METHOD AND APPARATUS FOR DYNAMIC ALIGNMENT OF SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide method and apparatus for dynamic alignment of a wafer which can operate during transportation of the wafer without increasing the transportation time of the wafer. SOLUTION: A wafer is transported on a blade of a robot and along a path through a port and into a module of semiconductor manufacturing equipment. Position of the center of the wafer with respect to the center of the blade is determined as the blade transporting the wafer transports the wafer from one module to another through a slot. Two through-beam sensors 274 positioned along the traverse axis according to the latency characteristics of the sensors are used. The positioning of the sensors assures that the moving wafer will break or make a beam of a first of the sensors and that the first sensor will generate a first transition signal before the moving wafer will break or make a beam of a second of the sensors and the second sensor generates a second transition signal.