JPS5823489A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a cheap electrode having high reliability by forming a film, the principal ingredient thereof is nickel, through an electroless plating method and using the film as the electrode. CONSTITUTION:The figure shows a NCS1 with a transparent conductive film 3 and P20, I19 and N18 structure on a light transmitting substrate 7. A resist film 31 is formed selectively onto a base body through a screen printing method. The resist film is dried (at 100-200 deg.C generally), and the surface is activated and washed by water. These all surfaces containing the surface 35 of a semiconductor and the surface 36 of the transparent conductive film are activated. The surface is immersed in an electroless nickel plating liquid (Schumer) at 60-90 deg.C, and the metallic film 32, the principal ingredient thereof is nickel, is shaped onto these surfaces through the electroless plating method. The surfaces are lightly washed by water and hot water, the Schumer liquid is removed and the surfaces are heated and dried for thirty min at 100-200 deg.C. The whole is immersed in a resist removing agent, the resist film 31 is removed, and a metallic film 34 or another metallic film 33 on a semiconductor film are formed. The whole is sintered at the temperature of 100-350 deg.C.

Description

Detailed Description of the Invention The present invention provides a non-single crystal semiconductor (amorphous film or A general term for semiconductors formed in the form of a thin film, abbreviated as NO8 in this specification), or the purpose of providing an electrode containing nickel as a main component in close contact with a transparent conductive film provided as an electrode of this semiconductor. .

The object of the present invention is to provide a nickel electrode or a lead extending from the electrode in close ohmic contact with the semiconductor having conductivity type of P or N type constituting the NC8.

By forming a film mainly composed of aluminum using an electroless plating method and using this as an electrode, it is cheaper and cheaper than the conventional electrodes mainly composed of aluminum, which were formed using vacuum evaporation methods. In the present invention, a light-transmitting conductive film made of a metal oxide (indium oxide, tin oxide, atin oxide) or a mixture thereof, typically a nitride metal such as titanium nitride, is collectively referred to in the present invention. Then, a printing resist (simply referred to as TCP) is coated with a printing resist or a photoresist is selectively formed by photoetching, and a metal film, especially a nickel film, is selectively formed only on the regions where no film is formed on this resist or resist. The present invention relates to such selective formation, in which a lift-off method is applied to selectively etching a metal film, and the liquid erodes and erodes NC8 or TCP'. Resulting in. In order to prevent this, another feature is that such an etching solution is not used. Furthermore, the present invention shows that lift-off is possible when electroless plating is applied to a large-area substrate for screen printing, and that it is possible to form electrodes and leads in large quantities at low engineering cost. It is a feature of

Conventionally, a photoelectric conversion device, particularly an amorphous solar cell, is known as a typical semiconductor device in which an NC8 and a TOF are provided on the same substrate. Furthermore, an insulated gate field effect semiconductor device applying this N0EJ (for example, a semiconductor device and its manufacturing method, which is filed by an undiscovered disciple, 53-124)
021 (filed on October 7, 1978) is known.

However, in these semiconductor devices, an aluminum film was formed by vacuum evaporation to form an electrode on the upper electrode, especially on the NO8 formed by plasma OVD or low-pressure CVD. However, the vapor deposition equipment was extremely expensive, costing between 20 million yen and 40 million yen, and the efficiency of use of the materials used to form a film on the raw materials was less than 1%, and the other 99% or more was wasted. Furthermore, since aluminum is evaporated using an electron beam in mass production, the semiconductor surface on which it is formed is damaged by the electron beam.

For this reason, I started trying to make low-cost, large-capacity solar cells. This means that 1o OFl/W, or 100
It is possible to obtain a solar cell with an efficiency of 10 cm at m', and the coating manufacturing equipment is inexpensive at tens of thousands to hundreds of thousands of yen, and importantly, there is no need for semiconductors to produce this coating. No mechanical stress, no sputtering effects, and no damage effects caused by electron beam impact. Furthermore, the heat treatment temperature is 350'C, at which point the recombination center neutralizing element begins to be released to the outside! The temperature below (
5) It has many characteristics such as typically 100 to 250@O.

In addition, in conventional chemical etching of TCF, any acid can be easily etched onto so-called ITO.

Therefore, it was not possible to selectively chemically etch only the upper metal surface with acid, and the only way to form electrodes was to simply use a vapor deposition mask. However, with this vapor deposition mask, gaps between the mask and the substrate were likely to occur. Furthermore, the pattern was likely to become blurry, so it was not an optimal method from an engineering perspective.

In the present invention, instead of etching the metal itself with acid, the metal on the upper side is lifted off by dissolving the resist previously formed on the lower side with an organic solvent such as trichlene. This is a completely innovative method in which it is formed using the so-called lift-off field plating method.

The present invention will be explained below with reference to the drawings.

The flowchart in Figure 3 shows the method of the present invention. - Shows the main steps of the lift-off method.

