JPS60189923A - Manufacturing device for photovoltaic element - Google Patents

Abstract

PURPOSE:To enable semiconductor thin films of good characteristics without beating and driving out and floating the partial component of deposited residue by colliding generating ions to the inner wall by a method wherein a zero voltage or negative voltage is impressed by arranging ion inhibition electrodes by the side of opposing electrodes. CONSTITUTION:After vacuum-drawing in a chamber 2, a given negative voltage is impressed on the ion inhibition electrodes 7. Successively, the producing gas in a gas bomb G1 is supplied by opening e.g. a valve V1. The producing gas between the opposed electrodes 1 and 1' is decomposed by glow discharge by impressing a high voltage across the electrodes 1 and 1' from a high frequency power source 4, resulting in the production of a required semiconductor thin film on the surface of a substrate 5. At this time, the residue of decomposition of the producing gas deposits on the inner wall 2a of the chamber 2. On the other hand, ions N generating by glow discharge are drawn to the inhibition electrodes 7 and flow to the ground, not reaching the inner wall 2a of the chamber 2. Even when the gas is changed, the residue keeps the state of deposition on the inner wall 2a without scattering due to beating and driving out by ion impact.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a photovoltaic device manufactured by the plasma CV I) method, and particularly proposes a method for manufacturing a photovoltaic device that can increase the photoelectric conversion efficiency of the photovoltaic device. It is something to do.

In manufacturing a photovoltaic device by the plasma CVD method, as shown in FIG. 1, silane gas, diborane gas, etc., which are raw materials for forming a semiconductor thin film, are placed in a metal chamber 2 that houses a pair of electrodes 1.1 facing each other. , while feeding a predetermined production gas through the gas feed pipe 3. A high voltage is applied between the electrodes 1.1 by a DC power source or a high frequency power source 4, and the generated gas is decomposed by glow discharge between the opposing electrodes 1.1, and then placed on the electrode 1. board 5
A photovoltaic element, which is a solar cell, is manufactured by forming a predetermined semiconductor thin film on the surface of a solar cell.

By the way, in a photovoltaic element such as a solar cell, it is generally necessary to stack a plurality of semiconductor thin films with different characteristics on the surface of the substrate 5. A production gas of extremely high purity suitable for exhibiting the characteristics of each semiconductor thin film is fed into the chamber 2. As shown in Fig. 1, the production gas is fed as shown in Figure 1.
a gas cylinder G filled with different types of generated phase gas connected to the gas feed pipe 3 via valves V to V4;
, G2. G3. A suitable valve V consisting of G4, or V4
Precise control of the appropriate mixing ratio and flow rate is achieved by selectively opening the . However, if we were to open the valve vl and feed the generation gas from the gas cylinder G1 into the chamber 2 to cause glow discharge and generate the first @th semiconductor thin film on the surface of the substrate 5, then The residue of the generation gas decomposed by the discharge also flies to the inner wall of the chamber 2 and adheres thereto. Next, when a second layer of semiconductor thin film having different characteristics is to be generated on the surface of the 11th semiconductor thin film that has just been generated, the generation gas that has been fed into the chamber 2 is stopped. After the exhaust pipe 6 is discharged once and the inside of the chamber 2 is made into a vacuum state, another valve v2 is opened again.
After opening the gas cylinder G2, a new generation gas of extremely high purity is controlled at a precise flow rate at an appropriate mixing ratio (sometimes one type), and is fed into the chamber 2 to cause a glow discharge. A new second semiconductor thin film having different characteristics is formed on the surface of the first semiconductor thin film formed previously.

In this case, 21! ! Due to the glow discharge of the generation gas that generates eyes, some of the generated positive ions N (hereinafter referred to as ions) are attracted by the potential difference (electric field) with the inner wall of the grounded metal chamber 2, and are drawn into the child chamber 2. The glow discharge generated during the formation of the first layer of semiconductor thin film impacts and decomposes the residue attached to the inner wall of chamber 2, and part of it or the residue is transferred to the chamber 2. 2, the purity of the generation gas used to generate the second semiconductor thin film will be significantly lowered, or the mixing ratio and amount of the gas components will change. As a result, the properties of the semiconductor thin film produced in the second step were significantly different from those expected, and the properties were generally forced to deteriorate, which was found to impede the increase in the photoelectric conversion efficiency of the photovoltaic device.

