JP2000196116A - Integrated thin-film element and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated thin-film element by which the manufacturing yield can be improved, and at the same time, the manufacturing cost can be reduced by forming an ohmic contact without requiring long time by preventing the peeling of the element, and a method for manufacturing the element. SOLUTION: After solar battery elements 10 are transferred to a plastic film substrate 21, a separating groove 31a is formed by projecting a laser beam LB from the substrate 21 side in a direction perpendicular to the arranging direction of the elements 10. Then another plastic film substrate 22, in which a reflecting mirror 23 is formed, is stuck to the rear surfaces of the elements 10 with an adhesive layer 25. Successively, an element isolation layer 31 is formed by filling up the groove 31a with a flexible transparent insulating material, such as EVA, etc. After the formation of the layer 31, through-holes 15a which reach cathodes 13 and anodes 14 are formed by projecting the laser beam LB from the substrate 21 side. Successively, contact electrodes composed of silver paste are formed so as to electrically connect the adjacent solar battery elements 10 to each other through the through-holes 15a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated thin-film element in which a thin-film element such as a solar cell is integrated on a supporting substrate, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, some solar cells have been put to practical use. In order for this solar cell to be used in earnest, it is important to save resources and reduce costs, and consider energy conversion (light-to-electric conversion) efficiency and shortening the energy recovery period. In this case, a thin-film solar cell is preferable to a thick-film solar cell. Furthermore, a thin-film solar cell can be bent to some extent, and can be mounted on, for example, a curved surface of an automobile body or a curved external portion of a portable electric product to generate power. It has the advantage of spreading.

[0003] Therefore, the same applicant as the present applicant firstly
As a preferred method for manufacturing a thin-film solar cell, forming a porous layer as a separation layer on a single crystal silicon substrate,
After growing a semiconductor layer made of thin-film single-crystal silicon to be a solar cell on this porous layer, a thin plastic plate is bonded on the semiconductor layer using an adhesive, and then the plastic plate is removed from the single-crystal silicon substrate. Also, a method of peeling the semiconductor layer has been proposed (Japanese Patent Application Laid-Open Nos. Hei 8-213645 and Hei 10-135500).

By the way, when using a solar cell,
In many cases, several or dozens or more solar cell elements are connected in series and used as an integrated solar cell. When a device composed of a single solar cell element is manufactured using a silicon substrate having a relatively large area, the output current of the battery becomes 1
This is because it reaches 0 A or more, and the energy conversion efficiency is greatly reduced due to the resistance loss.

[0005] An example of a method of manufacturing this integrated solar cell is disclosed in Japanese Patent Application Laid-Open No. 10-15 / 1998.
There is a method disclosed in JP-A-0211. In this method, a semiconductor layer is divided by etching before the semiconductor layer is separated from a silicon substrate, and thereafter, a plurality of solar cell elements are formed. As another method, an electrode serving as a positive electrode is formed on the front surface of the battery, and a metal serving as a negative electrode (for example, aluminum (Al)) is provided on the back surface in the same manner as in the method for manufacturing a thin film solar cell described above. There is a method of producing a plurality of solar cell elements on which electrodes are formed and then electrically connecting the solar cell elements to each other to form an integrated type (Japanese Patent Application No. 9-225076).

[0006]

However, in the method disclosed in Japanese Patent Application Laid-Open No. Hei 10-150211, the semiconductor layer is divided by etching before the semiconductor layer is separated from the silicon substrate. In the process of forming the solar cell element after the division of the semiconductor layer, the thinned portion has a high probability of peeling from the silicon substrate. That is, this method has a problem that the production yield is low.

Further, when the back electrode is made of aluminum, good ohmic contact can be achieved by sintering at 300 to 400 ° C., but in the other methods described above, sintering at such a temperature is not possible. The plastic plate melts. Therefore, sintering must be performed at a low temperature of about 150 ° C., and a long time is required to ensure good ohmic contact, which causes a problem that manufacturing cost is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing problems, and has as its object to prevent the element from being separated, to improve the production yield and reduce the production cost without requiring a long time for forming the ohmic contact. It is an object of the present invention to provide an integrated type thin film element which can be manufactured and a method for manufacturing the same.

[0009]

According to the present invention, there is provided an integrated type thin film device in which a plurality of thin film devices formed on a semiconductor layer are arranged in at least one direction with respect to a flexible supporting substrate. It has a configuration including at least one element isolation layer made of a flexible insulating material between adjacent elements among the thin film elements.

According to a method of manufacturing an integrated type thin film element according to the present invention, a step of forming a semiconductor layer including a plurality of thin film elements on a flexible supporting substrate, and simultaneously irradiating the supporting substrate and the semiconductor layer with an energy beam. Forming a separation groove in the support substrate and the semiconductor layer, separating the semiconductor layer into a plurality of thin film elements, and forming an element separation layer by filling the separation groove with a flexible insulating material. Including.

