ELECTROMIGRATION FAILURE IN A FINITE CONDUCTOR WITH A SINGLE BLOCKING BOUNDARY

The (one-dimensional) electromigration boundary-value problem is considered for the case of a single blocking boundary with a constant vacancy supply at the other boundary. Using the drift/diffusion model expressed by the Fokker-Planck equation, we find that the saturation time (tsat) increases exponentially with current density (j) and not as j-2, as has been suggested. However, it is not the saturation time which determines the lifetime (tbd); it is the time to reach some critical vacancy concentration (c*). In agreement with experimental results and numerical calculations, we find that tbd∼j-2. We also find that tbd∼c*. © 1994 American Institute of Physics.