Method and apparatus for real time metal film thickness measurement

摘要

A semiconductor processing system is provided. The semiconductor processing system includes a first sensor configured to isolate and measure a film thickness signal portion for a wafer having a film disposed over a substrate. A second sensor is configured to detect a film thickness dependent signal in situ during processing, i.e. under real process conditions and in real time. A controller configured to receive a signal from the first sensor and a signal from the second sensor. The controller is capable of determining a calibration coefficient from data represented by the signal from the first sensor. The controller is capable of applying the calibration coefficient to the data associated with the second sensor, wherein the calibration coefficient substantially eliminates inaccuracies introduced to the film thickness dependent signal from the substrate. A method for calibrating an eddy current sensor is also provided.