Drift-velocity experiments were performed on multicrystalline lines of the pure metal in order to determine the electromigration activation energy of the lines. Lines were analyzed which had been cut from films that were processed by using partially ionized beam deposition techniques. One set of lines was analyzed in the as-deposited condition, while the others were annealed before testing. The measured drift velocities differed markedly for the 2 types of film; as did the grain-boundary character distributions, as measured via orientation imaging. The data were analyzed, on the basis of Borisov’s equation, so as to obtain mean grain-boundary energies. The grain-boundary energy of films which exhibited a poor electromigration performance was calculated to be that reported for random boundaries, while that for the more reliable films was calculated to be equal to that reported for twin boundaries. Percolation theory was used to interpret the results in terms of the content and connectivity of special boundaries in the films.

Electromigration Properties of Multi-Grain Aluminium Thin Film Conductors as Influenced by Grain Boundary Structure. O.V.Kononenko, V.N.Matveev, D.P.Field: Journal of Materials Research, 2001, 16[7], 2124-9