A well-posed moving boundary-value problem, describing the dynamics of curved interfaces and surfaces associated with voids and/or cracks that interacted with grain boundaries, was obtained. Extensive computer simulations were performed for void configuration evolution during intergranular motion, under the actions of capillary and electromigration forces in thin-film metallic interconnects with bamboo structures. The analysis of experimental data, utilizing the mean time-to-failure formulas derived here, gave consistent values for the interface diffusion coefficients and the enthalpies of voids. A value of 5.85 x 10–5exp[–0.95(eV)/kT]m2/s was obtained for voids that formed in the interior of the Cu interconnects; avoiding any surface contamination. A value of 1.80 x 10–4exp[–1.20(eV)/kT]m2/s was obtained for voids that nucleated at triple junctions or at grain-boundary surface intersections (grooves), where chemical impurities such as Si, O, S - and even C - segregated during the metallization and annealing processes and could act as trapping centers for hopping vacancies.

Electromigration-Induced Void Grain-Boundary Interactions - the Mean Time to Failure for Copper Interconnects with Bamboo and Near-Bamboo Structures. T.O.Ogurtani, E.E.Oren: Journal of Applied Physics, 2004, 96[12], 7246-53