JPS5850733A - Mass-production apparatus of thin film for solar cell - Google Patents

Abstract

PURPOSE:To make possible the automatic flow production for thin film by forming a laminated semiconductor thin film on a substrate supplied intermittently from a stocking room and moved continuously and sending intermittently a finished substrate to a rear room for extraction. CONSTITUTION:An intermediate room 13 has the degree of vacuum higher than those of reaction rooms 1, 2, 3. Even if a substrate 10 with a p-layer formed thereupon is moved from the reaction room 1 to the reaction room 2, an atmosphere containing diborane or secons products in the room 1 does not move with the substrate or a conveyor to the room 2 because a reverse air flow at the entrance from the intermediate room 13 to the room 2 prevents it from entering the room 2. With a door 8 closed, material substrates are brought into a fabrication room 15 through an insertion door 9, and with the door 9 closed the room 15 is made vacuous. Then, with the door 8 open the substrate 10 is sent to a front room 4. The finished substrate 10 in a rear room 5 is transferred to an extraction room 16 where, after being returned to normal pressure, it is extracted by opening an airtight door 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a production apparatus for automatically mass-producing semiconductor thin films for solar cells in series.

For example, amorphous silicon (hereinafter referred to as a-81 and -f)
Thin-film solar cells based on these materials are attracting attention for their use in utilizing solar energy or converting illumination light into electricity, and are desired to be reduced in price depending on volume. When using a pn junction for internal electrophoresis layer formation in a thin film solar cell, a p layer, one layer, or one layer of semiconductor thin films must be laminated on the same substrate. An apparatus shown in FIG. 1 has been proposed as an apparatus that sequentially generates each layer. That is, it consists of a reaction chamber 112.3 in which the p-layer, 1-layer, and n-layer are formed, and a front chamber 4 and a rear chamber 5 arranged before and after the reaction chamber 112.3. reaction chamber 1,
After 2゜3 is evacuated from the exhaust pipe 6, the gas introduction pipe 7
Silane gas as a reaction gas is introduced to a predetermined degree of vacuum. In addition to silane gas, diborane gas is added to the gas introduced into reaction chamber 1, which generates a p-layer, in accordance with the desired impurity concentration of the produced film.
In addition to silane gas, an appropriate amount of 7-osfin gas is added to the gas introduced into the tank. After airtightly shutting off the space between the reaction chamber 1 and the reaction chamber 1 through the door 8, the solar cell substrate 10 is inserted into the front chamber 4 through the insertion door 9, the insertion door is closed, and a vacuum with the same degree of vacuum as the reaction chamber 1 is introduced through the exhaust pipe 6. The substrate 10 is then heated to the same temperature as in the reaction chamber 1. The substrate 10 is then fed into the reaction chamber 1 by actuation 1' of the conveyor 11.

The substrate 1O, on which the a-81 p layer is generated by decomposition of silane gas due to glow discharge generated between electrodes (not shown) in the reaction chamber 1, is then sent into the reaction chamber 2.

In the illustrated example, half of the substrates 10, in which one layer is laminated on the p layer, are fed into the reaction chamber 3 at the same time in the reaction chamber 2, which is twice as wide as the reaction j11. A further Kn layer is laminated in the reaction chamber 3 flp-1-! The substrate with the *-81 thin film of l structure is sent into the rear chamber 5 at the same time. When the substrate 10 is moved between the chambers, the doors 8 between the chambers are at least partially opened 4, and after the movement is completed, the doors 8 are closed to prevent gases from mixing between the chambers. The finished substrate that has entered the rear chamber 5 is cooled, breaks the vacuum, and is taken out through the takeout door 12.

The production of the a-8i thin film is performed by stopping the conveyor 11 for a certain period of time. In the example of FIG. 1, each substrate 10 in the reaction chamber 2
The stopping time, that is, the thin film formation time, is twice that in the other two chambers 1.3, and therefore, assuming other reaction conditions are the same.
The thickness of the first layer is approximately twice that of the p layer or n layer.

However, in such a generation device, when the substrate is moved between reaction chambers, there is a high possibility that the air from the previous reaction chamber or the production byproducts in that chamber will move with the substrate (
, 6-rich, it is difficult to control impurities in the reaction gas. °As a solution to this problem, I cannot think of a method to completely replace the gas by repeatedly introducing gas from the inlet pipe 7 and evacuation from the exhaust pipe 6 after the reaction chamber is interrupted. Since it is necessary to lower the partial pressure to maintain a state in which there is no growth of 1-81, this method is undesirable from this point of view.

In addition, even if it is attempted to change the residence time of the substrate in the reaction chamber in order to adjust the layer thickness, the residence time must be set to an integral multiple of the residence time in other reaction chambers.

The present invention is a method for mass production of thin films for solar cells that can automatically generate semiconductor thin films having a desired conductivity type and impurity concentration on a substrate that moves continuously, rather than intermittently, with high production efficiency. The purpose is to provide equipment.

The purpose of this is to arrange mass production equipment adjacent to each other with an intermediate vacuum evacuation chamber between them. A predetermined reaction gas is introduced into the substrate in vacuum to form a semiconductor thin film having a predetermined conductivity type and impurity concentration on the substrate. A reaction chamber row consisting of a multi-contact reaction chamber capable of generating a reaction chamber, a front chamber adjacent to one end of the reaction chamber row that can be evacuated, and a front chamber adjacent to the front chamber through a door that can be hermetically shut off for substrate insertion. a preparation chamber that can be evacuated and has an airtight door, a rear chamber that is adjacent to the other end of the reaction chamber row and that can be evacuated, and a semiconductor thin film that is adjacent to the rear chamber through a door that is airtight and that can be interrupted. A take-out chamber that can be evacuated and has an airtight door for taking out seven substrates, a transport means for continuously KIR-feeding substrates from the front chamber through each reaction chamber and an intermediate vacuum evacuation chamber, and a The present invention includes a transport means for intermittently transporting a plurality of substrates at once to a chamber, and a transport means for intermittently transporting a plurality of substrates on which a plurality of semiconductor thin films are laminated from a rear chamber to a take-out chamber at once. achieved by.

Embodiments of the present invention will be described below with reference to the drawings. The same parts in each figure as in FIG. 1 are given the same reference numerals. As shown in FIG. 2, a slightly smaller intermediate chamber 13 is provided between the reaction chambers 1 and 2.3 for forming the p-layer, ill-layer, and n-layer. The intermediate chamber 13 is maintained at a higher degree of vacuum than the reaction chambers 1, 2.3 by evacuation through the exhaust pipe 6. Although the walls 14 are used to partition the reaction chambers 1 and 2.3 and the intermediate m 13, the reaction chamber 1 and the front chamber 4, and the reaction chamber 3 and the rear chamber 50, they are not airtightly separated. A substrate 10, which is constantly moved by a conveyor 11 underneath, can pass, in the vicinity of which there is always an air flow from the reaction chambers 1, 2.3 to the intermediate chamber 13 - as well as to the front chamber 4 and the rear chamber 5. -・ru. Therefore, even if the substrate IO on which the p-layer is deposited in the reaction chamber 1 moves toward the reaction chamber 2, when it enters the reaction m2 from the intermediate chamber 13, it will encounter a reverse airflow, so the diporan in the reaction chamber 1 or The ambient air containing rigid products does not enter the reaction chamber 2 together with the substrate or the conveyor, and the ambient air within the reaction chamber 2 is maintained at a predetermined purity. The same goes for the movement from the reaction chamber 2 to the reaction chamber 3, and the atmosphere in the reaction i13 can be maintained at a predetermined phosphine concentration. In this way, the substrates are moved continuously from the front chamber 4 to the rear chamber 5 by the conveyor 11K, and layers A-8G of the p layer, layer 1, and layer n can be layered on top of the substrate under the specified conditions. . The layer thickness produced can be selected arbitrarily by K simply by varying the length of the reaction chamber.

As described above, the movement of the substrate from the front chamber to the rear chamber through the reaction chamber can be carried out continuously according to the present invention. The conveyor shall not be stopped for any reason. For this purpose, the present invention provides a preparation chamber 15 in front of the front chamber.
, a take-out chamber 16 is provided after the rear chamber. Preparation room 15
A door 8 that can be shut off airtight is provided between the front chamber and the front chamber.

