolization has been carried out.
We were able to provide high added product value.

In FIG. 2, only one second opening (15) is present inside the semiconductor, particularly near the center. However, even if a plurality of openings (2 to 4 openings) are made between the first and third opening grooves in the Y direction along the broken line, the semiconductor (3
) may be formed along the first open groove (16).

In addition, the positional relationship of the first opening groove (16), the second opening hole (15), and the third opening groove is determined by the connecting portion (12
) is preferably as narrow as possible. However, in practice, it has a diameter of 30 to 100μ, which results in a reduction in effective irradiation area of only 1% compared to the 1 cm (10,000μ) in cells (11) and (13). Therefore, it is possible to overlap the grooves and holes by up to 50%.

The above description is not limited to the pattern of FIG. 2 of the present invention. The number and size of cells are determined by the design specifications. In addition, semiconductors are manufactured by plasma CVD method, reduced pressure C
A VD method, a photo-CVD method, or a photo-plasma CVD method was used.

Applications are possible not only to PIN junctions, heterojunctions, and tandem junctions that have non-single crystal silicon as the main component, but also to many structures.

In the present invention, the irradiation light is irradiated from below as shown in (10) of FIG. 2(C). However, it is also effective to use a substrate having a flexible insulating surface, which is made of metal foil and a heat-resistant inorganic insulating film is formed on the upper surface. That is, a flexible metal film-insulating film-first electrode-semiconductor-second electrode-semiconductor second electrode structure was provided, and at least the second electrode was made translucent.

In this case, it became possible to adopt a light irradiation method from the top.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a conventional photoelectric conversion device. FIG. 2 shows a plan view and a longitudinal sectional view of the photoelectric conversion device of the present invention according to the manufacturing process. Patent Applicant No. 22

Claims (1)

[Claims] (1) A plurality of first electrodes arranged on a substrate having an insulating surface, a photovoltaic force generated by light irradiation provided on the first electrodes and the gap between the electrodes. non-single crystal semiconductor,
and a plurality of photoelectric conversion elements having a plurality of second electrodes provided on the semiconductor corresponding to the first electrodes, the first and second electrodes of adjacent elements are connected to the non-single electrodes. A photoelectric conversion semiconductor device characterized by having a connecting portion electrically connected through an opening provided inside a crystalline semiconductor. 2. In claim 1, the connecting portion is provided with an opening in the first electrode having approximately the same shape as the opening provided in the non-single crystal semiconductor, and on a side of the first electrode. A photoelectric conversion semiconductor device characterized in that materials constituting the second electrode are provided in close contact with each other.