Wafer handling traction control system

Patent metadata

Field	Value
Publication number	US-9184084-B2
Application number	US-201414166771-A
Country	US
Kind code	B2
Filing date	Jan 28, 2014
Priority date	Jan 28, 2014
Publication date	Nov 10, 2015
Grant date	Nov 10, 2015

Abstract

A wafer handling traction control system is provided that is able to detect slippage of a semiconductor wafer with respect to an end effector and is able to adjust the end effector's movement in order to minimize further slippage. Upon the detection of relative motion of the semiconductor wafer with respect to the end effector past a threshold amount, the end effector's movements are adjusted to minimize slippage of the semiconductor wafer. The wafer handling traction control system may include a sensor that detects relative motion between the semiconductor wafer and the end effector.

First claim

What is claimed is:

1. An apparatus comprising:
a first robot arm configured to support a first semiconductor wafer on a first end effector;
a first sensor configured to detect relative movement between the first semiconductor wafer and the first end effector; and
a controller with one or more processors and a memory, wherein the one or more processors, the memory, the first robotic arm, and the first sensor are communicatively connected and the memory stores program instructions for controlling the one or more processors to:
a) cause the first robot arm to move according to a first acceleration profile while the first semiconductor wafer is supported by the first end effector,
b) receive first sensor data from the first sensor,
c) analyze the first sensor data to determine first motion data based on relative movement of the first semiconductor wafer with respect to the first end effector during motion of the first robot arm while the first semiconductor wafer is supported by the first end effector,
d) determine whether the first motion data attributable to movement of the first robot arm according to the first acceleration profile exceeds a first threshold motion metric, and
e) cause the first robot arm to move according to a second acceleration profile when the first motion data attributable to movement of the first robot arm according to the first acceleration profile exceeds the first threshold motion metric, wherein the first motion data attributable to movement of the first robot arm according to the second acceleration profile stays within the first threshold motion metric.

2. The apparatus of claim 1 , wherein the first motion data is based on data from which the relative acceleration of the first semiconductor wafer with respect to the first end effector during motion of the first robot arm while the first semiconductor wafer is supported by the first end effector can be calculated.

3. The apparatus of claim 1 , wherein the first motion data is based on data from which the relative velocity of the first semiconductor wafer with respect to the first end effector during motion of the first robot arm while the first semiconductor wafer is supported by the first end effector can be calculated.

4. The apparatus of claim 1 , wherein the first motion data is based on the relative displacement of the first semiconductor wafer with respect to the first end effector during motion of the first robot arm while the first semiconductor wafer is supported by the first end effector.

5. The apparatus of claim 1 , wherein the first motion data is based on a combination of two or more relative motion parameters selected from the group consisting of:
relative acceleration of the first semiconductor wafer with respect to the first end effector during motion of the first robot arm while the first semiconductor wafer is supported by the first end effector;
relative velocity of the first semiconductor wafer with respect to the first end effector during motion of the first robot arm while the first semiconductor wafer is supported by the first end effector; and
relative displacement of the first semiconductor wafer with respect to the first end effector during motion of the first robot arm while the first semiconductor wafer is supported by the first end effector.

6. The apparatus of claim 1 , wherein:
the first acceleration profile is a first calibration acceleration profile;
the second acceleration profile is a second calibration acceleration profile; and
the memory stores further instructions for additionally controlling the one or more processors to:
f) cause the first robot arm to move according to a first operational acceleration profile associated with the first calibration acceleration profile after d) when the first motion data attributable to the movement of the first robot arm according to the first acceleration profile does not exceed the first threshold motion metric, and
g) cause the first robot arm to move according to a second operational acceleration profile associated with the second calibration acceleration profile after e) when the first motion data attributable to the movement of the first robot arm according to the first acceleration profile exceeds the first threshold motion metric and the first motion data attributable to the movement of the first robot arm according to the second acceleration profile does not exceed the first threshold motion metric.

7. The apparatus of claim 6 , wherein the memory stores further instructions for additionally controlling the one or more processors to, prior to a) and e):
h) determine, after f) or g), whether the first motion data attributable to the movement of the first robot arm according to the first or second operational acceleration profile exceeds a second threshold motion metric, and
i) cause the first robot arm to move according to a third operational acceleration profile when the first motion data attributable to the movement of the first robot arm according to the first or second operational acceleration profile exceeds the second threshold motion metric, wherein the first motion data attributable to the movement of the first robot arm according to the third operational acceleration profile stays within the second threshold motion metric.

8. The apparatus of claim 6 , wherein the memory stores further instructions for additionally controlling the one or more processors to:
h) cause the first robot arm to move N additional times according to the first operational acceleration profile after d) and without performing a) or e) for N additional semiconductor wafers when the first motion data attributable to the movement of the first robot arm according to the first calibration acceleration profile does not exceed the first threshold motion metric, and
i) cause the first robot arm to move N additional times according to the second operational acceleration profile after e) and without performing a) or e) for the N additional semiconductor wafers when the first motion data attributable to the movement of the first robot arm according to the first calibration acceleration profile exceeds the first threshold motion metric and the first motion data attributable to the movement of the first robot arm according to the second calibration acceleration profile does not exceed the first threshold motion metric, wherein N is an integer greater than or equal to 1.

9. The apparatus of claim 6 , wherein the memory stores further instructions for additionally controlling the one or more processors to:
h) cause the first robot arm to move according to a third calibration acceleration profile after d) when the first motion data attributable to movement of the first robot arm according to the first acceleration profile is below the first threshold motion metric, wherein the first motion data attributable to movement of the first robot arm according to the third calibration acceleration profile stays within the first threshold motion metric, and
i) cause the first robot arm to move according to a third operational acceleration profile associated with the third calibration acceleration profile after h) when the first motion data attributable to the movement of the first robot arm according to the first acceleration profile is below the first threshold motion metric and the first motion data attributable to the movement of the first robot arm according to the third acceleration profile does not exceed the first threshold motion metric.

10. The apparatus of claim 9 , wherein the first motion data attributable to the third calibration acceleration profile exceeds the first motion data attributable to the first calibration acceleration profile.

11. The appa

Assignees

• Lam Res Corp

Inventors

• Rodnick Matthew J

Classifications

• H10P74/238

  comprising acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection or in-situ thickness measurement · CPC title

• H10P72/7602

  the wafers being placed on a robot blade or gripped by a gripper for conveyance · CPC title

• H10P72/0606 Primary

  Position monitoring, e.g. misposition detection or presence detection · CPC title

• H10P74/277

  Circuits for electrically characterising or monitoring manufacturing processes, e.g. circuits in tested chips or circuits in testing wafers · CPC title

• H10P72/30

  for conveying, e.g. between different workstations · CPC title