Implementation of a wafer positioning system
Yi-Cheng Chen, Yun-Yen Lee, Ju-Yi Lee, Jianyou Chen · Society of Instrument and Control Engineers of Japan · 2011
This study implements a system for determining the precise location of a moving wafer in a process chamber. An array of optical sensors positioned along an axis transverse to the path of a moving wafer is employed in this wafer positioning system. A computer program for wafer center calculation is developed based on the time dependent signals from the optical sensing module. The developed computer program has a human machine interface, and estimates the center position as well as the moving direction of the wafer.