Patent ID: 6402595
Filing Date: 2002-06-11
Classification: B24B

Abstract:
A method of polishing a wafer comprising the steps of:holding a wafer having a center, by a wafer carrier while biasing the wafer against a pad for polishing the wafer, relatively moving the wafer and the pad in more than one direction, such that the wafer, when not rotating about its own center, traces a path comprising tangentially connected arcs on the pad with a constant relative velocity with respect to the pad, the improvement comprising the step of; rotating the wafer about said center while relatively-moving the wafer and the pad in more than one direction such that a relative velocity for at least one point on the wafer with respect to the pad differs from said constant relative velocity by at least 0.1% wherein the step of rotating the wafer further comprises, rotating the wafer carrier while holding the wafer by the wafer carrier.