JPS6085572A - Manufacture of photoelectric conversion semiconductor device - Google Patents

Abstract

PURPOSE:To contrive to generate no insulating property on a contact interface in a photoelectric conversion semiconductor device by a method wherein the device is made into a constitution, wherein the first electrode of a photoelectric conversion element and the second electrode of its adjacent photoelectric conversion element are electrically coupled by forming a conductive film made of oxide. CONSTITUTION:A light-transmittig conductive film 37 is formed on the whole surface of a light- transmitting substrate 1. A first opening groove 13 is formed in this film 37 and a first electrode 12 is respectively formed at each interelement region 31 and 11. A non-single crystal semiconductor layer 3, where a photoelectromotive force is made to generate by performing a light-irradiation, is formed on the electrodes 12 and the opening groove 13. A second opening groove 18 is formed in the side way of the opening groove 13 by a laser scribing process. The opening groove 13 and the insulator made of oxide in its vicinity are removed, and at the same time, a group is formed under the electrode 2 of the first element 31. A second electrode 4 on the back surface and a coupling part 30 are formed. Conductive oxide films 45 and 45' are used for forming the electrode 4. As a result, the bottom surface 6 of the film 37 and the electrode 4 can be electrically well coupled, and moreover, there is no possibility that the coupling part 30 is migrated in the semiconductor, because the conductor constituting the coupling part 30 has been constituted of oxide from the first.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a photoelectric conversion element (simply called a photoelectric conversion element) in which a non-single crystal semiconductor including an amorphous semiconductor having at least one junction capable of generating photovoltaic force upon irradiation with light is provided on a transparent insulating substrate. It relates to a photoelectric conversion device that generates a high voltage by electrically connecting a plurality of elements (also referred to as elements) in series.

The present invention relates to a structure of a connecting portion that connects two elements using a maskless process using a laser scribing method (hereinafter referred to as LS).

The arrangement, size, and shape of elements in the device of the present invention are determined by design specifications. However, in order to simplify the content of the present invention, in the following detailed description, the first electrode on the lower side (substrate side) of the first element and the second electrode of the second element disposed on the right side thereof will be described. This description is based on the case where the electrodes (on the semiconductor, that is, on the side away from the substrate) are electrically connected in series.

In such a configuration, the second groove for connecting the first element and the second element not only removes the non-single crystal semiconductor but also removes the first electrode of the first element. A conductive film (hereinafter referred to as CTF) was also removed by LS. Further, a portion of the upper part of the insulating substrate below the second groove is also removed by Zide etching. Then, the oxide conductive film constituting the second electrode of the second element was brought into contact with the upper side (the bottom surface of the CTF) of the group (groove small hole or horizontal hole) created by this side etching, thereby forming a connecting part. It is something.

With this invention, the upper surface of the CTF becomes insulating due to damage caused by laser beam irradiation, so it is possible to create a CT with no decrease in conductivity.
The bottom surface of F was exposed by side etching, and the oxide conductive film extending from the second electrode was brought into contact with this bottom surface (bottom surface contact 1~), thereby reducing the contact resistance to a low value of 1 Ω/cm or less. It is something.

In the photoelectric conversion device of the present invention, particularly the thin film type photoelectric conversion device, each of the thin film layers, the conductive layer for electrodes and the semiconductor layer, has a thickness of 500 μm to 1 μm and a thickness of 0.2 μm to 1 μm, respectively.
It was found that it was 0μ thin and could be manufactured using a computer-controlled automatic mask alignment mechanism by using the Ls method.

As a result, instead of the conventional mask alignment process, the present invention is a maskless process that does not use a mask at all, is extremely simple and highly accurate, and reduces the manufacturing cost of the device, resulting in a manufacturing cost of 500 yen/W. The objective is to provide an extremely innovative photoelectric conversion device that can be manufactured at a price of 100 to 200 yen/W by expanding the manufacturing scale.

