JPH062949B2 - Gas phase reactor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a gas phase reactor. More specifically, the present invention relates to a vapor phase reactor such as a plasma CVD or plasma etching process, which is arranged in an L shape so that the wafer loader section and the wafer unloader section are substantially orthogonal to the reaction chamber.

[Prior Art] As a thin film forming method, one widely used in the semiconductor industry is vapor phase epitaxy (CVD:
Chemical Vapor Deposition
n). CVD refers to a process in which a gaseous substance is chemically reacted into a solid substance and deposited on a substrate.

The characteristics of CVD are that various thin films can be obtained at a deposition temperature well below the melting point of the thin film to be grown, and
Since the grown thin film has a high purity and has stable electrical characteristics even when grown on Si or a thermal oxide film on Si, it is widely used as a passivation film on a semiconductor surface.

The CVD methods are roughly classified into three types: (1) normal pressure, (2) reduced pressure, and (3) plasma.

Due to the rapid progress of VLSI technology in recent years,
The word “I” also began to be heard. Along with this, Si devices became more highly integrated and faster, and 6 inch to 8 inch, and even 12 inch large diameter substrates were used. .

With the progress of high integration of semiconductor devices, high-quality and high-precision insulating films have been required, and it has become difficult to cope with them by the atmospheric pressure CVD method. Therefore, the plasma CVD method using plasma chemistry has been receiving attention.

This method obtains the energy required for activation of the CVD reaction by glow discharge plasma in a vacuum. The growth occurs at a low temperature of around 300 ° C., and step coverage (wraparound or pattern step coverage) ) Is good, the strength of the film is strong, and the moisture resistance is also excellent. Further, the film formation rate (deposit rate) of the plasma CVD method is much higher than that of the low pressure CVD method.

[Problems to be Solved by the Invention] The plasma CVD method is carried out under a vacuum condition of about 1-0.4 Torr. Therefore, the wafer loading and unloading operations must be performed by the loader section and the unloader section housed in the preliminary chamber separated from the reaction chamber by the gate valve. That is, the pressure in the reaction chamber is made equal to the pressure in the loader section or the unloader section, and then the gate valve is opened to load or unload the wafer. When the loader section and the unloader section are housed in the spare chamber, there is also an advantage that foreign matter can be prevented from adhering to the wafer.

The method conventionally adopted as the method of arranging the loader section and the unloader section in the reaction chamber is, for example,
There is a method in which one wafer carrier arm also serves as the unloader section. In this case, since only one spare room is required, the device becomes compact and the space saving effect is great.
However, the throughput is significantly reduced.

Another arrangement method is a method of arranging the first preliminary chamber containing the loader section and the second preliminary chamber containing the unloader section in parallel and connecting them to the reaction chamber. This method can be applied only to a large reaction chamber having a size capable of arranging two auxiliary chambers in parallel. Attempts have been made to make the reaction chamber rectangular and to connect the first and second auxiliary chambers in parallel. However, in the rectangular reaction chamber, internal conditions such as the flow pattern and glow discharge of the reaction gas fed in the furnace become non-uniform,
The film quality deteriorates. As a result, the yield of products also decreases.

In another arrangement method, the first spare chamber containing the loader section and the second reserve chamber containing the unloader section are sandwiched between the reaction chambers.
It is a method of arranging in a relation of °. In this case, the entire device becomes vertically long, and space is wasted. Therefore, it is not necessarily an appropriate arrangement in terms of the basis efficiency of the device design. Furthermore, the space for arranging the device is limited in the semiconductor manufacturing factory. That is, the line configuration is dimensionally determined. Even if the wafer size is increased from 5 inches to 6 inches, the total length of the line cannot be arbitrarily extended in accordance with the increase in the diameter of the wafer.

As another aspect of arranging the reaction chamber, the first preliminary chamber, and the second preliminary chamber at 180 °, an attempt has been made to provide multiple reaction chambers and / or preliminary chambers. This aims at improving the throughput by sharing the reaction chamber and / or the spare chamber. If multiple reaction chambers are used, it is possible to distinguish between those during film formation reaction and those during film formation preparation (for example, wafer loading / unloading), and wasteful waiting time is saved to improve throughput. It is an attempt to improve. However, in this case, when a trouble occurs in one device in the group, the whole effect is exerted, and the operation of the entire group must be stopped. As a result, the throughput cannot be improved as expected.

