Patent ID: 7141146

Claim:
A system for electrochemical mechanical processing of a conductive face of a wafer using a process solution, comprising: a wafer carrier holding the wafer; a solution chamber to hold the process solution, the solution chamber having an upper opening; a compressible and flexible pad, having a polishing surface and fluid channels, placed between the upper opening of the solution chamber and the conductive face of the wafer, wherein the compressible and flexible pad is configured to bow and apply more pressure near the center of the conductive face than the rest of the conductive face as the pressure of the process solution in the solution chamber increases; an electrode in contact with the process solution, wherein the system is configured to apply a potential difference between the conductive face of the wafer and the electrode; and a control system programmed to control pressure to ensure bowing the pad while relatively moving the conductive face of the wafer and the pad into contact.