Patent ID: 7112270

Claim:
A method of determining removal of material from a plurality of points on a wafer, the removal being effected at least in part by electro-chemical activity, the method comprising: determining trajectories for a plurality of points on a wafer relative to a plurality of electrodes each capable of being separately biased at different bias levels during electro-chemical processing; based on the trajectories, determining an amount of time each of the plurality of points spends being affected by each of the electrodes; based on the trajectories and a predetermined charge-removal relationship relating charge removed to amount of material removed from the wafer, determining an average amount of material removed from the wafer as effected by each of the electrodes; and for each point of the plurality of points on the wafer, calculating an amount of material removed at the point as the sum of the average amounts of material removed from the wafer as effected by each of the electrodes weighted by the corresponding amount of time spent being affected by the respective electrode.