JPH027476A - Amorphous silicon semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve productivity by forming a rear surface electrode layer of a resin containing metal powder to thereby allow screen-printing. CONSTITUTION:A rear electrode layer is formed at a position corresponding to a transparent electrode layer 12 as a second electrode layer 16 on a transparent substrate 10 to which an amorphous silicon-containing semiconductor layer 14 is bonded, and an amorphous silicon-containing semiconductor element 18 is made up of a first electrode layer (transparent electrode layer) 12, the amorphous silicon layer-containing semiconductor layer 14 and the second electrode layer (rear electrode layer) 16. The rear electrode layer 16 is formed by printing the paste made of metal powder mixed with a resin into a predetermined pattern by e.g., a screen-printing, and then by being set. The powder-like metal to be used is one that can have an ohmic contact with amorphous silicon and both conductive and thermally resistant; preferably Ni, Cr, Ti, and Mo.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an amorphous silicon semiconductor device and a method for manufacturing the same.

[Conventional technology]

Amorphous silicon semiconductor devices are the third example.
As shown in the figure, it is composed of l or a plurality of amorphous silicon semiconductor elements 5 formed by sequentially laminating a transparent electrode layer 2, an amorphous silicon semiconductor layer 3, and a back electrode layer 4 on a transparent substrate 1. . The back electrode layer 4 of this amorphous silicon semiconductor device is formed by depositing a metal material such as aluminum or chromium Cr on a mask with a predetermined pattern after the amorphous silicon semiconductor layer 3 is deposited. Alternatively, it was formed by sputtering.

[Problem to be solved by the invention]

In order to form the back electrode layer 4 by vapor deposition, it is necessary to set the transparent substrate 1 on which the amorphous silicon-based semiconductor N3 is deposited in a vapor deposition apparatus, and also to adjust the position of a mask on which a predetermined pattern is formed. , the work was complicated and time consuming, and the productivity was poor. Furthermore, it was necessary to create a high vacuum inside the vapor deposition apparatus, which required expensive equipment. Moreover, lumps of molten metal are often scattered due to bumping of the metal material during vapor deposition and break through the amorphous silicon semiconductor layer 3, damaging the amorphous silicon semiconductor N3, and this damage reduces the yield of the amorphous silicon semiconductor device. It was also the cause of the decline.

Therefore, the present inventors have made various efforts to improve the productivity and workability of amorphous silicon semiconductor devices.
As a result of extensive research, we have arrived at the present invention.

[Means to solve the problem]

The gist of the amorphous silicon-based semiconductor device according to the present invention is an amorphous silicon-based semiconductor device configured by sequentially stacking a first electrode layer, an amorphous silicon-based semiconductor layer, and a second electrode layer on an insulating substrate. In the amorphous silicon semiconductor device in which at least one element is formed, the first electrode layer or the second electrode layer is made of a resin layer containing metal powder.

Furthermore, the gist of the method for manufacturing an amorphous silicon semiconductor device according to the present invention is to produce an amorphous silicon semiconductor device formed by sequentially laminating a transparent electrode layer, an amorphous silicon semiconductor layer, and a back electrode layer on an insulating substrate. A method for manufacturing an amorphous silicon-based semiconductor device in which one or more elements are formed, including a step of printing a resin containing metal powder in a predetermined pattern to form the back electrode layer, and a step of printing the back electrode layer. The present invention includes a step of heat-treating the processed product.

[For production]

According to the present invention, the second electrode layer for a transparent substrate such as glass as an insulating substrate and the first electrode layer for an opaque insulating substrate such as metal each contain metal powder. It is formed by printing in layers using a printing method that includes coating resin.

A resin layer containing a certain amount or more of metal powder has good conductivity,
Can function as an electrode.

