JPS5941470A - Multi-chamber type thin film fabricating apparatus - Google Patents

Abstract

PURPOSE:To provide the titled apparatus preventing the mixing of impurities and facilitating the adjustment of a treating time, constituted so as to successively convey a substrate into plural pretreating chambers and film forming chambers connected to an air-tight chamber through partition valves through the gas-tight chamber to perform treatment and the formation of a film. CONSTITUTION:A pretreating chamber 1 for carrying out etching or the like and a plurality of film forming chambers 2-8 connected to an air-tight chamber 10 through partition valves 91-98 are provided. A substrate is conveyed into the above mentioned air-tight chamber 10 from the valve 15 of an intermediate chamber 14 connected to said chamber 10 through a valve 13 and, after the intermediate chamber 14 is evacuated by an exhaust system 16, inert gas is introduced from an inert gas source 11. In the next step, the substrate is conveyed into the air-tight chamber 10 filled with inert gas at atmospheric pressure or higher and subsequently conveyed into the pretreating chamber 1 filled with inert gas to apply required treatment to the substrate. The substrate after treatment is again returned to the air-tight chamber 10 and succeedingly and successively passed through the film forming chambers 2-8 to perform required formation of a film without being contacted with the air and mixing impurities.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides plasma C
Various film forming methods including VD, evaporation, ion-blating cathode sputtering, or in some cases resist formation and etching as a pre-lithography process9 Exceptionally, at a pressure of about atmospheric pressure9 Usually, to a certain degree Although there are differences, this relates to an apparatus that performs film formation or film processing within a certain type of reduced pressure space.

Each film formation and thin film processing process will be explained below using the A-8I film forming apparatus as a representative example.

Conventional a-8! An example of the film forming apparatus is as shown in FIGS. 1 and 2. Figure 1 shows a so-called external electrode type capacitively coupled device, in which (a) is the reaction chamber body made of a stable insulating material such as a quartz tube, and (1) and (C) are the reaction chambers each made of a rubber gasket. (a) and the bottom plate and top plate (di) that are airtightly attached, (d2) are plate-shaped electrodes arranged to enclose the reaction tube (a), and (e) is a sample usually called a susceptor. (f) is the substrate for forming the a-8i film on its top surface; (g) is the substrate heated at 250°C to 30°C.
Heat to about 50°C and a-8! The substrate for forming a film (g) is a heater for heating the substrate to about 250°C to 350°C to form a-8ip, (h) is a support rod for the septa (e), (i) is a conduit for aerating the reaction chamber (a) with a vacuum pump, and (j) is a gas conduit for guiding the reaction gas to the reaction chamber (a) (k) (1)
tn) are gas sources for depositing p-, i-, and n-type semiconductors on the substrate, respectively; generally B2H6/AIHI/
/H2, IH4/H with PH for 8111 extension 2-1
Gases such as 2 are used. (n) is the electrode (di) (d
This is a power supply for applying high frequency voltage to 2).

21↓For ease of understanding, the same symbols as in Fig. 1 are used in Fig. 2, and the symbols are added with a dash. However, the difference from the format in Fig. 1 is that the electrodes (d1'') are arranged inside the reaction chamber (a), and there are 9 buildings;
jf is passing through. Furthermore, in Figure 1, the substrate (f) is located below the gas inlet, and in Figure 2, their relative positions are reversed, but this also depends on the scale of the experimental operation and other circumstances. However, it is not an essential difference.

Now, taking the '181st example, stainless steel substrate (f)
To generate a Hede four-joint type A-8I film on the top, first, B2"6A (H4/H2) is flowed from the gas source OQ to decompose and excite it in the plasma, and then the p layer is deposited on the substrate (f). After that, a layer of Si 114/82 was deposited on the p layer by flowing Si 114/82 gas from the gas source (1).
) to form a layer of PH3AIH4AI2 to form a Peter welded type A-8I solar cell. This is a generally known glow discharge method. At this time p,
The thickness of each layer i and n is 100 and 5000.50OA, respectively.
If the film-forming rate f: 2%c, the film-forming time is 50,2500.250 seconds, which is different. Academically, research has been conducted on the use of 5i2)-]6 gas to create the i-layer, and when this is used, the film formation rate is 10 ~
Although it is said that Si2H6 can be accelerated by 20 times, Si2H6 is not easily available at present.

Moreover, it is expensive, and currently it is not economical, so the reality is that we have no choice but to accept that the film formation times for each layer are different.

