JPH07142553A - Method and equipment for sensing position wafer in boat - Google Patents

Abstract

PURPOSE:To transfer wafers to and from a boat smoothly and efficiently which protecting the boat and the wafers from damage, by avoiding contact of the boat with tweezers or the wafer. CONSTITUTION:A transfer device 3 is moved vertically three wafers in each section such as the uppermost section, lowermost section, etc., of a boat 2 previously registered on a control section 6 are sensed by a wafer position sensor 4 installed to the device 3, observed values and registered values (the distances of the wafers in the uppermost section and lowermost section of the boat, the average of the pitch of the three wafers in each section and the displacement of reference positions) are compared, and the observed values are registered on the main control section 6 when these displacements are within the tolerance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boat side wafer position detecting method in a semiconductor manufacturing apparatus such as a vertical diffusion CVD apparatus.

[0002]

2. Description of the Related Art Vertical diffusion CVD is one of semiconductor manufacturing devices.
There is a device. In this apparatus, a wafer loaded in a cassette is transferred to a boat by a transfer machine, and the boat is inserted into a reaction chamber in a furnace for heating reaction. Normally, when transferring from a wafer cassette to a boat by a wafer transfer machine, the wafer insertion position of the boat must be registered for the wafer position and the number of wafers in the cassette in the main control unit that controls the transfer machine. .

The wafer position and the number of wafers in the cassette are detected by relatively scanning the wafer detection sensor in the vertical direction with respect to the wafer cassette mounted on the cassette stage. As an example of the method, Japanese Patent Application No. 2-3446
There is a method described in Japanese Patent Application Laid-Open No. 3-237739. Alternatively, as an example of a method of mounting a cassette on a cassette stocker that stores a plurality of cassettes from the cassette stage in multiple rows and using a wafer detection sensor attached to a lifting table of a transfer machine, Japanese Patent Application No. 2-1789
There is a method described in Japanese Patent Laid-Open No. 42-67283 (Japanese Patent Laid-Open No. 4-67283), and these methods and the like can automatically detect and register the wafer position and the number of wafers in the cassette.

Conventionally, the wafer insertion positions (wafer pitch interval and number of mounted wafers) of the boat are registered because the wafers in the cassette are taken out by the tweezers and accurately placed in the groove portions on the boat when they are transferred to the quartz boat. Then, a wafer or an equivalent product is used to perform a transfer operation, and as shown in FIG. 3, one wafer 1 is inserted into a predetermined groove of the quartz boat 2, for example, the uppermost groove and the lowermost groove, by human visual inspection. The optimum position is registered in the main control unit (main controller) as a search reference value, and the wafer pitch interval and the number of mounted wafers are input from the operation unit 13 connected to the main control unit (main controller). After this, process, dummy and monitor wafers are inserted and placed in each groove of the boat.
Although the quartz boat is inserted into the reaction chamber and reacted by heating, the quartz boat is deformed by heat during the use of the quartz boat, and the quartz boat is pulled out from the reaction chamber.

[0005]

In the above-mentioned conventional example, the wafer 1 is transferred from the boat 2 to the tweezer 3 of the transfer machine 3.
Transport error (adsorption error, etc.) when pulling out by A
In the worst case, the wafer 1 and the tweezers 3A come into contact with each other, and when the wafer is inserted into the boat, the boat 2 and the wafer 1 come into contact with each other and collide with each other.
Alternatively, there is a problem that the boat 2 is damaged and the correct function of transfer cannot be performed. In addition, the position registration for inserting the wafer 1 into the boat 2 of the transfer machine 3 is performed by the human eyes,
Feeling, etc., manually put the wafer 1 in the groove of the boat 2 at the lowest position.
Since the method is to find a position where the wafer can be inserted without touching it and register it in the main control unit by hand, it requires a skill and a lot of time to adjust the wafer insertion. is there.

