Molecular dynamics simulation of Al grain boundary diffusion for electromigration failure analysis

The grain boundary (GB) diffusion for Al interconnections has been characterized for the first time by using the molecular dynamics (MD) simulation with the embedded atom potential. The activation energy for grain boundary diffusion is found to be 0.55 eV. The simulated GB diffusivity almost agrees with the experimental data in the literature (Baluffi and Blakely, Thin Solid Films, vol. 25. p. 363, 1975). The GB diffusivity is found to be suppressed by the compressive strain and to be highly dependent on the GB rotation angle.