We present an indirect broadband optical monitoring approach based on using several witness substrates that are brought to a measurement position in a special sequence. Different witness substrates are used to monitor not groups of successive design layers but specially chosen design layers. An attractive feature of the presented monitoring approach is the ability to reliably control thin dielectric and metal layers. Considered examples demonstrate a good accuracy of the proposed approach.
© 2009 Optical Society of America
Original Manuscript: February 4, 2009
Manuscript Accepted: March 21, 2009
Published: April 14, 2009
Valery G. Zhupanov, Evgeny V. Klyuev, Sergey V. Alekseev, Ivan V. Kozlov, Michael K. Trubetskov, Michael A. Kokarev, and Alexander V. Tikhonravov, "Indirect broadband optical monitoring with multiple witness substrates," Appl. Opt. 48, 2315-2320 (2009)