Additionally, since amorphous silicon has more point defects than crystals due to its structure, it has a large interdiffusion coefficient with metals, and is easily alloyed with metals even at relatively low temperatures, making it easy to form ohmic contacts. Therefore, an electrode layer made of a resin layer containing metal powder that is formed in contact with an amorphous silicon semiconductor layer is heat-treated to form an ohmic contact between the metal and the amorphous silicon, and is firmly bonded to the amorphous silicon semiconductor layer. I am made to do so.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings. Note that the drawings are shown enlarged as appropriate for the purpose of explanation.

In FIGS. 1 and 2, the reference numeral 1o indicates an insulating substrate, and the insulating substrate 1O is composed of a transparent substrate such as glass or a polymer film, an opaque substrate such as a metal foil subjected to insulation treatment, or a ceramic substrate. The first electrode Ji12 is deposited on the insulating substrate 10, which may be flexible in addition to the rigid one, and if the insulating substrate 10 is a transparent substrate, the first electrode layer 12 is A transparent electrode layer is formed, and when the insulating substrate 10 is an opaque substrate, a back electrode layer is formed as the first electrode layer 12.

First, a case where the insulating substrate 10 is a transparent substrate will be described as an example.

A transparent electrode layer is formed as a first electrode 1112 on the transparent substrate 10 by sputtering or the like. The transparent electrode layer 12 is made of ITO, Sn0g, ITO/5nOt, or the like, and is formed into a predetermined pattern by photoetching, laser scribing, masking, or the like.

On the plurality of transparent electrode layers 12 formed into a predetermined pattern, an amorphous silicon semiconductor layer 14 is deposited by an ion blasting method, a vacuum evaporation method, a plasma CVD method, a sputtering method, or the like. The amorphous silicon semiconductor N14 is, for example, amorphous silicon a-Si + hydrogen hydrogenated 7 full silicon at
:H + water hydrogenation 7 rulphous silicon carbide a5k
C:H, in addition to those consisting of amorphous materials such as amorphous silicon nitride, they also contain microcrystals, and silicon St.
and carbon C.

Amorphous silicon-based semiconductors made of alloys with other elements such as germanium Ge and tin Sn are pin-type.

pn type, Ml! 9 type, heterozygous type, homozygous type, Schittky barrier type, or a combination of these types.

On the transparent substrate 10 on which the amorphous silicon semiconductor layer 14 is deposited, a back electrode layer is formed as a second electrode N16 at a position corresponding to the transparent electrode layer 12. ) 12, the amorphous silicon semiconductor layer 14, and the second electrode layer (M-plane electrode layer) 16 constitute an amorphous silicon semiconductor element 18.

The back electrode N16 is formed by kneading metal powder with resin to form a paste, printing it into a predetermined pattern by screen printing or the like, and then solidifying it.

The powdered metal used here should preferably be one that can form an ohmic contact with amorphous silicon, has electrical conductivity, and is heat resistant (particularly nickel, Ni, chromium, titanium, Tt, and molybdenum).
'lo is preferred.In addition, conventionally, ohmic contact has been obtained with aluminum AI, silver^g, etc. for silicon Si single crystal, but ohmic contact cannot be obtained for crystalline silicon Si unless it is fired at high temperature. No alloy layer was obtained. However, in amorphous silicon, nickel N
Heat treatment at 150° C. for about 60 minutes with respect to i, etc. causes sufficient interdiffusion, and an ohmic bond can be obtained without denaturing the amorphous silicon due to heat.

In addition, the particle size of the metal powder is preferably about 50 μm or less, and the shape is preferably spherical. In particular, when the particle size of the metal powder is 111 m or less, the film of the amorphous silicon semiconductor N14 Even if the thickness is about 1 μm, the metal powder will not destroy the bond.
An amorphous silicon-based semiconductor device 18 with low leakage current between electrodes is obtained. Therefore, for electronic desk calculators, watches, etc. that are used in low illuminance of about 5QIux,
It can be suitably used. The back electrode layer 16 obtained by kneading metal powder with resin and screen printing does not have metallic luster, and power generation by reflected light on the back electrode J116 cannot be expected, but it is difficult to generate electricity in this example under low illuminance. When an amorphous silicon semiconductor device is used, the amount of incident light is originally small, so the decrease in output is slight and can be ignored.

