An alternative oxidation technique is developed and built up, which provides monatomic oxygen during the whole oxidation process. The set-up consists of a tungsten lamp furnace and a microwave-plasma. A number of different gases can be introduced into the oxidation quartz tube. In addition, an Al2O3-layer is deposited on a part of the oxide layers by atomic layer chemical vapor deposition (ALCVD). First oxidation runs result in encouraging low values of the density of interface states Dit and in the flatband voltage UFB. It turns out that with the present experimental conditions, the comparison of MOS capacitors fabricated with different dielectric layers favors gate dielectrics grown in O2/N2-ambient.