Patent ID: 7248375
Filing Date: 2007-07-24
Classification: G01B,G03F

Abstract:
1. An apparatus for evaluating the geometry of a feature having a size significantly less than a micron formed on a sample comprising: a laser for generating a probe beam that is directed substantially normal to the sample surface; an optical element for focusing the probe beam to a spot overlapping the feature on the sample surface in a manner so that the rays within the probe beam create a spread of angles of incidence from zero to about 70 degrees and wherein the spot size on the probe beam on the sample is on the order of about one micron in diameter so that the probe beam is diffracted upon reflection; a detector array for monitoring the diffracted probe beam light, said detector array simultaneously generating a plurality of independent output signals corresponding to a plurality of different angles of incidence; and a processor for analyzing the output signals generated by the detector according to a scatterometry model to evaluate the geometry of the feature on the sample.