JP2000114187A - Semiconductor manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the yield of the formation of a MOS transistor and shorten its overall processing time, in the atmospheric-pressure formation process of its gate oxide film and the reduced-pressure formation process of its silicon polycrystalline film. SOLUTION: In a batch-processing type reduced-pressure processing chamber 32, a load-lock chamber 44 is provided, thereby interrupting the pressure communication of the reduced-pressure processing chamber 32 to a single-wafer processing type atmospheric-pressure processing chamber 31. On the sides of the atmospheric-pressure and reduced-pressure processing chambers 31, 32, carriage chambers 33, 35 are provided respectively, and between both the carriage chambers 33, 35, a buffer shelf 34 for temporarily storing thereon wafers is provided. As a result, with respect to both the atmospheric-pressure and reduced- pressure processing chambers 31, 32, the wafers can be carried independently of each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus having a plurality of processing chambers and continuously performing processing in the plurality of processing chambers without exposing a substrate to be processed to the atmosphere. The present invention relates to a semiconductor manufacturing apparatus in which one is under an atmospheric pressure such as an atmospheric pressure state and the other is under a reduced pressure such as a vacuum or a reduced pressure state.

[0002]

2. Description of the Related Art In the processing of semiconductor wafers, a plurality of single-wafer processing chambers capable of processing one wafer or a small number of wafers are connected to a load-lock type transfer chamber, and the plurality of single-wafer processing chambers are continuously connected between the plurality of single-wafer processing chambers. 2. Description of the Related Art A semiconductor manufacturing apparatus capable of performing processing is known. For example, as shown in FIG. 4, the semiconductor manufacturing apparatus includes a load-lock type transfer chamber 13 at the center, and a first single-wafer processing chamber 11 and a second single-wafer type so as to surround the transfer chamber 13. A loading chamber 15 in which a processing chamber 12 is provided, and a cassette containing wafers is further loaded;
A dispensing chamber 16 for dispensing a cassette is connected. These first and second single-wafer processing chambers 11 and 12, loading chamber 15,
Gate valves 18, 19, 20, 21 for airtight connection are provided between the discharge chamber 16 and the transfer chamber 13.

A semiconductor manufacturing apparatus for processing one or a small number of such wafers can reduce the processing time per wafer as compared with a batch processing apparatus for processing a large number of wafers at a time in a batch system. A thin film can be formed with good controllability. Another advantage is that after completing one process, the wafer can be transferred to the next processing chamber without delay without exposing the wafer to the atmosphere and the next process can be performed. The formation of an unintended natural oxide film due to oxygen and moisture in the atmosphere and the attachment of contaminants in the atmosphere to the wafer can be greatly suppressed.

[0004]

However, in a semiconductor manufacturing apparatus for processing one wafer or a small number of wafers, a plurality of single-wafer processing chambers include an atmospheric pressure processing chamber and a reduced pressure processing chamber. A problem arises when performing continuous processing using these atmospheric processing chambers and reduced pressure processing chambers. For example, as shown in FIG.
When forming the gate oxide film 52 of the S transistor and the silicon polycrystalline film 53 serving as the upper electrode, a first single-wafer processing section for forming a gate oxide film under atmospheric pressure, and forming a polycrystalline silicon film under reduced pressure And the case of exchanging with the second single-wafer processing unit that performs the above.

[0005] In FIG. 4, a transfer chamber 13 is transferred from an input chamber 15 to an atmospheric pressure processing chamber as a first single-wafer processing chamber 11 through a load-lock type transfer chamber 13 under atmospheric pressure. After the processing in the atmospheric pressure processing chamber is completed, it is necessary to reduce the pressure in the transfer chamber 13 in order to transfer it to the decompression processing chamber as the second single-wafer processing chamber 12. Therefore, as shown in FIG. 5, after taking out the wafer from the atmospheric pressure processing chamber, it is necessary to wait for the transfer to the reduced pressure processing chamber until the target pressure is reached while holding the wafer in the transfer jig 17 (A ).

[0006] Alternatively, as shown in FIG. 6, a buffer shelf 14 for temporarily storing wafers is provided, and the wafers that have been processed in the atmospheric pressure processing chamber are released from the transfer jig 17 and temporarily evacuated to the buffer shelf 14. , Next wafer to be processed
5 to an atmospheric pressure processing chamber, the transfer chamber 13 is depressurized while the processing is proceeding in the atmospheric pressure processing chamber, and the wafer in the buffer shelf 14 is transferred to the reduced pressure processing chamber.

