JP3016792B2 - Wafer transfer system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a wafer transfer system, and more particularly, to a wafer transfer system using a wafer transfer vehicle.

[Conventional technology]

Conventionally, this type of wafer transfer system has used an open or closed wafer storage device to transfer the wafer storage device in the atmosphere.

Next, a conventional technique will be described with reference to the drawings. FIG. 5 is a block diagram of a wafer transfer system showing an example of the related art. This wafer transfer system includes a transfer vehicle 1 for transferring a wafer storage device to wafer processing apparatuses 5a and 5b and a wafer storage shelf 6 arranged on one side of a track 2, and a transfer between the transfer vehicle 1 and each apparatus. It is composed of devices 3a, 3b and 3c.

In the operation of the wafer transfer system, first, the transfer vehicle 1 runs on the track 2 and stops in front of the wafer processing apparatus 5a. Next, the wafer processing device 5 stores a large number of processed wafers in the wafer storage device in the transfer device 3a by the interface 4a. Next, the wafer storage device storing the wafer is transferred to the carrier 1 by the transfer device 3a. next,
The carrier 1 loaded with the wafer storage device runs on the track 2 and stops in front of the wafer storage shelf 6. Next, the wafer storage device is transferred from the carrier 1 to the wafer storage shelf 6 by the transfer device 3b. Next, the wafer storage device in which the unprocessed wafers are stored from the wafer storage shelf 6 is loaded on the carrier 1 by the transfer device 3b.

Next, the transport vehicle 1 moves and stops in front of the wafer processing apparatus 5b. Next, the wafer storage device is transferred from the carrier 1 to the transfer device 3c by the transfer device 3c. Next, wafer processing equipment
Wafers are sequentially supplied from 5a to 5b. Such an operation is repeated, and the wafer is transported to process the wafer. The transfer of the wafer is performed in an air-conditioned atmosphere, and the air-conditioning control is particularly performed in the room where the system is disposed so that dust in the air does not exceed a certain limit.

[Problems to be solved by the invention]

In the conventional wafer transfer system described above, since all the wafers are transferred in the atmosphere, the wafer taken out from one wafer processing apparatus is transferred to the next wafer processing apparatus while being exposed to the atmosphere. For this reason, particles or impurities in the air adhere to the wafer, the surface of the wafer is oxidized, or chemically react with the active gas mixed in the air. These have the disadvantage that they adversely affect the semiconductor devices on the wafer.

In the case where there is an apparatus for processing a wafer in a vacuum, an operation for changing the chamber containing the wafer from the atmospheric pressure to a vacuum or vice versa in the apparatus must be performed. However, when pumping down from atmospheric pressure to vacuum, or when venting from vacuum to atmosphere, if pumping down or venting is performed suddenly, a strong airflow is generated in the container, and particles in the container are wound up This must be done slowly as these particles adhere to the wafer. Therefore, it takes a long time to pump down and vent, and if this time is longer than the wafer processing time of the wafer processing apparatus, there is a disadvantage that the throughput time of the wafer processing apparatus is reduced.

An object of the present invention is to provide a wafer transfer system that solves such a problem.

[Means for solving the problem]

The wafer transfer system according to the present invention is a wafer transfer system having a first device, a second device, and a wafer transfer vehicle for transferring a wafer between the first and second devices. Is characterized by comprising a chamber for accommodating a wafer in an airtight state, means for reducing the pressure of the chamber, and means for increasing the pressure of the reduced pressure chamber.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the wafer transfer system according to the present invention, FIG. 2 is a diagram showing the carrier of FIG. 1 extracted, and FIG. 3 is a diagram showing the transfer device of FIG. FIG. In FIG. 1, a carrier 11 moves on a loop-shaped track 12. When the transport vehicle 11 arrives at the target transfer device 13, it stops, and the transfer device 13 and the transport vehicle 11 are connected to each other at the connection portion 24 in FIG. 2 and the connection portion 31 in FIG. 3 while maintaining the vacuum. Then, the wafer is transferred in a vacuum. Further, the transfer device 13 is connected to the wafer processing device 15 via the interface 14 in a vacuum state, and the transfer device 13 exchanges the wafer with the wafer processing device 15 via the interface 14 in a vacuum. Do. The transfer device 13 is also connected to a vacuum-evacuated wafer storage shelf 16, a conversion device 17, and the like, and these also transfer wafers in a vacuum.
Here, the vacuum wafer storage shelf 16 is a warehouse for storing wafers in a vacuum. The conversion device 17 is also connected to the transfer device 13, receives the wafer from the transfer device 13 in a vacuum, switches the wafer to atmospheric storage, and then transfers the wafer to the transfer device 18.
Handover, and vice versa. Carrier 11
A track 12 on which the vehicle travels is provided.

The carrier mounts a container 22 containing a wafer in a vacuum chamber 21 and runs by a traveling mechanism 28 by itself.
The chamber 21 can be evacuated by the pump 26 by opening the valve 25. If necessary, valve 27
Can be opened to atmospheric pressure. Further, when transferring the wafer, the flange of the connecting portion 31 of the transfer device 13 is connected to the connecting portion 24 of the carrier 11 having a flange, and the inside of the connecting portion is evacuated. Hand over.

