KR20040079615A - Load-lock chamber for semiconductor device manufacture including the sensor for position control of wafer cassette - Google Patents

Abstract

PURPOSE: A load-lock chamber for semiconductor device manufacture including the sensor for position control of a wafer cassette is provided to prevent collision between an elevator or a wafer cassette and an upper part or a lower part of a main body of the load lock chamber by installing a sensor in the inside of the main body of the load lock chamber. CONSTITUTION: A wafer cassette is used for storing a wafer. A main body(200) includes a door into which the wafer cassette is inserted. An elevator(240) is installed in the inside of the main body in order to elevate the wafer cassette. A driver(250) is used for operating the elevator. A controller(260) is used for controlling the driver. The wafer cassette includes a wafer cassette position control sensor. The first sensor(220) is installed at an upper part of the inside of the main body in order to detect a rising limit of the wafer cassette. The second sensor(230) is installed at a lower part of the inside of the main body in order to detect a falling limit of the wafer cassette.

Description

Load-lock chamber for semiconductor device manufacture including the sensor for position control of wafer cassette

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load-lock chamber used in a semiconductor device manufacturing facility, and in particular, a limit position according to each of them when a wafer cassette is raised or lowered by an elevator. It relates to a load lock chamber for manufacturing a semiconductor device having a detector for controlling the position of a wafer cassette capable of detecting a.

Many of the processes for fabricating semiconductor devices are made using process chambers, which typically have special environmental conditions such as high vacuum, high temperature, and high pressure. Special environmental conditions within such process chambers can cause stress on the wafer during direct wafer feed into it, resulting in damage to the wafer, and direct wafer feed into the process chamber must be maintained precisely. It can act as a factor to destabilize the environmental conditions inside the process chamber. The load lock chamber is a buffer chamber used to prevent these problems, and allows the wafer to encounter environmental conditions close to those in the process chamber before the wafer is fed into the process chamber. It is configured to act as a blocking area to block the influence from outside.

The load lock chamber generally performs the raising and lowering operations on the wafer cassette in which the wafer is stored, the main body provided with a door for entering and exiting the wafer cassette, and the wafer cassette configured in the main body and placed in the main body. An elevator, a drive unit for driving the elevator, and a control unit for controlling the drive unit have a structure including a conventional load lock chamber for manufacturing a semiconductor device with reference to the drawings.

1 is a view schematically showing a structure and a problem of a conventional load lock chamber for manufacturing a semiconductor device.

As shown in FIG. 1, in a conventional load lock chamber for manufacturing a semiconductor device, when the wafer cassette 50 is placed on the elevator 140 inside the main body 100 through the door 114, the elevator 140 descends. In the wafer cassette 50 on the lowered elevator 140, the received wafers 10 are configured to be transferred to a transfer chamber 170 through a handler 172. The presence or absence of the wafer 10 in the wafer cassette 50 is checked when the wafer cassette 50 is raised or lowered through the wafer detector 112 formed in the middle portion of the main body 100. The conveyed wafer cassette 50 is lifted to the original position by the elevator 140 and discharged to the outside through the door 114. When the lowering operation is completed, the elevator 140 has a distance of 5 mm or less from a lower portion thereof and an inner lower surface of the main body 100. When the lowering operation is completed, the elevator 140 of the wafer cassette 50 placed on the elevator 140 is disposed. The distance between the upper part and the inner upper surface of the main body 100 is 5 mm or less.

The elevator 140 performs the raising and lowering operation through the driving shaft 153 connected to the lower portion thereof, and the driving shaft 153 is the linear operation of raising and lowering in response to the rotation amount of the lead screw 152. It moves in conjunction with a drive arm (154) to perform the lead screw 152 is rotated by the rotation operation of the electric motor 151 and the electric motor 151 is the position of the elevator 140 from the control unit 160 and It operates by receiving a signal corresponding to the operation. The lead screw 152 has a hard stop key 155 formed at a portion of an upper portion thereof, which is a hard stop pin formed on the drive arm 154 when the drive arm 154 is raised. Since the electric motor 151 is initialized in contact with the back part, the motor 151 serves as a reference point according to the lifting and lowering operation of the elevator 140, and thus, it is important to determine the limit position of the lifting and lowering operation of the elevator 140.

