Patent ID: 8135485

Claim:
A method for aligning a substrate to a process center of a support mechanism, wherein said process center representing a focal center for processing said substrate in a plasma processing chamber, comprising: determining a plurality of thickness values for said substrate after substrate processing at a plurality of orientations and at a plurality of radial distances from a geometric center of said substrate; deriving a set of process rate values from said plurality of thickness values and a process duration; creating an off-centered plot for a first process rate of said set of process rate values, wherein said off-centered plot represents a substantially concentric circle whose points on a circumference of said off-centered plot having substantially said first process rate; applying a curve-fitting equation to said off-centered plot to determine a set of parameters for offsetting said substrate in relation to said support mechanism; and teaching a set of robot arms said set of parameters, thereby enabling said set of robot arms to align another substrate that is supported by said support mechanism with said process center of said support mechanism when said set of robot arms positions said another substrate in said plasma processing chamber for processing.