FIG. 1 is a vertical cross-sectional view showing a photoelectric conversion device, which is a semiconductor device of the present invention, and a method for manufacturing the same. In FIG. 1(A), a transparent conductive film (3) on a light-transmitting substrate (7), pl, NC8 width with Iα inversion Nα frame structure (
The IpP type and N type semiconductor layers (a) and α barrels were formed using a plasma vapor phase method to film thicknesses of 50 to 20 OA and 150 to 30 OA, respectively. Formed. Furthermore, the semiconductor α of having an intrinsic or substantially intrinsic conductivity type is 0.4 to
The film is formed to a thickness of 0.8μ by plasma vapor phase method. Regarding the method for forming this semiconductor film, there is a patent application filed by an unexplored student (Semiconductor device manufacturing method 53-45288).
'i' 853.1210 application) and patent application (Semiconductor device 53-(7) 083467853, F, 8 application Corresponding US patent He
terO Junction Sem1conduct
or Device Haku I (4, 254, 4291
911, 3, 3 public notice).

This process in Figure 1 (A) is for a photoelectric conversion device, but NO8
Or, the base body (general term including the substrate and NC8 or TCF) having at least a part of NO8 and TOF is the second
The process is shown in Figure (1). This may be a photoelectric conversion semiconductor device, an insulated gate field effect transistor, an integrated structure, a photosensor, a photosensor array, an image sensor, or the like. The present invention is effective for any of these semiconductor devices.

Furthermore, in FIG. 1CB), a resist film (31) was selectively formed on these substrates by screen printing. This selectively spreads the resist film through a screen mask.
It was printed to a thickness of ~30μ.

Of course, it is also possible to obtain the image shown in FIG. 1(B) by using the known photoetching method, that is, by coating the entire surface with a resist, curing the resist using ultraviolet light or an electron beam through a photomask, and removing the unhardened portions. The process is shown in Figure 2 (2). Furthermore, this resist film is heated (generally 100~zooc) (3
6) and activated all these surfaces.

i.e. sagetizer (e.g. SnO'1□1g/l
.

3 ml of HCl (remaining water) for 5 to 20 minutes at room temperature. Furthermore, 5 to 2
The surfaces of these substrates were activated by immersion for 0 minutes. Figure 2 (5
), and further coat this surface with an electroless nickel drawing liquid (Schumer) at a temperature of 60 to 90 degrees, for example 70 DC, for 5 seconds to 5 minutes.
After soaking for a minute, a metal film containing nickel as a main component is formed on the surface of the nickel. It may also facilitate ohmic contact to the type semiconductor. In this way, a metal film (32) having a thickness of 500 to 5000 A was formed on the surface by electroless plating.

Thereafter, the Schumer's solution was removed by gentle washing with water and hot water, and the semiconductor surface of the plated film was dried by heating at 100 to 200°C, for example 120°C (9), for 30 minutes.

The t% property with the surface of the transparent conductive film was improved. It is important that this temperature is low enough that the resist film (31) does not harden.

Thereafter, the entire structure was immersed in a resist remover, such as a trichloride solution, and a diluted salt was added thereto to oxidize the resist film (31). As a result, the metal film on the resist film peels off,
As a result, as shown in the cross-sectional view of FIG. 1(C), the TC
A metal film (34) is placed on F and another metal film (34) is placed on the semiconductor film.
3) could be formed. In Figure 2, process (8)
corresponds to

Further, the whole of these is 100-350'O, typically 15
Sintering is performed for 15 to 30 minutes at a temperature of 0 to 200'O, and if necessary, soldering may be performed on the nickel film by immersing it in a hang bath for 5 to 10 seconds. The layer has a conductivity type of P or N type, and its electrical conductivity is typically 10 to 4 or more, which is advantageous because it facilitates ohmic contact.

00) Its contact resistance is 10-0.1. n/mm, there was practically no problem at all.

In Fig. 1, the reliability of the semiconductor device is 100 to 100% because the upper electrode uses nickel, which has higher heat resistance than aluminum, as the main component.
When left at a high temperature of 1$5'O, it improved by 15 to 16 times.

Furthermore, since the lift-off method does not use strong acids such as hydrofluoric acid, nitric acid, sulfuric acid, etc. to form the electrodes, but uses organic solvents such as trichlene, NO8, TC! As F is etched, it is also possible to selectively form bare solder etc. on this metal film to lower the resistance of the film, and to connect it with other MEG (IC) etc. as a component. It has characteristics such as easy to use.

In addition, this process can handle large areas of substrates (10 cm to 5 cm) at one time.
It is possible to control a large amount of 0 cm), and since a vacuum deposition method is not used, depreciation costs are low.

What is more important is that NO8 and TOF are extremely soft and easily damaged materials. The temperature at which the bond between silicon and germanium, which is a semiconductor, is broken is 350°C.
It is preferable in all respects, such as not requiring treatment (temperatures higher than 'C).

In Figure 1 (0), A M 1 (1 oomw/am)
(30) 8.0-12. o%/c
m could be created using a 5 cm' photoelectric conversion device.

FIG. 2 shows the method of the present invention step by step. In the drawings, the metal to be electrolessly plated is a metal whose main component is nickel (including only nickel). However, the method of the present invention is applicable not only to nickel but also to other metals such as titanium and molybdenum.
The same applies to metals.