In addition to creating an a-Si film by glow discharge using gas, sputtering methods using an Sl target and vapor deposition methods using various heating methods are also being researched, but these methods consume a large amount of power. Because it uses recycled silicone, it can be used as an alternative energy absorbent, which is the original purpose.
As a method for producing Si, there are problems both practically and economically.

As explained above, 5il (4/1(2)
In forming a -Si film, one serious drawback is that the film formation time varies, but another problem is that impurities are mixed in. In other words, in order to create the p layer first, B2
H6,/! li IH4/II2 gas into reaction chamber (a)
S to stop the supply and create the i layer.
When iH4/II2 flows into the reaction chamber (a), the i-layer,
As the name suggests, it should be a genuine semiconductor, and it is easy to think that there should be no mixing of impurities outside the control limits to form the p-type semiconductor poured before it. According to recent academic research, there is a theory that the i-layer is not a true genuine semiconductor, and that doping with a small amount of impurities is effective, but this too should be doped in a completely controlled manner. It cannot exist randomly. This random impurity mixture is shown in Figure 1.
As shown in Figure 2, when the conduits (j) (jf) are common, the gas is generated in this conduit, and by clever contrivance, gas 6g4 (k) (suni) is generated in separate conduits, respectively. (fk) (! I) Even if (f-) is provided independently, it is impossible to erase the history of impurities remaining in the reaction chamber (a).

An apparatus shown in FIG. 3 has been proposed as a thin film forming apparatus that solves these drawbacks. As is clear from a comparison with FIG. 2, this thin film forming apparatus is equipped with a gate valve or a structure that performs an equivalent function in the reaction chamber (B5) shown in FIG. (at)
(B2) Each p+Fn layer is formed in sequence in (B3).

This type of so-called in-line equipment has traditionally been used to deposit thin films for different purposes one after another without breaking the vacuum, as in the case of multilayer thin film deposition for optical lenses or aluminum backs for large color cathode ray tubes. This is a technology that is applied to the production of a-Si films in a conventional reaction chamber, but compared to the conventional evaporation and sputtering mentioned above, there is a large difference in the time required for each film formation process, so the takt time is the shortest. This process takes a long time, and there is a problem in that it is dominated by the time required to form the i-layer. In addition, plasma CVD, which is different from vapor deposition and sputtering, has the disadvantage that powdery substances stick to the surrounding walls of the container, and it is somewhat difficult to solve this problem by installing a barrier sign like in vapor deposition and sputtering. It's big.

As a method to solve the disparity in the tact time, it is possible to install iR film-forming chambers in series within the limit of economic efficiency, or to make the single-layer film-forming chamber longer in the longitudinal direction.

i Il? Attempts have also been made to provide one or more parallel plate facing electrodes.

However, even if such a method is used, as mentioned above, a heavily contaminated film forming chamber will appear in this line, which will prevent the film forming conditions from becoming constant, and the line will have to be completely stopped for cleaning. It has the serious drawback of not being able to obtain

Above we have detailed the problems of the conventional method for manufacturing p+"+" type semiconductors as a-st films.
The final electrode wiring must be done with I etc.

However, the a-8i film is originally a very sensitive material (F), and if it is taken out into the atmosphere after the process shown in Figure 3 is completed, it will be exposed to I, even if it is made in a clean room.
It is unavoidable that the ITO and AI films will be influenced by water vapor in the atmospheric pressure atmosphere before they are transported to the TO and λl deposition chambers, so if possible, the ITO and AI films should be formed in a controlled atmosphere without being exposed to the atmosphere. It is desirable to be moved inside. However, if film forming chambers for other processes are connected in series with respect to Fig. 3, it will encourage the occurrence of uneven takt times (
Time to form the i-layer! (Although 1ll is short), it has the disadvantage of reducing productivity.

The present invention provides a thin film forming apparatus capable of solving the above-mentioned various problems and improving conversion efficiency and yield.

Similar to the above example, the embodiment of FIG. 4 is a heterozygous a-8
i A solar cell manufacturing apparatus is shown. (1) is a surface etching chamber for stainless steel substrates, with an etching electrode inside and an etching gas inlet.

Although the room has an exhaust port and an exhaust system unique to this room, illustration of these incidental equipment is omitted since they are not directly related to the present invention. In the following, illustrations of items that are not directly related to the present invention or incidental equipment that can be easily understood from the previous illustrations will be omitted. (2) is the n-layer deposition chamber, and its structure is shown in Figure 1.

Any glow discharge or other type of deposition a configuration as shown in FIG.