Another method of manufacturing an integrated type thin film device according to the present invention comprises a step of forming a semiconductor layer including a plurality of thin film devices on a flexible supporting substrate, and a step of forming the supporting substrate and the semiconductor layer by plasma CVM (Chemical Chemical). Vaporization Machinin
g) forming a separation groove in the supporting substrate and the semiconductor layer by selective removal by the method, separating the semiconductor layer into a plurality of thin film elements, and filling the separation groove with a flexible insulating material. Forming an element isolation layer.

In the integrated type thin film device according to the present invention, since the flexible device isolation layer is interposed between the adjacent thin film devices, the stress generated when the thin film device is bent is reduced. For this reason, the plurality of thin film elements are easily bent together with the support substrate.

In the method of manufacturing an integrated thin film device according to the present invention, the support substrate and the semiconductor layer formed on the support substrate are simultaneously irradiated with an energy beam to form a separation groove and to connect the semiconductor layer to a plurality of thin film devices. Separated. After that, the isolation groove is filled with a flexible insulating material,
An element isolation layer is formed.

In another method of manufacturing an integrated thin film device according to the present invention, the support substrate and the semiconductor layer formed on the support substrate are selectively removed by a plasma CVM method to form an isolation groove and to form the semiconductor layer. It is separated into a plurality of thin film elements. After that, the isolation groove is filled with a flexible insulating material, and an element isolation layer is formed.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
1 illustrates a configuration of an integrated solar cell according to an embodiment. FIG. 2 is a simplified view of a part of the cross-sectional structure along the line AA of the integrated solar cell shown in FIG. In FIG. 1, the protective film 33 shown in FIG. 2 is omitted.

This integrated solar cell is constituted by arranging a plurality of solar cell elements 10 electrically connected to each other in one direction (x direction in FIG. 1). These solar cell elements 10 are adhered to, for example, a region except for a region near an end face of a thin plastic film substrate 21 that is transparent and flexible. Each solar cell element 10 is electrically separated from an adjacent element by an element separation layer 31 formed along a direction (y direction in FIG. 1) orthogonal to the arrangement direction of the elements. In the present embodiment,
The element isolation layer 31 is formed of a flexible insulating material, for example, ethylene vinyl acetate (EVA). Adjacent solar cell elements 10 are connected to a contact electrode 15 provided on the surface of a plastic film substrate 21.
Are electrically connected to each other. Note that the plastic film substrate 21 corresponds to the support substrate of the present invention.

The opposite side of the solar cell element 10 from the plastic film substrate 21 (hereinafter referred to as the back side) is shown in FIG.
As shown, a continuous common transparent thin plastic film substrate 22 is provided. The plastic film substrate 22 has, for example, a corrugated uneven surface. Solar cell element 10 and plastic film substrate 2
2, a continuous common reflecting mirror 23 is formed along the uneven surface of the plastic film substrate 22. The reflecting mirror 23 is made of, for example, aluminum (Al) or silver (Ag).
Is reflected, and particularly long-wavelength light that is easily transmitted, is reflected to increase the amount of light incident on the solar cell element 10. The plastic film substrates 21 and 22
For example, it is made of fluororesin, polycarbonate or polyethylene terephthalate. An adhesive layer 24 is formed between the plastic film substrate 21 and the solar cell element 10.
Further, the plastic film substrate 22 and the solar cell element 10 are bonded to each other by the bonding layer 25. These adhesive layers 24 and 25 are respectively made of ethylene vinyl acetate (EVA), ultraviolet curable resin, fluoroplastic (THV), or the like.
Note that the plastic film substrate 22 corresponds to another support substrate of the present invention.

The solar cell element 10 is formed on a semiconductor layer, for example, a semiconductor layer 11 having a thickness of about 1 to 50 μm. In the semiconductor layer 11, for example, a p-type layer 11a having a thickness of 1 to 49 μm and containing a p-type impurity such as boron (B) at 1 × 10 ¹⁵ to 1 × 10 ¹⁸ atoms / cm ³ is formed. The thickness of the p-type layer 11a on the side of the plastic film substrate 21 (hereinafter referred to as the front side) is, for example, 0.05 to 1 μm.
And n-type impurities such as phosphorus (P) at a high concentration (1
N ⁺ -type layers 11b containing about × 10 ¹⁹ atoms / cm ³ ) are provided adjacent to the p-type layers 11a. On the surface side of the p-type layer 11a, for example, a thickness of 0.0
P ⁺ type layer 1 having a high concentration (about 1 × 10 ¹⁹ atoms / cm ³ ) of p type impurities such as boron
1c is formed in a region apart from n ⁺ -type layer 11b.