However, in this method, as shown in FIG. 7, when the processing in the atmospheric pressure processing chamber is completed when the transfer chamber 13 is in a reduced pressure state, there is a pressure difference, so that the gate between the atmospheric pressure processing chamber and the transfer chamber 13 is removed. The valve 18 cannot be opened, and the wafer in the atmospheric pressure processing chamber cannot be collected in the transfer chamber 13. As a result, the wafer is made to stand by in the atmospheric pressure processing chamber (B), and the wafer staying time in the atmospheric pressure processing chamber cannot be kept constant, and the processing time varies. As a result, the gate oxide film and the polycrystalline silicon film of the MOS transistor cannot be efficiently formed.

[0008] In order to reduce such a waiting time, it is necessary to combine processing chambers all under reduced pressure or all at atmospheric pressure.
It is necessary to configure a transfer procedure that takes into account the pressure reduction time of the transfer chamber 13 and the atmospheric pressure return time.

However, in the former case, there is a limitation that only the atmospheric pressure processing chamber or the reduced pressure processing chamber can be combined. In the latter case, the pressure in the transfer chamber must be reduced and the atmospheric pressure must be restored for each transfer, which inevitably results in a significant increase in the overall processing time, and the advantage of continuous processing without exposure to air is lost. .

An object of the present invention is to solve the above-mentioned problems of the prior art, and to efficiently perform continuous processing of atmospheric pressure processing and decompression processing without losing the advantage that continuous processing can be performed without exposure to the atmosphere. An object of the present invention is to provide a semiconductor manufacturing apparatus capable of performing the above.

[0011]

SUMMARY OF THE INVENTION The present invention is directed to a single-wafer processing chamber for performing a first process on a substrate to be processed one or a few at a time under atmospheric pressure, and a single-wafer processing chamber. A batch-type processing chamber for accommodating a large number of substrates to be processed in a boat in a boat and performing a second process on each of the substrates under reduced pressure; and a substrate to be processed with respect to the batch-type processing chamber. And a load lock chamber for loading and unloading a boat containing a large number of substrates in a vacuum state, and a large number of substrates to be processed after the first processing or substrates to be processed after the second processing under atmospheric pressure. A substrate transfer chamber for temporarily storing, a first transfer unit for exchanging a substrate to be processed between the substrate transfer chamber and the single-wafer processing chamber under atmospheric pressure, the substrate transfer chamber, and the load lock; A second method for exchanging a substrate to be processed under atmospheric pressure with a chamber A substrate processing apparatus including a feeding portion.

The reduced pressure state includes a vacuum state. The atmospheric pressure state includes not only a state close to the atmospheric pressure, but also a state lower than the atmospheric pressure where a large pressure difference occurs between the depressurized state and a state higher than the atmospheric pressure. The decimal number is 2 to 5, preferably 2 to 3. The substrate transfer chamber is constituted by a buffer shelf or the like, and the number of substrates to be processed is preferably larger than the number of substrates to be stored in the boat. It is preferable that the first transfer unit and the second transfer unit exchange one or a small number of substrates to be processed. The loading and unloading of the boat from the load lock chamber to the batch type processing chamber is performed by a boat up-down mechanism.

[0013] Under the atmospheric pressure state via the first transport section,
One or a small number of substrates to be processed loaded into the apparatus are transferred to a single wafer processing chamber. Similarly, the first processing is performed on the substrate to be processed in the single-wafer processing chamber under the atmospheric pressure. The substrate to be processed processed in the single-wafer processing chamber is stored in the substrate transfer chamber via the first transfer unit under atmospheric pressure every time the processing is completed.

When the number of substrates to be processed accommodated in the substrate transfer chamber reaches the number of substrates that can be accommodated in the boat, the plurality of substrates to be processed in the substrate transfer chamber are loaded via the second transport unit under atmospheric pressure. It is stored in the boat in the lock room. When a predetermined number of substrates are accommodated in the boat, the load lock chamber is evacuated. A boat containing a large number of substrates to be processed is put into a batch processing chamber under reduced pressure from a load lock chamber. The second processing is performed on the substrate to be processed in the batch processing chamber. After the second processing, the boat is taken out of the batch processing chamber into the load lock chamber where the vacuum is maintained. Return the load lock chamber to atmospheric pressure. A large number of substrates to be processed accommodated in the boat are transferred from the load lock chamber to the substrate transfer chamber via the second transport unit.
When the transfer of all the substrates to be processed accommodated in the boat is completed, the substrates to be processed are discharged from the substrate transfer chamber to the outside of the apparatus via the first transfer unit.