The details of the invention are shown below in accordance with the drawings.

FIG. 1 is a longitudinal cross-sectional view showing the manufacturing process of the present invention.
The length (in the left-right direction in the drawing) was 60 cm, and the middle was 20 cm). Furthermore, a light-transmitting conductive film such as ITO (indium oxide/tin oxide mixture, that is, a film in which 10% by weight of tin oxide is added to indium oxide) is applied to the entire upper surface (approximately 1500 people) +SnO, (200 to 400 people)
Alternatively, a transparent conductive film (1,500 to 2,000 layers) containing tin oxide as a main component to which a halogen element such as fluorine was added was formed by vacuum evaporation, LPCVD, plasma CVD, or spraying.

did. Further, this irradiated laser beam was scanned to form a first opening a (13) which was a scribe line.

Each was completely cut and electrically isolated.

After this, the electrode (2) is placed on the top surface of the open groove (13).
2~0.111μ Typically formed to a thickness of 0.5μ (100 people) - r type amorphous or semiamorphous 5
ixCl-xx = 0.9 About 50 people are stacked and 7-ts (
7) Kundem-type l'lNl'IN, ..., PIN junction semiconductor (3) having two piN junctions and one PN junction made of PISixGe I-X semiconductor-N type St semiconductor.

Furthermore, as shown in FIG. 1(B), a first open groove (1
A second open groove (18) was formed over the left side (first element side) of 3) by the second LSI process.

This second open groove may be 30μ or more leftward than the side surface (16) of the first electrode of the second element (11), and may be 30μ to 2μ.
00μ shifted to the first element side. That is, it is characterized in that it is provided over the first electrode position of the first element.

As a typical example of this, as shown in FIG. 2(B), it may enter the inside (9) of the first electrode (37) of the first element (31).

In this drawing, the first and second open grooves (13>, <18
) are shifted by 100μ.

The second open groove (18) thus forms a side surface (8>) of the first electrode.
, < 9) were also exposed.

Further, this substrate was etched for 10 seconds to 1 minute, typically for 30 seconds, with dilute hydrofluoric acid (1/10 liver prepared by diluting 48% HF with 10 times water was used here). In this method, microwaves were used to make fluoride gas such as CF4 into radicals, and the radical shower was used to perform plasma etching in a direction parallel to the substrate, that is, in a direction where side etching was more effective. Then the semiconductor (3
), CTF (2) was able to remove low-grade porous silicon oxide produced by reacting with oxygen in the atmosphere by LS. In addition, part of the glass (silicon oxide) on the substrate was removed, and the thickness was 0.1 to 5μ in the depth direction and 0.1μ in the lateral direction.
A side etch of ~10μ, for example, 0.3μ in depth and 3μ in the lateral direction, was performed. Thus, 4 m (7 m) in Figure 1 (B)
> and the bottom surface (6) of the CTF (37) was exposed.

That is, as is conventionally known, in order to expose the surface of the first electrode, it is impossible to make a good contact because this surface is insulated by the laser beam.

That is, it seems that some silicon oxide remains in the CTF due to the laser irradiation, and the crystal structure of the CTP is modified to become insulating. For this reason, such upper contact l-(
A feature of the present invention is that it does not use T, op contact ). That is, the present invention provides a bottom surface contact (bottom contact) using a bottom surface that is not insulated by laser light.
r+Lact) mainly using electrical connections. Of course, in addition to this bottom contact, a part of the connector (corresponding to (30) in 30
It is effective to promote electrical conductivity. Furthermore, during this connection, it goes without saying that the scales are also connected to a part of the upper surface of the CTF.

In FIG. 1, as shown in FIG. 2(C), a second electrode (4) and a connecting portion (connector><30) on the back surface are further formed on this upper surface, and then a third LS is cut. A third open groove (20) for separation was obtained.

