A method and system to measure misalignment error between two overlying or interlaced periodic structures are proposed. The overlying or interlaced periodic structures are illuminated by incident radiation, and the diffracted radiation of the incident radiation by the overlying or interlaced periodic...http://www.google.com.au/patents/US7656528?utm_source=gb-gplus-sharePatent US7656528 - Periodic patterns and technique to control misalignment between two layers
