Patent ID: 6913516
Filing Date: 2005-07-05
Classification: B24B

Abstract:
1. A dummy process, suitable for a chemical mechanical polishing (CMP) apparatus including a polishing head, a polishing table, and a polishing pad, wherein the polishing pad is disposed on the polishing table, the polishing head comprises a protective hood, a base, a retaining ring and a wafer supporting assembly, and wherein the base is below the protective hood, the retaining ring is fixed around a rim of the base, the wafer supporting assembly is located below and in a distance from the base, and a wafer receiving recess is defined by an inner surface of the retaining ring and the wafer supporting assembly, the dummy process comprising: providing a wafer; attaching the wafer onto the wafer receiving recess; moving up the wafer supporting assembly to make the bottom surface of the retaining ring more protrusive than the bottom surface of the wafer; moving the polishing head onto the polishing table; pressing down the base such that the retaining ring contacts a surface of the polishing pad and the wafer does not contact the surface of the polishing pad; and rotating the polishing table.