Probability distribution modelling of electromigration induced failure times

Abstract

It has been shown that life data from electromigration tests on TiW+Al/Cu bilayer interconnects, under four different ambient temperatures are better fitted to a log extreme value distribution than to a Weibull or a lognormal one. The combination of the authors' results with simulated life data modeling done by J.M. Schoen (1980) indicates the same trend. It is believed that the lognormal distribution, which has been extensively used in electromigration studies, may be an inaccurate model of the phenomenon.<>