GERMANIUM BEHAVIOR DURING THE LOW-TEMPERATURE PLASMA-ASSISTED OXIDATION OF SIGE ALLOYS

In this paper, we investigate the germanium behaviour during the low-temperature plasma-assisted oxidation of strained epitaxial Si1-xGex (x = 0.1, 0.2) layers. For an oxidation temperature of 500 degrees C and an oxide thickness between 80 and 200 Angstrom, using Auger depth profiling, we find that the oxidation process leads to the formation of a pure SiO2 top layer and the rejection of Ge at the oxide/alloy interface. Taking into account in a suitable way the broadening effect affecting the Auger profiles, we show that a pure Ge layer is formed at the interface.