Chemical mechanical polishing of patterned copper wafer surface using water-soluble fullerenol slurry

Cu-CMP has become a key fabrication process by which high-performance semiconductor devices are realized. Therefore, a novel Cu-CMP technique using water-soluble fullerenol slurry was developed. The experimental results show that the proposed Cu-CMP technique realizes a high material removal rate and low dishing performance for the polishing of a patterned Cu-wafer. An XPS analysis and SEM observation showed that these advantageous polishing performances were achieved by the chemical effect of using fullerenol as a polishing agent. The fullerenol was found to chemically react with the copper to form a complex brittle layer which was fragile enough to be removed by rubbing with a polishing pad.