JPH065687A - Vacuum treatment device - Google Patents

Abstract

PURPOSE:To enable wafers to be efficiently transferred between vacuum treatment chambers and a load lock chamber and taken in or out of them so as to enhance a vacuum treatment device in throughput. CONSTITUTION:A vacuum treatment device is of multi-chambered structure, where a transfer chamber surrounded with vacuum treatment chambers 4a to 4d and a load lock chamber 3 is divided into an upper and a lower transfer chamber, 1a and 1b, and substrate handling arms 7a and 7b, which are made to turn as indexed out to the positions of the vacuum treatment chambers respectively and to take wafers 6 in or out of the vacuum treatment chambers extending or shrinking, are provided to the transfer chambers 1a and 1b. The handling arms 7a and 7b are made to operate in an idle time produced due to the inequality of the vacuum treatment chambers 4a to 4d in treatment time to smoothly take wafers 6 in or out of the vacuum treatment chambers 4a to 4d from or to the load lock chamber 3 and to efficiently transfer the wafers 6 between the vacuum treatment chambers 4a to 4d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum processing apparatus for accommodating a semiconductor substrate in a vacuum container and performing a thin film forming process, an etching process, and the like. Related to a vacuum processing apparatus having a plurality of solids.

[0002]

2. Description of the Related Art At present, vacuum processing apparatuses are used in many fields including the semiconductor industry. Particularly, vacuum processing apparatuses in semiconductor manufacturing include a sputtering apparatus and a CVD apparatus for forming a thin film on the surface of a semiconductor substrate, and conversely, a dry etching apparatus for etching the surface of a substrate.

In recent years, with the miniaturization and multi-layering of wiring due to high integration of LSI, thin films of different materials are continuously formed in vacuum under different conditions, or sputtering, CVD, dry etching, etc. There is an increasing demand for continuous processing of different types of processes in a vacuum without exposing the semiconductor substrate to the atmosphere.

In response to these requirements, a multi-chamber type vacuum processing apparatus having a plurality of vacuum processing chambers each having an independent exhaust system has been developed and put into practical use. This multi-chamber structure type vacuum processing apparatus is also called a multi-chamber type apparatus, and since each chamber is completely independent, mutual contamination such as sputter material and reaction product process gas does not occur, It has the advantage that semiconductor substrates can be processed under different conditions for each chamber. Further, it is possible to arbitrarily select the order of passing through the processing chamber according to the order of steps of the semiconductor substrate, and there is an advantage that various kinds of processing can be continuously performed by one device.

4A and 4B are a plan view showing an example of a conventional vacuum processing apparatus and a sectional view of a vacuum processing chamber.
Usually, this type of vacuum processing apparatus, for example, as shown in FIG. 4A, accommodates a storage cassette 2 that is arranged around a transfer chamber 1 located in the center and that stores a plurality of semiconductor substrates. Load lock chamber 3 and a plurality of vacuum processing chambers 4a, 4b, 4c, 4d, and each vacuum processing chamber 4a-4d
And a gate valve 5a between the load lock chamber 3 and the transfer chamber 1
5b, 5c, 5d and 5e, and the vacuum processing chambers 4a to 4d,
The load lock chamber 3 and the transfer chamber are independently vacuum-evacuated.

In the vacuum processing apparatus, the number of vacuum processing chambers is four in the drawing, but the number changes depending on the application. Generally, there are many cases where there are 3 to 5 vacuum processing chambers. Further, inside the transfer chamber 1, there is provided a substrate handling arm 7 for transporting a wafer 6 which is a semiconductor substrate. The substrate handling arm 7 has a rotational movement about a vertical line in the drawing as a central axis, and The wafer 6 is loaded / unloaded into / from the load lock chamber 3 and each of the vacuum processing chambers 4a to 4d by performing expansion / contraction motions in a horizontal plane.

