Closed-loop control for effective pad conditioning

摘要

A method and apparatus for conditioning a polishing pad is provided. The conditioning element is held by a conditioning arm rotatably mounted to a base at a pivot point. An actuator pivots the arm about the pivot point. The conditioning element is urged against the surface of the polishing pad, and translated with respect to the polishing pad to remove material from the polishing pad and roughen its surface. The interaction of the abrasive conditioning surface with the polishing pad surface generates a frictional force. The frictional force may be monitored by monitoring the torque applied to the pivot point, and material removal controlled thereby. The conditioning time, down force, translation rate, or rotation of the conditioning pad may be adjusted based on the measured torque.