Patent ID: 7115017

Claim:
A method for removing at least a portion of a material layer from a first surface of a work piece utilizing a CMP apparatus having a work piece carrier with a plurality of pressure adjustable zones, wherein each zone is configured to exert a pressure against a second surface of the work piece during a CMP process, the method comprising the steps of: determining a first thickness T z,n−1 of the material layer underlying a first zone z, where z is an integer from 1 to Z f , Z f is the total number of zones, n is an integer from 1 to N, and N is the total number of times thickness measurements are assessed; removing a first portion of the material layer underlying the first zone for a time interval (t n −t n−1 ) wherein the first zone is configured to exert a first pressure P z,n against the second surface of the work piece; determining a second thickness T z,n of the material layer underlying the first zone; selecting a target thickness T z,n+1 of the material layer within zone z corresponding to a predetermined thickness profile to be produced before the material layer is substantially removed; calculating a second pressure P z,n+1 using the first pressure P z,n , the first thickness T z,n−1 , the second thickness T z,n , and the target thickness T z,n+1 , wherein the second pressure is to be exerted against the second surface of the work piece by the first zone during removal of a second portion of the material layer; adjusting the pressure exerted by the first zone against the second surface of the work piece to the second pressure P z,n+1 ; and repeating the foregoing steps for a second zone.