Patent ID: 9082802
Filing Date: 2015-07-14
Classification: G05B,H01L

Abstract:
1. An apparatus for positioning a wafer on a support of a rotatable chuck, the apparatus comprising: a plurality of sensor lights positioned symmetrically around a center coordinate of the rotatable chuck; a plurality of sensor detectors positioned symmetrically around the center coordinate of the rotatable chuck, the sensor detectors in communication with the sensor lights and operable to determine wafer position information relative to the center coordinate of the rotatable chuck when the wafer is positioned on the rotatable chuck; a wafer arm; and a wafer arm controller, wherein the wafer arm controller is operable to adjust the wafer arm to position a center coordinate of the wafer in alignment with the center coordinate of the rotatable chuck when the wafer is positioned on the rotatable chuck based on the wafer position information determined by the sensor detectors.