INTERFACIAL AND SURFACE ENERGETICS OF COSI2

The energetics of the CoSi2-Si interface and the CoSi2 surface have been investigated by analyzing the equilibrium shapes of isolated silicide precipitates. CoSi2 precipitates grown by heating 2 Angstrom of Co on a clean, reconstructed Si{100} surface formed with a number of orientations that remained stable upon annealing to high temperatures. Precipitates buried by a Si capping layer were shown to form along {111} and {100} interfaces. A ratio of the CoSi2-Si interfacial free energies has been measured from the shapes of a large number of buried precipitates indicating that gamma{100}/gamma{111}=1.43+/-0.07. It is suggested that the shape of CoSi2 equilibrated within vacuum consists of {111}, {100}, and {110} facets.