The epitaxial growth conditions for silicon on germanium substrates were investigated as a function of growth temperature and epilayer thickness. 3D Stranski-Krastanow growth was observed in a temperature range from 400 to 750 degrees C, although strong alloying with the substrate occurred for the highest temperatures. At a lower growth temperature alloying is reduced. For the growth at 550 degrees C island formation takes place only after a wetting layer thickness of about 14 monolayers. With decreasing temperature the wetting layer thickness shifts to lower Si coverages. Nevertheless, the equilibrium critical thickness for dislocation formation in the wetting layer is reached for temperatures down to 450 degrees C. Partial ordering of the islands along < 110 > oriented lines could be seen at higher Si coverages, which is most likely caused by ordering along misfit dislocation segments. (c) 2008 Elsevier B.V. All rights reserved.