18 April 2013 A framework for exploring the interaction between design rules and overlay control
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Overlay control is becoming increasingly more important with the scaling of technology. It has become even more critical and more challenging with the move toward multiple-patterning lithography, where overlay translates into CD variability. Design rules and overlay have strong interaction and can have a considerable impact on the design area, yield, and performance. This paper offers a framework to study this interaction and evaluate the overall design impact of rules, overlay characteristics, and overlay control options. The framework can also be used for designing informed, design-aware overlay metrology and control strategies. In this work, The framework was used to explore the design impact of LELE doublepatterning rules and poly-line end extension rule defined between poly and active layer for different overlay characteristics (i.e., within-field vs. field-to-field overlay) and different overlay models at the 14nm node. Interesting conclusions can be drawn from our results. For example, one result shows that increasing the minimum mask-overlap length by 1nm would allow the use of a third-order wafer/sixth-order field-level overlay model instead of a sixth-order wafer/sixth-order field-level model with negligible impact on design.
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Rani S. Ghaida, Rani S. Ghaida, Mukul Gupta, Mukul Gupta, Puneet Gupta, Puneet Gupta, } "A framework for exploring the interaction between design rules and overlay control", Proc. SPIE 8681, Metrology, Inspection, and Process Control for Microlithography XXVII, 86810C (18 April 2013); doi: 10.1117/12.2013619; https://doi.org/10.1117/12.2013619

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