JPS60227484A - Semiconductor device manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

The present invention irradiates a non-single-crystal semiconductor in the immediate vicinity of the light irradiation surface side with intense light with a wavelength of 500 nm or less to promote crystallization of a P- or N-type semiconductor layer and an I-type semiconductor layer adjacent thereto, and thereby The aim is to reduce light absorption here (reduce absorption loss). Furthermore, in order to reduce the density of recombination centers near the PI junction or Nl junction interface, this junction interface was made to have the same crystallinity in terms of morphology, although it had an electrical junction.

In the present invention, on the contrary, an amorphous or a non-single-crystalline semiconductor having a low degree of crystallinity is used, in which hydrogen or a halogen element is added inside one layer, and here, on the contrary, photoelectric conversion is performed by increasing light absorption. It is closed.

In particular, in the present invention, in the process before forming an electrode of a transparent conductive film that easily acts as a filter for ultraviolet light on the light irradiation surface side, intense light of 500 nm or less, generally 300 to 450 nm, where the light absorption is large, is applied. Irradiate and table.

So-called photo-annealing was performed to promote crystallization near the surface (1000 Å or less).

In the present invention, the accompanying increase in electrical conductivity due to the subsequent annealing must not interfere with isolation in the integrated structure. Therefore, in the method of the present invention, after this optical annealing, a transparent conductive film for the second electrode is formed, and then this conductive film and the non-single crystal semiconductor underneath are exposed to laser light (Q switch). It was removed "at the same time" using a YAG laser beam. As a result, since the polycrystalline region obtained by laser annealing is also removed, isolation between each cell can be completed without any extra steps, and the desired photovoltaic region of the present invention can be achieved. It has the feature of being able to create a conversion device.

The present invention has a flexible metal foil as a base material, and this seedling soil has an insulating surface coated with a heat-resistant organic resin film or an insulating film with a thickness of 0.1 to 3 μm. This uses a flexible substrate sheet (hereinafter simply referred to as the substrate).

This invention uses a laser scribing method (hereinafter referred to as LS), which is a maskless process, in order to reduce the area required for connecting multiple elements to 1/10 to 1/100 of the conventional mask alignment method. It is characterized by the fact that

In the present invention, a laser beam is irradiated onto the surface to be machined, and the heat of the laser beam is used for LS, or LCSC (laser,
Chemical scribe) is collectively called laser scribe (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. The pattern 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.

Then, a laser beam for LS, for example, a YAG laser (focal length 40n+m, laser beam diameter 25μ) having a wavelength of 1.06 μm or 0.53 μm is irradiated onto this defined position.

Further, it is moved at an operating speed of 0.05 to 5 m/min, for example, llllZ, to create an open groove in a dependent relationship with the previous process.

In the present invention, when the substrate is made of light-transmitting glass, even if the optical annealing of the present invention is performed, this glass substrate absorbs ultraviolet light. It is not possible to encourage

The present invention eliminates the complexity of such processes, forms a semiconductor on a non-light-transparent substrate, and performs ultraviolet annealing when the upper surface is irradiated with light, thereby increasing the yield without increasing the manufacturing process. The object of the present invention is to provide an innovative method for manufacturing a photoelectric conversion device that can increase the conversion rate from about 60% to 87% in the conventional method.

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

FIG. 1 is a longitudinal sectional view showing the manufacturing process of the present invention.

In the drawing, a metal foil surface substrate (6) with an insulating surface treatment is shown, for example, 10 to 200μ, generally 20 to 50μ.
0.1 of polyimide resin (7) on stainless steel foil with a thickness of
〜3μ Generally, the substrate (1) is formed to a thickness of about 1.5μ, and the length is 60cm (in the left and right direction in the drawing).
A medium length of 20 cm was used. Furthermore, a first conductive film (2) was formed over the entire upper surface. That is, the metal film (25) containing chromium or chromium as a main component has a thickness of 0.1 to 0.5μ.
It was formed by sputtering, particularly magnetron DC sputtering, to a thickness of . To improve the properties, add 1 to 50% copper or silver by weight2 to chromium, a reflective metal with high optical reflectance.
With added sublimable (for laser light) metals,
It was preferable that no residue remained during LS. Furthermore, such Cu-Cr (chromium-copper alloy) and Cu-Ag (chromium-silver alloy) are 500 to 700 nm smaller than chromium conductor materials.
The reflected light in the wavelength region was as large as about 10χ, and it was particularly effective for optical confinement devices when reflection from the back surface was used.