On the other hand, when using metal powder with a particle size of 50 μm or less, the metal powder may temporarily destroy the amorphous silicon semiconductor layer 14 and cause the amorphous silicon semiconductor element 1B to break down.
Even if the parallel resistance of the amorphous silicon semiconductor element 18 becomes small (in other words, even if the leakage current increases)
Suitable for outdoor use as it has little effect on output.

As the resin that is the binder for the metal powder, thermosetting resins such as epoxy resins and phenolic resins, or reaction-curing resins are used, and it is particularly desirable to use solvent-resistant resins that are insoluble in organic solvents such as acetone and ethanol. The curing conditions or curing acceleration conditions for the resin include a temperature of 120~
L80'C, the time is preferably 20 to 80 minutes, and it is desirable to satisfy the conditions necessary to cure the resin and at the same time make an ohmic contact between the amorphous silicon and the metal contained in the resin. The composition ratio (weight) of the metal powder is 1 part resin to 0.0 parts metal powder.
The number is desirably 5 to 15, and is selected within a range that ensures conductivity and prevents the metal powder from peeling off after the resin is cured.

In this way, resin containing metal powder is printed on the amorphous silicon semiconductor 7114 in a predetermined pattern and solidified by heat treatment to form the back electrode layer 16, and at the same time, the amorphous silicon and the metal are ohmic bonded. There is.

Here, since nickel Nt has excellent affinity with solder, when forming the back electrode N16 using nickel Ni powder, the nickel paste is also printed on the current extraction electrode 20, and the nickel paste is printed on the current extraction electrode 20. is formed 0
The present inventors printed 20 parts of the take-out electrode using a paste made by kneading nickel Nt powder with resin, and then applied 300 parts of eutectic solder containing 1% silver to the take-out electrode 20.
A tin-Sn coated lead wire with a diameter of 0.7 L1m+ was soldered with W and a tip temperature of 300°C. Then, when this lead wire was pulled and a destructive test was performed on 20 parts of the lead-out electrode, it was destroyed with a strength of I kg. This strength was found to be sufficiently larger than the strength of the extraction electrode portion obtained by conventional vapor deposition.

As is clear from the detailed description above, according to this embodiment, after the transparent electrode N12 and the amorphous silicon semiconductor layer 14 are deposited on the transparent substrate 10, a resin containing metal powder is screen printed. However, since the back electrode fii16 is formed by heat treatment at low temperature,
This not only improves productivity but also makes it possible to provide inexpensive amorphous silicon semiconductor devices. Furthermore, ohmic contact can be obtained through heat treatment at low temperatures, and compared to conventional amorphous silicon semiconductor devices in which the back electrode layer is formed by vapor-depositing metal, the quality is not inferior to that of conventional amorphous silicon-based semiconductor devices, which have a high layer yield. Thus, an amorphous silicon-based semiconductor device can be obtained.

Next, a case where the insulating substrate 10 is an opaque substrate such as metal foil will be described. In this case, the resin containing the metal powder described above is screen printed on the opaque substrate 10, and then the back electrode layer (12) is formed as the first electrode layer 12. Then, an amorphous silicon semiconductor layer 14 is deposited in the same manner as described above, and a transparent electrode layer is further deposited as a second electrode layer 16, thereby manufacturing an amorphous silicon semiconductor device.

Here, the amorphous silicon of the amorphous silicon semiconductor 114 and the metal of the first electrode layer 12 are brought into ohmic contact by the heat generated when the amorphous silicon semiconductor layer 14 is deposited. It is desirable to ensure that ohmic contact is obtained.