For this second electrode (4), a conductive oxide film (COX45, <45'), which is a feature of the present invention, was used. Its thickness is 7
It was formed to a thickness of 00 to 1400 people.

As this CO, a mixture X45) containing ITOUWI indium tin oxide as a main component was formed here. It is also possible to form CO with indium oxide as the main component. This ITO is deposited using an electron beam evaporation method.
When formed by CVD or PCVD, dust is more likely to occur during film formation than with other metals. Therefore, it is well within group (7) and CTF'(3
7) and electrically connect it to the bottom (6) of the contact 1-
Configuration is now possible. That is, CO is in close contact with the semiconductor (4
5), <45'), and this connector (30)
Since the conductor constituting the conductor is composed of an oxide compound from the beginning, there is no migration during the process, and high reliability can be achieved. Furthermore, a metal (46) from which CO and this metal can be easily removed was formed on the upper surface when forming the third groove by the third LS. Here the chrome was formed to a thickness of 300 to 3000 people.

Furthermore, it is effective to form nickel or copper on the upper surface as an electrode for external connection.

For example, 1050 ITO as CO, 16 chrome
00 people, and nickel was made into a triple structure with 200 to 500 people.

The ITO and reflective metal are used to promote reflection of long wavelength light on the back surface side and to effectively photoelectrically convert long wavelength light of 600 to 800 nm.

Furthermore, nickel is applied to the external lead electrode (2) in the electrode part (5).
This is to improve the adhesion with 3).

Since these do not deteriorate the semiconductor layer using the electron beam evaporation method or the CVl, J method,
Formed at temperature.

ITO, which is CO, is extremely important in the present invention. The effect is as follows: [1] The connection part (
12) forms a contact with the bottom surface of the first electrode (37) of the first element, and since they are both oxides, the insulation at the interface increases during long-term use in this contact part. There is no. That is, if a metal such as aluminum and CTF (37) come into contact, the metal
This reacts with oxygen over a long period of time to produce insulating properties (alumina) at this interface, but in this oxide-oxide contact 1- due to CO, such insulating properties do not occur at the contact interface. Significant improvement in reliability.

[2] The metal (46), <46') of the second electrode is silicon (
3), which prevents field lightning from being diffused into the semiconductor (3) and short-circuiting between the upper and lower electrodes. That is, it is useful for improving the reliability at the back electrode-semiconductor interface in a high temperature storage test at 150 to 200°C.

[3] Promote reflection of long-wavelength light not absorbed in the semiconductor (3) in the incident light (10) by the reflective metal (46), especially when the thickness of the ITO is 900~i, preferably an average of 100 people. With a thickness of 1050 nm, the reflection of long wavelength light of 600 to 800 nm is increased, which is effective in improving conversion efficiency.

[When forming the open groove (20) of the 4-layer FF13 of the present invention, the high temperature of 1800°C or more of the laser beam, especially in the scribe area (
20), the chromium metal (46) penetrates into the semiconductor (3) and the leakage current between the electrodes (39) and (38) increases to 1O-
It is possible to prevent generation of 1A/cin or more. Therefore, it is possible to prevent a decrease in manufacturing yield due to the formation of the third open groove.

[5] In the connector (30) part, the semiconductor, especially the PIN
The presence of CO adjacent to the sensitive active layer behind the semiconductor prevents the metal from migrating.

[6] CO compatible with P- or N-type semiconductors on semiconductors
i.e., in close contact with the N-type semiconductor.
By providing CO whose main component is O or indium oxide, the contact resistance between the semiconductor and the electrode can be lowered, and the fill factor and conversion efficiency can be improved.

Next, in the present invention, C constituting this second electrode is
In order to prevent electrical short circuit between O (45) and connector (3o), the third open groove (2Ω) is connected to the first element region (31
). That is, the electrical isolation between the electrode (39), <38) where the open circuit voltage of the first element is generated is achieved by applying a laser beam (20 to 100μφ, typically 5oμφ) to the second open groove (18). They were formed at a distance of 50 μm. That is, the center of the third open groove (2o) is provided over the first element side at a depth of 30 to 200 μm, typically 100 μm, compared to the center of the second open groove (30).

