METHOD AND APPARATUS FOR APPLYING DIFFERENTIAL REMOVAL RATES TO A SURFACE OF A SUBSTRATE

摘要

A system for processing a wafer is provided. The system includes a chemical mechanical planarization (CMP) tool. The CMP tool includes a wafer carrier defined within a housing. A carrier film is affixed to the bottom surface and supports a wafer. A sensor embedded in the wafer carrier. The sensor is configured to induce an eddy current in the wafer to determine a proximity and a thickness of the wafer. A cluster of sensors external to the CMP tool is included. The cluster of sensors is in communication with the sensor embedded in the wafer carrier and substantially eliminates a distance sensitivity. The cluster of sensors provides an initial thickness of the wafer to allow for a calibration to be performed on the sensor embedded in the wafer carrier. The calibration offsets variables causing inaccuracies in the determination of the thickness of the wafer during CMP operation. A method and an apparatus are also provided.