MBE-grown SiGe nano-structures assisted with in situ implantation of 1keV Ge+ ions were investigated by transmission electron microscopy and atomic force microscopy. Self-assembled Ge islands of small size and no extended defects were observed by transmission electron microscopy after low ion fluence pre-implantation at high temperature. Implanted SiGe nano-structures of larger size produce threading dislocations. High dose implantation at low temperature results in formation of semi-spherical SiGe/Si nanostructures of a twin-related type. Epitaxial islands of 30-40nm in base diameter and 11nm in height, and a density of about 6 x 1010/cm2 were produced in this case. It was evidenced by XTEM that the islands have a complicated inner structure and consist of micro-twin nucleus and semi-spherical nano-layers of a various SiGe composition. The results were discussed in terms of strain relaxation through implantation induced defects.

Extended Defects in Ion Assisted MBE Grown SiGe/Si-Nanostructures. P.I.Gaiduk: Physica Status Solidi C, 2009, 6[8], 1922-6