JPH06169004A - Semiconductor wafer detector - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the reliability of the presence / absence detection of a wafer in a semiconductor wafer detection device and to clean the inside of the device. A transmissive sensor is provided at a position where a wafer mounting plate 10 supported by a semiconductor wafer transfer mechanism can approach, and when a medium such as light emitted from a sensor sending unit 11 is blocked by the wafer 1, the sensor is provided. The reception signal from the detection unit 12 stops, the signal processing unit 14 detects reception interruption, and determines that the wafer is present.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer detecting apparatus for detecting the presence or absence of a wafer in a semiconductor wafer processing apparatus.

[0002]

2. Description of the Related Art A wafer is transferred in a semiconductor wafer processing apparatus by receiving a wafer on a wafer mounting plate and moving the wafer mounting plate by a wafer transfer mechanism. Further, in wafer transfer, it is essential to detect the presence / absence of a wafer during wafer transfer in order to ensure the reliability of wafer transfer.

Therefore, the wafer transfer mechanism of the conventional semiconductor wafer processing apparatus is equipped with a wafer detection device for detecting the presence / absence of a wafer based on the presence / absence of a vacuum when a wafer placed on a plate is sucked.

A conventional wafer detection device shown in FIG. 3 will be described.

In the figure, 1 is a wafer, 2 is a wafer mounting plate, and the wafer mounting plate 2 is supported by a plate holder (not shown). The wafer mounting plate 2 has a strip shape, and a suction path 7 extending in the longitudinal direction is bored inside the wafer mounting plate 2, and the tip of the suction path 7 is the wafer mounting plate 2. 2 is open to the top end side. Further, the base end of the suction passage 7 is opened to the base end side of the lower surface of the wafer mounting plate 2, and a pipe 8 is connected to the base end side opening 9.

The pipe 8 is branched in two directions by a joint 6, a vacuum sensor 3 is connected to one branch passage, and a vacuum pump 5 is connected to the other branch passage via an electromagnetic valve 4. .

Next, a wafer presence / absence detection method will be described.

The wafer 1 is placed on the wafer mounting plate 2 by the wafer transfer mechanism, the electromagnetic valve 4 is opened, and the suction passage 7 is evacuated by the vacuum pump 5.
At this time, when the wafer 1 is mounted on the wafer mounting plate 2, the inside of the suction passage 7 and the pipe 8 connected to the suction passage 7 is in a vacuum state, so the vacuum sensor 3 Detects the vacuum state and judges that there is a wafer.

On the contrary, when the wafer 1 is not mounted on the wafer mounting plate 2, the suction passage 7 and the inside of the pipe are not in a vacuum state, so that the vacuum sensor 3 does not operate. , Judge that there is no wafer.

In the conventional semiconductor wafer detecting apparatus, the wafer is detected as described above.

[0011]

However, in the conventional semiconductor wafer detection apparatus, since the wafer is vacuum-sucked in order to detect the presence or absence of the wafer on the wafer mounting plate, the suction surface of the wafer, that is, the back surface. May cause peeling or the like to damage the wafer, and dust generated by peeling the wafer may contaminate the inside of the apparatus and reduce the accuracy of semiconductor wafer processing.

Further, since the wafer mounting plate contacts the central portion of the wafer, the inside of the apparatus may be contaminated by the contact between the wafer and the wafer mounting plate.

In view of the above situation, the present invention aims to provide a semiconductor wafer detection apparatus which is capable of cleaning the inside of the apparatus and improving the reliability of semiconductor wafer transfer and the yield of wafers.

[0014]

According to the present invention, a transmission type sensor is provided at a position where a wafer mounting plate supported by a semiconductor wafer transfer mechanism can be approached.

[0015]

When the wafer interrupts the medium such as light emitted from the sensor sending unit of the transmissive sensor, the reception signal from the sensor detection unit is stopped, and the signal processing unit detects the reception interruption, and the wafer presence is detected. to decide.

[0016]

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

The wafer mounting plate 10 is in the shape of a strip, and the mounting surface of the wafer 1 is provided with shelves 15 and 15 for supporting the peripheral portion of the wafer 1 facing each other. , 15 is provided with an escape portion 16 for preventing the back surface of the central portion of the wafer 1 from coming into contact with the wafer mounting plate 10.

Further, the wafer mounting plate 10 is supported by a plate holder (not shown) which is a part of a semiconductor wafer transfer mechanism, and the plate holder holds the wafer mounting plate 10 on a vertical axis. Heart (not shown)
It can be rotated around.

Next, the transmissive sensor will be described. The transmissive sensor includes a sensor sending unit 11 and a sensor detecting unit 12. The sensor sending unit 11 is connected to a power supply unit 13 and emits detection light to the sensor detecting unit 12, and the sensor detecting unit 12 is a signal processing unit. 14 is connected to the signal processing unit 1
Reference numeral 4 determines the light receiving state of the sensor detector 12 and detects the presence or absence of a wafer from the light receiving state.

The sensor sending section 11 and the sensor detecting section 1
Both 2 are provided on the fixed portion of the semiconductor wafer transfer mechanism. More specifically, the sensor delivery section 11 is provided at a position where the wafer mounting plate 10 can be approached, and the sensor detection section 12 is spaced apart from the sensor delivery section 11 by a required distance and faces the vertical direction. It is provided.

When the wafer mounting plate 10 is moved and rotated as described above to mount the wafer 1 and returns to a predetermined position, when the wafer 1 is mounted on the wafer mounting plate 10, The light emitted from the sensor sending unit 11 is blocked by the wafer 1 and the light reception by the sensor detecting unit 12 is blocked. On the contrary, when the wafer 1 is not mounted on the wafer mounting plate 10,
The light emitted from the sensor sending unit 11 is the wafer 1
Since there is no interruption due to, it is detected by the sensor detection unit 12.

When the sensor detector 12 detects the light emitted from the sensor transmitter 11, the signal processor 1
4 converts the light into a signal to indicate that the wafer is not mounted on the wafer mounting plate 10. If the sensor detector 12 does not detect light, the signal processor 14 confirms the placement of the wafer.

In the above embodiment, the method for detecting the presence / absence of one wafer has been described. However, if a plurality of wafer mounting plates, sensor sending units, and sensor detecting units are arranged in the vertical direction, a plurality of wafers can be placed. It is also possible to detect the presence or absence of the wafer.

Further, although the detection medium is light in the above embodiment, it is needless to say that it may be an ultrasonic wave.

[0025]

As described above, according to the present invention, by using the transmission type sensor, it is possible to detect the presence or absence of a wafer during wafer transfer without contacting the wafer.
It does not damage the wafer such as peeling, and at the same time, does not contaminate the inside of the device with dust generated by peeling. Therefore, it is possible to increase the yield of the wafers and to reliably transfer the wafers. Further, since vacuum piping such as vacuum suction is not required, it is possible to save space and simplify the apparatus.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a plan view showing the above-mentioned embodiment.

FIG. 3 is a side view showing a conventional example.

[Explanation of symbols]

 1 Wafer 10 Wafer Placement Plate 11 Sensor Sending Section 12 Sensor Detection Section 14 Signal Processing Section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuto Ikeda 2-3-13 Toranomon, Minato-ku, Tokyo Kokusai Electric Co., Ltd. (72) Inventor Riichi Kano 2-3-13 Toranomon, Minato-ku, Tokyo No. Kokusai Electric Co., Ltd.

Claims (1)

[Claims] 1. A semiconductor wafer detection apparatus, wherein a transmission type sensor is provided at a position at which a wafer mounting plate supported by a semiconductor wafer transfer mechanism can be brought close to it.