On the back side of the p-type layer 11a, for example, a p ⁺ -type layer 11d having a thickness of about 1 μm and containing p-type impurities such as boron at a high concentration (about 1 × 10 ¹⁹ / cm ³ ) is provided. Is provided. The p ⁺ -type layer 11d reflects electrons generated in the p ⁺ -type layer 11a by light, reduces recombination of electrons and holes in the p ⁺ -type layer 11c, and increases photoelectric conversion efficiency. It is.

An antireflection film 12 is formed on the surface of the semiconductor layer 11.
Is provided. The antireflection film 12 has, for example, a thickness of 6
The surface of the semiconductor layer 11 (particularly, the n ⁺ -type layer 11) is made of titanium oxide (TiO ₂ ) of about 0 nm.
b) to prevent light from being reflected. Openings are formed in the antireflection film 12 corresponding to the n ⁺ -type layers 11b. n ⁺ type layer 11
A cathode 13 made of, for example, aluminum or titanium palladium silver (TiPdAg) is electrically connected to b through this opening. In the antireflection film 12, openings are formed corresponding to the p ⁺ -type layers 11c. through the opening in the p ⁺ -type layer 11c example A
1 and TiPdAg anodes 14 are electrically connected to each other.

The plastic film substrate 21 and the adhesive layer 24 are formed with through holes 15a communicating with the cathode 13 and the anode 14, respectively. The contact electrode 15 is formed on the plastic film 21. The contact electrode 15 causes the cathode 13 and the anode 14 of the adjacent solar cell element 10 to pass through the through hole 1.
They are electrically connected to each other via 5a. The contact electrode 15 is formed of, for example, silver. Also,
Contact electrodes 1 of solar cell element 10 arranged at both ends
5 are connected to extraction electrodes 32, respectively, so that the electromotive forces generated from the plurality of solar cell elements 10 are extracted by the extraction electrodes 32. The lead electrode 32 is formed of, for example, a copper (Cu) line.

A continuous common protective film 33 for protecting the contact electrode 15 is adhered to the surface of the plastic film substrate 21. The protective film 33 is formed of a transparent plastic material having flexibility, for example, fluororesin or polycarbonate.

In this integrated solar cell, when light is irradiated, a part of the light passes through the protective film 33 and the plastic film 21 and enters the solar cell element 10 to be absorbed. In addition, part of the light transmitted through the solar cell element 10 is:
The light is reflected by the reflection plate 23, enters the solar cell element 10 again, and is absorbed. Electron-hole pairs are generated in the n ⁺ -type layer 11b and the p-type layer 11a that have absorbed light. p ⁺ -type layer electrons generated in 11d and the p-type layer 11a is pulled field enters the n ⁺ -type layer 11b, holes generated in the n ⁺ -type layer 11b enter the p-type layer 11a is drawn to the field . As a result, a current proportional to the amount of incident light is generated and extracted from the extraction electrode 32.

In the integrated solar cell according to the present embodiment, a plurality of elements are bonded to a thin plastic film substrate 21 having flexibility, and an element isolation layer 31 for insulating and separating between elements has flexibility. Since it is formed of a material having the same, it can be easily bent together with the plastic film substrate 21. Therefore, it can be easily installed at various places such as a curved portion of a carport, for example, and the application can be expanded as compared with the related art.

Next, a method for manufacturing the integrated solar cell will be described with reference to FIGS.

First, as shown in FIG. 3A, a silicon substrate 41 for forming a plurality of solar cell elements 10 is prepared. As the silicon substrate 41, for example, 0.01 to 0.02 Ω · c doped with a p-type impurity such as boron is used.
Single crystal silicon having a specific resistance of about m is used. Next, as shown in FIG. 3B, a porous silicon layer 42 is formed on the surface of the silicon substrate 41 by, for example, anodization.

In this anodization method, the silicon substrate 4
1 is used as an anode in a hydrofluoric acid solution, for example, as described in “Surface Technology Vol.46.No.5.p8-
13,1995 [Anodic formation of porous silicon] "
It can be performed by the double cell method. In this method, a silicon substrate 41 on which a porous silicon layer 33 is to be formed is arranged between two electrolytic solution tanks, and a platinum electrode connected to a DC power supply is installed in both electrolytic solution tanks. Then, an electrolytic solution is put into both electrolytic solution tanks, and a DC voltage is applied using the silicon substrate 41 as an anode and the platinum electrode as a cathode. Thereby, one surface of the silicon substrate 41 is eroded and becomes porous.

Here, for example, HF (hydrogen fluoride): C ₂ H ₅ OH as an electrolytic solution (anodizing solution)
(Ethanol) = 1: 1 electrolytic solution, for example, 0.1.
A first porous layer having a small porosity is formed by performing the first stage anodization at a current density of about 5 to 3 mA / cm ² for 8 minutes. Subsequently, for example, 3 to 20 mA / cm ²
The second stage of anodization is performed at a current density of 8 minutes to form a second porous layer having a medium porosity. Furthermore, a third porous layer having a large porosity is formed by performing the third step of anodization at a current density of, for example, 40 to 300 mA / cm ² for several seconds. Incidentally, the third porous layer is a source of a later-described separation layer 42a (FIG. 3C). As a result, a porous silicon layer 42 having a thickness of about 8 μm is formed.