The transfer of wafers to and from the transport vehicle first requires the connection mechanism 32
After connecting the connecting part 31 and the connecting part 24 of the transporting vehicle and sealing, the inside of the connecting part is pumped down by the pump 43 by opening the valve 42 and evacuated. After the connection is evacuated, the valve 33 and the valve 23 of the carrier are opened. Next, the transfer mechanism 34 transfers the container 36 containing the wafer in the chamber 35 of the transfer device 13 into the transfer vehicle chamber 21 or vice versa.
Transfer to the inside. The chamber 35 can be pumped down by the pump 40 by opening the valve 39. Further, the inside of the chamber can be vented to the atmospheric pressure by the valve 41. When transfer is completed, valve 33 and valve
By closing the valve 23 and opening the valve 44, the connection portion is brought to the atmospheric pressure, and the connection portion 31 is separated from the carrier by the connection mechanism 32. The transfer device and the other devices are connected in a vacuum state by the connection unit 38, and the transfer of the wafer between the transfer device and the other devices is performed by the transfer mechanism 37.

FIG. 4 is a diagram extracting and showing the conversion device of FIG.
As shown in FIG. 4, the conversion device 17 for transferring from the transport vehicle 11 traveling on the track 12 to the transport vehicle 1 traveling on the track 2 has a connecting portion 51 connected to the transfer device 18 and a connection portion 51 connected to the transfer device 13. A connection part 45 is provided on both sides, and a chamber 47 for storing a container 48 is provided at the center. Between the transfer device 13 and the conversion device 17,
When delivering the container 48 for storing the wafer,
First, the connection unit 38 of the transfer device 13 and the connection unit 45 of the conversion device 17 are connected. The chamber 47 is slowly pumped down by the pump 57 through the needle valve 54 by opening the valve 53. After a certain time, the valve 56 is opened and the pump is switched to the pump-down state bypassing the needle valve 53. After the inside of the chamber 47 is evacuated, the valve 46 is opened, and the transfer of the wafer container is performed by the transfer mechanism 37 from the chamber 35 of the transfer device 13 in a vacuum state in advance. After the transfer is completed, the valve 46 is closed.

Also, the wafer container 48 is transferred from the conversion device 17 to the transfer device 18.
When the transfer is performed, first, with the connection portion 51 of the conversion device 17 connected to the connection portion of the transfer device 18, the valve 53 is opened, and the inside of the chamber 47 is slowly evacuated through the needle valve 53 and the filter 52. Introduce. After a certain time, the valve 55 is opened to bypass the needle valve 53 and introduce air. After the pressure in the chamber 47 reaches atmospheric pressure, the valve 49
Is opened, and the transfer container 50 transfers the wafer container 48 to the transfer device 18 via the connection portion 51. Then, as described above, the wafer container is transferred from the transfer device 18 to the carrier 1. As the transfer mechanism in the above-described embodiment, a transfer mechanism using a known mechanism may be used.

〔The invention's effect〕

As described above, the wafer transfer system of the present invention performs the transfer of the wafers between the wafer processing apparatuses in a vacuum, so that the wafers are exposed to particles and impurities in the atmosphere caused by exposure of the wafers to the atmosphere. This has the effect of preventing phenomena that adversely affect semiconductor devices on the wafer surface, such as adhesion of the wafer, oxidation of the wafer surface by oxygen, and chemical reaction between the active gas mixed into the atmosphere and the wafer surface. In addition, since pump down and venting performed in the wafer processing apparatus can be performed in the wafer transport system, there is no need to perform long-time pump down and venting in the wafer transport apparatus. This has the effect of reducing the throughput time.

[Brief description of the drawings]

FIG. 1 is a block diagram of a wafer transfer system showing one embodiment of the present invention, FIG. 2 is a diagram showing a transfer vehicle extracted from FIG. 1, and FIG. 3 is a view showing a transfer device of FIG. Figure shown,
FIG. 4 is a diagram showing the conversion device of FIG. 1 extracted, and FIG. 5 is a block diagram of a wafer transfer system showing an example of a conventional device. 1,11… Carrier, 2,12… Track, 3a, 3b, 3c, 13,18… Transfer equipment, 4a, 14… Interface, 5a, 5b, 15… Wafer processing equipment, 6, 16: Wafer storage shelf, 17: Conversion device, 21, 35, 47 ... Chamber, 22, 36, 48 ... Container, 23, 2
5,27,33,39,41,42,44,46,49,53,56,… valve, 24,31,
38,45,51 …… Connections, 26,40,43,57 …… Pumps, 28 ……
Traveling mechanism, 32 Connection mechanism, 34, 37, 50 Transfer mechanism, 52
…… Filter, 54 …… Needle valve.

Claims (3)

(57) [Claims] 1. A wafer transfer system comprising: a first apparatus, a second apparatus, and a wafer transfer vehicle that transfers a wafer between the first and second apparatuses, wherein the wafer transfer vehicle includes a wafer. And a means for reducing the pressure of the chamber, and a means for increasing the pressure of the reduced pressure chamber. 2. The wafer transfer vehicle according to claim 1, wherein
2. The wafer transfer system according to claim 1, wherein the pressure reduction or the pressure increase is performed during a period in which the wafer is transferred between the apparatuses. 3. The wafer transfer vehicle according to claim 1, wherein
2. The wafer transfer system according to claim 1, wherein the pressure reduction or the pressure increase is performed while making the pressure of the apparatus substantially equal to the pressure of the chamber.