In order to solve the above-mentioned problem, the present invention provides an ion suppression electrode on the side of the opposing gap 14i≠44i of the electrodes opposed in the chamber, and applies zero or negative voltage to the ion suppression electrode. By glow-discharging the generation gas while applying , the ions generated thereby are prevented from colliding with the inner wall of the chamber, and the residue attached to the inner wall of the chamber 2 is prevented from being decomposed or floating. , photovoltaic by producing individual semiconductor thin films while maintaining extremely pure production gas conditions.

This paper proposes a method for manufacturing a photovoltaic device that can further increase the photoelectric conversion efficiency of the photovoltaic device.

The method of manufacturing the electromotive force element of the present invention will be described below with reference to FIG.

In FIG. 2, reference numerals 1 and 1 are electrodes disposed facing each other in a chamber 2 made of metal, and these electrodes 1.1 are connected to a DC power supply or high frequency type M, 4, is grounded. Further, a substrate 5 is placed on the lower electrode 1'. The chamber 2 is provided with a gas supply pipe 3 and an exhaust pipe 6 that communicate with the inside of the chamber 2. Further, inside the chamber 2, there is a space between the electrode 1.1 and the inner wall 2a of the chamber 2, which is on the side of the gap between the electrodes 1.1 and the chamber 2, which are opposed to each other.
An ion suppression electrode 7 is disposed along the inner wall 2a between the inner wall 2a and the inner wall 2a. The ion suppressing electrode 7 is made of a rod-shaped conductor 7a made of stainless steel, copper, aluminum, etc. with a suitably small diameter, wound in a spiral cylindrical shape at a predetermined pitch, and its axial length is the same as that of the opposing electrodes 1. 1
The dimensions are slightly longer than the distance between the two. This ion suppression electrode 7 is connected to a negative electrode of an ion suppression power source 8, and its positive electrode is grounded. A negative voltage is applied to this ion suppression voltage si7 by the ion suppression power source 8, and the magnitude of the negative voltage is determined by the ion suppression power source 8.
can be adjusted as necessary. Usually, the magnitude of the negative voltage of the ion suppression electrode is set to about 0 to 10 volts or to an ambient voltage of about 0 to 10 volts. To the gas supply pipe 3, via valves v1 to V4,
Gas cylinders G to G4 filled with different generation gases
are connected, and by opening predetermined valves Vl to V4, predetermined generation gases G1 to G4 can be fed into the chamber 2 through the gas feed pipe 3.

A method for manufacturing a photovoltaic device using the photovoltaic device manufacturing apparatus configured as described above will be described. First, after the chamber 2 is brought into a vacuum state, a predetermined negative voltage is applied to the ion suppression electrode 7. Subsequently, for example, the valve vI is opened to supply the generation gas from the gas cylinder G1 into the chamber 2. Thereafter, high lightning pressure is applied between the electrodes 1.1' from the high-frequency power source 4, and the generated gas between the opposing electrodes 1.1 is decomposed by glow discharge, and a predetermined semiconductor thin film is formed on the surface of the substrate 5. to be generated. At this time, residues of the decomposed generation gas adhere to the inner wall 2a of the chamber 2. On the other hand, the ions N generated by the glow discharge try to rush toward the inner wall 2a of the chamber 2, which is grounded and has zero voltage. Under the influence of the electric field of the suppression electrode 7, the ions N are attracted to the ion suppression electrode 7, flow to the ground, and do not reach the inner wall 2a of the chamber 2. After the first semiconductor thin film is produced in this manner, the gas in the chamber 2 is exhausted, and then the chamber 2 is again brought into a vacuum state. after that,
2 on the surface of the first layer semiconductor thin film that has now been formed on the substrate 5.
In order to generate the semiconductor thin film of the second layer, for example, a new generation gas from the gas cylinder C2 is fed into the chamber 2 by opening the valve v2, and a glow discharge is performed in the same manner as described above to generate the first layer of semiconductor thin film that was previously generated. 2 Different characteristics on the surface of the semiconductor thin film of the eye
Generate a single semiconductor thin film. In this case as well, the generation gas is decomposed and its residue adheres to the inner wall 2a of the chamber 2 in the same manner as described above. Although ions N are generated, they are attracted to the ion suppression electrode 7 and do not reach the inside W2a of the chamber 2. Therefore, no impact is applied to the residue adhering to the inner wall 2a, and the residue is not knocked out and scattered by the impact of the ions and remains on the inner wall 2a.
remain attached to the surface. Therefore, the generation gas for producing the second layer of semiconductor thin film is not contaminated with the residue, the gas adsorbed to this residue, or the gas released by decomposing this residue, and is an extremely pure generation gas. A semiconductor thin film is produced. Thereafter, in the same manner, the generation gases of the other gas cylinders G3 and G4 are respectively fed into the chamber 2 to generate the third and fourth semiconductor thin films. Power devices can be manufactured. In this manner, each semiconductor film is always generated using a generating gas of extremely high purity, so that the photovoltaic device produced has a significantly high photoelectric conversion efficiency.

