Abstract
CMP has been practiced by polishing wafers with white polyurethane pads that contain pores. These pores may reduce the contact areas at the interface so the polishing rate is increased by enhanced pressure. Moreover, the pores also serve as the reservoir for storing excess slurry that can replenish the consumed abrasive particles at the polishing site from time to time. A new design of black pads has eliminated the need of built in pores. Instead, submicron graphite particles are impregnated in polyurethane matrix. The graphite particles can be plucked off at the polishing site so the contact pressure at the polishing site is increased as if pores are present. Furthermore, graphite particles are hydrophilic so slurry can be retained better than that in water repelling white pad. The wetting can also lubricate the polishing site and allow faster polishing of the wafer without damaging the local circuitry. This reports summarizes various features of the black pads including their CMP performance compared to conventional white pads.