In this way, the second electrode (4) is irradiated with the third LS laser beam from above to be cut and separated to form an open groove (2o).

Due to this LS, the 100 to 50
4o) Remaining conductor in the open groove between the adjacent first element (31) and second element (11) or This prevents crosstalk (leakage current) from occurring due to conductive semiconductors.

Furthermore, the semiconductor layer under this groove (20) is heated to room temperature to 200°C.
oxidation in an oxidizing atmosphere (2-10 days) or in a plasma oxidizing atmosphere to form silicon oxide (34) to a thickness of 100-1000 μm to reduce the crosstalk between the two electrodes (39), <38 was further prevented.

Thus, as shown in FIG. 1(C), a plurality of elements (
31) and <11) were connected in series at the connecting part (12).

FIG. 1(D) shows the attempt to further complete the present invention as a photoelectric conversion device, that is, a silicon nitride film (21) with a thickness of 500 to
It was formed uniformly to a thickness of 2,000 mm to further prevent leakage current between each element due to adsorption of moisture, etc.

Furthermore, an external lead-out terminal was provided at the peripheral portion (5).

These were filled with an organic resin (22) such as polyimide, polyamide, carboxylic acid, or epoxy.

In this way, the photovoltaic force generated by the irradiation light (10) is transmitted from the bottom contact to the first element of the first element as shown by the arrow (32).
The current flowed from the electrode to the second electrode of the second element, and the series connection could be established.

As a result, on this substrate (60cm x 20cm), each element was placed in a 35mm space with 150
1" 10mm of the external extraction electrode part, 4mm of the peripheral part
Therefore, substantially 580InII+×192IIIllI
It has 40 stages in I, effective area (192+++m x 1
4.35mm 40 stages 1102 c! i.e. 91.8%)
I was able to get

If the segment has a conversion efficiency of 10.8% (1.05 cm), the panel will have a conversion efficiency of 7.7% (theoretically 9.8%, but the effective conversion efficiency will be reduced due to the resistance of the 40-stage connection). decreased X/IMI C1C10O/c+it)
), it was possible to have an output power of 8.1.

Furthermore, when this panel was subjected to a high temperature storage test at 150° C., after 1000 hours, the deterioration was less than 10%, for example, with 20 panels, the worst case was only 4% (X = 1.5%).

This was an astonishing value considering that when a reliability test was conducted under the same conditions using the conventional mask method, as many as 16 panels were rendered inoperable in 10 hours.

FIG. 2 is a longitudinal cross-sectional view and a plan view (end portion) showing the most typical positional relationship of the grooves formed in three tS steps.

The numbers and steps are the same as in FIG.

25th (A) is 1st opening t (13), ff1H
7) Element (31), second element (11), connection part (12)
)have.

Furthermore, the second open groove (18) is provided across the first electrode (2) side of the semiconductor (3) that constitutes the first element, and both of these grooves are removed.

A group (7) is also created by side etching, connecting the CO of the second electrode to the bottom surface (6) of the first electrode.

Therefore, the first electrode (37) of this first element (31)
) and the second electrode (38) of the second element (11) are connected to the opening groove (1) from the second electrode (38) at the connecting portion (12).
8) CO connector (30) extending along the side of the
The bottom surface (6) and side surface (8) of the first electrode (2) are
), and the two elements are connected in series.

This third open groove (20) is shifted to a depth of about 30μ toward the first element (31).

Therefore, the right end portion of the third open groove (20) is provided by hollowing out a part of the :1 connector portion (30).

In this way, the respective second electrodes (4) of the first and second elements (3D, (11) are electrically cut and separated, and the leakage between these electrodes is also reduced to 1 (1-' A /cm (1c
It was possible to reduce the size to below (meaning the order of 10-'A per m width).

