Patent ID: 7206066
Filing Date: 2007-04-17
Classification: G01N

Abstract:
1. An optical measuring system for evaluating a substrate, the system comprising a laser configured to generate an intensity stabilized light beam; an optical system for directing the beam to a spot on a substrate being evaluated; drive mechanism to rotate the substrate; track and support structures to bring about relative motion of the light beam relative to the surface of the substrate as the substrate rotates; a detection system configured to receive and detect light reflected from the substrate; said detection system including polarizers to convert the reflected beam to s and p polarized light and detectors to read the information content of the s and p polarized reflected beams; and, an elliptical cavity positioned adjacent to the point of impingement by the beam onto the substrate to capture the scattered light from the substrate and to detect the information incorporated into the detected scattered light to provide surface information of the substrate under evaluation.