| 摘要 |
A wafer carrier for polishing or planarizing semiconductor workpieces or wafers includes a pressure plate configured to hold a wafer to be polished or to be planarized against a polishing pad, and is further configured to rotate the wafer during the polishing or planarizing process. A retaining ring for holding the wafer is mounted about the periphery of the pressure plate. The retaining ring slides vertically and independently relative to the pressure plate. A polishing pad load ring is also slideably mounted about the periphery of the retaining ring. The pad load ring is biased against the polishing pad, and slides vertically and independently of the pressure plate and the wafer retaining ring. In operation, the wafer carrier is moved across the polishing pad, which is sufficiently compliant to cause wave deformation of the surface of the pad. The pad load ring provides a buffer area which displaces wave deformation of the polishing pad away from the edge of the wafer, and thus minimizes the beveling of the wafer lower peripheral edge.
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