Patent ID: 6242879
Filing Date: 2001-06-05
Classification: G03F,H01L

Abstract:
A method for automatically calibrating the positioning of a wafer handling robot to a precise, desired location within an enclosure forming a process station having an opening and exterior structural features, said robot having an articulated arm with an end-effector that is movable in the vertical (Z), angular (.crclbar.), and radial (R) directions and is connected to a controller having memory and logic sections, said method including the steps of:(1)--selecting a plurality of said structural features on said enclosure and storing in said controller, rough distance and geometrical data defining the relative location of said features to said robot;(2)--programming said controller to cause said robot arm to move toward said process station enclosure in a series of sequential movements, each said movement culminating in said robot end-effector touching a preselected said exterior feature of said process station;(3)--sensing a signal response when each end-effector touching occurs and storing such data in said controller relative to the location of each said exterior feature when it is touched by said end-effector; and(4)--combining said stored data from each said touching location to compute a precise calibrated target position of said robot end-effector within said enclosure.