Patent ID: 9004838
Filing Date: 2015-04-14
Classification: G01G,H01L,Y10S

Abstract:
1. A method for characterizing a wafer comprising: a) placing the wafer on an aligner comprising a rotary chuck; b) determining the offset of the center of rotation of the wafer from the center of rotation of the chuck; c) moving the chuck and wafer vertically with respect to a through hole of a cantilevered arm of a weighing scale to place the wafer on the cantilevered arm with the through hole surrounding the chuck; d) measuring the weight the wafer with the weighing scale; e) moving the chuck horizontally so as to align the center of rotation of the wafer with the center of rotation of the chuck; and f) moving the chuck and wafer vertically to remove the wafer from the cantilevered arm.