During the exchange of substrates to be processed between the substrate transfer chamber and the load lock chamber, or between the load lock chamber and the batch processing chamber, the first processing in the single wafer processing chamber and the transfer to the substrate transfer chamber are performed. The transfer is operating in parallel, and the substrates to be processed that have completed the first processing are sequentially stored in the substrate transfer chamber.

[0016]

Embodiments of the present invention will be described below.

FIG. 1 shows a typical semiconductor device, an MO.
This is an example of a semiconductor manufacturing apparatus in which two processes of a process of forming a gate oxide film or an oxynitride film of an S transistor and a process of forming a silicon polycrystalline film as an upper electrode are continuously performed without exposing a wafer to the atmosphere. Here, by performing the two processes continuously without exposing the wafer to the atmosphere, the formation of a natural oxide film and the attachment of contaminants can be suppressed, so that the performance and yield of the MOS transistor are improved. Also, to form a thin oxide film, one wafer is required, rather than batch oxidation.
Alternatively, it is known that it is more advantageous to process and oxidize a few sheets at a time in terms of film thickness controllability and processing speed. Also,
The oxidation process is usually an atmospheric pressure process, and the silicon polycrystalline film forming process is usually a decompression process.

As shown in FIG. 1, a semiconductor manufacturing apparatus includes an atmospheric pressure processing chamber 31 for performing an oxide film processing on a wafer as a substrate to be processed, one or a small number of them at atmospheric pressure, and an atmospheric pressure processing chamber. A reduced pressure processing chamber 32 for accommodating a large number of wafers having been subjected to the oxide film processing in the boat 45 and performing a process of forming a polycrystalline silicon film on each wafer in a reduced pressure state; A buffer shelf 34 as a substrate transfer chamber for temporarily storing a large number of wafers on which a film has been formed under atmospheric pressure and a wafer exchange between the atmospheric pressure processing chamber 31 and the buffer shelf 34 at atmospheric pressure. It mainly includes a first transfer chamber 33 that is performed using the transfer jig 42 in the state. The transfer jig 42 holds the wafer 1
The structure is such that sheets or a small number of sheets can be conveyed simultaneously.

The first transfer chamber 33 is located substantially at the center of the apparatus, and is loaded so as to surround the first transfer chamber 33 with the atmospheric pressure processing chamber 31, the buffer shelf 34, and a cassette containing wafers. A dispensing chamber 37 for dispensing cassettes is provided side by side with the chamber 36 and the loading chamber 36. The atmospheric pressure processing chamber 31, the input chamber 36, and the discharge chamber 37
And gate valves 38, 39, 40 for hermetic connection between the first transfer chamber 33 and the first transfer chamber 33.

A buffer shelf 34 on which the wafers are temporarily placed has a wafer under atmospheric pressure between the buffer shelf 34 and a load lock chamber 44 for processing the wafer without exposing the wafer to the atmosphere. Transfer chamber 35 for exchanging data using a transfer jig 43 is connected to the second transfer chamber 3.
5 is connected to a load lock chamber 44 for taking in and out a wafer boat 45 containing a large number of wafers with respect to the decompression processing chamber 32. This load lock chamber 44
The box has a vacuum chamber structure, and a load lock structure allows the wafer boat 45 to be taken in and out while keeping the inside of the reduced pressure processing chamber 32 in a reduced pressure state or a vacuum state.

The arrangement of the buffer shelf 34, the second transfer chamber 35, the load lock chamber 44, and the decompression processing chamber 32 is shown in FIG.
FIG. 2 is a sectional view taken along the line A-A '. A second transfer chamber 35 is connected to the buffer shelf 34 in an open state, and a load lock chamber 44 is connected to the second transfer chamber 35 via a gate valve 41 in an airtight state. The decompression processing chamber 32 is provided right above the load lock chamber 44. The loading and unloading of the wafer boat 45 into and out of the decompression processing chamber is performed by an elevator 46 as a boat vertical mechanism.

