The microstructure of CoSi2/SiGe/Si(001) heterostructures, in which the SiGe layer was grown by molecular beam epitaxy and the silicide was formed via various post-deposition reaction paths, was investigated by using a combination of high-resolution cross-sectional transmission electron microscopy, high-resolution X-ray diffraction, and secondary-ion mass spectrometry. In 2 of the 3 configurations which were investigated, Co was either deposited directly onto a strained SiGe layer or onto a sacrificial molecular beam epitaxial Si over-layer on Si0.9Ge0.1. In the third sample configuration, SiGe was grown onto an (001) Si substrate which contained a buried ion-implanted CoSi2 layer. Only in the second of these configurations was it possible to obtain a fully-strained almost defect-free CoSi2/Si0.9Ge0.1 structure. A high density of threading dislocations, which corresponded to about 60% relaxation of the Si0.9Ge0.1/Si interface, was observed in the first configuration, while the third configuration (in addition to dislocations) exhibited pronounced faceting of the CoSi2/Si interface.

O.Nur, M.Willander, L.Hultman, H.H.Radamson, G.V.Hansson, M.R.Sardela, J.E.Greene: Journal of Applied Physics, 1995, 78[12], 7063-9