As the silicon substrate 41, from the viewpoint of forming the porous silicon layer 42 thereon by anodization, it is desirable to use a p-type single-crystal silicon substrate. May be used.

Subsequently, the solar cell element 10 is formed on the porous silicon layer 42. That is, first, for example, 11
Hydrogen annealing is performed at a temperature of 00 ° C. for 30 minutes to close a hole existing on the surface of the porous silicon layer 42. Then, for example, as shown in FIG.
2 on a p 2 using a gas such as SiH ₄ or SiCl _4.
^The semiconductor layer 11 composed of the ⁺ -type layer 11d and the p-type layer 11a is epitaxially grown. The growth temperature for epitaxial growth is, for example, 10 when SiH ₄ is used.
70 ° C. and, for example, 114 when SiCl ₄ is used.
0 ° C.

As described above, during the hydrogen annealing and the epitaxial growth, the silicon atoms in the porous silicon layer 42 are moved and rearranged. As a result, the portion of the porous silicon layer 42 where the porosity is large is reduced. Further, a layer having the smallest tensile strength, that is, a separation layer 42a is formed. However, while the solar cell element 10 is formed on the porous silicon layer 42, the separation layer 42a is formed on the silicon substrate by partially or entirely covering the p ⁺ -type layer 11d and the p-type layer 11a. It has a sufficient tensile strength that it does not peel off from 41.

Next, as shown in FIG. 3D, an n-type impurity such as phosphorus is introduced into the p-type layer 11a at a high concentration by ion implantation, for example, so as to correspond to the formation region of the solar cell element 10. N ⁺ -type layer 11b having a thickness of about 0.02 to 1 μm
To form Further, the p-type layer 1 is formed by ion implantation, for example.
A p-type impurity such as boron is introduced at a high concentration into 1a to form ap ⁺ -type layer 11c having a thickness of about 0.02 to 1 μm. n
After forming each of the ⁺ type layer 11b and the p ⁺ type layer 11c, an antireflection film 12 made of titanium oxide is formed on the semiconductor layer 11 by, for example, a sputtering method.

Subsequently, the n ⁺ type layer 11b of the antireflection film 12
An opening is formed by selectively removing a region corresponding to each of p and p ⁺ -type layers 11c. After that, the antireflection film 12
The cathode 13 and the anode 14 made of Al are formed in the openings formed by, for example, the sputtering method. The cathode 13 and the anode 14 are made of TiPd in consideration of the easiness of ohmic contact with the Ag contact electrode described later.
Ag may be used.

After the solar cell element 10 is formed in this way, as shown in FIG.
A plastic film substrate 21 having a larger area, for example, made of fluororesin, polycarbonate or polyethylene terephthalate is prepared, and the plastic film substrate 21 is attached to the surface of the solar cell element 10 with an adhesive layer 2.
4 to adhere.

After bonding the plastic film substrate 21 to the solar cell element 10, as shown in FIG.
The solar cell element 10 is separated from the silicon substrate 41 at the separation layer 42a together with the plastic film substrate 21,
The solar cell element 10 is transferred to the plastic film substrate 21. At the time of peeling, for example, a method of applying a tensile stress between the plastic film substrate 21 and the silicon substrate 41, immersing the silicon substrate 41 in a solution such as water or ethanol, and irradiating ultrasonic waves to form the separation layer 42a Separation layer 42 by a method of peeling with reduced strength, adding centrifugation
The method of peeling off by reducing the strength of a, or a plurality of the above three methods are used in combination.

Incidentally, with respect to the silicon substrate 41 after the solar cell element 10 has been peeled off, if the porous silicon layer 42 remaining on the surface is removed by a usual polishing method, electrolytic polishing or silicon etching, the next solar cell layer 41 is removed. It can be reused in the battery element manufacturing process.

After transferring the solar cell element 10 to the plastic film substrate 21, as shown in FIG.
The separation groove 31a is formed by irradiating a laser beam LB such as a carbon dioxide laser, a YAG (Yttrium Aluminum Garnet) laser or an excimer laser from the plastic film 21 side so as to be orthogonal to the arrangement direction of the solar cell elements 10. In this embodiment, the laser beam L is penetrated from the front surface to the back surface of the silicon substrate 41.
Irradiate B. Thereby, the semiconductor layer 11 is divided,
The solar cell elements 10 are individually separated. For example, if the plastic film substrate 21 and the adhesive layer 24
When it is composed of 0 μm fluororesin and 350 μm EVA resin, or 300 μm polycarbonate and ultraviolet curable resin, respectively, the carbon dioxide laser beam is completely irradiated by irradiating 60 pulses at an output of 18 J / cm ² , for example. The solar cell element 10 can be separated.