In such a conventional structure of a load lock chamber for manufacturing a semiconductor device, the rise and fall of an elevator, such as incorrect or damaged positioning of a hard stop key configured in the lead screw, occurs in the rise and fall of the wafer cassette according to the rise and fall of the elevator. In case of a problem that the necessary reference point is changed, the elevator operates beyond the existing rising and falling limit positions, so that the wafer cassette placed on the elevator or the elevator may collide with the upper or lower portion of the load lock chamber body. This could act as a factor of damage to the wafer stored in the wafer cassette and overload of the motor.

Accordingly, the present invention detects the lift and the lower limit position of the wafer cassette by the elevator, thereby preventing the elevator and the wafer cassette from colliding with the load lock chamber body and the like, and thus resulting in wafer damage in the wafer cassette and the motor. It is an object of the present invention to provide a load lock chamber for manufacturing a semiconductor device configured to eliminate a factor of overload.

1 is a view schematically showing a structure and a problem of a conventional load-lock chamber for manufacturing a semiconductor device;

FIG. 2 is a view showing a structure of a load lock chamber for manufacturing a semiconductor device having a detector for controlling a position of a wafer cassette according to a first embodiment of the present invention;

3 is an enlarged view of portion A of FIG. 2;

4 is an enlarged view illustrating a portion B of FIG. 2;

5 is a view illustrating a structure of a load lock chamber for manufacturing a semiconductor device having a sensor for controlling a position of a wafer cassette according to a second embodiment of the present invention;

6 is an enlarged view of portion C of FIG. 5, and

FIG. 7 is an enlarged view of portion D of FIG. 5.

<Explanation of symbols for the main parts of the drawings>

L: laser 10: wafer

50: wafer cassette 100, 200, 300: main body

112, 212, 312: wafer detectors 114, 214, 314: door

220: first laser detector 230: second laser detector

222, 232: light emitting unit 224, 234: light receiving unit

320: first limit switch 330: second limit switch

140, 240, 340: elevator 150, 250, 350: drive unit

152, 252, 352: lead screw 151, 251, 351: electric motor

154, 254, 354: drive arm 153, 253, 353: drive shaft

172, 272, 372: handler 160, 260, 360: control unit

155, 255, 355: hard stop key

170, 270, 370: transfer chamber

In order to achieve this object, the present invention provides a wafer cassette in which a wafer is accommodated, a main body provided with a door for entering and exiting the wafer cassette, and a lifting and lowering operation of the wafer cassette configured in the main body and placed in the main body. In a load lock chamber for manufacturing a semiconductor device comprising an elevator to perform, a driving unit for driving the elevator, and a control unit for controlling the driving unit, an upper limit position of the wafer cassette by the elevator is detected on an inner upper portion of the main body. And a second detector for detecting the lower limit position of the wafer cassette by the elevator is provided in the lower part of the main body, wherein the first detector is provided. Provide a load lock chamber.

Hereinafter, a load lock chamber for manufacturing a semiconductor device having a sensor for position control of a wafer cassette according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a view illustrating a structure of a load lock chamber for manufacturing a semiconductor device having a sensor for controlling a position of a wafer cassette according to a first embodiment of the present invention, and FIG. 3 is an enlarged view of portion A of FIG. 4 is an enlarged view of a portion B of FIG. 2.

2 to 4, the load lock chamber for manufacturing a semiconductor device according to the first embodiment of the present invention in its overall configuration, the wafer cassette 50 inside the main body 200 through the door 214 When placed on the elevator 240, the elevator 240 descends, and in the wafer cassette 50 on the lowered elevator 240, the received wafers 10 are transferred to the transfer chamber 270 through the handler 272. Consists of. In addition, a first laser sensor 220 and a second laser sensor 230 are installed on the inner upper and lower portions of the main body 200 so that the elevator 240 according to the rising and falling of the elevator 240 and The limit position of the wafer cassette 50 is detected.

