IN-SITU PERFORMANCE PREDICTION OF PAD CONDITIONING DISK BY CLOSED LOOP TORQUE MONITORING

摘要

Polishing pads used in CMP machines are consumable components that are typically replaced after a specific number of wafers have been processed. The life of a polishing pad is optimized by controlling the rate of material removal from the polishing pad by the conditioning disk. The conditioning disk removes enough material so the polishing surface can properly process the wafers but does not remove any excess material. Preventing excess material removal extends the life of the polishing pad. During CMP processing, the controller receives data concerning the torque applied to the conditioning disk and the torque applied to the arm to sweep the conditioning disk across the polishing pad. Based upon the detected operating conditions, the system can predict the rate of material removal and adjust the forces applied to the conditioning disk so that the life of the polishing pad is optimized.