In the present embodiment, the area of the plastic film substrate 21 is larger than the area of the semiconductor layer 11, and the silicon substrate 41 is not bonded to a region near the end face of the plastic film substrate 21. Therefore, when the separation groove 31a is formed by irradiating the laser beam LB, even if the semiconductor layer 11 is completely separated for each element by removing the region near the end face of the plastic film substrate 21, the solar cell element 10 can be used. Plastic film substrate 21
There is no danger of leaving.

Subsequently, the porous silicon layer 42 remaining on the back surface of the semiconductor layer 11 is removed by etching.
Here, when the separation surface of the semiconductor layer 11 (that is, the inner wall surface of the separation groove 31a) is broken and the damage layer D is formed when the separation groove 31a is formed, hydrofluoric acid, nitric acid, acetic acid, or the like is used. Then, the damaged layer D is removed using the etching solution. At that time, if the porous silicon layer 42 and the damaged layer D are simultaneously etched and removed, the manufacturing process is simplified, and the manufacturing cost is reduced. This damaged layer D corresponds to the damaged portion of the present invention.

After separating the solar cell elements 10 individually,
As shown in FIG. 5 (B), a plastic film substrate 22 having, for example, a corrugated uneven portion, on which a reflecting mirror 23 made of aluminum, silver, or the like is formed by, for example, a vapor deposition method, is bonded to an adhesive layer. 25 solar cell element 1
0 is adhered to the back side (the lower side in the figure). Subsequently, the isolation groove 31a between the solar cell elements 10 is filled with a transparent insulating material having flexibility, for example, EVA, to form the element isolation layer 31.

After the element isolation layer 31 is formed, a laser beam LB, for example, a carbon dioxide gas laser beam is irradiated from the plastic film substrate 21 side to form a through hole 15 a reaching the cathode 13 and the anode 14. The plastic film substrate 21 and the adhesive layer 24 each have 50
In the case where the plastic film 21 and the adhesive layer 24 are formed of a fluorine resin of 350 μm and an EVA resin of 350 μm, a carbon dioxide laser beam is irradiated with 60 pulses at an output of, for example, 18 J / cm ² to remove the plastic film 21 and the adhesive layer 24 in the corresponding regions. can do. When the plastic film 21 and the adhesive layer 24 are each made of 300 μm polycarbonate and an ultraviolet curable resin, the carbon dioxide laser beam is applied to, for example, 18J.
By irradiating 7 pulses at an output of / cm ² , the plastic film 21 and the adhesive layer 24 in the corresponding regions can be removed.

If the resin forming the plastic film substrate 21 and the adhesive layer 24 remains after the formation of the through hole 15a, the through hole 1
5a, for example, by plasma etching or R
Cathode 1 by IE (Reactive Ion Etching)
3 and anode 14 are completely exposed. This residual resin can be removed by corona discharge.

After forming the through-hole 15a, FIG.
As shown in (1), a contact electrode 15 made of silver paste is formed by, for example, a printing method so that adjacent elements are connected in series. Further, the contact electrode 1
A laser beam LB is applied to a contact portion between the cathode 5 and the cathode 13 and the anode 14 to obtain a good ohmic contact between the cathode 13 and the anode 14 and the contact electrode 15 (laser bonding). When a carbon dioxide laser is used, seven pulses are emitted at an output of, for example, 18 J / cm ² .
Thereby, the anode 14 and the cathode 13 of the adjacent solar cell element 10 are electrically connected. When the cathode 13 and the anode 14 are formed of TiPdAg, as described above, the contact electrode 1 made of silver paste or the like is used.
Since ohmic contact is easily obtained between the substrate 5 and the substrate 5, the ohmic contact can be obtained by performing a heat treatment at about 150 ° C. without irradiating the laser beam LB.

After the solar cell elements 10 are connected to each other, the cathode 13 of the solar cell element 10 at one end in the arrangement direction and the anode 14 of the solar cell element 10 at the other end via contact electrodes 15 respectively. An extraction electrode (output terminal) 32 is formed so as to be electrically connected to the substrate. Finally, a protective film 33 made of, for example, a transparent plastic film is adhered so as to cover the contact electrode 15 and the exposed surface of the plastic film substrate 21, thereby completing the integrated solar cell shown in FIG.

The protective film 33 and the element isolation layer 3
1. If all of the adhesive layer 25 and the plastic film substrate 22 are formed using a transparent or translucent material, a see-through integrated solar cell can be manufactured.
In this case, the separation groove 31a is formed in a region corresponding to 5% to 90%, preferably 30% to 70%, more preferably 30% to 40% of the semiconductor layer 11.

