Growth mechanism of Si nanowhiskers and SiGe heterostructures in Si nanowhiskers: X-ray scattering and electron microscopy investigations

Abstract

Silicon nanowhiskers have been grown by molecular beam epitaxy on Si (111) by vapor-liquid-solid mechanism induced by gold droplets. Very thin Ge containing layers have been incorporated in Si nanowhiskers in order to grow SiGe heterostructures. Si and Ge growth rate in nanowhiskers, shape, and sidewall facets of nanowhiskers have been investigated by scanning electron microscopy and grazing incidence small angle x-ray scattering. Anomalous grazing incidence x-ray diffraction and transmission electron microscopy observations show a strong intermixing of Si with Ge in nanowhiskers and formation of SiGe heterostructures which are highly strained to Si.