Illustrated example - This is a structure in which the Fi and I layers are formed in three chambers (3), (4), and (5), respectively, but this number should be determined from an economic standpoint and is not limited to three chambers. . (6
) is a p-layer deposition chamber, (7) is an ITO deposition chamber, and in some cases, a chamber for achieving stoichiometric deposition by introducing oxygen is provided as a subsequent or branched chamber. It is possible. (8) is a deposition chamber for final aluminum wiring. As mentioned earlier, each of these chambers (]) to (8) has its own exhaust system, and each chamber has a gas introduction evaporation mechanism and an exhaust system depending on the purpose of the chamber. It generally forms a flexible vacuum container. Furthermore, each of these chambers (1) to (8) is a shibōben (91) to (9).
8) is connected to the airtight chamber 0Q.

The gas-tight chamber θI is supplied with gas from an inert gas source θ] through two conduits θ, and is not required to be strictly vacuum-resistant. However, to prevent outside air from entering with water vapor, the pressure is always maintained at a level higher than atmospheric pressure, and even if a leak occurs, the inert gas inside will leak outside. It's a matter of character. Note that the gas source Qυ is connected to each of the chambers (1) to (8) as a part of the conduit 0→. The airtight chamber (10) is connected to the intermediate chamber θa via the pulp 03, and the intermediate chamber a4 is further communicated with the outside world (atmospheric pressure) via the pulp ah.

The airtight chamber (IQ and intermediate chamber (B) are equipped with a transport mechanism of an appropriate structure as necessary, and may also have a monitoring window. Most of the airtight room 0Q is made of transparent plates such as acrylic. In this case, even if a window is not required, a glove may be provided to allow manual transportation or other operations inside the interior, but these additional facilities mentioned above are also shown in the diagram. omitted.

In addition, the gas system 0-valve is equipped with most valves that require sufficient airtightness between each load, and any type of controller (e.g. sequencer, microcomputer, etc.) required to operate these valves is also included. Although it is provided, its illustration is omitted because it has nothing to do with the essence of the tree.

Now, next, all the rooms (υ~(8) are set aside.

In principle, how a certain workpiece (substrate) is processed within this apparatus will be explained step by step.

Intermediate chamber ((open valve 19 when brown is at atmospheric pressure and close valve 09 when the work is carried into (14) chamber θ4)
The inside of the room 0 is evacuated by the exhaust system 0O, which is unique to the system, and after sufficient exhaustion is completed, the connection between the cold 04) and the exhaust system 000 is closed. Then, the inside of the chamber 0 is filled with inert gas through the conduits θ. The 10th volume of Pal is opened at -H, but since the airtight chamber OQ is also filled with inert gas, the workpiece is sent into the chamber OI with the same air, and the valve θ1 is closed. Next, assuming that the chamber (1) is also filled with inert gas, the workpiece is transported to the front of the chamber (1), the valve (9) is opened, the workpiece is charged into the chamber (1), and the valve is opened. (91
) close. In this case, (1) is evacuated by a unique exhaust system, an appropriate amount of surface etching gas is flowed in, and current is applied to the etching electrode to perform surface etching.

At the same time, the next workpiece is loaded into the intermediate chamber θ→. Once the workpiece has been etched, it is moved to chamber (1), which is pressurized to the same pressure as JQ, and then transported to chamber QO, in reverse of the previous procedure, and then stopped in front of chamber (2). The next workpiece is loaded into the chamber (2) in the same manner as in the previous procedure.The next workpiece is of course placed in the chamber (1) for etching.
charged inside.

If the p-layer is deposited in the chamber (2), the process is the same as before. In the reverse procedure, the workpiece is carried out into the chamber QQ and enters the chamber (3) to form the i-layer. During this time, other workpieces pass through the etching electrode film and enter the chamber (4) and chamber (4) respectively to form a single layer. (5). When the film formation of one layer in the chamber (3) is completed, the workpiece is loaded into the chamber (6), the 0 layer is formed, and the ITO is deposited in the chamber (7).
In 8), Al'f is evaporated and carried out again into the chamber (II).The thus completed solar cell undergoes steps such as opening and closing of the transport mechanism, and isopressurizing with an inert gas.
It passes through time and is transported to the outside world.

I1. If for some reason the chamber (
If the contamination of chamber (3) is significant, instructions or measures will be taken automatically or manually to stop regular use of chamber (3), and production will continue with this removed.
3) It is possible to clean the inside.

