Self-centering calibration tool and method of calibrating

摘要

A self-centering calibration tool for a wafer platform or a heater in a chemical vapor deposition chamber is disclosed. The self-centering calibration tool is constructed of a circular calibration disc that has at least one alignment mark on a top surface for aligning a robot arm, and a centering device mounted juxtaposed to a bottom surface of the disk. The centering device is detachably mounted to the calibration disk by a bolt threadingly engaging a center aperture in a calibration disk and a center aperture in the centering device. The centering device is constructed by at least three links, or legs extending radially outwardly from the center aperture equally spaced circumferentially from each other adapted for engaging an undercut groove provided in a raised edge of the wafer platform to effectuate a self-centering calibration. A method for calibrating the movement of a robot arm for loading a wafer onto a wafer platform or a heater is also disclosed.