Furthermore, on this metal (25), a transparent conductive film containing tin oxide as a main component or ITO (tin oxide indium) to which a halogen element such as fluorine is added is added.
(15) (50-2000 people typically 500-1
A first conductive film was formed using a sputtering method or a spray method.

This first conductive film may be made of only the metal (25), but a blocking layer of tin oxide (13) was extremely effective in preventing the metal from back-diffusing into the semiconductor in a subsequent process. Furthermore, this tin oxide has excellent ohmic contact with the P-type semiconductor layer on its upper surface, and ITO has excellent ohmic contact with the N-type semiconductor layer on its upper surface. It was also extremely effective for improving the reflection effect when increasing the substantial optical path length due to reflection at the electrodes.

After that, a YAG laser processing machine (Nippon Denki type) is used to produce an output of 0.3 to 3- (focal length 40 mm) from the upper side of this substrate.
), and the spot diameter is 20 to 70μφ, typically 40μ.
φ is controlled by a microcomputer, a laser beam is irradiated from above, and a first groove (13) for a scribe line is formed by scanning, and a region (31) between each element is formed.
, (11) The first electrode (37) was produced.

The open grooves (13) formed by LS had a width of about 50 μm and a length of 20 cm, and the depths were completely cut and separated to form the first electrodes.

Thus the first element (31) and the second element (11)
The width of the area that makes up the area is 5 to 40III11, for example 15
It was formed as mm.

Thereafter, a non-single-crystal semiconductor that generates photovoltaic force by light irradiation, that is, a non-single-crystal semiconductor to which hydrogen or halogen elements are added having a PN or PIN junction, is formed on the upper surface by plasma CVD, photo-CVD, or LPCVD. Layer (3) was formed to a thickness of 0.3-1.0μ, typically 0.7μ.

A typical example is P type (SixC, -x O < x < 1
) Semiconductor (approximately 300 people) (42) - Type 1 amorphous or semi-amorphous silicon semiconductor (approximately 0.7
μ'') (43) - A non-single-crystalline semiconductor with one PIN junction consisting of a semiconductor (44) with N-type microcrystals (about 200), or an N-type microcrystalline silicon (about 300) semiconductor - I type semiconductor - P type machine crystallized St semiconductor - P type 5I
XCI-X (approximately 50 people, X=0.2-0.3) is a semiconductor.

Such a non-single crystal semiconductor (3) was formed to have a uniform thickness over the entire surface.

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.

In this drawing, the first and second openings (13), (1
4) are shifted by 50μ between the centers.

Thus, the second opening (18) is the side surface (8) of the first electrode.
, (9) was exposed.

Furthermore, the present invention provides a transparent conductive film (
15) Furthermore, only the surface of the metal film (5) may be exposed, but in order to improve manufacturing yield, the laser beam should be
For example, 0.8- is a little too strong, and this first electrode (
37) in the depth direction. As a result, the connector (30) with the second electrode (38) in FIG.
Even if they are in close contact, the contact resistance generally becomes an oxide-oxide contact (tin oxide-ITO contact) and no insulating barrier is formed at the interface, so there is no abnormality such as increase, and there is no problem in practical use. Ta.

In FIG. 1, a second surface conductive film (5) and a connector (30) were further formed on this upper surface as shown in FIG. 1(C).

Furthermore, an outline of an optical annealing apparatus and method for emitting light with a wavelength of 500 nm or less (generally 200 to 450 nm) in the method of the present invention is shown in FIG.

The irradiated substrate (60) is shown in FIG. 1(B).

The structure before forming the transparent electrode was used as a target substrate in the optical annealing apparatus shown in FIG.

The light source used was a rod-shaped ultra-high pressure mercury lamp with an output of 50 or more (emission wavelength 200 nm to 650 r+m). In particular, a Toshiba ultra-vacuum mercury lamp (KHM-50, output 5KW) was used here. That is, the power supply (50) has a negative voltage of AC200V, 3
0^ and secondary voltage (52) AC4200V, 1.1
~1.6A. Furthermore, in order to suppress the heat generated by the mercury lamp and to prevent the occurrence of thermal annealing due to the heat generated by the substrate, the outside of the mercury lamp was supplied with water from cooling (519, (51')).

