Raman spectroscopy and atomic-force microscopy were used to study the morphology of nano-islands grown onto strained Si1−xGex sub-layers. It was shown that the growth of the nano-islands not only induced their spatial ordering, but also enhanced the role of interdiffusion processes. An unusually high island-volume increase during epitaxy was attributed to anomalously strong material diffusion from the sub-layer and into the islands. This, in turn, was attributed to the non-uniform field of elastic strains.

Gigantic Uphill Diffusion during Self-Assembled Growth of Ge Quantum Dots on Strained SiGe Sublayers. M.Y.Valakh, P.M.Lytvyn, A.S.Nikolenko, V.V.Strelchuk, Z.F.Krasilnik, D.N.Lobanov, A.V.Novikov: Applied Physics Letters, 2010, 96[14], 141909