The first laser detector 220 is installed on the inner upper portion of the main body 200 so that the light emitting unit 222 and the light receiving unit 224 are horizontally aligned with each other, and the second laser detector 230 has an inner lower portion of the main body 200. Also, the light emitting unit 232 and the light receiving unit 234 are installed in a straight line horizontally, and each installation position is a limit position of the elevator 240 and the wafer cassette 50 according to the rising and falling of the elevator 240. Each of the laser detectors 220, 230 is a laser L between the light emitters 222, 232 and the light receivers 224, 234 by the bottom of the elevator 240 or the top of the wafer cassette 50 that is out of the limit position. By blocking), it is detected that the elevator 240 or the wafer cassette 50 has reached the limit position. When the elevator 240 detects that the elevator 240 moves out of the limit position through the laser detectors 220 and 230, a detection signal corresponding thereto is transmitted to the controller 260 to stop the operation of the driver 250 or correspond to the corresponding signal. Perform a series of actions.

FIG. 5 is a view illustrating a structure of a load lock chamber for manufacturing a semiconductor device having a sensor for controlling a position of a wafer cassette according to a second embodiment of the present invention. FIG. 6 is an enlarged view of a portion C of FIG. 5. 7 is an enlarged view of portion D of FIG. 5.

5 to 7, the load lock chamber for manufacturing a semiconductor device according to the second embodiment of the present invention, in its overall configuration, the wafer cassette 50 inside the body 300 through the door 314 When placed on the elevator 340, the elevator 340 is lowered, and in the wafer cassette 50 on the lowered elevator 340, the received wafers 10 are transferred to the transfer chamber 370 through the handler 372. Consists of. The first and second limit switches 320 and 330 are installed at upper and lower inner portions of the main body 300 so that the elevator 340 and the wafer cassettes are raised and lowered as the elevator 340 rises and falls. The limit position of 50 is detected.

The first limit switch 320 is provided at a position where a collision with the wafer cassette 50 may occur due to deviation of the lift limit position of the elevator 340 in the upper portion of the main body 300, and the second limit switch 330 ) Is installed at a position where a collision with the lower part of the elevator 340 may occur due to deviation of the lower limit position of the elevator 340 in the inner lower part of the main body 300, and each installation position may be raised in the elevator 340. And limit switches 320 and 330 as the limit positions of the elevator 340 and the wafer cassette 50 according to the lowering, respectively, by the limit switch 320 or the elevator 340 or the wafer cassette 50 outside the limit positions. Using the phenomenon that the 330 is pressed, the elevator 340 detects that the operation moves out of the limit position. When the elevator 340 detects that the elevator 340 moves out of the limit position through the limit switches 320 and 330, a detection signal is transmitted to the control unit 360 to stop or correspond to the operation of the driving unit 350. Perform a series of actions.

The detection of the elevator or wafer cassette out of the limit position by using a sensor such as a laser detector or a limit switch is used to raise or lower the elevator, such as incorrect or damaged positioning of the hard stop key of the lead screw. Even if the problem of changing the necessary reference point occurs, it is possible to prevent a problem such as a wafer cassette placed on an elevator or an elevator colliding with the upper or lower portion of the load lock chamber body.

As described above, according to the structure of the load lock chamber for manufacturing a semiconductor device having the detector for position control of the wafer cassette according to the present invention, it is possible to detect whether the elevator is out of the limit position through a detector installed inside the body of the load lock chamber. This causes the elevator or wafer cassette to collide with the top or bottom of the body of the load lock chamber even if there is a problem of changing the reference point for raising and lowering the elevator, such as incorrect or damaged positioning of the hard stop key of the lead screw. And the effect of eliminating the resulting wafer damage and overloading of the motor in the wafer cassette. In addition, depending on the configuration, the hard stop key can be used by the sensor to act as a hard stop key. Such as configurator to remove A can be obtained, which can simplify effect.

Claims (3)

A wafer cassette containing a wafer; A main body provided with a door for accessing the wafer cassette; An elevator configured inside the main body to perform an up and down operation on the wafer cassette placed in the main body; A driving unit for driving the elevator; And A load-lock chamber for manufacturing a semiconductor device, comprising: a control unit configured to control the driving unit; A first detector configured to detect an upward limit position of the wafer cassette by the elevator at an inner upper portion of the main body; A second detector capable of detecting a lower limit position of the wafer cassette by the elevator at an inner lower portion of the main body; A load lock chamber for manufacturing a semiconductor device, comprising a detector for position control of a wafer cassette. The load lock chamber of claim 1, wherein each of the first detector and the second detector is a laser sensor including a light emitting part and a light receiving part. The load lock chamber according to claim 1, wherein the first detector and the second detector are limit switches.