2 April 2014 Mask contribution to intra-field wafer overlay
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Shrinking wafer overlay budgets raise the importance of careful characterization and control of the contributing components, a trend accelerated by multi-patterning immersion lithography [1]. Traditionally, the mask contribution to wafer overlay has been estimated from measurement of a relatively small number of standard targets. There are a number of studies on test masks and standard targets of the impact of mask registration on wafer overlay [2],[3]. In this paper, we show the value of a more comprehensive characterization of mask registration on a product mask, across a wide range of spatial frequencies and patterns. The mask measurements will be used to obtain an accurate model to predict mask contribution to wafer overlay and correct for it.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
William Chou, William Chou, Hsien-Min Chang, Hsien-Min Chang, Chao Yin Chen, Chao Yin Chen, M. Wagner, M. Wagner, K.-D. Roeth, K.-D. Roeth, S. Czerkas, S. Czerkas, M. Ferber, M. Ferber, M. Daneshpanah, M. Daneshpanah, F. Laske, F. Laske, R. Chiang, R. Chiang, S. Klein, S. Klein, "Mask contribution to intra-field wafer overlay", Proc. SPIE 9050, Metrology, Inspection, and Process Control for Microlithography XXVIII, 90501Q (2 April 2014); doi: 10.1117/12.2049000; https://doi.org/10.1117/12.2049000


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