Although the embodiments of the present invention have been described in detail above, the present invention can be implemented in other forms. For example, the pattern of the amorphous silicon semiconductor element 18 is not limited to the shape shown in the drawings. , which can take various forms.

Further, the number of amorphous silicon semiconductor elements formed on the insulating substrate may be one, or as shown in the above example, a plurality of amorphous silicon semiconductor elements may be formed.
In order to obtain the necessary electromotive force, a plurality of amorphous silicon semiconductor elements are connected in series by connecting the first electrode layer and the adjacent second electrode layer of the amorphous silicon semiconductor elements. Alternatively, a system semiconductor device may be obtained.

In addition, the present invention may be subjected to various modifications and modifications based on the knowledge of those skilled in the art without departing from the spirit thereof.

It can be implemented in an improved manner.

A 1.1m+IrIJ- soda lime glass was used as an insulating substrate, and ITO was sputtered onto the glass substrate by 300 people (surface resistance 80Ω/hole, transmittance 80%).
;550r+m) After depositing, the prescribed 4 as shown in FIG.
An etching pattern was made on the series cells.

Next, amorphous silicon was deposited on the glass substrate covered with the transparent electrode by glow discharge.

150 people and 5,500 people for iN and n-tier, respectively.

Next, nickel paste was printed on the deposited amorphous silicon semiconductor layer using a 5US 250 mesh screen plate, and then cured at 160°C for 60 minutes. A back electrode was formed. The film thickness of the back electrode was 20 μm.

Furthermore, the obtained amorphous silicon semiconductor device was
Heat treatment was performed at 80° C. for 130 minutes to ensure sufficient ohmic contact between the amorphous silicon of the amorphous silicon semiconductor layer and the metal powder of the back electrode.

Here, the nickel paste was created as follows.

First, 50% acid anhydride was added as a hardening agent to the epoxy resin (Epicoat 828), and 3% was added to adjust the viscosity.
0% Cerasolve Acetate was added, and further 1% of a leveling agent (Nippon Uniriki A187) and 1% of an antifoaming agent (Toshiba Silicone SH200) were added to obtain a resin to serve as a binder.

Next, as a metal powder, particle size lum is determined by organic acid salt decomposition.
The following nickel Ni powder (Kujunyu Kagaku ■, product number 811
0101) was mixed at a ratio of 300% by weight to the resin obtained, and then rolled using three rolls with a gap of 0.02
After kneading with m5+ for three passes, vacuum defoaming was performed to prepare a nickel paste.

A performance test was conducted on the obtained amorphous silicon semiconductor device. The light receiving area of this amorphous silicon semiconductor device was 1.6 cm''.

Under F L5Q lux, the short circuit current is l5c=6.8
1! ^/c Ugly” + open circuit voltage is Voc・2.50V, fill factor is FF=62%, output is 10.5a
It was H.

The results are shown in Table 1.

For comparison, a transparent electrode and an amorphous silicon semiconductor layer were deposited on a glass substrate in the same manner as in Example 1, and then aluminum was deposited as a back electrode layer.
An amorphous silicon based semiconductor device was obtained. The light receiving area was 1.6 cm". Under FL50 lux, the short circuit current was 1sc = 6.8 μA/C11 - the open circuit voltage was Vo
c=2-45L film factor is FF-60%,
The output was lO3θμ.

The results are shown in Table 1.

Table 1 For the resin obtained in the same manner as Example 1, the particle size was 50.
A nickel paste was prepared by adding and kneading 10 times the weight of nickel powder having a size of 10 μm or less.

Using this nickel paste, an amorphous silicon semiconductor device was manufactured under the same conditions as in Example 1. However, in this example, the heat treatment (180° C.) after the formation of the back electrode was performed in Example 1.

When the particle size of nickel in the obtained back electrode layer was observed with a scanning microscope, the average particle size was 1.
The diameter was 0 μm, the maximum was 50 μm, and the shape was spherical.

