Scatterometers and methods of using scatterometry to determine several parameters of periodic microstructures, pseudo-periodic structures, and other very small structures having features sizes as small as 100 nm or less. Several specific embodiments of the present Invention are particularly useful in...http://www.google.de/patents/US20060289790?utm_source=gb-gplus-sharePatent US20060289790 - Apparatus and method for enhanced critical dimension scatterometry
