Low-temperature microwave-based plasma oxidation of Ge and oxidation of silicon followed by plasma nitridation

In the semiconductor industry Germanium is expected as the promising channel material for future high-mobility CMOS transistors because of its highest hole mobility among common elemental and compound semiconductors, and an electron mobility that is two times larger than that of Si. This article shows that oxides can be grown and/or in a subsequent process step nitridized for planar Ge and Si devices at very low temperatures (T < 460°C). The stable oxide growth on Germanium through plasma processing is studied as a function of relevant processing parameters like time, gaseous ambient etc. For Silicon the bonding structure of pure and nitridized low-temperature grown SiO2 is analyzed, followed by an electrical characterization of 0.8 to 1.2 nm interfacial layers on Si.