Impact of microstructure and current crowding on electromigration: A TCAD study

Electromigration (EM) degradation and failure in modern interconnect structures are result of several physical phenomena acting together. In order to increase reliability thoroughly understanding of these phenomena and their interplay is necessary. In the case of dual-damascene technology both geometry and microstructure of the interconnect play an important role, determining the development of EM degradation. In this paper we use a state-of-the-art EM modeling and simulation for a comparative study of EM performance of standard straight interconnect structure and a structure with a right angle. It has been shown that by applying a detailed model of EM driven vacancy dynamics in the presence of grain boundaries, current crowding due to right angle of the interconnect geometry has a less impact than microstructure.