FIG. 2(B) shows a top view, and at its end (lower side in the drawing) the first . Second and third open grooves (13), (18
), <20) are provided.

In order to further reduce leakage in this direction, the semiconductor (3
) covers the first electrode (2) to reduce short circuits between the first and second electrodes.

In addition, at the end of the element (bottom side of the drawing), the first electrode (2) was cut and separated at (13'). Furthermore, the milk is a semiconductor (3
) 4 was covered with the material of the second electrode (4), and further this second electrode conductor (4) was separated by a third groove (50) at the outer end side of (13').

This longitudinal sectional view is similar to the end of FIG. 3(A).

In this case as well, a passivation film is formed covering these open grooves (50).

In this drawing, the first, second, and third open grooves 111 are 7
0 to 20μ, with 250 to 80μ in the joint, typically 120μ.

By reducing the spono-diameter of the YAG laser mentioned above based on the technical concept, the area required for this connection part can be further reduced, and the effective area (effective efficiency) as a photoelectric conversion device can be further improved. It has a sexual nature.

FIG. 3 shows the external lead electrode portion of the photoelectric conversion device.

FIG. 3 (A> corresponds to FIG. 1, but the external extraction electrode part (5) has a band (49) that contacts the external extraction electrode (47), and this pad (49) is connected to the second is connected to the electrode (upper electrode) (4). At this time, the pressure on the electrode (47) is too strong and the band (49) is connected to the semiconductor (3) below it.
(49) and (
2) is provided with an open groove (13') to prevent a short circuit.

Further, in the outer part, the first electrode, the semiconductor, and the second electrode are simultaneously cut and separated by an open groove (50) scribed with one LS.

Furthermore, FIG. 3(B) shows that another noxode (48) connected to the lower first electrode (2) is made of a second electrode material (1).
8').

Further, the bar 2 (48) is in contact with an external extraction electrode (46) and is electrically connected to the outside.

Here again, the band (48) is electrically isolated from the adjacent photoelectric conversion device by the open grooves (18'>, (20''>, (50)), and the first electrode (,18') 2) and the bottom contact are made up of (6).

That is, the photoelectric conversion device was covered with an organic resin mold (22) except for the electrode portion (5) (<45), thereby improving moisture resistance.

Also, this panel for example 40cm x 60cm or 6
0cm x 20cm, 40cm x 120cm 2
Packaged by combining 4 pieces or 1 piece in aluminum sash or carbon fiber frame, 120cm
It is possible to provide a high power panel of + x 40 cm NE[IO standard.

This NEDO standard panel can also be bonded with a fluorine-based protective film using Seaflex on the reflective surface side (upper side in the drawing) of the photoelectric conversion device of the present invention to increase its mechanical strength against wind pressure, rain, etc. It is valid.

In the present invention, glass is particularly used as the substrate among light-transmitting insulating substrates.

However, it is effective to use a composite substrate in which aluminum oxide, silicon oxide, or silicon nitride is formed on a flexible organic resin, aluminum, stainless steel, etc. to a thickness of 0.1 to 2 .mu.m.

In particular, when this composite substrate is applied to the above-mentioned embodiment, aluminum oxide is immersed in phosphoric acid, silicon oxide or silicon nitride is immersed in dilute hydrofluoric acid, and a group is created in which the lower side of CTI' is ν-ide etched. I was able to form a one-person contact.

Further, the details of the present invention will be supplemented by describing examples below.

Example 1 This embodiment is illustrated according to the drawing in FIG.

That is, chemically strengthened glass with a thickness of 1.1 as the transparent substrate (1)
mm, length 60 cm, and medium 20 cm were used.

Furthermore, IT 01600 people + 5nOz CTF on top of that
300 people were fabricated by electron beam evaporation.

