Advanced Overlay: Sampling and Modeling for Optimized Run-to-Run Control

In recent years overlay control schemes have become more complicated in order to meet the ever shrinking margins of advanced technology nodes. As a result, new challenges must be addressed for effective run-to-run overlay control. Two of these challenges are addressed in this study by new advanced analysis techniques: (1) sampling optimization for run-to-run control; and (2) bias-variance tradeoff in modeling. The sampling and modeling solutions proposed are validated by APC simulations to estimate run-to-run performance, lot-to-lot and wafer-to-wafer model term monitoring to estimate stability, and ultimately high volume manufacturing tests to monitor on-product overlay by densely measured overlay data.

SPOTLIGHT: 2011 Lithography Users’ Forum Keynote Presentation

Coinciding with the 2011 SPIE Advanced Lithography exhibition, KLA hosted its one-of-a-kind Lithography Users' Forum (LUF). Annually, this event brings together the industry’s leading lithographers for networking, information sharing, and discussions surrounding challenges facing the industry and possible solutions.

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