As described above, in the present embodiment, the semiconductor layer 11 bonded to the plastic film substrate 21 is irradiated with the laser beam LB to separate the solar cell elements 10 individually and to form the contact electrodes. Through holes 15a are formed. Therefore, unlike the case where these processes are performed by etching or the like, a mask is not required and processing can be performed in a short time. In addition, since the ohmic contact is obtained by irradiating a laser beam to a connection portion between the cathode 13 and the anode 14 and the contact electrode 15, a good ohmic contact can be obtained in a very short time,
The production yield is improved, and the production cost can be reduced.

Further, after the plurality of solar cell elements 10 are formed, they are separated from the silicon substrate 41 to separate these solar cell elements 10, so that the semiconductor layer 11 is separated from the silicon substrate 41 when forming the solar cell elements. There is no possibility of peeling.

In addition, in the present embodiment, since the plurality of element isolation layers 31 are formed of a flexible material, the stress generated when the solar cell is bent along the element arrangement direction is reduced. As a result, the radius of curvature of the bending can be reduced. Therefore, the use of the solar cell is expanded.

(Second Embodiment) FIG. 7 shows a second embodiment of the present invention.
1 shows a planar configuration of an integrated solar cell according to an embodiment. In this integrated solar cell, in addition to the element isolation layer 31, another element isolation layer 31 ′ crossing, preferably orthogonal to, the element isolation layer 31 is provided, so that the solar cell element 10 can be moved in two directions (x− (y direction). Others have the same configuration, operation and effect as those of the first embodiment. Therefore, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

The element isolation layer 31 ′ is, for example, an element isolation layer 3.
1 is made of an insulating material having the same flexibility. That is, this integrated solar cell can be easily bent in any of the two directions of xy together with the flexible block film substrates 21 and 22.

Here, in the present embodiment, if the separation grooves 31a and the separation grooves 31a 'for forming the element separation layers 31' are formed in a lattice shape by the same method as in the first embodiment, Of the solar cell element 10 is separated from the plastic film substrate 21 and falls off. Therefore, in the present embodiment, after the silicon substrate 41 is peeled off, the plastic film substrate 22 with the reflecting mirror 23 needs to be bonded to the back surface of the semiconductor layer 11 before forming the separation grooves 31a and 31a '. . When the plastic film substrate 22 is bonded, the output of the laser beam is adjusted so that the beam does not completely pass through the plastic film substrate 22, and the separation grooves 31a and 31a 'are formed in the thickness direction. It needs to be terminated on the way. However, since the adjustment of the output of the laser beam is troublesome, the separation groove may completely penetrate the plastic film substrate 22 in any one of the xy directions. Thereby, the solar cell element 10 does not fall off, and the workability of forming the separation groove is improved.

As described above, according to the present embodiment, since the device isolation layers 31 and 31 'which intersect with each other in two directions are provided, the solar cell can be easily bent in two directions. More flexibility than in the embodiment. Therefore, the use of the solar cell can be further expanded.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the above embodiment, and can be variously modified. For example, in the above embodiment, the case where the separation groove 31a is formed by irradiating the laser beam LB has been described, but the plastic film substrate 21, the adhesive layer 24, and the semiconductor layer 11 are formed by plasma CVM
The separation groove 31a can be formed in a short time even if the separation groove 31a is formed by selective removal by a (Chemical Vaporization Machining) method. In this plasma CVM method, atoms having a high chemical activity such as halogen are excited in a spatially localized high-frequency (for example, 150 MHz) plasma in a high-pressure atmosphere (1 atm), and a high-density neutral radical is generated. This is a processing method that removes by converting it to a volatile substance by reacting it with a workpiece (here, a photovoltaic cell element) by generating, and realizing high-speed processing by setting the processing atmosphere to a high pressure. be able to.
Also in this method, the semiconductor layer 1 is formed when the solar cell element is formed.
There is no possibility that 1 is peeled off from the silicon substrate 41.

In each of the above embodiments, FIG.
In the steps (A), (B) and (C), the semiconductor layer 11 is grown on a single-crystal silicon substrate, but the semiconductor layer is grown on a substrate made of amorphous silicon or polycrystalline silicon. You may.

Further, in each of the above embodiments, the integrated solar cell including the transparent plastic film substrate 22 together with the reflecting mirror 23 on the back side of the solar cell element 10 has been described in each of the above embodiments. A configuration may be adopted in which a thin metal film such as aluminum or silver is adhered to the side. However, when bonding the metal thin films, it is necessary to use an adhesive made of an insulating material so as not to short-circuit the solar cell elements 10.

In the above embodiment, the uneven surface (ie, the reflecting surface) of the plastic film substrate 22 has been described as having a corrugated shape. However, by forming the reflecting surface into a random shape having irregularities, the transmitted light can be reduced. May be diffusely reflected toward the solar cell element.

Further, in the above-described embodiment, the solar cell element 10 has been described as an example of the thin film element.
The present invention is widely applied to the case where other thin film elements such as other light receiving elements or light emitting elements, liquid crystal display elements, integrated circuit elements, etc. are provided.

