28 March 2017 Topography based wafer clustering for wafer level overlay correction
Author Affiliations +
Non-linear overlay deformation is a well-known problem in critical lithography steps. A significant root cause is nonuniform stress, often caused by high temperature processes. Non-uniform stress in the wafer causes vertical deformation of the wafer, which can be measured by topography measurement equipment. In this case study, clustering is done on the topography data to sort each wafer into groups. Using the context information from the clustering, overlay feedback is computed on a wafer level basis. The evaluation of the approach is done with a run-to-run simulation, which allows optimization of this method and evaluation of the on-product overlay performance improvement. In the analysis, different wafer zones are distinguished to characterize the improvement potential for the different zones.
Conference Presentation
© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Hongoo Lee, Hongoo Lee, Sangjun Han, Sangjun Han, Heongsoo Kim, Heongsoo Kim, Boris Habets, Boris Habets, Enrico Bellmann, Enrico Bellmann, Steven Tottewitz, Steven Tottewitz, Stefan Buhl, Stefan Buhl, Martin Rößiger, Martin Rößiger, Seop Kim, Seop Kim, } "Topography based wafer clustering for wafer level overlay correction", Proc. SPIE 10145, Metrology, Inspection, and Process Control for Microlithography XXXI, 101450Q (28 March 2017); doi: 10.1117/12.2259858; https://doi.org/10.1117/12.2259858

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