Thermal-Aware EM Reliability for Advanced Metal Interconnects of Complementary FET

Electromigration (EM) of metal interconnects is the continuous reliability concern for high-density integration beyond 5-nm technology, especially for the buried power rails in vertically stacked device structure. In this work, EM reliability of alternative metal interconnects based on complementary FET (CFET) is investigated by kinetic Monte Carlo (KMC) method. The microscopic evolutions of void formation in power rails can be well reproduced by considering the coupled effects of thermal and stress distribution during the EM simulation. The influences of grain boundary in different metal materials on EM lifetime are analyzed to provide the optimal strategy of process integration. Thermal-aware EM reliability is further predicted, indicating the importance of self-heating on EM evaluation of power rails in CFET.