FIG. 3 shows another embodiment using the present invention.

FIG. 3(4) shows a device in which a plurality of photoelectric conversion devices of FIG. 1(0) are integrated.

In other words, the irradiation layer (30) is selectively provided on the transparent substrate (〒), and the transparent conductive film (3), (d), <<6 provided as one electrode of the semiconductor (1). Then, the semiconductor (1) is irradiated and photoelectric conversion is performed. This electronic
The hole pair drifts to a back electrode (2), (,i), whose main component is a transparent conductive film on one side and a metal such as nickel made by electroless plating on the other side. This nickel electrode (2) is the back electrode of the semiconductor (1), and the front electrode (5) of the semiconductor (i).
In addition, an attempt was made to obtain three times the voltage at the external connection terminals (4) and (6) by connecting three consecutive photoelectric conversion devices in series with the electrode (the crest is at (5)). Of course, these may be connected in parallel. FIG. 3(B) shows two insulated gate type field effect semiconductor devices provided on a substrate.

That is, an intrinsic or substantially intrinsic semiconductor (8) was formed on the substrate (ma) to a thickness of 0.1 to 1 .mu.m. This may be amorphous or may be a silicon semiconductor having a semi-amorphous structure (referred to as SAS).

For high applications: Semi-amorphous semiconductors having a t value of I·1 or having microcrystallinity are preferred. Thus, the electrical conductivity is very close to that of a single crystal semiconductor film], XIO ~ 1×
10 (2 am)).

Furthermore, after this, a P or N type NCB semiconductor layer is selectively formed on this upper surface by plasma vapor phase method and photoetching method to form source (9), (9) train (1)
0), (10'). Then the field insulator (
39) to 0.3 to 3 μm of silicon oxide by plasma vapor phase method.
It was formed to a thickness of . Thereafter, by oxidizing the semiconductor layers (9), (10) and (8), and (40) and (8) on which the Sigate insulating film was formed using the plasma+f/j conversion method, a film of 300 to 100 OA was formed. After that, a plasma hydrogen annealing method was performed.

Further, on the upper surfaces of these electrodes, a gate electrode α-transfer and source or drain electrodes such as αI and (J) were formed selectively in the same manner as in FIGS. 1 and 2.

All of this semiconductor device is processed at a temperature of 350'0 or below, and is not only an integrated insulated gate field effect semiconductor device, but also an image sensor,
It can be used as a phototransistor play.

Figure 3 (0) shows a substrate α made of stainless steel, a P-type semiconductor layer (e), an intrinsic semiconductor layer aL, an N-type semiconductor layer a → a different NO8αη, and an anti-reflection film and an electrode on its upper surface. A transparent conductive film (c) is provided. This TO
? A comb-shaped, fishbone-shaped nickel electrode (A) and an external lead electrode (Q) are provided on the top, and a solder (K) is applied to a thickness of 50 to 300 μm to reduce the resistance of the voltage. .

It was possible to obtain 10 to 14% under AMl using irradiation light (30), and the reliability of durability was extremely improved. In particular, the N-type semiconductor layer (II is Si
C! ,, (0<
By continuously forming a structure in S (amorphous), we were able to obtain an internal voltage of as much as 0.3V.

In addition, by making the P-type semiconductor layer (E) a hard P-type semiconductor layer with Sin, (0<X<1), the P4 junction can be completed in the semiconductor manufacturing process, and a high-resistance barrier layer can be formed at the interface. The characteristic of many things that have been lost is 13 to 1 maximum.
I was able to get 4%/curl).

However, what is even more important in this drawing is that due to the improved heat resistance of the nickel electrode, no deterioration in reliability was observed even in continuous irradiation in a 9AM1 ash 00^ convex 0C atmosphere, making it extremely excellent. .

It is believed that these effects have been found to be great in these explanations.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing the manufacturing process of a semiconductor device using the method of the present invention. FIG. 2 is a flowchart illustrating the present invention. FIG. 3 shows an embodiment of another semiconductor device of the present invention. Figure 1 #2 Figure

Claims (1)

[Claims] 1. A metal coating is selectively formed by electroless plating on a non-single crystal semiconductor containing hydrogen, a halogen element, or an alkali metal element, or a transparent conductive film provided as an electrode of the semiconductor. A method for manufacturing a semiconductor device, characterized in that an electrode having ohmic contact is formed at a temperature of 350°C or less. 2. In claim 1, a resist is selectively formed on a non-single crystal semiconductor or a transparent conductive film, and then activated and immersed in an electroless plating solution to form a metal film mainly composed of nickel. A semiconductor device characterized in that an electrode/IJ-de of a metal film is selectively formed on the semiconductor or transparent conductive film by removing the resist and the metal film on the upper surface thereof by a lift-off method after formation. Fabrication method. 3. In claim 1 or 2, the electroless plating step is performed at a temperature of room temperature to 100''C, 50 to 20
Drying process of plating film at 0'O or 50-350'
1. A method for manufacturing a semiconductor device, comprising a step of forming an ohmic contact with a semiconductor film using O.