In the layout example shown in FIG. 1, the second transfer chamber 35, the load lock chamber 44, and the decompression processing chamber 32 are connected to the buffer shelf 34 with respect to the input chamber 36 and the discharge chamber 37.
Are connected in series so as to extend in the opposite direction (the direction of the arrow) to the mounting side of, but this is to reduce the installation area. If the installation area is acceptable, it may be extended in the side-by-side direction in which the input chamber 36 and the payout chamber 37 are arranged. In any case, the layout is free.

Now, the operation of the above configuration will be described with reference to FIG.
This will be described with reference to FIG.

First, gate valves 38 and 39 provided between the first transfer chamber 33, the charging chamber 36 and the atmospheric pressure processing chamber 31 are opened. The transfer jig 42 is inserted into the loading chamber 36, one or two or three wafers are taken out of the cassette loaded into the loading chamber 36, and transported to the atmospheric pressure processing chamber 31 (a). At this time, the pressure in the first transfer chamber 33 is atmospheric pressure. The gate valve 38 of the atmospheric pressure processing chamber 31 is closed and the oxide film processing is performed in the atmospheric pressure processing chamber 31 (b). The gate valve 38 is opened and the wafer after the oxide film processing is completed is stored in the buffer shelf 34 by the transfer jig 42 (c). The above operation is repeated until a predetermined number of sheets are stored in the buffer shelf 34.

After the above operation is repeated, the gate valve 41 of the load lock chamber 44 is opened, and the transfer jig 43 in the second transfer chamber 35 is used to transfer the batch type processing in the load lock chamber 44 from the buffer shelf 34. The wafers are sequentially transferred (d) and stored in the wafer boat 45 of (e). When the number of sheets that can be processed at one time is stored in the wafer boat 45, the gate valve 41 is closed, and the load lock chamber 44 is depressurized (f). The wafer boat 45 is moved to the vacuum processing chamber 32.
Load using elevator 46 inside (g), boat 4
5 and forming a polycrystalline silicon film by closing the reduced pressure processing chamber 32 (h). After the formation of the polycrystalline silicon film,
The wafer boat 45 is unloaded from the reduced pressure processing chamber 32 (i) and returned to the load lock chamber 44. Gate valve 41
Is opened to return the load lock chamber 44 to the atmospheric pressure (j), the wafer stored in the boat 45 is transferred by the transfer jig 43 (k), and the wafer is again stored in the buffer shelf 34 from the boat 45 (k). l).

During this time, the oxide film processing (b) in the atmospheric pressure processing chamber 31 and the transfer (a) to the buffer shelf 34 are operating in parallel.
4 are sequentially stored (c).

After the formation of the polycrystalline silicon film in the atmospheric pressure processing chamber 31 and the wafer stored in the buffer shelf 34, the wafer is oxidized in the atmospheric pressure processing chamber 31 during the oxidizing process, and the transfer jig is used. By opening the gate valve 40 using the idle time of the operation 42, the wafer is conveyed from the buffer shelf 34 to the dispensing chamber 37 (m), is discharged from the dispensing chamber 37 (n), and all processing is performed. Complete.

In the embodiment, the buffer shelf 34 is located at the center of the process, the atmospheric pressure processing chamber 31 is connected to one of the buffer shelves 34 via the first transfer chamber 33, and the second is connected to the other of the buffer shelves 34. Processing chamber 32 via the transfer chamber 35
And a load lock chamber 44 is provided in the decompression processing chamber 32 so that pressure communication between the decompression processing chamber 32 and the atmospheric pressure processing chamber 31 is cut off.
The transfer to the buffer shelf 34, the transfer from the buffer shelf 34 to the decompression processing chamber 32, and the transfer from the decompression processing chamber 32 to the buffer shelf 34 can be performed independently without being affected by the pressure difference.

Since the transfer chamber 33 on the side of the atmospheric pressure processing chamber 31 and the transfer chamber 35 on the side of the reduced pressure processing chamber 32 are provided separately,
Wafers can be exchanged between the atmospheric pressure processing chamber 31 and the buffer shelf 34 and between the buffer shelf 34 and the load lock chamber 44 in parallel.