[0059]

As described above, according to the integrated thin-film element according to any one of claims 1 to 11, an insulating material having flexibility between adjacent elements among a plurality of thin-film elements. Since the element isolation layer is provided, the stress generated when the element is bent is reduced. Therefore, the plurality of thin film elements can be easily bent together with the flexible supporting substrate, and can be installed at an arbitrary position in an arbitrary shape.

In particular, according to the integrated thin film element of the ninth aspect, the flexible element isolation layer is provided along two directions intersecting each other, so that it is flexible in two directions, and is more convenient and convenient. It has excellent applicability.

According to a method of manufacturing an integrated thin film device according to any one of claims 12 to 29,
Since the semiconductor layer is separated into a plurality of thin film elements by irradiating an energy beam and forming a separation groove in the semiconductor layer, a mask is not required unlike the case where the separation layer is formed by etching or the like. In addition, the separation groove can be formed in a short time. Therefore, the production yield can be improved and the production cost can be reduced.

In particular, according to the method of manufacturing an integrated thin film device according to claim 25 or 26, after transferring a semiconductor layer including a plurality of thin film devices to a supporting substrate, the semiconductor layer is separated into a plurality of thin film devices. Accordingly, there is no possibility that the semiconductor layer is separated from the semiconductor substrate when the thin film element is formed on the semiconductor substrate, thereby improving the production yield.

Further, any one of claims 15 to 17
According to the method for manufacturing an integrated thin film element described in the section, in addition to the formation of the separation groove, the opening for forming the wiring is formed by irradiating the energy beam, thereby further reducing the manufacturing cost. can do.

Further, according to the method of manufacturing an integrated thin-film element according to the sixteenth aspect, the ohmic contact between the electrode and the wiring is made by irradiating the energy beam, so that a good ohmic contact can be obtained in a short time. be able to. This also has the effect of improving the manufacturing yield and production efficiency.

In addition, according to the method of manufacturing an integrated thin-film element of the present invention, the semiconductor substrate is formed by selectively removing the supporting substrate and the semiconductor layer by the plasma CVM method to form a separation groove in the semiconductor layer. Since the layer is separated into a plurality of thin film elements, a separation groove can be formed in a short time. Therefore, the production yield can be improved and the production cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating an overall configuration of an integrated solar cell according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view for explaining an internal structure of the integrated solar cell shown in FIG.

FIG. 3 is a cross-sectional view illustrating a manufacturing process of the integrated solar cell illustrated in FIG.

FIG. 4 is a sectional view illustrating a manufacturing step following FIG. 3;

FIG. 5 is a sectional view illustrating a manufacturing step following FIG. 4;

FIG. 6 is a sectional view illustrating a manufacturing step following FIG. 5;

FIG. 7 is a plan view illustrating a configuration of an integrated solar cell according to a second embodiment of the present invention.

[Explanation of symbols]

10 ... solar cell element, 11 ... semiconductor layer, 11a ... p-type layer, 11b ... n ⁺ -type layer, 11c, 11d ... p ⁺ -type layer, 1
2: anti-reflection film, 13: cathode, 14: anode, 15: contact electrode, 15a: through hole, 21: plastic film substrate (supporting substrate), 22: plastic film substrate (other supporting substrate), 23: reflecting mirror , 24, 25
... Adhesive layer, 31 ... Element isolation layer, 31a ... Separation groove, 32 ...
Leader electrode, 33: protective film, 41: silicon substrate, 42: porous silicon layer, 42a: separation layer

Continued on the front page (72) Inventor Shinichi Mizuno 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5F051 BA15 BA17 DA01 EA02 FA14 GA04 GA05 GA06 GA14 GA20 HA20

Claims (30)

