The quantitative assessment of stress-induced voiding in process qualification

Stress-induced voiding was studied on submicron aluminum interconnects. A phenomenological model is derived to describe the median time of failures which are caused by the growth of stress-induced voids. Based on this model, a procedure for lifetime prediction is proposed. Furthermore, the influence of stress-induced voids on the electromigration performance is discussed. It is shown that a reduced current density exponent is found in stress-induced void damaged lines, leading to a decrease of electromigration lifetimes.