On the other hand, inside the vacuum processing chambers 4a-4d, substrate stages 8a, 8b, 8 for mounting the wafer 6 thereon.
c and 8d, and the substrate lifters 9a and 9d that support the substrate from the back side and perform linear movement in the vertical direction on each substrate stage.
b, 9c, 9d are built in. This board lifter 9
As shown in FIG. 4B, the substrate a is transferred to and from the substrate handling arm 7 by stopping at two height positions α and β.

5A and 5B are flow charts for explaining the operation of the vacuum processing apparatus of FIG. 5, and FIG. 6 is a diagram showing a state in which a wafer is transferred to each vacuum processing chamber. Next, the operation of returning the processed wafer from the vacuum processing chamber to the transfer chamber after the processing in the vacuum processing chamber and the operation of feeding the unprocessed wafer from the transfer chamber to the vacuum processing chamber will be described. Here, the numbers shown in each chamber in FIG. 6 indicate the numbers of the wafers, and the wafers are numbered in the order of 1, 2, 3, ...
.. are processed in this order.

First, the operation of returning the processed wafer from the vacuum processing chamber to the transfer chamber will be described. First, in step A of FIG. 5A, the substrate lifter 9a is raised from the position α to the position β, as shown in FIG. 4B. Next, in step B, the sluice valve is opened and the substrate handling arm 7 is extended to enter the vacuum processing chamber. Next, in step C, the substrate lifter 9a is lowered from the position β to the position α, and the wafer is placed on the substrate handling arm 7. Next, in step D, the substrate handling arm 7 retracts to return the wafer to the transfer chamber.

When a wafer is transferred from the transfer chamber to the vacuum processing chamber, first, in step A of FIG. 5B, the substrate handling arm 7 of FIG. 4 extends and returns from the vacuum processing side to the transfer chamber. Next, in step B, the substrate lifter is raised from the position α to the position β to load the wafer. Next, in step C, the substrate handling arm 7 extends and the wafer is loaded into the vacuum processing chamber. Then, in step D,
The substrate lifter descends from the position β to the position α, and the wafer is placed on the substrate stage.

Further, the cycle operation of carrying out the processed wafer and carrying in the unprocessed wafer will be described.
First, in FIG. 6 (a), the wafers numbered 5 and 6 are waiting in the load lock chamber 3, and the vacuum processing chambers 4a, 4b, 4c.
Wafers numbered 4, 3, 2 and 1 are stored in 4 and 4d, respectively, and different treatments are performed. Next, when the processing of the first wafer is completed in the vacuum processing chamber 4d, the first wafer is unloaded from the vacuum processing chamber 4d by the above-described operation by the substrate handling arm, and the load lock chamber is moved as shown in FIG. 6B. It is stored in 3. Subsequently, as shown in FIG. 6C, the second wafer in the vacuum processing chamber 4c is moved to the vacuum processing chamber 4d.
Be delivered to. Hereinafter, as shown in FIGS. 6D to 6F, the wafers are processed in the vacuum processing chamber in the clockwise direction and finally housed in the load lock chamber to complete the processing of all the wafers. It was

[0012]

The above-mentioned conventional multi-chamber structure type vacuum processing apparatus can automatically perform a plurality of processing steps with one apparatus, but has the following problems.

For example, in the vacuum processing apparatus of FIG. 4, the substrate handling arm is operated once until a wafer is taken out from the load lock chamber or one vacuum processing chamber and sent to the next vacuum processing chamber or load lock chamber. When the process of carrying in and out the wafers and moving all the wafers located in each chamber to the next chamber is regarded as a one-cycle transportation process,
As described with reference to FIG. 6, five cycles of loading and unloading operations are required in the one-cycle transport process. Here, it is assumed that the substrate handling arm takes about 20 seconds for one loading / unloading operation,
If it takes about 5 seconds for the rotation operation when moving to the next loading / unloading operation, (20 + 5) in the above-mentioned one-cycle transportation process.
A transport time of about × 5 = 125 seconds is required. Therefore, when the processing time in the vacuum processing chamber is shorter than 125 seconds, for example, in the case of processing for 60 seconds, there is a waiting time of 65 seconds for conveyance after the processing is completed. If the wafer processing time in the four vacuum processing chambers is 60 seconds, the throughput in this case is about 4 hours for 20 wafers,
The value is lower than that of the batch system. This means that the conventional multi-chamber type vacuum processing equipment has many advantages in terms of process performance, but the throughput is affected by the processing steps that require the longest processing time, and wafers are transferred until they are transferred. However, there is a drawback that the waiting time in the vacuum processing chamber is added, and the throughput becomes low as a whole.

