Atomic flux divergence-based AC electromigration model for signal line reliability assessment

In this paper, we develop an AC electromigration (EM) model for signal lines manufactured with copper dual damascene process. For the first time, the healing factor of AC EM is quantitatively modeled. To measure EM reliability of interconnects considering timing margins we introduce AC EM functional lifetime. We also develop an atomic flux divergence (AFD)-based void growth model to explain the resistance curves of measured results and calculate the functional EM lifetime of AC signal lines without extracting parameters from experiments. We demonstrate fidelity of the proposed model with measured results for both the healing factor and the rate of resistance change.