Specific wavelengths to use in optical metrology of an integrated circuit can be selected using one or more selection criteria and termination criteria. Wavelengths are selected using the selection criteria, and the selection of wavelengths is iterated until the termination criteria are met....http://www.google.de/patents/US7474993?utm_source=gb-gplus-sharePatent US7474993 - Selection of wavelengths for integrated circuit optical metrology
