JP2010251380A - Method and apparatus for loading/unloading wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for loading/unloading a wafer for improving through-put by shortening a time to be required for opening/closing the door of a wafer cassette. <P>SOLUTION: An apparatus for loading/unloading a wafer includes a wafer cassette placement part 26 having the door 13 arranged in a take-out port and opened/closed, and placing the wafer cassette 10 for storing a plurality of wafers W; door movement mechanisms 22-25 for moving the door 13; and a waver carrying arm 30 for carrying-in/out the wafers to/of the wafer cassette 10, and the door 13 is closed in a normal case, opened immediately before carrying-in/out the wafer, and closed after carrying-in/out the wafer. The door movement mechanisms change the opening position of the door, according to the storage position of the wafer to be carried-in/out inside the wafer cassette. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wafer loading / unloading method and apparatus for unloading / loading wafers to / from a wafer cassette containing a plurality of wafers, and in particular, has a door that is opened and closed provided at the take-out port of the wafer cassette, The present invention relates to a wafer loading / unloading method and apparatus in which a door is normally closed, the door is opened immediately before unloading / loading a wafer, and the door is closed after unloading / loading a wafer.

  In a semiconductor manufacturing process, it is necessary to transfer a wafer between processes. In order to prevent contamination of the wafer surface during transfer, the wafer is accommodated in a wafer cassette and transferred in a sealed state.

  FIG. 1 shows a widely used wafer cassette 10. As shown in FIG. 1, a wafer cassette 10 includes a main body portion 11 having a support portion on which a plurality of wafers W are placed, a wafer take-out port frame 12 for unloading and loading the wafer W, and a frame 12. And a door 13 that can be attached and detached. By attaching the door 13 to the frame 12, the inside of the main body portion 11 is hermetically sealed and accommodated inside to prevent contamination of the wafer W.

  2A and 2B are diagrams for explaining the opening / closing operation of the door 13, wherein FIG. 2A shows a state in which the door 13 is closed, and FIG. 2B shows a state in which the door is opened. Reference numeral 14 is a leg provided on the bottom of the cassette 11.

  When processing the wafer W accommodated in the wafer cassette 10, the frame 12 of the wafer cassette 10 is pressed against a wall 21 provided with a take-out port of a processing apparatus whose inside is a clean environment. The outlet of the wall 21 is sealed with a movable sealing plate 22, and the inside of the processing apparatus is in a clean state. In a state where the wafer cassette 10 is pressed against the wall 21, the connecting portion 23 provided on the sealing plate 22 removes the key provided on the door 13 and holds the door 13 by air suction. In this state, the sealing plate 22 once moves in the horizontal direction and then moves downward. As a result, the wafer W can be unloaded / loaded into / from the wafer cassette 10. After the processing of the wafer W is completed and the processed wafer W is returned into the wafer cassette 10, the door 13 is attached to the frame 12 and the sealing plate 22 is pressed against the wall 21 by the reverse operation. In this state, the inside of the wafer cassette 10 and the inside of the processing apparatus are sealed. Then, the wafer cassette 10 is removed.

  The door 13 and the sealing plate 22 move to a position where all the wafers W in the wafer cassette 10 can be carried out, that is, to a fully opened state.

  The mechanism for moving the door 13 of the wafer cassette 10 as shown in FIG. 2 can reduce the portion required for wafer loading / unloading for attaching / detaching the door, and is widely used. Yes. Therefore, further explanation is omitted.

  After the internal wafer W is set in an accessible state, the processing of all the wafers W in the wafer cassette 10 is completed and the processed wafers W are returned to the wafer cassette 10 until the processed wafers W are returned to the wafer cassette 10. If the door 13 is held open, the atmosphere inside the processing apparatus affects the wafer W in the wafer cassette 10, or the wafer W in the wafer cassette 10 protrudes out of the wafer cassette 10 due to vibration caused by the operation of the processing apparatus. The problem of coming. In particular, when the processing time of one wafer W is increased, this influence is increased.

  Therefore, after the wafer W is taken out from the wafer cassette 10 to the processing apparatus, the door 13 is once closed, and when the processing of the wafer W in the processing apparatus is completed, the door 13 is opened, and the processed wafer W is returned to the wafer cassette 10. Next, after the wafer W to be processed is taken out from the wafer cassette 10, the operation of closing the door 13 again is performed.