The mercury lamp (54) generates short wavelength light of 300 to 450 nm, and at the same time, long wavelength light of 500 nm or more is canted by a filter (59) and condensed by a quartz lens (55).

This mercury lamp had a rod shape with a length of 20 cm, and a cylindrical lens was used for the lens. Furthermore, a shutter (56) was placed before sufficiently condensing the light or between the lens and the mercury lamp.

The linear ultraviolet light thus focused had a width of 100 μm to 2 mm and a length of 18 cm. The energy density was approximately 5K11/a (in the case of a width of 1 mm).

This irradiation light (57) is focused on the irradiated surface and focused
It was moved at a constant speed on the table (61).

In this way, most of the ultraviolet light centered on 300 to 450 nI11 was absorbed into the non-single crystal semiconductor at a depth of 1000 Å or less, and it was possible to crystallize a region much thinner than this surface. In addition, since the annealing in the method of the present invention is photo-annealing, the hydrogen or halogen elements already contained are not degassed.

In addition, since the crystallinity is promoted by photoannealing, it has the dual advantage of being able to reduce the optical absorption coefficient through crystallization without reducing the optical Eg.

However, this means that the interior of one layer, which is the active region, must be kept in a state B (34) with high light absorption, ie, amorphous or low crystallinity, and must not become so-called polycrystalline. On the other hand, in order to selectively reduce the optical absorption coefficient of P or N type or one layer near it, and in addition, to reduce the density of recombination centers at the bonding interface, It is important to achieve polycrystallization (33). From this, it was revealed that selective optical annealing only near the semiconductor surface using short wavelength light is important.

Thereafter, a plurality of second electrodes (39) and (38) were isolated and formed by cutting and separating using a third LS, thereby obtaining a third electrode (20).

This second conductive film (4) is a transparent conductive oxide film (CTF)
(45) was used. Its thickness was formed by 300 to 1500 people.

As this CTF, ITO (a mixture containing indium oxide and tin oxide as main components) (45) which makes good ohmic contact with the N-type semiconductor was formed here. It was also possible to form this CTF with indium oxide as the main component. As a result, the second electrode (3
8), (39) was obtained. As this CTF, a light-transmitting conductive film made of a non-oxide conductive film such as a chromium-silicon compound may be used.

These methods include electron beam evaporation, sputtering, and photolithography.
A CVD method including a CVD method and a photo-plasma CVD method was used to form the semiconductor layer at a temperature of 250° C. or lower in order to prevent deterioration of the semiconductor layer.

Furthermore, the depth of this third opening is determined by not only removing only the second electrode, but also removing the underlying semiconductor layer (3), including the polycrystalline layer (33), and removing the first electrode as well. By exposing a portion of the second electrode, a portion of the second electrode may remain due to variations in the LS irradiation intensity (power density) when forming the groove, making it impossible to electrically separate the two elements. I prevented that.

This laser light also excavates and removes the semiconductor, especially the non-single crystal semiconductor (31) that is in close contact with the lower surface of the second electrode, and especially the polycrystalline semiconductor layer (33) that has high electrical conductivity. The non-single crystal semiconductor in the area was insulated at the same time as this LS, and the two electrodes (38)
, (39) perfected the insulation between them.

For this reason, the CTF of the first electrode on the lower side of the semiconductor is
When the main component is tin oxide, which has better heat resistance than the first electrode, the semiconductor that easily absorbs the thermal energy of the laser beam is selectively removed along with the second electrode material, leaving this first electrode. could be easily formed.

Furthermore, in terms of manufacturing yield, the leakage is 10-5 to 10-7 people/
For seriously defective devices (containing 5 to 10% of the total), add 1 part hydrofluoric acid, 3 parts nitric acid, and 5 parts acetic acid to 5 cm with water.
It is possible to reduce leakage by diluting ~10 times and lightly etching only the surface area to chemically remove silicon and lower oxides in the open grooves along with metal impurities such as indium to a depth of 50 to 200 mm. was effective.

(as shown in FIG. 1(C)), a plurality of elements (
31) and (11) were connected in series at the connection part (4) to create a photoelectric conversion device.

