Patent ID: 7628905

Claim:
A method for processing a substrate to achieve a target profile by electropolishing, comprising: determining a pre-processing profile for the substrate, wherein the pre-processing profile reflect thickness of a plurality of locations on the substrate; determining a desired removal profile comprising: determining a difference between the pre-processing profile and the target profile; and determining a target charge value for each of at least two independently biased zones according to an amount of time that each of the plurality of locations on the substrate is effected by each zone during electropolishing; electropolishing the substrate to selectively remove conductive material from the substrate according to the each target charge value of the desired removal profile; determining an amount of charge removed by each zone; and terminating the electropolishing when each of the target charge value of the desired removal profile is substantially achieved, wherein the electropolishing the substrate comprises generating a relative motion between the substrate and the at least two independently biased zones corresponding to at least two independently biasable electrodes, the relative motion is one of an orbital, rotary, linear, curvilinear, and the combinations thereof, and wherein the determining the target charge value further comprises calculating the amount of time each of the plurality of locations on the substrate is effected by each zone according to a trajectory of each location on the substrate relative to each zone.