Germanium nanoislands formation on silicon oxide surface by molecular beam epitaxy

The discussion deals with experimental data on the process of formation of self-organized Ge islands on the oxidized atomically pure Si(1 0 0) surface. Unlike the Stranski-Krastanow mechanism, which is characteristic of Ge growth on the pure silicon surface, the Volmer-Weber growth mechanism is observed on the oxidized silicon surface. The growth process is accompanied by a considerable change (up to 7%) in the surface unit cell of Ge relative to the parameters of Si. The elastically strained nanoislands are less than 10 nm in base size and more than 2×1012 cm−2 at the Ge film not thicker than 5 monolayers. Bimodal size and density distribution of islands is observed on the oxidized Si(1 0 0) surface at germanium film thickness of more than 5 monolayers.