FIG. 1(D) shows an attempt to further complete the present invention as a photoelectric conversion device. That is, a silicon nitride film (21) is uniformly formed as a banshihation film to a thickness of 500 to 2,000 layers by plasma vapor phase method or photo plasma vapor phase method, and the leakage current between each element is caused by adsorption of moisture, etc. This further prevented the outbreak.

Further, an external lead terminal (23) was provided at the peripheral portion.

In this way, each element is exposed to the irradiating light (10) in a substrate (60 cm x 20 cm) as in this example.
．． It is provided on a strip of 35 mm x 192 mm, and furthermore, the width of the connecting part is 150 mm, the external extraction electrode part is 1710 mm, and the peripheral part is 4 mm, so that there are essentially 40 stages within 580 mm x 192 mm, and the effective area (192 m + n x 14.
35mm 40 stages 1102cm2, 91.8χ) could be obtained.

As a result, the segment was 11.3% (1,05 cm2)
If the panel has a conversion efficiency of 6.6% (theoretically 9.1%), the effective conversion efficiency decreased due to the resistance of 40 stages connected in series (AMI (100mW/cm
”)), it was possible to have an output power of 68.4W.

Furthermore, this spring J example & i 40cm x 40
120cm x 120cm x 120cm 40cm N
It is possible to provide a channel for high power according to the EDO standard.

In addition, according to this NEDO standard panel precaution, the top surface of the photoelectric conversion device of the present invention is aligned with the back surface of the glass substrate (opposite the surface of the photovoltaic device), and the wind pressure,
It is also effective to increase mechanical strength against rain, etc.

Furthermore, the details of the present invention will be supplemented by four examples below.

Example 1 This Example 91 is shown in accordance with the drawing in FIG. 1. 1-0, that is, as a metal foil substrate (1) having an insulating coating, a stainless steel foil with a thickness of approximately 50 μm was made of G-column IJ imide resin using PIG. The length of the substrate coated with a thickness of 1.5μ is 5Qcm.
, use the medium 20cm.

Furthermore, the copper on top is 1.0 to 10% by weightbi 2
Add s wt % of chromium to a thickness of 0.1 to 0.2 mm by pouring chromium onto the magnetron, and then add Snow to the top surface to a thickness of 1050 mm.・Produced using the ivy method.

Next, after this, the first open groove is spot 1 flea 50μ, output 0
．． A 5-YAG laser was controlled by a microcomputer at a scanning speed of 13 to 3 IIlZ minutes (3 m/min on average).

The element regions (31) and (11) were set to 15 mm dl.

Thereafter, a non-single-crystal semiconductor having one PIN junction as shown in FIG. 1 was manufactured by a known PCVD method, photo-CVD method, or photo-plasma CVD method.

Its total thickness was approximately 0.7μ.

After that, the first opening of the port was monitored on the TV, and the spot diameter was 50μ, the average output was 0.5W, the frequency was 3KH2, and the first element (31) was shifted by 50μ.
l A second opening (14) was produced by LS at an operating speed of 60 cm/min.

Thereafter, the P-type semiconductor layer was subjected to photo-annealing using the apparatus shown in FIG. Then, the region (33) of this microcrystalized P-type semiconductor layer and the I-type semiconductor layer (45) below it.
) is configured as a polycrystalline region, and this region (
The ■-type semiconductor (34) below 33) could be left as an amorphous or low-grade microcrystalline hydrogen-containing silicon semiconductor.

The crystalline semiconductor (33) has a thickness of about 800 nm, and it became possible to make the optical annealing deeper or shallower by varying the continuous movement speed of the table or by repeatedly applying irradiation.

The thus obtained semiconductor was immersed in 1/10IIF to remove the insulating oxide on the surface, and the entire semiconductor was then immersed in CTF.
A second conductive film (5) and a connector (30) were formed using ITO having an average thickness of 700 mm by sputtering.

Further, the third open groove (20) is similarly connected to the first element (31) by LS to a depth of 50μ from the second open groove (14).
) side to obtain Fig. 1(C).

At this time, the depth of the third groove was such that the bottom reached the surface of the first electrode, as shown in the drawing.

Therefore, the CTF and semiconductor layer were completely removed.

The average power of the laser beam was 0.5 - and the other conditions were the same as those for producing the second open groove.

In this way, FIG. 1(C) was produced.

