A normal incidence spectroscopic polarimeter is combined with an oblique incidence spectroscopic polarimeter to provide an accurate characterization of complex grating structures, e.g., structures with sloping sidewalls, with notches and with multiple underlying layers. The normal incidence spectroscopic...http://www.google.ca/patents/US6713753?utm_source=gb-gplus-sharePatent US6713753 - Combination of normal and oblique incidence polarimetry for the characterization of gratings
