A method and apparatus uses photoluminescence to identify defects in one or more specified material layers of a sample. One or more filtering elements are used to filter out predetermined wavelengths of return light emitted from a sample. The predetermined wavelengths are selected such that only return...http://www.google.ca/patents/US7504642?utm_source=gb-gplus-sharePatent US7504642 - Photoluminescence imaging with preferential detection of photoluminescence signals emitted from a specified material layer of a wafer or other workpiece