The plasma CVD apparatus and the plasma etching apparatus are different only in the reaction gas used, and in principle have the same structure.

[Object of the Invention] Accordingly, an object of the present invention is to provide a compact gas-phase reaction apparatus which has no waste in space and has a high basis efficiency in apparatus design.

[Means for Solving Problems] As means for solving this problem, the present invention is
In a vapor phase reaction apparatus having a loader section for loading a wafer into a reaction chamber and an unloader section for unloading a wafer from the reaction chamber, a first preliminary chamber accommodating the loader section and a second accommodating the unloader section The preliminary chamber is arranged in an L shape so as to be substantially orthogonal to the reaction chamber,
Provided is a gas phase reaction device which is connected to the reaction chamber.

[Operation] As described above, in the gas phase reaction apparatus of the present invention, the preliminary chamber for accommodating the loader / unloader portion and the reaction chamber are arranged in an L-shape, so that the exhaust system and the drive system are arranged in this L-shaped space. Can accommodate a variety of peripherals. As a result, the entire gas-phase reaction device is grouped into a square shape, resulting in an extremely compact device having high basis efficiency.

[Embodiment] An embodiment of the present invention will be described in more detail below with reference to the drawings.

FIG. 1 is a schematic perspective view showing one embodiment of the gas phase reaction apparatus of the present invention.

As shown in FIG. 1, the gas phase reactor of the present invention is arranged in an L-shape so that the first preliminary chamber 12 and the second preliminary chamber 14 are substantially orthogonal to the reaction chamber 10. The first preliminary chamber 12 and the second preliminary chamber 14 are connected to the reaction chamber 10 via respective gate valves (not shown).

The reaction chamber 10 has a symmetrical shape with a square cross section. In the symmetrical reaction chamber, the flow pattern of the reaction gas fed into the chamber becomes uniform, and good film formation results can be obtained. The symmetrical shape may be circular. In the case of plasma CVD or plasma etching, if the reaction chamber is symmetrical, the discharge will be stable and better results will be obtained.

A wafer mounting table 16 is arranged inside the reaction chamber.
The wafer mounting table is constructed so that a large-diameter wafer such as 12 inches can be mounted. Around the wafer mounting table, a wafer receiving claw 18 for lifting a wafer placed on the mounting table is arranged. The wafer receiving claw is configured to be replaceable according to the diameter of the wafer used.

A shutter ring 20 is arranged on the outer periphery of the wafer mounting table in order to define a reaction space around the wafer mounting table in a circular shape.
With this shutter ring, the cross section of the reaction space can be made into a circular symmetrical shape, and not only the flow pattern of the reaction gas to the wafer on the wafer mounting table becomes more uniform, but also the density of plasma discharge is always constant and the film quality is improved. A film having excellent properties is obtained.

Although not shown, the reaction chamber is covered with a top cover equipped with a reaction gas feed nozzle and / or parallel plate electrodes to seal the reaction chamber in an airtight structure.

A loader unit 22 for loading a wafer into the reaction chamber is housed inside the first preliminary chamber 12. Loader unit 22
Can be moved back and forth by a drive mechanism (not shown) arranged in the spare chamber. The loader unit 22 includes a wafer carrier arm 22a and a wafer carrier plate 22b.
Have. The carrier plate 22b is the carrier arm 2
It is screwed to 2a.

Next, the operation of loading the wafer into and out of the reaction chamber will be described.

The wafer 24 supplied from the wafer cartridge (not shown) is placed on the hopper table 26 of the first wafer transfer mechanism 25, and the wafer track 3 of the wafer transfer fork 28 advanced by belt drive or air bearing.
Reaches 0. When the first wafer detector detects a wafer,
The first wafer transfer arm 32 vacuum-adsorbs the wafer from the lower side, rotates in that state, and transfers the wafer to the wafer transfer pawl 36 provided under the first lid 34, and onto the pawl. Place the wafer. The first lid portion 34 has a viewing window 38. The first lid portion 34 is screwed or fixed to the vertically movable arm of the first lid opening / closing mechanism 40. Wafer transfer claw 3
When the wafer 24 is placed on the carrier 6, the ascendable / descendable arm 42 descends and enters the spare chamber through the first opening 44 formed in the upper portion of the first spare chamber 12, and the carrier plate 22b.
Place the wafer on. The ascendable / descendable arm 42 is further lowered, the first lid portion 34 covers the first opening portion 44, and seals the first preliminary chamber 12.

