AUTOMATIC STICKING SYSTEM FOR SEMICONDUCTOR WAFER

摘要

PURPOSE:To judge a true orientation flat (OF) by a method wherein the turned volume corresponding to an angle which is formed by the starting point and the end point of the orientation flat in relation to the center of a wafer is obtained with a view to judging whether this turned volume is within a prescribed range or not. CONSTITUTION:When it is confirmed that a wafer 2 is sucked by an alignment table 20, the wafer 2 is turned in succession by a motor 24 clockwise and counterclockwise. During this turning operation, the starting edge OS and the end edge OE of an orientation flat (OF) is detected by a photoelectric device PUSW 1. A CPU calculates the turned volume corresponding to an angle theta which is formed by both edges OS, OE of the OF in relation to the center of the semiconductor wafer 2 on the basis of the turned volume of said motor 24 until said starting edge and said end edge are detected. It is detected whether this turned volume is within a prescribed range of the reference turned volume or not. If the volume is within the range, it is judged that the orientation flat is detected.