Characteristics of oxides formed from a Si0.5Ge0.5 alloy

Abstract X-ray photoelectron spectroscopy (XPS) combined with Auger electron spectroscopy (AES) have been used to study the oxides from a Si 0.5 Ge 0.5 alloy grown by molecular beam epitaxy (MBE). The oxidation was performed at 1000°C wet atmosphere. The oxide consists of two layers: a mixed (Si,Ge)O x layer near the surface and a pure SiO x layer underneath. Ge is rejected from the pure SiO x and piles up at the SiO x SiGe interface. XPS analysis demonstrates that the chemical shifts of Si 2p and Ge 3d in the oxidized Si 0.5 Ge 0.5 are significantly larger than those in SiO 2 and GeO 2 formed from pure Si and Ge crystals.