The 1-dimensional electromigration boundary-value problem was considered for the case of a single blocking boundary, with a constant vacancy supply at the other boundary. By using a model for drift diffusion which was based upon the Fokker-Planck equation, it was found that the saturation time increased exponentially with the current density, and not as the inverse square of the current density; as had been suggested. However, it was not the saturation time which determined the lifetime but the time which was required in order to reach some critical vacancy concentration. In agreement with experimental results and numerical calculations, it was found that the lifetime was inversely proportional to the square of the current density, and directly proportional to the critical vacancy concentration.

V.M.Dwyer, F.S.Wang, P.Donaldson: Journal of Applied Physics, 1994, 76[11], 7305-10