A Comprehensive LER-Aware TDDB Lifetime Model for Advanced Cu Interconnects

A time-dependent dielectric breakdown (TDDB) lifetime model predicting the impact of line-edge roughness (LER) on Cu interconnect reliability is proposed. The structure, validity, and accuracy of the model are evaluated and discussed. The model is applied to an interconnect scaling scenario that includes conventional patterning and spacer-defined patterning of nanometer-scale Cu wires. LER-aware TDDB lifetime predictions are obtained from the model, and consequent recommendations on how to improve the TDDB lifetime of future interconnects are derived.