Comparison of Physical Gate-CD with In-Die At-Speed Non-Contact Measurements for Bin-Yield and Process Optimization

摘要

We report on a performance-based measurement (PBM) technique from a volume production 65-nm multi-product wafer (MPW) process that shows far more sensitivity than the standard physical gate-length (CD) measurements. The performance (the electrical "effective" gate length, L_(eff)) variation results measured by PBM can NOT be explained alone by CD (physical gate) measurement and show that the non-destructive (non-contact) PBM is able to monitor and control at first-level of electrical connectivity (≥M1), the bin-yield determining in-die variation that are NOT captured or realized by physical CD measurement. Along with this higher sensitivity, we also show that the process-induced variation (excursion) has a distinct signature versus "nominal" expected behavior.