The local structure around Ge, in Si/Ge superlattices which contained so-called inverted-hut nanocrystals, was investigated by using the extended X-ray absorption fine structure technique. The results which were obtained for various Ge wetting-layer thicknesses furnished direct evidence that the intermixing of Ge and Si took place in a zone of some 1 to 3 monolayers on each side of the Si/Ge interface. This intermixing of the atoms permitted the operation of a mechanism, other than the usual formation of misfit dislocations, for the release of strain energy due to the lattice mismatch between Si and Ge.

“Inverted Hut” Structure of Si-Ge Nanocrystals Studied by Extended X-Ray Absorption Fine Structure Method. Y.L.Soo, G.Kioseoglou, S.Huang, S.Kim, Y.H.Kao, Y.H.Peng, H.H.Cheng: Applied Physics Letters, 2001, 78[23], 3684-6