ELECTROMIGRATION FAILURE IN A FINITE CONDUCTOR WITH A SINGLE BLOCKINGBOUNDARY

The (one-dimensional) electromigration boundary-value problem is consi dered for the case of a single blocking boundary with a constant vacan cy supply at the other boundary. Using the drift/ diffusion model expr essed by the Fokker-Planck equation, we find that the saturation time (t(sat)) increases exponentially with current density (j) and not as j (-2), as has been suggested. However, it is not the saturation time wh ich determines the lifetime (t(bd)); it is the time to reach some crit ical vacancy concentration (c). In agreement with experimental result s and numerical calculations, we find that t(bd) similar to j(-2). We also find that t(bd) similar to C. (C) 1994 American Institute of Phy sics.