Fabrication of device structures based on laterally self-ordered systems without the use of expensive and time-consuming nanolithography could have undoubted advantages. For such applications, it was proposed to use misfit dislocation networks from partially relaxed SiGe layers on (100) Si substrate as a template for the growth of highly ordered SiGe islands. Ion bombardment during molecular beam epitaxy of metastable SiGe layers leads to such a partial relaxation by misfit dislocation networks. The ions were generated by the interaction of the evaporated Si flux with the electrons in an electron beam evaporator, which causes a partial ionization of Si atoms in the molecular beam. It was demonstrated by atomic force microscopy that subsequent growth of SiGe on such relaxed SiGe (25 to 50%Ge) layers leads to the formation of uniform three-dimensional islands highly ordered in <110> directions.

Highly-Ordered SiGe-Islands Grown by Dislocation Patterning using Ion-Assisted MBE. J.Werner, M.Oehme, K.Lyutovich, E.Kasper, C.Hofer, C.Teichert: Surface Science, 2007, 601[13], 2774-7