Detection of optically transparent substrate wafer involves providing surface of transparent wafer with coating of opaque material such as metal or silicon monitoring light flow to sensor

摘要

The detection method involves monitoring the light flow from a light source of a wafer positioning system to an optical sensor. A surface of the optically transparent wafer is provided with a coating of opaque material such as a metal or silicon. AN Independent claim is also included for the following: an optically transparent substrate wafer.