[Claims] 1. An integrated thin-film element in which a plurality of thin-film elements formed on a semiconductor layer are arranged in at least one direction with respect to a flexible supporting substrate, wherein an adjacent element among the plurality of thin-film elements is provided. An integrated thin film device comprising at least one device isolation layer made of a flexible insulating material between them. 2. The integrated thin film device according to claim 1, wherein the thin film device is a solar cell device having a pair of electrodes on a surface of the semiconductor layer. 3. An opening for forming a wiring reaching the electrode of the solar cell element is formed in the support substrate, and an electric connection between the electrodes of two adjacent solar cells through the opening is formed on the element isolation layer. 3. The integrated thin-film element according to claim 2, further comprising a contact electrode for electrically connecting. 4. The semiconductor device according to claim 1, wherein the semiconductor layer is formed in an internal region excluding a region near an end face of the support substrate, and the separation groove is formed through the semiconductor layer only in the internal region of the support substrate. The integrated thin-film element according to claim 1, wherein 5. The integrated thin-film element according to claim 1, wherein the separation groove is formed along a direction orthogonal to an arrangement direction of the thin-film elements. 6. The integrated thin film device according to claim 1, further comprising another flexible supporting substrate bonded to the semiconductor layer on the side opposite to the supporting substrate. 7. The integrated thin-film element according to claim 6, wherein a reflection mirror is provided on a surface of the other support substrate on the semiconductor layer side. 8. The integrated thin-film element according to claim 7, wherein said reflecting mirror has a corrugated or randomly shaped uneven surface. 9. The integrated thin film element according to claim 1, wherein said thin film elements are arranged in two directions intersecting each other, and said separation grooves are formed along each of the two directions. . 10. The integrated thin film device according to claim 1, wherein said device isolation layer is formed of a transparent or translucent material. 11. 5% or more and 90% of the semiconductor layer
11. The integrated thin-film element according to claim 10, wherein an element isolation layer is formed in a region corresponding to the following range. 12. A step of forming a semiconductor layer including a plurality of thin film elements on a flexible support substrate, and irradiating the support substrate and the semiconductor layer with an energy beam simultaneously to form the support substrate and the semiconductor layer. Forming a separation groove and separating the semiconductor layer into a plurality of thin film elements; and forming an element separation layer by filling the separation groove with a flexible insulating material. Manufacturing method of an integrated type thin film element. 13. The method according to claim 12, wherein a laser beam is used as the energy beam. 14. A solar cell element having a pair of electrodes is formed as the thin film element.
4. The method for manufacturing an integrated thin film element according to 3. 15. The method according to claim 15, further comprising the step of irradiating an energy beam from the side of the support substrate to form an opening for forming a wiring reaching the electrode of the solar cell element in the support substrate. 15. The method for manufacturing an integrated thin film element according to 14. 16. A method of forming a wiring layer by using another conductive material different from a material forming the electrode by using the opening for forming the wiring, and irradiating an energy beam with the wiring layer to connect the electrode and the wiring. The method according to claim 15, wherein ohmic contact is made. 17. The method according to claim 16, wherein the wiring is formed after the inner wall surface of the opening is etched to expose the surface of the electrode of the solar cell element. 18. The semiconductor layer is formed in an internal region excluding a region near an end face of the support substrate, and the energy beam is applied only to an internal region of the support substrate to penetrate and separate the semiconductor layer. The method according to claim 12, wherein a groove is formed. 19. The method according to claim 12, wherein the separation groove is formed along a direction orthogonal to an arrangement direction of the thin film elements. 20. The method according to claim 12, further comprising the step of bonding another flexible support substrate to the semiconductor layer on the side opposite to the support substrate. 21. The method according to claim 20, wherein a reflecting mirror is provided on the surface of the other support substrate on the semiconductor layer side. 22. The reflection mirror according to claim 21, wherein the reflection mirror has a corrugated or randomly shaped uneven surface.
A manufacturing method of the integrated thin film element according to the above. 23. Arranging the thin film elements in two directions intersecting with each other, bonding the another supporting substrate to the semiconductor layer, and irradiating the semiconductor layer with an energy beam to thereby separate the separation grooves in the two directions. 13. The method for manufacturing an integrated thin-film element according to claim 12, wherein the method is formed along the following. 24. The method according to claim 12, wherein a transparent or translucent material is filled in the isolation groove to form an element isolation layer. 25. The method according to claim 12, further comprising the step of forming the semiconductor layer on another semiconductor substrate different from the support substrate, and then transferring the semiconductor layer from the semiconductor substrate to the support substrate. Manufacturing method of integrated thin film element. 26. The semiconductor layer is transferred from the semiconductor substrate to the support substrate by forming the semiconductor layer on the semiconductor substrate via a porous layer and using the porous layer as a peeling means. The method for manufacturing an integrated thin film device according to claim 25, wherein: 27. The method according to claim 12, wherein the separation groove is formed in the supporting substrate and the semiconductor layer by irradiating the energy beam, and an inner wall surface of the separation groove is etched to remove a damaged portion. A manufacturing method of the integrated thin film element according to the above. 28. After forming the separation groove by irradiating the energy beam, an inner wall surface of the separation groove is etched simultaneously with a porous layer remaining on the semiconductor layer side after peeling to remove a damaged portion. The method for manufacturing an integrated thin-film element according to claim 26, wherein: 29. The integrated thin film device according to claim 25, wherein a substrate made of single crystal silicon is used as the semiconductor substrate, and the semiconductor layer is formed by growing single crystal silicon on the semiconductor substrate. Manufacturing method. 30. A step of forming a semiconductor layer including a plurality of thin film elements on a flexible supporting substrate; and selectively removing the supporting substrate and the semiconductor layer by a plasma CVM method to form the supporting substrate and the semiconductor layer. Forming a separation groove in the semiconductor layer and separating the semiconductor layer into a plurality of thin film elements; and forming an element separation layer by filling the separation groove with a flexible insulating material. A method for manufacturing an integrated thin film element, characterized by comprising: