JPS5850734A - Mass production apparatus for laminated thin film - Google Patents

Abstract

PURPOSE:To always form a laminated thin film under a specified reaction condition by preparing an intermediate pumping room between reaction rooms to prevent the mixture of adjacent reaction room atmospheres. CONSTITUTION:Reaction rooms 1, 2, 3 and an intermediate room 14 are made vacuous with a pumping pipe 6. Since reaction gases are introduced into the reaction rooms 1, 2, 3 through each gas introducing pipe 7, the degree of vacuum of the intermediate room 14 is higher than that of each reaction room. 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 second products in the room 1 does not move with the substrate or a conveyor 11 into the room 2, because in the spaces between a wall 15 and the conveyor the flow of air exists from the reaction room to the intermediate room, thereby preventing the atmosphere from entering the room 2 from the room 14. Thus, the atmosphere in the room 2 can be maintained at a specified purity. The same is also true for the substrate movement from the reaction room 2 to a reaction room 3, i.e., an atmosphere in the room 3 can be maintained at a specified phosphine concentration.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for stacking layers such as semiconductor thin films having a pn junction for solar cells. :Relates to a laminated thin film mass production device that continuously produces thin films of different properties in a series of multiple chambers having different ambient atmospheres.

For example, thin-film solar cells based on amorphous silicon (hereinafter referred to as A-8L and Y1) are attracting attention for their use in utilizing solar energy or converting BA light into electricity. There is. When using a pn junction to form an internal electric field in a thin film solar cell, it is essential to stack a p layer, an n layer, or one layer of semiconductor thin films on the same substrate. The one shown in FIG. 1 has been proposed as such a sequential row 5 device that generates each layer. 1 so 4 p layer,
Reaction chambers 1 and 2.3 in which the 1st and nth layers are formed, and t'l? - Consists of a front chamber 4 and a rear chamber 5. After the reaction chambers 1 and 2.degree. 3 are evacuated through the exhaust pipe 6, silane gas as a reaction gas is introduced through the gas introduction pipe 7 to a predetermined degree of vacuum. Diporane gas is added to the gas introduced into the reaction i11 where the p-layer is formed, depending on the desired impurity concentration of the formed film, and silane gas is added to the gas introduced into the reaction chamber 3 where the p-layer is formed. In addition to this, an appropriate amount of 2-osfin gas is added as well. 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. and heat the substrate 10 to the same temperature as in the reaction chamber 1. Next, the substrate 10 is sent into the reaction chamber 1 by the conveyor 11. In the reaction chamber 1, a p-layer of a-8i is deposited on the substrate IO by decomposition of silane gas due to glue discharge occurring between electrodes (not shown). Subsequently, the substrate 10 with the p-layer deposited thereon is sent into the reaction chamber 2 by the operation of the conveyor 11. In the illustrated example, half of the substrates 1o, in which one layer of silane gas produced by goo-discharge decomposition is laminated on the p-layer in a reaction*2 which is twice the size of reaction chamber 1, are simultaneously placed in reaction chamber 3. sent. A further K11 layer is laminated in the reaction chamber 3, and the substrate with the a-8i thin layer of p"i-n structure is simultaneously fed into the rear chamber 5. The finished substrate that has entered the rear chamber s is cooled. After that, the vacuum is broken and the material is ejected from the take-out door 12. The a-81 thin film is produced by stopping the conveyor 11 for a certain period of time.

In the example of FIG. 1, the stopping time of each substrate 1o in reaction chamber 2, ie, the thin film growth time, is twice as long as that of 4 in the other two chambers 1 and 3, and therefore other reaction conditions are the same. Assuming -ft'l, the thickness of the mass layer is approximately 2 times that of the p layer or the n layer.
It's double.

In such a generation apparatus, in order to avoid mixing of ambient air between each reaction chamber, even if each chamber is separated by an airtight door 13, the door 13 is closed when the substrate 10 is moved.
must be opened at least somewhat. At that time -m-
There is a high possibility that the ambient air of the previous reaction chamber or by-products generated in the previous reaction chamber may move into the subsequent reaction chamber due to interdiffusion or mixing of the ambient air in both reaction chambers, or due to the moving substrate. .

Therefore, it is difficult to control impurities in the reaction gas in each chamber.

An object of the present invention is to eliminate such drawbacks and provide a laminated thin film mass production apparatus in which thin films are always produced and laminated under predetermined reaction conditions in each reaction chamber without mixing of ambient air between adjacent reaction chambers. do.

This purpose is to create and laminate thin films with different properties on the same substrate in multiple reaction chambers under false vacuum.
This is achieved by providing an intermediate evacuation chamber between each reaction chamber that is evacuated to a higher degree of vacuum than the reaction chamber.

Embodiments of the present invention will be described below with reference to FIG. In FIG. 2, parts common to those in FIG. 1 are designated by the same reference numerals. As shown in the figure, there is a reaction chamber X for the visualization of the p-layer, five-layer, and n-layer; 2. A small intermediate room 1 between a
4 is available. Reaction chamber 1.2.3 and intermediate chamber 1
4 is evacuated by the exhaust pipe 6 of the intermediate chamber 14, and the reaction gas is introduced into the reaction chambers 1, 2.3 from the gas introduction pipe 7, so the degree of vacuum in the intermediate chamber 14 is the same as that of each reaction chamber. taller than. In other words, the pressure is low. Reaction chambers 1, 2.3 and intermediate chamber 14
Although the chamber is partitioned by a wall 15, it is airtight and there is no interruption, and the substrate 10 on the conveyor can be moved as it is to the next reaction chamber. An air flow from the reaction chamber to the intermediate chamber exists in the gap between the wall 15 through which the substrate 10 passes and the conveyor 11. Therefore, for example, even if the substrate 10 on which the p-layer is deposited moves toward the reaction chamber 2 in the reaction chamber 1, the intermediate i11
When entering the reaction chamber 2 from the reaction chamber 4, there is a reverse air flow, so the feces containing diborane or by-products in the reaction chamber 1 do not enter the reaction chamber 2 together with the substrate or conveyor, and the feces in the reaction chamber 2 The surrounding air 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 chamber 2 can be maintained at a predetermined 7-osphine concentration.

The space between the reaction chamber 1 and the front chamber 4 and the space between the reaction chamber 3 and the rear chamber 50 can be sealed off airtight by the door 8 as in the case of FIG. Removal also occurs intermittently.

The present invention is applicable not only to the production of solar cells made of amorphous silicon films having pn junctions, but also to the production of elements having multiple layers of films produced in vacuum. Furthermore, since there is no mixing of the ambient air in each reaction chamber, it can also be applied to the lamination of thin films using a plurality of reaction gases based on different types of gases.

As described above, the present invention is an apparatus for growing thin films with different properties in each chamber on a substrate passing through a plurality of vacuum reaction chambers. This prevents mixing and allows the reaction to take place under predetermined conditions in each chamber, eliminating the need to shut off the reaction chambers in a vacuum-tight manner after moving the substrate. Since lamination can be carried out easily and continuously, it is extremely effective for mass production of thin film devices such as solar cells.

[Brief explanation of the drawing]

Section 1 shows an example of conventional laminated thin film mass production equipment;
Figure fs2 is a sectional view showing one embodiment of the present invention. 1t2t3...Reaction chamber, 6...Exhaust pipe, 7...Gas introduction pipe, lO...Substrate, 11...Conveyor, 14
...Intermediate vacuum evacuation chamber. 1 illustration 26 = 14:

Claims (1)

[Claims] l) When thin films of different properties are sequentially produced and laminated under vacuum in multiple reaction chambers on the same substrate, an intermediate chamber that is evacuated to a higher degree of vacuum than the reaction chambers is provided between each reaction chamber. Laminated thin film mass production equipment featuring: