JPH0610687Y2 - Wafer transfer machine safety device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wafer transfer machine used in a semiconductor manufacturing process, and more specifically to a safety device for a wafer transfer machine.

2. Description of the Related Art In the semiconductor manufacturing process, wafers are transferred from a carrier to a quartz boat, or vice versa.This transfer is automatically performed using a wafer transfer machine. Done.

This wafer transfer machine includes a wafer claw (wafer chuck) for holding a wafer, a means for opening and closing the claw, and a means for vertically moving the claw.

When transferring wafers, the wafer claws are moved inwardly to clamp the wafers in the carrier and the claws are lowered to insert the wafers into the support grooves of the quartz boat, and then the claws are moved outward from each other. Move to and release the wafer.

Problems to be Solved by the Invention In the conventional wafer transfer machine, when wafers are batch-transferred to a quartz boat by a batch method, it is premised that there is no obstacle on the quartz boat.

However, on the quartz boat, there may be obstacles such as quartz fragments, wafers cracked by heat, or wafers that are thermally deformed and do not enter the support groove. In such a case, the wafer is blocked by the obstacle and cannot enter the support groove, which causes an accident such as wafer damage.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent a wafer damage accident at the time of wafer transfer.

Means for Solving the Problems This invention provides a pair of wafer claws having a plurality of wafer grooves horizontally and vertically, and after simultaneously gripping a plurality of wafers in a wafer container by the movement of the wafer claws, A wafer transfer machine in which a wafer claw is positioned on a transfer container to transfer a plurality of wafers at a time and an optical sensor having an optical axis across the wafer groove is provided on a supporting member of the wafer claw. The safety device is a safety device for a wafer transfer machine, wherein the optical sensor detects an obstacle in a transfer container by lifting a gripped wafer.

Action The wafer claw holding the wafer is moved to just above the quartz boat and then lowered to transfer the wafer to the quartz boat. At this time, if there is an obstacle on the quartz boat, the wafer is lifted by the obstacle. As a result, the light from the light emitting portion of the position sensor is blocked, so that no light enters the light receiving portion, so that an alarm is issued.

Embodiment An embodiment of the present invention will be described with reference to the accompanying drawings, in which the same reference numerals have the same names and functions.

A plurality of wafer grooves 3 and 4 are formed in the facing wafer claws 1 and 2 (wafer chuck).

The wafer claws 1 and 2 are opened and closed by drive lots 7 and 8 connected to the support members 5 and 6.

The support member 5 includes a position sensor 10 held by the arm 9.
Is provided.

The sensor 10 is a transmissive sensor including a light emitting portion 11 and a light receiving portion 12 that face each other. Light from the light emitting portion 11 passes outside the upper peripheral edge Wa of the wafer W and its optical axis 11a.
Is in the direction of the generatrix of the wafer W.

The wafer claws 1 and 2 are moved up and down by a vertical movement device (not shown) provided on the support base of the drive rods 7 and 8. The arrows A1 to A3 indicate the moving directions of the wafer claws 1 and 2.

Next, the operation of this embodiment will be described. While operating the position sensor 10, the drive rods 7 and 8 are slid to move the wafer claws 1 and 2 inward and push them up in a carrier (not shown). The wafer W that is held in the wafer grooves 3 and 4
Insert it in and pinch it.

Next, after moving the wafer claws 1 and 2 right above the quartz boat 13, the vertical movement device is driven to move the wafer claws 1 and 2 to the arrow A.
The wafer is moved in three directions and the lower part of the wafer is inserted into the support groove 14 of the quartz boat 13 to be in the WA state.
The wafer W on the supporting groove 14 in which the existence of the wafer exists is prevented from entering the supporting groove 14 by the obstacle and is lifted to the WB state.

In this state, the light of the light emitting unit 11 is blocked by the wafer WB and does not enter the light receiving unit 12, so that an alarm device (not shown) is activated to issue an alarm. Due to this alarm, the operator stops the operation of the apparatus and removes the obstacle 15 on the quartz boat. In the above embodiment, the case where the wafer is transferred from the carrier to the quartz boat has been described. However, it is needless to say that the present invention can be applied to the case where the wafer is transferred from the quartz boat to the carrier as shown in FIGS. 5 and 6. Is.

When the obstacle 52 is present on the groove 53 of the push-up device 51 shown in FIGS. 5 and 6, the wafer W is lifted to be in the WB state and comes into contact with the optical axis 11a of the position sensor 10. Therefore, no light enters the light receiving unit 12, and an alarm is issued.

As a position sensor, a reflective sensor may be used instead of the transmissive sensor as described above.

When the wafer is transferred, if the support groove of the quartz boat and the wafer do not match correctly, the wafer is lifted and the light from the light emitting part of the position sensor is blocked, so this device is also used for the alignment of the two. it can.

Effect of the Invention Since the invention is configured as described above, for example, when an obstacle is present on the quartz boat, the wafer clamped by the wafer claw is lifted by the obstacle and the light of the light emitting portion of the position sensor is emitted. Cut off.

As a result, an abnormal state of the wafer is detected and notified to the operator, so that an accident such as damage of the wafer can be prevented.

[Brief description of drawings]

1 and 2 are views showing an embodiment of the present invention.
The figure is a front view, FIG. 2 is a plan view, FIG. 3 and FIG.
FIG. 3 is a front view, FIG. 4 is a side view, FIG. 5 is a plan view showing another embodiment, and FIG.
It is a partially expanded perspective view of FIG. 1, 2 ... Wafer claw 10 ... Position sensor W ... Wafer

Claims (1)

[Scope of utility model registration request] 1. A pair of wafer claws having a plurality of wafer grooves are provided horizontally and vertically so that a plurality of wafers in a wafer container are simultaneously gripped by the movement of the wafer claws, and then the wafer claws are transferred. A safety device for a wafer transfer machine, which is positioned above to transfer a plurality of wafers at a time, and which is provided with an optical sensor having an optical axis in a direction crossing the wafer groove on a supporting member of the wafer claw, A safety device for a wafer transfer machine, wherein an optical sensor detects an obstacle in the transfer container by lifting the gripped wafer.