In this embodiment, a conductor 7a having a circular cross-sectional shape wound in a spiral cylindrical shape was used as the ion suppression electrode 7, but a wire mesh curved into a cylindrical shape may also be used. Furthermore, the fine wire for the safe can be formed into a spiral cylindrical shape with an extremely small pitch. In that case, a predetermined winding frame is required to support the thin metal wire. On the other hand, although the ion suppression power source 8 is a separate power source from the high frequency power source 4, the negative i[IE may be taken out from the high frequency power source 4. Furthermore, if two ion suppression electrodes are arranged concentrically, and the inner ion suppression electrode is set to zero voltage, that is, grounded, and the outer ion suppression electrode is set to negative voltage, ions can reach the inner wall 2a in the chamber 2. can be more effectively prevented.

The voltage applied to the ion suppression electrode may be zero or a negative voltage, and is not limited to a specific voltage value. Although the chamber 2 is not shown, it goes without saying that it has a structure that can be divided into upper and lower halves so that substrates can be taken in and out.

As explained above, in the method for manufacturing a photovoltaic device according to the present invention, the electrodes 1, facing each other in the metal chamber 2,
By arranging an ion suppression electrode 7 on the side between the opposing electrodes 1.1 and applying zero or negative voltage, the ions N generated by decomposition of the production gas are transferred to the chamber 2. In order to avoid collision with the inner wall 2 of the chamber 2
Some components of the residue adhering to the inner wall 2a are not knocked out and made to float. Therefore, a state is obtained in which only extremely pure production gas for producing a predetermined semiconductor thin film is fed into the chamber 2, and a semiconductor thin film with extremely good characteristics can be produced. In particular, even if different generation gases are sequentially supplied in one chamber 2, the purity of the generation gas will be low.Since semiconductor thin films with good characteristics can be sequentially stacked and generated, the photoelectric conversion efficiency can be improved using inexpensive equipment. It is possible to produce high photovoltaic devices.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a manufacturing apparatus used in a conventional method for manufacturing a photovoltaic element, and FIG. 2 is an explanatory diagram showing a manufacturing apparatus used in a method for assembling a photovoltaic element according to the present invention. 1.1...electrode, 2...chamber, 3...gas feed pipe, 4...high frequency electric field, 7...ion suppression electrode, 8...
...Power supply for ion suppression. Agent Patent Attorney Hiroshi Nakai η・tan (No change in content) Figure 1 Figure 2 Procedure NeyamajE Deaf'' (Voluntary initiative) 1. Indication of the case Patent Application No. 45798 of 1982 2. Invention Name of photovoltaic device manufacturing method 3, which ministry case to amend Patent applicant No. 2-1-11 Tayo, Yodoyo-ku, Osaka (026) Osaka Transformer Co., Ltd.? , 1 4. Address of the agent: 2-1-11 Tayo, Yodoyo-ku, Osaka 532 [Contact information: (06) 301-1212] 5. Subject of amendment Drawing - Figure 1 and Figure 2 6, Amendment Contents Figures 1 and 2 of the drawings are corrected as shown in the attached sheet. that's all

Claims (1)

[Claims] 1. Plasma CVD (Chemical
In the method for manufacturing a photovoltaic device using the Vapor Deposition method, an ion suppression electrode is disposed on the side between the opposing electrodes, and the ion suppression electrode is set at zero voltage or negative pressure with respect to the metal chamber. A method for manufacturing a photovoltaic device that suppresses ions generated by glow emission from reaching the inner wall of a chamber and forms a thin film on a substrate.