First, the door 8 is closed, and the substrates stacked in a cassette, for example, are placed into the preparation chamber 15 through the insertion door 9. Next, insert door '9
◎Then, the door 8 is opened and the stacked substrates 10 are transported by an intermittent conveyor such as an extrusion device. The door 8 is shut off again by feeding into the evacuated front chamber 4. In the front chamber 4, the substrates 10 are automatically arranged in a plane on the conveyor 11 by means not shown, and are heated to a predetermined temperature while being placed on the conveyor 1.
1 K, it is continuously fed in the direction of the reaction chamber. The finished substrates 10 that have entered the rear chamber 5 are stored in a certain quantity and cooled down, and then transferred to the evacuation chamber 16 which is evacuated through the door 8 between them.
It is fed by an intermittent conveyor at an open temperature. Next, close the n layer with () to make the space between the rear chamber 5 and the take-out chamber 160 airtight, and after returning the pressure in the take-out chamber 16 to normal pressure, open the take-out airtight door 12 and take out the finished substrate 1.゜Then, the take-out door 12 is closed for the next take-out, and the take-out chamber 16 is evacuated again.In this case, it takes time to airtightly close the loading chamber or the take-out chamber and to evacuate it, which reduces the efficiency of loading and unloading. In order to increase the temperature, a plurality of loading and unloading chambers 16 shown in FIG. 3 may be provided and used alternately.

In the example shown in the figure, the substrates that have not been loaded into the preparation chambers 15 on both sides are as shown by arrow A (they are not fed into the front chamber 4 alternately,
The finished substrate that has passed through the first step and entered the rear chamber 5 is indicated by arrow C.
As shown in Fig. 1, the liquid is alternately stored in one side of the rear chamber 5 and delivered to one extraction chamber 16 on that side.

As described above, the solar cell thin film mass production apparatus according to the present invention continuously moves the substrates supplied from the preparation chamber intermittently, and deposits the laminated semiconductor thin films having pn junctions and flea pin junctions on the substrates. During this process, an intermediate evacuation chamber is installed between each reaction chamber to prevent mixing and contamination of the air surrounding each reaction chamber, and the finished substrate is also intermittently taken out to the rear chamber, which allows for the production of solar cells. The production of laminated semiconductor thin films in a vacuum reaction chamber at any desired film thickness ratio is now possible using an automatic flow production method. Therefore, the present invention has an extremely large effect on cost reduction through mass production of solar cells.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an example of a conventional A-81 film automatic generation device for solar cells, FIG. 2 is a side sectional view of one embodiment of the present invention, and FIG. 3 is a plane sectional view of another embodiment. It is a diagram.

Claims (1)

[Claims] 1) A semiconductor thin film having a predetermined conductivity type and impurity concentration is produced on one substrate in a vacuum by placing them adjacent to each other through an intermediate vacuum evacuation type and introducing a predetermined reactive gas therebetween. There is a reaction chamber row consisting of multiple reaction chambers, a front chamber adjacent to one end of the wrinkled reaction chamber row that can be evacuated, and an axillary front chamber that is airtight and adjacent through a door that can be interrupted for substrate insertion. A preparation chamber that can be evacuated and has an airtight door for
1IIK Adjacent to the rear chamber, which can be evacuated; and an evacuation chamber, which is adjacent to the rear chamber through a door that can be airtight and interrupted, on which a semiconductor thin film is laminated, and which has an airtight door for taking out the substrate; , a transport means for continuously transporting the substrates from the front chamber to the rear chamber through each reaction chamber and intermediate vacuum/air chamber, and transport means for intermittently transporting a plurality of substrates at once from the preparation chamber to the front chamber. 1. An apparatus for mass production of thin films for solar cells, characterized by comprising: a means for mass-producing thin films for solar cells; and a means for intermittently transporting substrates on which a plurality of semiconductor thin films are stacked in bulk from a rear chamber to a take-out chamber. 2. An apparatus for mass production of thin films for solar cells according to claim 1, characterized in that the intermediate evacuation pressure is lower than the pressure in the adjacent reaction chamber. 3) A thin metal weighing device for a solar cell according to claim 1 or 2, characterized in that the front chamber has a plurality of charging holes adjacent to each other. 4) An apparatus for mass production of thin films for solar cells according to any one of claims 1 to 3, characterized in that a plurality of extraction chambers are adjacent to the rear chamber.