Patent ID: 6849151
Filing Date: 2005-02-01
Classification: C23C,G01N,H01J

Abstract:
1. A substrate processing chamber comprising: a support to support a substrate; a gas supply to provide a process gas in the chamber; a gas energizer to energize the process gas to process the substrate; a light beam source comprising one or more lenses adapted to focus and direct a light beam onto a portion of the substrate having a periodic pattern of features while processing the substrate, the light beam comprising multiple wavelengths that are selected so that the light beam is reflectively diffracted by the periodic pattern of features to generate a reflectively diffracted light beam having wavelengths with intensities that modulate if there is a change in the width of the features; a light detector to detect the intensities of the multiple wavelengths of the reflectively diffracted light beam and generate a signal in relation to the detected intensities; and a controller to receive and evaluate the signal to determine the occurrence of a change in the width of the features from any modulation in the signal.