Statistical study of electromigration in gold interconnects

During operation of integrated circuits, electromigration gradually degrades the metallic interconnects, eventually leading to complete failure. In recent decades, electromigration has been studied mainly for the widely used aluminum and copper interconnects, however, gold interconnects used for GaAs devices also experience significant electromigration degradation. We present physics-based modeling and simulation of electromigration in gold interconnects. A comprehensive analysis of the statistical properties of electromigration failure and the influence of varying temperature and geometric properties is performed. The previously published experimental observations on the behavior of the mean failure time and the associated standard deviation are in agreement with the obtained simulation results. In particular, the simulation reproduces an 85% decrease of the standard deviation for a via surface of 31.36μm2 compared to the value for a via surface of 6.76μm2.