Recently, semiconductor manufacturers have been striving for high speed, large scale multi-layer wafer surface measurement. In this paper, we propose a novel technique in multi-layer wave-front sensing. The measurement uses a gated camera in pico second shutter that can be synchronized to a pico second laser pulse, up to μm accuracy. Subsequently, we propose a compensation technique using time-of-flight wave-front sensing to reconstruct the multilayer surfaces using our proposed gated imaging technique.

Date Published: 22 June 2013
PDF: 6 pages
Proc. SPIE 8769, International Conference on Optics in Precision Engineering and Nanotechnology (icOPEN2013), 87690B (22 June 2013); doi: 10.1117/12.2020845

Published in SPIE Proceedings Vol. 8769:
International Conference on Optics in Precision Engineering and Nanotechnology (icOPEN2013)
Chenggen Quan; Kemao Qian; Anand Asundi, Editor(s)