Ab initio method for electromigration analysis

The reliability of interconnects in modern integrated circuits is determined by the magnitude and direction of the effective valence for electromigration (EM). The effective valence depends on local atomistic configurations of fast diffusivity paths such as metal interfaces, dislocations, and the grain boundary; therefore, microstructural variations lead to a statistically predictable behavior for the EM life time. Quantum mechanical investigations of EM have been carried out on an atomistic level in order to obtain numerically efficient methods for calculating the effective valence. The results of ab initio calculations of the effective valence have been used to parameterize the continuum level electromigration model and the kinetic Monte Carlo model. The impact of fast diffusivity paths on long term EM behavior is demonstrated with these models.