[0006]

The present invention has been made to solve the above problems, and it is possible to automatically find a wafer insertion position into a boat and register it in the main control unit. An object of the present invention is to provide a position detection method and device. That is, according to the method and apparatus of the present invention, as shown in FIG. 1, the transfer machine 3 is raised and lowered, and the three wafers 1U of each part such as the uppermost part and the lowermost part of the boat 2 already registered in the main control part 6 are provided. , 1D is detected by the wafer position detection sensor 4 attached to the transfer machine 3, and the measured value and the registered value (the distance between the uppermost and lowermost wafers of the boat, the average wafer pitch of three wafers in each part, and the deviation of the reference position) Is compared, and if the deviation is within the allowable range, it is registered in the main control unit 6.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view showing the constitution of one embodiment of the method and apparatus of the present invention, and FIGS. 2 (A) and 2 (B) are an explanatory view of wafer position detection and an explanatory view of a boat in this embodiment, respectively. is there. In the present embodiment, as shown in FIGS. 1 and 2, the groove position of the reference position and the wafer pitch which are already registered in the main control unit (main controller) 6 are set in the uppermost and lowermost grooves of the boat 2, respectively. Based on the calculation, the transfer machine 3 automatically or artificially inserts the three wafers 1U and 1D into the boat 2. Ultrasonic type reflective wafer position detection sensor 4
Transfer device lifting mechanism 9 for lifting the transfer device 3 to which the
The screw shaft 14 is rotated by, for example, the motor 7, which constitutes the above structure, and the transfer machine 3 including the lifting table screwed onto the screw shaft 14 and the tweezers 3A moving in the horizontal direction on the lifting table is moved up or down. ing. 5 is a cap.

As shown in FIG. 2, when the groove at the reference position is the lowermost portion of the boat 2 at the beginning, the reflection type wafer position detection sensor 4 is moved below the reference position according to the value registered in the main controller 6. Move to position. Next, as shown in FIG. 1, the sensor 4 is raised by the motor 7, and the actual movement of the sensor 4 is obtained by the rotary encoder 8. As shown in FIG. Wafer 1D is detected. As shown in FIG. 1, the wafer position detection (presence / absence) signal output from the reflective wafer position detection sensor 4 and the value of the sensor position detection signal of the rotary encoder 8 are input to the wafer detection unit 10, and a certain process is performed. The deviation of the reference position and the average value of the wafer pitch inserted in each groove at the bottom of the boat 2 are obtained. It is determined whether the wafer detection width preset as a parameter by the main control unit 6 is within the permissible range and whether the wafer pitch interval is within the permissible range of the registered value. For example, a process as disclosed in Japanese Patent Application No. 3-216325 can be considered.

Next, the reflection type wafer position detection sensor 4 is
According to the value registered in the main control unit 6, the three wafers 1U inserted in the grooves at the top of the boat 2 are detected. As a result, the distance between the uppermost and lowermost wafers 1U and 1D of the boat 2 and the average value of the wafer pitch inserted in the uppermost portion of the boat 2 are obtained, and the same determination as above is performed. If it is within the allowable range, the wafer can be transferred more accurately and surely by registering it as correction data in the main controller 6. If the measured value does not fall within the allowable range due to the sensor adjustment state, the readjustment is performed again. However, since the position adjustment of the wafer position detection sensor 4 is displayed on the display unit, the readjustment can be easily performed. In this embodiment, the wafer 1 is loaded in each of the three grooves at the uppermost and lowermost portions of the boat 2 and the number of detection wafers is three. However, three or more wafers may be used. More accurate detection is possible. As shown in FIG. 1, the reaction process, the position of the wafer detected by the boat in use, and the number of wafers are not limited to these. Further, the sensor 4 may be a light reflection type sensor instead of the ultrasonic wave sensor, and may be a transmission type instead of a reflection type.

As described above, in this embodiment, three wafers 1U and 1D are placed in the upper and lower portions of the boat 2, respectively. The transfer machine 3 is moved in the vertical direction, and the wafers 1U and 1D that have been placed are read by the sensor 4 attached to the transfer machine 3. An average value between the wafers 1 is obtained from the read position data, and the wafers 1 are evenly distributed according to the number of grooves in the boat 2. From this value, the width of the position where the wafer 1 can be inserted and placed without touching the boat 2 is calculated, and the value is registered in the main controller 6 as the wafer insertion position. According to this embodiment, the position registration adjustment time for transferring the wafer 1 to and from the boat 2 and transferring the wafer 1 from the boat 2 can be significantly shortened, and the boat 2 and the tweezers 3A or the wafer can be shortened. It is possible to prevent the boat 2 or the wafer 1 from being damaged by avoiding contact with the wafer 1, and to transfer the wafer smoothly and surely.

[0011]

As described above, according to the present invention, the transfer machine 3
The upper and lower parts of the boat 2 which are already registered in the main control unit 6 and are moved up and down, and each of the three wafers 1U, 1
D is detected by the wafer position detection sensor 4 attached to the transfer machine 3, and the measured value and the registered value (the distance between the uppermost and lowermost wafers of the boat, the average wafer pitch of three wafers in each part, and the deviation of the reference position) In comparison, if the deviation is within the allowable range, the method and the device are characterized in that they are registered in the main control unit 6. Therefore, the transfer of the wafer 1 to the boat 2 and the transfer of the wafer 1 from the boat 2 are performed. The position registration adjustment time for the boat 2 or the wafer 1 can be significantly reduced, and the contact between the boat 2 and the tweezers 3A or the wafer 1 can be avoided.
Can be prevented and the wafer can be transferred smoothly and surely.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the configuration of an embodiment of a method and apparatus of the present invention.

2A and 2B are an explanatory view of wafer position detection and an explanatory view of a boat in the present embodiment, respectively.

FIG. 3 is an explanatory diagram of a main part showing a configuration of an example of a conventional method and apparatus.

[Explanation of symbols]

 1 wafer 1U (uppermost) upper wafer 1D (lowermost) lower wafer 2 boat 3 transfer machine 3A tweezers 4 wafer position detection sensor 6 main control unit (main controller) 7 drive unit (motor) 8 sensor position detection unit (rotary) Encoder) 9 Transfer device lifting mechanism 10 Wafer detection unit 11 Drive unit (motor) controller 12 Drive unit (motor) driver

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuto Ikeda 2-13-13 Toranomon, Minato-ku, Tokyo Kokusai Electric Co., Ltd. (72) Inventor Development Hideki 2-3-13 Toranomon, Minato-ku, Tokyo International Electric Co., Ltd.

Claims (3)

[Claims] 1. Three or more wafers (1U, 1D) are inserted and placed on the upper and lower portions of a boat (2), and the upper and lower wafers (1U, 1D) are transferred by a transfer machine (1). 3)
Is moved up and down, and the wafer position detection sensor (4) attached thereto detects the movement of the sensor by the sensor position detection unit (8) to detect the wafer position detection signal and the sensor position detection signal. Department (1
0), and determines whether or not the value is preset within the main control unit (6) as a parameter and is within an allowable range. 2. When the value of the wafer position is within the allowable range, the value is registered as correction data in the main control unit (6), and the operation of the transfer machine (3) is corrected by the correction data. The boat-side wafer position detecting method according to claim 1, wherein 3. A transfer device elevating mechanism (9) comprising a wafer position detection sensor (4) for detecting three or more wafers (1U, 1D) inserted and placed on the upper and lower parts of the boat (2), respectively. It is mounted on a transfer machine (3) that is moved up and down by the sensor, and the movement of the wafer position detection sensor (4) is detected by a sensor position detection unit (8). The wafer position detection signal and the sensor position detection signal are detected by the wafer detection unit (10). ) To determine whether or not it is within an allowable range with respect to the value set as a parameter in advance, and the transfer machine lifting mechanism (9) is output by the main controller (6). A boat side wafer position detecting device comprising a drive controller (11) for controlling the drive (7) and a drive driver (12) for operating the drive (7) by the drive controller (11).