Furthermore, after this, a first open groove was formed with a spot diameter of 50 μm and a scanning speed of 3 m/min by controlling a YAG laser with an output power of 3 m/min.

Furthermore, the semiconductor for the first electrode is scanned rectangularly at the edge of the panel with a laser beam output of 1 W at a distance of 5 mm inside the edge of the glass. Prevented.

The element region (31) <11> was 15 mm wide.

Thereafter, a non-single crystal semiconductor having one PIN junction as shown in FIG. 2 was manufactured by a known PCVD method.

Its thickness was approximately 0.5μ.

After this, the first element (31) is removed by 100μ from the first groove.
A second open groove (18) was produced as shown in FIG. 2(B) by LS in the atmosphere with an output IW and an output IW at f'M of 50 μφ.

Furthermore, this entire board was immersed in a 1/10 scale for 30 seconds to remove the oxide insulator in the open grooves, and in addition, expose the bottom surface (6) (depth approximately 3μ) of the group (7) and CTF (2). Ta. Furthermore, ITO as CO was formed on the entire surface by electron beam evaporation to an average thickness of 1050 mm, and chromium was further formed on the top surface by electron beam evaporation to a thickness of 1600 mm, thereby forming the second electrode (45) connector ( 30) was constructed.

Further, a third opening m (20) is similarly formed by the third LS to a depth of 100μ from the second opening groove (18), shifted toward the first element (31) side, as shown in FIG. (C) was obtained. The laser beam had an output of IW, and the other conditions were the same as those for producing the second open groove.

In addition, a third groove for electrical isolation from the frame was formed at the periphery of the substrate (FIGS. 2 and 3, 050).

Thereafter, a banshihesion film (21) was formed using PCVD to form a silicon nitride film with a thickness of 1000 mm at a temperature of 200°C.

As a result, it was possible to create 40 stages of 15 mm elements on a 20 cm x 60 cm panel.

The effective efficiency of the panel is ΔMl (100mW/cnl
), we were able to obtain an output of 7.7% and an output of 8.1K.

The effective area is 1102 cal, and the total panel area is 91.
8% could be used effectively.

In this example, as shown in FIG. 1(D), by polymerizing the upper protective organic resin (22),
It has a structure in which a photoelectric conversion device is sandwiched between organic resin sheets, has flexibility, and can be mass-produced at extremely low cost.

In FIGS. 1 and 2, light was incident from the lower translucent insulating substrate.

However, in the present invention, the light incident side is not limited to the lower side, and it is also possible to irradiate light from the upper side by using ITO as the upper electrode, and it is also possible to use a flexible substrate instead of a glass substrate. It is possible.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing the manufacturing process of the photoelectric conversion device of the present invention. FIG. 2 is a longitudinal sectional view of the photoelectric conversion device of the present invention. FIG. 3 is a partially enlarged vertical sectional view of another photoelectric conversion device of the present invention. patent applicant

Claims (1)

[Claims] 1. A step of forming a plurality of electrode regions by forming a first region on a transparent conductive film on a substrate having an insulating surface;
a step of forming a non-single crystal semiconductor that generates a photovoltaic force by light irradiation on the open groove and the electrode region; and irradiation and removal of the semiconductor of the first element and the first electrode thereunder with laser light. After forming a second trench, the trench and the oxide insulator in the vicinity thereof are removed, and the first trench is removed.
forming a group under the first electrode of the device, and forming an oxide conductive film on the semiconductor and the second groove to form a group under the first electrode of the group, and forming a group under the first electrode of the device;
A method for manufacturing a photoelectric conversion semiconductor device, characterized in that the second electrode of the element is connected by the oxide conductive film. 2. In claim 1, the group is made by immersing the second groove on the glass substrate and its vicinity in a hydrogen fluoride liquid and etching it to expose the bottom surface of the transparent conductive film. A method for manufacturing a photoelectric conversion semiconductor device, characterized in that: