an improved pad and process for polishing metal damascene structures on a semiconductor wafer . the process includes the steps of pressing the wafer against the surface of a polymer sheet in combination with an aqueous - based liquid that optionally contains sub - micron particles and providing a means for relative motion of wafer and polishing pad under pressure so that the moving pressurized contact results in planar removal of the surface of said wafer , wherein the polishing pad has a low elastic recovery when said load is removed , so that the mechanical response of the sheet is largely anelastic . the improved pad is characterized by a high energy dissipation coupled with a high pad stiffness . the pad exhibits a stable morphology that can be reproduced easily and consistently . the pad surface resists glazing , thereby requiring less frequent and less aggressive conditioning . the benefits of such a polishing pad are low dishing of metal features , low oxide erosion , reduced pad conditioning , longer pad life , high metal removal rates , good planarization , and lower defectivity .