After the process shown in FIG. 1(C), the first electrode, semiconductor, and second electrode are all rectangularly scanned with laser light output 111 inside the glass edge 411II11, and the panel frame is This prevents electrical short circuits.

After this, the passivation film (21) is formed by converting it into a silicon nitride film of 100% by PCVO method or photo plasma CVD method.
It was manufactured at a temperature of 250° C. to a thickness of 0.0 mm.

As a result, we were able to create 40 stages of 15 mm wide elements on a 20 cm x 60 cm panel.

The effective efficiency of the panel is 8Ml (100mW/cm”
), we were able to obtain 6.7% and a cuff output of 3.8W.

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

Example 2 As a substrate, a stainless steel foil with a thickness of 30 μm and a PIQ coating treatment was used, and the size was 20 cm + n × 60 cm.

Furthermore, one photoelectric conversion device for the calculator is 5CI11×1CI.
A plurality of samples No. 11 were fabricated on the same substrate. Here, the element shape was a 9 mm x 9 mm five-stage continuous array.

The first electrode was a reflective metal chromium-silver (silver 1-10% by weight, e.g. 2.5% by weight) alloy. ITO was formed by the same sputtering method, and the lower second electrode was formed by LS. Furthermore, a non-single crystal semiconductor having an NIP junction was provided on the top surface, and the back surface was further irradiated with light using a mercury lamp.
The vicinity of the surface at a depth of 00 Å or less was made polycrystalline. Furthermore, a second electrode was made using tin oxide (1050 oxide) on the P-type semiconductor. The rest is the same as in Example 1.

The connecting part is 100 μm, and the external electrode is as shown in Fig. 1 (A) (B
) were provided as external lead-out electrode structures at the left and right ends.

As a result, he was able to make 250 calculator devices at once.

Fluorescent cutting knife 50 is considered to be a good product with an effective conversion efficiency of 3.8% or more.
Tested at 0 lx.

As a result, a final production yield of 76% could be obtained.

This can only be achieved by 40-50% using conventional methods,
Considering that the area required for the connecting part was large, it was extremely effective.

The rest is the same as in Example 1.

Furthermore, when cutting from this sheet, automatic cutting became possible using LS using strong pulsed light of 10-15W.

In this example, a photoelectric conversion device is formed between the metal layer and the organic resin by superimposing a transparent protective organic resin (22), for example, 2P (resin that hardens by ultraviolet irradiation) on the upper light irradiation side. It can be made into a structure that sandwiches the material, has flexibility, and can be mass-produced at an extremely low cost.

In the present invention, ultraviolet light was applied using a mercury lamp. However, this wavelength light of 100 to 500 nm is converted into excimer laser.
It was effective to use nitrogen laser, argon laser, etc.

[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 shows an outline of an apparatus for performing optical annealing according to the present invention. Patent applicant χI■

Claims (1)

[Claims] 1. A first electrode made of a metal on a substrate having an insulating surface, or a first electrode made of the metal and a transparent conductive film on the metal, and a first electrode made of a metal and a transparent conductive film on the metal, and 1. A method for manufacturing a photoelectric conversion semiconductor device, comprising the step of forming a second electrode made of a transparent conductive film in close contact with a non-single-crystal nuclear semiconductor capable of generating a photovoltaic force upon irradiation with light. 2. Forming a first conductive film on a substrate having an insulating surface by a metal coating or a metal coating and a transparent conductive film on the metal coating, and irradiating the first conductive film with a laser beam. forming a first groove and dividing the first conductive film into a plurality of predetermined shapes to form a plurality of first electrodes; and photoactivation by irradiating the electrode and the groove with light. A step of forming a non-single crystal semiconductor that generates electric power, a step of irradiating the semiconductor with laser light to form a second trench or hole, and a step before or after forming the second trench. 500 in
a step of irradiating intense light with a wavelength of nm or less, a step of forming a second electrode of a transparent conductive film on the semiconductor and the second groove, and after the step, a second conductive film and A method for manufacturing a photoelectric conversion semiconductor device, characterized in that a plurality of second electrodes are formed by irradiating a first false semiconductor with a laser beam to form third grooves in the second conductive film and the semiconductor. 3. The photoelectric conversion according to claim 1 or 2, characterized in that a region in which crystallization is promoted is formed on or near the surface of a non-single crystal semiconductor by photoannealing. Semiconductor device manufacturing method.