Oxygen δ-doped Si multi-layers grown by molecular beam epitaxy

An oxygen δ-doped Si multilayer structure has been grown by molecular beam epitaxy (MBE). Thermal oxidation of a Si layer prepared by an MBE system at a low oxygen partial pressure resulted in a thin ordered oxide layer with a very flat surface. On the ordered oxide, Si was epitaxied through the solid phase epitaxy. Five periods of Si(2 nm)/SiO_x(1 nm) multilayers were grown successfully. The O-doped Si layer (SiO_x) was composed of 7 atomic layers and the crystalline structure of the SiO_x layer was the same as that of the Si substrate but had a relatively transverse displacement. The in-plane stress restricted the number of the oxide layers grown to a thickness of less than 6 atomic layers. This structure may be the gateway for realizing Si-based quantum wells.