After the first preliminary chamber is sealed, the first preliminary chamber is evacuated to a pressure equal to that of the reaction chamber. When the pressure becomes equal, a first gate valve (not shown) separating the first preliminary chamber and the reaction chamber is opened, and the wafer carrier plate 22b is advanced to the wafer mounting table 16 in the reaction chamber. When the carrier plate 22b reaches the predetermined position, the wafer receiving claw 18 moves up to receive the wafer from the carrier plate 22b. After that, the carrier arm 22a moves out of the reaction chamber, and the first
The gate valve is closed and the film formation reaction process is started.

Inside the second preliminary chamber 14, an unloader unit 46 for carrying out the film-forming processed wafer from the reaction chamber is housed. The unloader unit 46 can be moved back and forth by a drive mechanism (not shown) arranged in the spare chamber. The unloader unit 46 has a wafer carrier arm 46a and a wafer carrier plate 46b. The carrier plate 46b is screwed to the carrier arm 46a.

After the film formation reaction process is completed and the pressure in the second preliminary chamber 14 is made equal to the pressure in the reaction chamber 10, a second gate valve (not shown) that separates the reaction chamber and the second preliminary chamber is opened. .
The wafer for which the wafer receiving claw 18 has completed the film forming process lifts the wafer from the wafer mounting table 16. The carrier arm 46a of the unloader unit 48 advances and enters the lower side of the wafer lifted by the wafer receiving pawl 18. The wafer receiving claw 18 descends and mounts the wafer on the carrier plate 46b.

Thereafter, the carrier arm 46a withdraws from the reaction chamber, and stops the retreat when the carrier plate 48b reaches the position of the wafer transfer claw (not shown) arranged under the second lid portion 48. The second gate valve is closed when the carrier plate 46b is completely withdrawn from the reaction chamber. The second lid portion 48 also has a viewing window 54. The second lid portion 48 is screwed or fixed to the vertically movable arm 52 of the second lid opening mechanism 50.

After the pressure in the second auxiliary chamber 14 is returned to atmospheric pressure, the vertically movable arm 52 of the second lid opening / closing mechanism 50 is raised. Second
A second opening 58 is provided at a position where the second lid is applied in the upper part of the preliminary chamber. The wafer held by the wafer transfer claw passes through the second opening 58 and goes out of the second preliminary chamber.

Then, the second wafer transfer mechanism 60 vacuum-sucks the wafer held by the wafer transfer claw and transfers it to the second wafer transfer mechanism 62. When the second wafer detector 66 detects that the wafer is placed on the wafer track 64 of the second wafer transfer mechanism 62, the wafer is sent to the magazine stacker table 68 by a conveyor or an air bear. Then, the wafer is stored in a cassette (not shown), and a series of operations for one wafer is completed.

As mentioned above, the device of the present invention can be configured in the so-called cassette-to-cassette format.

The apparatus of the present invention is a so-called "single wafer type" in which wafers are loaded / unloaded one by one onto the wafer mounting table in the reaction chamber. The single-wafer method is particularly suitable for depositing a CVD film having a uniform thickness on the surface of a large-diameter wafer of 8 inches or more. However, it can also be applied to a conventional batch type reaction chamber. However, although the batch reaction chamber is suitable for small-diameter wafers, the difference in film thickness density becomes too large for large-diameter wafers, and product quality tends to vary. Particularly, in the case of the plasma CVD method or the plasma etching method, the batch method is not preferable because the discharge density is not constant and the yield is reduced.

An air cylinder can be used to drive the lid opening / closing mechanism, the loader / unloader section, and the wafer receiving claws. Therefore, the peripheral drive system such as the exhaust system and the air compressor necessary for driving the apparatus of the present invention can be arranged in the space surrounded by the first preliminary chamber and the second preliminary chamber. Thus, it is possible to manufacture a high-quality semiconductor device while maintaining a high throughput, and to obtain an extremely compact gas-phase reaction device which is excellent in basis efficiency in terms of device design.