In the above explanation, the number of 1-layer film forming chambers is 3, but as mentioned in the previous explanation, if you think about it arithmetically, ■) Based on waste, the i-layer has 50 chambers, and the n-layer has 5 chambers. Room, IT
This will require the installation of a number of membrane chambers for O and AI. However, in reality, the number of chambers should be determined with due consideration given to economic efficiency, and this invention has three chambers as shown in the example.
It is not limited to the number of chambers, nor does it require the installation of as many chambers as can be determined by simple arithmetic calculations.

Also, in Figure 4, chambers (υ~(8)) are all shown as independent chambers, but in reality, it is natural that they share the wall adjacent to each VA as shown in Figure 5. Needless to say, this makes the entire device extremely complex.

In the above explanation, the manufacturing apparatus for a heterojunction type A-8I solar cell was exemplified. The development of chairs and the drying of these processes are progressing day by day. Furthermore, depending on the type of mask, it is essential to perform precise mask alignment, and it is economically disadvantageous to perform all of this in-line as shown in FIG.

In the present invention, a completely common airtight chamber is provided as an example, but for example, steps A, B, and C are performed in-line as before, and the next step is performed in the airtight chamber, and then again. This also includes modifications in which steps such as E, 'F, . . . are performed in-line.

The number of series-parallel combinations is extremely large when each film forming, processing, and processing chamber is configured with an airtight chamber whose interior is kept at a pressure higher than atmospheric pressure. Therefore, the present invention naturally includes all of these high-performance multilayer thin film forming apparatuses comprising an extremely large number of serial and parallel working chambers, the airtight chambers, and intermediate chambers.

In addition, it is assumed that the pressure in the airtight chamber is kept higher than atmospheric pressure, but depending on special circumstances, this airtight chamber may also be constructed as a vacuum-resistant container.

Furthermore, although FIG. 4 shows that there is only one airtight chamber 0Q and that the intermediate chamber (14) is also provided at one end of the chamber θ, depending on the other end of the chamber 01 or the layout, the airtight chamber 0Q is provided at one end of the chamber θ. Provide multiple outlets at arbitrary positions or chamber QQ
It may be added to the other end of each chamber (1) to (8) in FIG. 4.

As explained above, a major feature of the multi-chamber thin film forming apparatus provided by the present invention is that it is possible to continue production without completely stopping the apparatus even when cleaning one or more film forming chambers. However, it goes without saying that unlike in-line systems, it is not necessary to completely stop the apparatus when performing maintenance, inspection, disassembly, and re-setting of the exhaust system that is attached to each film-forming chamber.

Furthermore, since the device of this invention has an airtight chamber that maintains positive pressure in the 21st part, most current devices are installed in vast lean rooms and are operated using massive amounts of electric cooling water. However, it has the ripple effect of simultaneously having the minimum required clean room for the equipment in an extremely efficient manner.

After the deposition chamber is assembled, oxygen or other suitable gas is introduced into the reaction chamber in an amount of 1-2:iM (10-10 Torr), and the inside is discharge-cleaned using the electrodes provided inside, thereby removing contamination. It is possible to perform more thorough cleaning than the current work in vast lean rooms, such as vacuum transportation of garbage.

As described above, the multi-chamber thin film forming apparatus according to the present invention is economical and provides excellent productivity and operability.

[Brief explanation of the drawing]

Figures 1 to 3 are diagrams schematically showing the configuration of a conventional device;
FIG. 4 is a diagram schematically showing the configuration of the device according to the present invention;
FIG. 5 is a diagram showing an example of the female form of the present invention. Go to (1) (8)... Film forming chamber (chamber) (91) ~
(98)...Gate valve α0...Airtight chamber 0υ...Inert gas source α椴...Conduit α30G...Pulp α
→...Intermediate chamber 0Q...Exhaust system patent applicant Shimadzu Corporation 1. Representative Patent Attorney Hako Takeishi・1゜

Claims (2)

[Claims] (1) When depositing a single layer or multiple layers of thin films on a certain substrate, a plurality of film forming chambers for pre-processing the substrate and forming each thin film are arranged in parallel or connected in series according to the process required for forming the thin film. At the same time, each film forming chamber is connected to another airtight chamber by a corresponding partition or the like, and the substrates after each film forming process are transported from the film forming chamber to the airtight chamber and then transported to the secondary process. A multi-chamber thin film forming apparatus characterized by: (2) The multi-chamber thin film forming apparatus according to claim 1, wherein the airtight chamber is maintained at a pressure higher than or equal to atmospheric pressure with a specific gas.