JP-A-9-306975 JP 2001-203252 A

  The door 13 and the sealing plate 22 are fully opened and fully closed each time the door 13 is opened and closed.

  In the wafer cassette 10 that accommodates a large number of wafers, the height of the wafer cassette 10 is increased, so that the time required for the fully opening operation and the fully closing operation becomes long. This increased time reduces the throughput of the processing apparatus.

  An object of the present invention is to shorten the time required to open and close the wafer cassette 10 and improve the throughput.

  In order to achieve the above object, in the wafer loading / unloading method and apparatus of the present invention, the opening position of the door is changed in accordance with the accommodation position of the wafer to be unloaded / loaded in the wafer cassette. Specifically, when unloading a wafer located above the wafer cassette and when loading a wafer into the upper portion of the wafer cassette, the door opening amount is reduced to shorten the time required to open and close the door. When the wafer located at the bottom of the wafer cassette is carried out and when the wafer is carried into the bottom of the wafer cassette, the door opening amount is fully opened as in the prior art.

  The door moving mechanism needs to be able to stop the door at an intermediate position between the fully closed position and the fully open position, and is preferably motor-driven to easily stop at the intermediate position.

  Further, a sensor for position detection and a stopper for each stop position may be provided so that the door can be accurately stopped at the intermediate position.

  According to the present invention, since the door of the wafer cassette moves only as much as necessary according to the accommodation position in the wafer cassette of the wafer to be carried in / out, the time required for opening and closing the door can be shortened and the throughput can be improved. In addition, when the door moving mechanism uses a stepping motor, the stop position can be arbitrarily set only by changing the driving sequence of the stepping motor, so the cost hardly increases. Even when using a motor whose position cannot be controlled, it can be realized at low cost simply by providing a position sensor and a stopper.

It is a perspective view which shows the structure of the wafer cassette generally used. It is a figure which shows the door opening / closing operation | movement of the conventional wafer cassette. It is a figure which shows the structure of the wafer loading / unloading apparatus of embodiment of this invention.

  FIG. 3 is a diagram showing the configuration and operation of the wafer loading / unloading apparatus according to the embodiment of the present invention. FIG. 3 (A) shows a case where the wafer located at the top of the wafer cassette is unloaded / loaded in. Indicates a case where a wafer located under the wafer cassette is unloaded and loaded. The same elements as those in FIGS. 1 and 2 are denoted by the same reference numerals, and the above description is incorporated.

  As shown in FIGS. 3A and 3B, in the processing apparatus 20, a moving member 24 that moves in the horizontal and vertical directions while holding the sealing plate 22 and a drive that moves the moving member 24 are provided. A door moving mechanism having a portion 25, a scale 27, and an indicator 28 is provided. The door moving mechanism is also provided with a mechanism for operating a key provided on the door 13 via the connecting portion 23. The parts other than the scale 27 and the indicator 28 are the same as those of the conventional wafer loading / unloading apparatus. The scale 27 and the indicator 28 are mechanisms for detecting the movement amount of the moving member 24, and can be realized by a technique that has been widely used.

  In addition, similarly to the conventional example, a transfer arm mechanism for unloading and loading the wafer W in the wafer cassette 10 is provided inside the processing apparatus 20. The transfer arm mechanism includes two-stage arms A1 and A2, a rotating shaft 31 that rotates the arms A1 and A2, and a shaft 32 that moves the rotating shaft 31 up and down. The transfer arm mechanism is also the same as the conventional example, and detailed description thereof is omitted.

  Further, the processing apparatus 20 is provided with a cassette mounting portion 26 for mounting the wafer cassette 10. The cassette placing unit 26 holds the placed wafer cassette 10 and presses it against the wall 21 of the processing apparatus 20. The cassette placing unit 26 is also realized by the conventional technology.

As shown in FIG. 3A, when the wafer located at the top of the wafer cassette 10 is unloaded / loaded in, the transfer arm mechanism positions the sealing plate 22 holding the door 13 at the top. The wafer to be moved is moved to a position where a minimum space (gap) in which the wafer can be unloaded and loaded is generated and stopped. In this state, the wafer is carried out / in, and when this operation is completed, the transfer arm mechanism operates to attach the door 13 to the frame 12. The sealing plate 22 is held at a position where the door 13 is attached to the frame 12.
As shown in FIG. 3B, when the wafer located at the bottom of the wafer cassette 10 is unloaded / loaded in, the transfer arm mechanism places the sealing plate 22 holding the door 13 at the bottom. The wafer to be moved is moved to a position where a minimum space (gap) in which the wafer can be unloaded and loaded, that is, a position similar to the conventional example is stopped. In this state, the wafer is carried out / in, and when this operation is completed, the transfer arm mechanism operates to attach the door 13 to the frame 12. The sealing plate 22 is held at a position where the door 13 is attached to the frame 12.

  When unloading / loading a wafer located between the uppermost part and the lowermost part of the wafer cassette 10, the transfer arm mechanism can unload / load the wafer positioned in the middle of the sealing plate 22 holding the door 13. Move to a position where a minimal space (gap) is created and stop. In this state, the wafer is carried out and carried in, and when this operation is completed, the transfer arm mechanism operates to attach the door 13 to the frame 12. The sealing plate 22 is held at a position where the door 13 is attached to the frame 12.

  Here, when the drive unit 25 of the door moving mechanism uses a stepping motor as a drive source, it can be stopped at an arbitrary position by a control signal of the stepping motor, so the drive sequence is changed. In this case, the scale 27 and the indicator 28 need not be provided. When the drive unit 25 uses a normal motor with reversible rotation as a drive source, the rotation control of the motor is performed according to the position signal generated by the scale 27 and the indicator 28, and the motor is stopped at a predetermined position.

  With the above operation, the door 13 is moved as much as necessary in accordance with the accommodation position in the wafer cassette of the wafer to be carried out / in, so that the time required for opening and closing the door can be shortened and the throughput can be improved.

  When the processed wafer is returned to the wafer cassette 10 and the wafer to be processed next is taken out from the wafer cassette 10, the position of the wafer cassette 10 to be returned and the position of the wafer cassette 10 to be taken out are determined. Different. In this case, the sealing plate 22 is moved according to the position of the wafer located below. Therefore, when the wafer is returned to one of the upper position and the lower position and the wafer is taken out from the other of the upper position and the lower position, the effect of the present invention is reduced. Since the wafer W accommodated in the cassette 10 is taken out from the top or bottom in order, processed, and then returned, the same effect as described above can be obtained.

  In the wafer loading / unloading method and apparatus according to the present invention, a wafer cassette to be processed is supplied and recovered using a wafer cassette containing a plurality of wafers. After the wafer is unloaded and loaded, the wafer cassette door is temporarily opened. The present invention can be applied to any semiconductor processing apparatus as long as the closing sequence is performed.

DESCRIPTION OF SYMBOLS 10 Wafer cassette 11 Wafer cassette main-body part 12 Frame 13 Door 22 Sealing plate 23 Connection part 26 Cassette mounting part

Claims (4)

A wafer loading / unloading method for carrying out and carrying in a plurality of wafers housed in a wafer cassette having a door that is opened and closed provided at a take-out port,
Normally, the door is closed, the door is opened immediately before unloading / loading the wafer, the door is closed after unloading / loading the wafer,
A wafer loading / unloading method, wherein an opening position of the door is changed in accordance with a position where a wafer to be loaded / unloaded is accommodated in the wafer cassette.   The wafer loading / unloading method according to claim 1, wherein the door moving mechanism is motor-driven. A wafer cassette mounting portion for mounting a wafer cassette for storing a plurality of wafers;
A door moving mechanism for moving the door;
A wafer transfer arm for carrying out and carrying in the wafer between the wafer cassette,
A wafer loading / unloading apparatus that normally closes the door, opens the door immediately before unloading / loading the wafer, and closes the door after unloading / loading the wafer,
The wafer loading / unloading apparatus, wherein the door moving mechanism changes an opening position of the door in accordance with an accommodation position in the wafer cassette of a wafer to be carried in / out.   4. The wafer loading / unloading apparatus according to claim 3, wherein the door moving mechanism is motor driven.

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