An object of the present invention is to provide a vacuum processing apparatus for improving throughput by increasing the efficiency of wafer transfer.

[0015]

A vacuum processing apparatus according to the present invention comprises a load lock chamber for accommodating a plurality of semiconductor substrates,
A transfer chamber arranged so as to surround a plurality of vacuum processing chambers for processing the semiconductor substrates one by one is divided into upper and lower parts, and each of the vacuum processing chambers and the load lock chambers are accommodated in the divided transfer chambers. A substrate handling arm for carrying in, placing and carrying out the semiconductor substrate between
Each of the vacuum processing chambers is provided with a substrate lifter that moves the semiconductor substrate by moving up and down in cooperation with these substrate handling arms.

[0016]

The present invention will be described below with reference to the drawings.

FIGS. 1A and 1B are a plan view and a sectional view of a vacuum processing apparatus showing an embodiment of the present invention.
In this vacuum processing apparatus, a transfer chamber located at the center is vertically separated into two transfer chambers 1a and 1b.
substrate handling arms 7a and 7b that are housed in a and 1b and are independently rotated and indexed around the center of the transfer chamber to load and unload wafers, and vacuum processing chambers 4a and 4b arranged around the transfer chamber. Gate valves 4a, 5b for partitioning the load lock chambers 4c, 4d and the transfer chambers 1a, 1b.
And 10a to 10d, and each vacuum processing chamber 4a, 4b, 4
Substrate lifter 9a for moving the wafer 6 in cooperation with the substrate stages 8a, 8b, 8c and 8d by moving the substrate handling arms 7a and 7b up and down at positions corresponding to the respective height positions of the substrate handling arms 7a and 7b. , 9b, 9c, 9d are provided.

FIG. 2 is a diagram for explaining the operation of the substrate lifter of FIG. Next, the operation of the substrate lifter corresponding to the substrate handling arm will be described. For ease of explanation here, the loading of the wafer 6 in the vacuum processing chamber 4a
Here is an example of unloading. As shown in FIG. 2, the board lifter 9a stops at the positions of α, β, γ and moves up and down.

First, the wafer is housed in the vacuum processing chamber 4a by the substrate handling arm 7a, and the substrate stage 8a.
If the wafer 6 is placed on the substrate lifter 9a,
In the position. Next, the substrate handling arm 7a on which the wafer 6 is placed on the tip is extended and inserted into the vacuum processing chamber 4a. Next, when the substrate lifter 7a rises and reaches the position of γ, the substrate lifter 9a places the wafer 6 on the substrate handling arm 7a. Next, the substrate handling arm 7a retracts and returns to the transfer chamber 1a. On the other hand, the substrate lifter 9a moves down to the position α, and the wafer 6 is transferred onto the substrate stage 8a.

Next, the case where the wafer is unloaded from the vacuum processing chamber 4a by the substrate handling arm 7a will be described. First, the substrate lifter 9a is raised from the position α to the position γ, and the wafer 6 is pushed up. Next, the substrate handling arm 7a extends from the transfer chamber and stops at a position slightly below the γ position. Next, the substrate lifter 9a descends from the position γ, transfers the wafer 6 to the substrate handling arm 7a, and descends to the position α which is the original position. On the other hand, the substrate handling arm 7a returns to the transfer chamber with the wafer 6 placed thereon.

On the other hand, the loading and unloading of the wafer 6 by the substrate handling arm 7b in the lower transfer chamber 1b is performed as follows.
As the substrate lifter 9a moves up and down with respect to the position of β, the wafer is loaded and unloaded as described above.

