Passivated and unpassivated monocrystalline lines, with (110), (133) or (111) planes parallel to the substrate, were studied. Both erosion voids, and slit-like voids with {111} facets, were observed. The slit-like voids lay along the in-plane direction, thus producing minimum surface-area voids among the crystallographically possible directions for {111}-faceted voids. The voids which nucleated in the lines appeared to be mobile. They could move towards the cathode end, and sometimes accumulated in the cathode pad. The (110)-textured lines failed due to erosion voids, slit-like voids, and pad voids; with roughly equal probability. However, (111)- and (133)-textured lines failed mainly due to pad voids. In both passivated and unpassivated lines, the median time to failure was texture-dependent; with the times decreasing in the order: (111) - (133) - (110), and with the time for (111) being an order of magnitude longer than that for (110). The activation energy for the failure of (110) lines was about 1eV; thus suggesting that Al/oxide interface diffusion was the predominant mechanism.

Y.C.Joo, C.V.Thompson: Journal of Applied Physics, 1997, 81[9], 6062-72