The apparatus of the present invention can be used for any type of CVD method including atmospheric pressure, reduced pressure and plasma.
It is preferably used for the method. Furthermore, as a recent technique, the photo-CVD method has been actively researched, and a device having a shape close to a practical machine is being prototyped in part. The L-shaped array system of the present invention can naturally be applied to this photo CVD apparatus.

[Effects of the Invention] As is clear from the above description, in the gas phase reactor of the present invention, the first preliminary chamber containing the loader section and the second preliminary chamber containing the unloader section are the reaction chambers. They are arranged in an L shape so as to be substantially orthogonal to each other and connected to the reaction chamber.

Various peripheral support devices for the exhaust system and the drive system can be accommodated in this L-shaped space. As a result, the entire gas-phase reaction device is grouped into a square shape, resulting in an extremely compact device having high basis efficiency. Therefore, it is possible to install a large number of units on the floor of a semiconductor manufacturing factory where the space is limited. Since the wafer mounting table is configured to be capable of responding to changes in the wafer diameter, it is not necessary to change the line configuration itself of the semiconductor manufacturing factory even when shifting from a 6-inch wafer to a 12-inch wafer, for example. As a result, the L-shaped array method of the present invention is more flexible than the conventional 180 ° array method.

Since the apparatus of the present invention is a single-wafer type of cassette-to-cassette, CVD of a uniform film pressure is applied to a large-diameter wafer of 6 inches or more.
It is particularly suitable for forming a film. Since the entire system is extremely compact, even if it is a single-wafer type, if multiple units are installed, the same processing capacity as the batch type will be demonstrated. Even if a trouble should occur in one of them, all the devices are independent, so the other devices can continue operating without any influence. Therefore, the throughput is higher than that of a CVD apparatus of a multiple reaction chamber type or a batch type in which the whole operation must be stopped when a trouble occurs.

To summarize the effects of the device of the present invention, it is possible to manufacture high-quality semiconductor devices with a high yield in a limited floor space while maintaining high throughput.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing one embodiment of the gas phase reaction apparatus of the present invention. DESCRIPTION OF SYMBOLS 10 ... Reaction chamber 12 ... 1st preliminary chamber 14 ... 2nd preliminary chamber 16 ... Wafer mounting table 18 ... Wafer receiving nail 20 ... Shutter ring 22 ... Loader part 22a
And 46a ... Wafer carrier arm 22b and 4
6b ... Wafer carrier plate 24 ... Wafer 25 ...
First wafer transfer mechanism 26 ... Hopper table 28 ...
Wafer transfer forks 30 and 64 ... Wafer track 32 ... First wafer transfer arm 34 ... First lid 36 ... Wafer transfer claws 38 and 54 ... Peep window 40 ... First lid opening / closing mechanism 42 and 52 ... Ascendable arm 44 ... 1st opening part 46 ... Unloader part 48 ... 2nd lid part 50 ... 2nd lid opening-and-closing mechanism 58
Second opening 60 Second wafer transfer mechanism 62 Second
Wafer transfer mechanism 66 ... Second wafer detector 68 ... Magazine stacker table

Claims (2)

[Claims] 1. A gas-phase reactor having a loader section for loading a wafer into the reaction chamber and an unloader section for unloading the wafer from the reaction chamber, wherein the reaction chamber is a single-wafer symmetric reaction chamber. A first auxiliary chamber accommodating the loader portion and a second auxiliary chamber accommodating the unloader portion are arranged in an L shape so as to be substantially orthogonal to the reaction chamber and connected to the reaction chamber, A first opening for carrying in a wafer is provided on the upper surface of the first preliminary chamber, and a lid having a wafer transfer claw at the bottom, and the lid opens and closes the first opening and the first opening. A first lid opening / closing mechanism including an elevating mechanism that elevates and lowers the lid to transfer the wafer through the unit is provided, and a second lid for wafer unloading is provided on the upper surface of the second auxiliary chamber. There is an opening A lid having a wafer transfer claw at a lower portion, and an elevating mechanism for opening and closing the second opening by the lid and elevating and lowering the lid to transfer the wafer to and from the unloader section through the second opening. A second lid opening / closing mechanism consisting of is provided. 2. The first and second preliminary chambers are connected to a reaction chamber through a gate valve, and the reaction chamber is subjected to plasma CVD treatment or plasma etching treatment. The gas phase reactor described.