V-NOTCH WAFER POSITIONING DEVICE

摘要

PROBLEM TO BE SOLVED: To accurately position a V-notch wafer so that the center of the wafer can be aligned with the center of rotation of the rotary stage of a laser surface inspection device. SOLUTION: A V-notch wafer positioning device positions a wafer 4 having a V-notch so that the center of the wafer 4 can be aligned with the center of rotation of a rotary stage by using at least three positioning pins 61-63. An eccentricity detecting means detects the eccentricity of the center of the wafer 4 from the center of rotation of the rotary stage by optically detecting the shape of the outer periphery of the wafer which is rotated when the rotary stage is rotated and, at the same time, the position of the V-notch of the wafer 4 on the rotational position of the stage. The eccentricity detecting means discriminates whether or not the precise positioning by means of at least the three positioning pins 61-62 is required based on the eccentricity of the wafer positioned on the stage.