Further, since the atmospheric pressure processing chamber 31 is not affected by the reduced pressure state of the reduced pressure processing chamber 32, the wafer is not always kept in the atmospheric pressure processing chamber 31 and the oxidation processing is performed from the atmospheric pressure processing chamber 31 at any time. The completed wafer can be taken out and transferred to the buffer shelf 34. Also, when taking out the oxidized wafer from the atmospheric pressure processing chamber 31 and transferring it to the buffer shelf 34, the load lock chamber 44 is interposed between the buffer shelf 34 and the decompression processing chamber 32, so that the decompression processing is performed. The communication between the chamber 32 and the buffer shelf 34 is cut off so that the reduced pressure state of the reduced pressure processing chamber 32 is not transmitted to the buffer shelf 34 and the first transfer chamber 33. There is no need to wait for the removal of the wafer from the wafer.

As described above, since the transport pressure adjustment time when the process under the atmospheric pressure condition and the process under the depressurized condition are continuously performed can be reduced, the processing efficiency is improved as a whole. In addition, since the optimal processing for one or a few sheets and the optimal processing for a batch processing in a batch system can be combined with each other, it is possible to combine the processings utilizing the respective advantages. By these combinations, especially MO
In the process of forming the gate oxide film and the polycrystalline silicon film of the S transistor, the two processes can be performed continuously without providing a waiting time for adjusting the transfer pressure, thereby improving the product yield and comprehensive processing. Time can be reduced.

In the above embodiment, the case where each of the atmospheric pressure processing chamber and the decompression processing chamber is one has been described.
The present invention can be applied to the case of a room or more. In addition, the first transfer chamber and the atmospheric pressure processing chamber are arranged on one side with the buffer shelf as the center, and the second transfer chamber, the load lock chamber, and the decompression processing chamber are arranged on the other side. It is. For example, the shape of each chamber is arbitrary, and the transfer jig provided in the transfer chamber is not limited.

[0033]

According to the present invention, a load lock chamber is provided for loading and unloading a boat containing a large number of substrates to and from a batch type processing chamber in a vacuum state. In the process of continuously performing two processes without exposing to the atmosphere, the two processes can be performed continuously without providing a waiting time for pressure adjustment in the transport unit, thereby improving product yield and comprehensively. The processing time can be shortened.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a semiconductor manufacturing apparatus according to an embodiment.

FIG. 2 is a sectional view taken along line AA ′ of FIG.

FIG. 3 is a time chart of the embodiment.

FIG. 4 is a schematic plan view of a conventional semiconductor manufacturing apparatus.

FIG. 5 is a time chart of a conventional example.

FIG. 6 is a schematic plan view of another conventional semiconductor manufacturing apparatus.

FIG. 7 is a time chart of another conventional example.

FIG. 8 is a schematic sectional view of a MOS transistor in which a silicon polycrystalline film is formed on a gate oxide film formed on a silicon substrate.

[Explanation of symbols]

 31 Atmospheric pressure processing chamber (single wafer processing chamber) 32 Decompression processing chamber (batch processing chamber) 33 First transfer chamber 34 Buffer shelf (substrate transfer chamber) 35 Second transfer chamber 36 Input chamber 37 Discharge chamber 38 Gate valve 39 Gate valve 40 Gate valve 41 Gate valve 42 Transfer jig 43 Transfer jig 44 Load lock chamber 45 Wafer boat 46 Elevator

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hisashi Nomura 3-14-20 Higashinakano, Nakano-ku, Tokyo F-term in Kokusai Electric Co., Ltd. 5F045 AA06 AB03 AB32 BB08 BB10 CA05 DP19 EB08 EB10 EB12 EN02 EN05

Claims (1)

[Claims] 1. A single-wafer processing chamber for performing a first processing on substrates to be processed one by one or a small number of substrates under atmospheric pressure, and a processing to be performed in the single-wafer processing chamber after the first processing is completed. A batch processing chamber for accommodating a large number of substrates in a boat and performing a second process on each substrate under reduced pressure, and a boat accommodating a large number of substrates for the batch processing chamber. A load lock chamber for loading and unloading in a state, and a substrate transfer chamber for temporarily storing a large number of the first processed substrate or the second processed substrate under atmospheric pressure, A first transfer unit for exchanging a substrate to be processed between the substrate transfer chamber and the single-wafer processing chamber under atmospheric pressure; and an atmospheric pressure between the substrate transfer chamber and the load lock chamber. And a second transfer section for exchanging the substrate under the condition. Apparatus.