FIG. 3 is a view showing a state in which a wafer is transferred to each vacuum processing chamber. Next, an example of loading / unloading cycle of wafers processed in each vacuum processing chamber in this vacuum processing apparatus will be described. Here, the number described in each chamber indicates the wafer number.

First, in the state shown in FIG. 3 (a), that is, the load lock chamber 3 accommodates wafers numbered 5 or more, and 4 wafers are provided in each of the vacuum processing chambers 4a, 4b, 4c, 4d.
It is assumed that wafers # 1 to # 1 are stored and are being processed.
After the lapse of a predetermined time, when the wafer No. 1 stored in the vacuum processing chamber 4a finishes processing, the two substrate handling arms move independently, and the wafer No. 1 is loaded as shown in FIG. 3 (b). The second wafer is transferred to the lock chamber 3 from the vacuum processing chambers 4c to 4d. Next, when a predetermined time elapses, as shown in FIG. 3C, the third wafer in the vacuum processing chamber 4b is in the vacuum processing chamber 4c, and the fourth wafer in the vacuum processing chamber 4a is in the vacuum processing chamber 4b. Is brought in. Next, as shown in FIGS. 3D and 3E, the processed wafer is loaded into the vacuum processing chamber of the next processing step. Then, as shown in FIG. 3F, the processed wafer is stored in the cassette in the load lock chamber 3 by the two substrate handling arms. At the same time, the unprocessed wafer 6 in the load lock chamber 3 is put in the first vacuum processing chamber 4a.

In this embodiment, the wafer is transferred between the vacuum processing chambers in the clockwise direction. However, the transfer method is not limited to this, and for example, the wafers in the load lock chamber may be transferred to the vacuum processing chambers 4a and 4b in this order. 1 and the vacuum processing chambers 4c and 4d in that order, the former is left to the substrate handling arm 7a in FIG. 1, and the latter is assigned to the second substrate handling arm 7b. Sequences can also be assembled. In this way, it is possible to set various transfer sequences by two sets of substrate handling arms according to the number of processing chambers and the processing order.

[0025]

As described above, in the multi-chamber type vacuum processing apparatus of the present invention, a transfer chamber surrounded by a plurality of vacuum processing chambers is separated into two chambers, an upper chamber and a lower chamber, respectively. An unbalanced processing time in each vacuum processing chamber is provided by providing a plurality of independently operating handling arms for loading and unloading wafers, and loading and unloading wafers between each vacuum processing chamber by multiple handling arms. There is an effect that the loss time due to is effectively used to improve the transport efficiency and the throughput can be improved as a whole.

[Brief description of drawings]

FIG. 1 is a plan view and a cross-sectional view of a vacuum processing apparatus showing an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the substrate lifter of FIG.

FIG. 3 is a diagram showing a state in which a wafer is transferred to each vacuum processing chamber.

FIG. 4 is a plan view of a vacuum processing apparatus showing a conventional example and a cross-sectional view of a vacuum processing chamber.

5 is a flowchart for explaining the operation in the vacuum processing chamber of FIG.

FIG. 6 is a diagram showing a state in which a wafer is transferred to each vacuum processing chamber.

[Explanation of symbols]

1, 1a, 1b Transfer chamber 2 Storage cassette 3 Load lock chamber 4a, 4b, 4c, 4d Vacuum processing chamber 5a, 5b, 5c, 5d, 5e, 10a, 10d Gate valve 6 Wafer 7a, 7b, 7 Substrate handling arm 8a , 8b, 8c, 8d substrate stage 9a, 9b, 9c, 9d substrate lifter

Claims (1)

[Claims] 1. A load lock chamber for accommodating a plurality of semiconductor substrates and a transfer chamber arranged so as to surround a plurality of vacuum processing chambers for processing the semiconductor substrates one by one are vertically divided, and these are divided. Substrate handling arms that are housed in the transfer chambers and that carry in, carry out, and carry out the semiconductor substrates between the vacuum processing chambers and the load lock chambers, and the substrate handling arms in the vacuum processing chambers. And a substrate lifter for transferring the semiconductor substrate by moving up and down in cooperation with the vacuum processing apparatus.