Multilayer X-ray reflectivity measurements were made of the Si–Ge interdiffusivity in epitaxial SixGe1−x/SiyGe1−y superlattices that had an average Ge composition of 91at%. The extracted activation enthalpy (3.20eV) was substantially smaller than that previously reported for Si-rich SiGe alloys and the interdiffusivity value at typical dopant anneal temperatures is, therefore, much larger for the Ge-rich heterostructures. The activation enthalpy for interdiffusion measured for the <XGe>=0.91 superlattice was reasonably consistent with a linear interpolation between the recently reported value for an alloy with <XGe> of about 0.5 and that reported for self-diffusion in pure Ge.

Silicon-Germanium Interdiffusion in High-Germanium-Content Epitaxial Heterostructures. N.Ozguven, P.C.McIntyre: Applied Physics Letters, 2008, 92[18], 181907