The 1-dimensional electromigration boundary-value problem under pulsed direct-current conditions was investigated numerically by using the transmission-line matrix modelling method. A perfectly blocking boundary, where void formation and failure occurred, was assumed to exist at one end of an interconnection line. At the other end, 2 possible boundary conditions were considered. An approach was proposed which converted the pulsed stress into an equivalent direct-current stress that would produce electromigration damage at a similar rate. On the basis of the fundamental diffusion-drift model, it was shown that the vacancy build-up behavior under a pulsed direct-current stress could be accurately described by using a direct-current stress which was scaled according to the parameters of the current pulse. The results also provided a theoretical confirmation of the j-2 dependence of pulsed electromigration failure.

X.Gui, S.K.Dew, M.J.Brett: Journal of Applied Physics, 1996, 80[9], 4948-51