Epitaxial cobalt disilicide thin films buried in (001)Si were grown by annealing a precipitate distribution in a nearly undisturbed Si matrix. The CoSi2/Si junction was studied by means of dedicated aberration-corrected scanning transmission electron microscopy. Previously identified were 2 different interface structures, the atomic arrangement and frequency of appearance of which, were consistent with the predictions of total-energy calculations. The interface dislocations were dealt with here in more detail. Due to the cubic crystal symmetry of both the silicide and the Si substrate, the interface consisted of a patchwork of different domains, which were rotated relative to each other by 90°. Dislocations were required at the boundaries of these domains. Misfit dislocations were also expected since, under the conditions of non-pseudomorphic growth, a relaxed interface was formed. A complex defect structure at the interface domain boundaries, always associated with {111}-facets, was found to satisfy both constraints, thus efficiently minimizing the interface energy of the system.

Misfit Dislocations at the CoSi2/Si (001) Interface Studied by Aberration-Corrected High Angle Annular Darkfield Imaging. M.Falke, U.Falke, A.Bleloch: Journal of Physics - Conference Series, 2006, 26, 21-4