Oxidation is a key process step in semiconductor device fabrication. Oxides are widely used in the production process as gate dielectrics, interfacial layers for high-k deposition, pad oxides, sacrificial oxides, screen oxides, protection oxides etc. Even though the used oxide thicknesses become thinner the thermal budget (roughly time at temperature) is generally not scalable with the thickness decrease due to the thermally activated oxidation process. However, for future sub-22 nm device structures a continuous reduction of oxidation temperatures is required to minimize dopant redistribution or deactivation, boron depletion, and oxidant enhanced diffusion effects. At the same time physical, chemical and electrical oxide quality has to be maintained. This is valid also for all process steps after device formation where high quality oxides are needed. BEOL applications like surface conditioning by oxidation is only one example.

In this contribution we show that oxides can be grown and/or in a subsequent process step nitridized with an excellent electrical quality for planar Si and Ge devices but also conformally on 3D Si devices at very low temperatures (T < 400 °C). First the oxide growth with or without subsequent nitridation as a multi-step process is studied as function of time, and gas ambient on silicon and germanium, second the electrical characteristics of these various films are demonstrated. In the industry Ge is expected as the promising channel material for future CMOS 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. Therefore it is important to show outstanding electrical results of the Ge passivation layers grown at very low temperatures.