A performance test was conducted on the obtained amorphous silicon semiconductor device, and the result was that the light receiving area was 1.6 cm.

Under F L50 lux, the short circuit current is l5c=6.7
u A/cm''+open circuit voltage was Voc·2.20V, and fill factor was FF·48%.

The results are shown in Table 2.

An amorphous silicon-based semiconductor device was obtained under the same conditions as in Example 2 using nickel having a main grain size of lpm or less. Note that in this example as well, the amorphous silicon-based semiconductor device obtained in the same manner as in Example 2 was not subjected to heat treatment.

As a result of performance tests on the amorphous silicon semiconductor device, the light receiving area was 1.6 cm", F L5
Under 0 lux, the short circuit current is l5c = 6.7 μA/
cg+”, the open circuit voltage was Voc·2.30V, and the fill factor was FF·53%.

The results are shown in Table 2.

When an outdoor device was made using the amorphous silicon semiconductor devices used in Example 2 and Example 3 of Table 2 and compared, no difference was observed depending on the particle size of nickel. This is thought to be because outdoor amorphous silicon semiconductor devices generate a large current and are less susceptible to leakage current (current of parallel resistance components).

〔Effect of the invention〕

In the present invention, the first electrode layer or the second electrode layer, which serves as the back electrode layer, is formed of resin containing metal powder, so screen printing is possible and productivity is improved. It is possible to improve the performance and reduce production costs.

Furthermore, unlike conventional vapor deposition methods, the amorphous silicon semiconductor layer is not destroyed by metal bumping during vapor deposition, resulting in fewer defective products.

Furthermore, heat treatment at low temperatures creates ohmic contact between the amorphous silicon of the amorphous silicon semiconductor layer and the 11iN metal on the back surface, resulting in an excellent bond both electrically and mechanically, resulting in high-quality amorphous silicon. The present invention has excellent effects such as the ability to obtain a system semiconductor device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view for explaining an amorphous silicon-based semiconductor device and a manufacturing method thereof according to the present invention, and FIG. 2 is a front cross-sectional view of a main part of FIG. 1. FIG. 3 is an explanatory diagram showing the structure of an amorphous thin semiconductor device in order to explain a conventional method of manufacturing an amorphous silicon semiconductor device. ; Insulating substrate; First electrode layer; Amorphous silicon-based semiconductor layer; Second electrode layer; Amorphous silicon-based semiconductor element; Take-out electrode Figure 1 Patent applicant Kanekabuchi Chemical Co., Ltd. Figure 3

Claims (5)

[Claims] (1) At least one amorphous silicon-based semiconductor element is configured by sequentially laminating a first electrode layer, an amorphous silicon-based semiconductor layer, and a second electrode layer on an insulating substrate.
1. An amorphous silicon-based semiconductor device in which the first electrode layer or the second electrode layer is made of a resin layer containing metal powder. (2) The amorphous silicon semiconductor device according to claim 1, wherein the metal powder is nickel Ni, chromium Cr, titanium Ti, or molybdenum Mo. (3) The amorphous silicon semiconductor device according to claim 1 or 2, wherein the metal powder has a particle size of 50 μm or less. (4) A claim characterized in that the first electrode layer and the adjacent second electrode layer are connected so that the electromotive forces of the plurality of amorphous silicon semiconductor elements formed on the insulating substrate are connected in series. The amorphous silicon semiconductor device according to any one of Items 1 to 3. (5) A method for manufacturing an amorphous silicon-based semiconductor device in which one or more amorphous silicon-based semiconductor elements are formed by sequentially laminating a transparent electrode layer, an amorphous silicon-based semiconductor layer, and a back electrode layer on an insulating substrate. , an amorphous silicon characterized by comprising: a step of printing a resin containing metal powder in a predetermined pattern to form the back electrode layer; and a step of heat-treating the process product on which the back electrode layer is printed. A method for manufacturing a semiconductor device.