Berlin 2005 – wissenschaftliches Programm
HL 26.1: Vortrag
Samstag, 5. März 2005, 12:30–12:45, TU P-N229
Growth of oxynitrides on Si-rich 4H-SiC(0001) surfaces — •Patrick Hoffmann, Andriy Goryachko, and Dieter Schmeißer — BTU Cottbus, Angewandte Physik - Sensorik, Konrad-Wachsmann-Allee 17, 03046 Cottbus
Oxynitride layers are grown on 4H-SiC(0001) by a thermal treatment in N2O. The nitrogen content is controlled by varying the growth conditions (N2O pressure and substrate temperature) and the nitrogen incorporation is found to be stronger for higher substrate temperatures and lower N2O pressures.
Excess carbon is generated due to SiC decomposition under such growth conditions (high temperature and low N2O pressure) which leads to unwanted high interface state density and has to be avoided. Our approach is to prepare a Si-rich or even Si-covered SiC surface by Si evaporation. Upon oxidation in N2O the additional silicon is expected to compensate the loss of silicon from the SiC while preparation.
The Si-rich SiC surface as well as the grown layers were investigated by photoelectron spectroscopy (XPS) for chemical analysis and by AFM/STM for analysis of the surface morphology. Concerning the chemical analysis we focus on the total nitrogen content, on the amount of silicon nitride Si3N4 and of silicon oxynitride SiOxNy, and on the existence of sub-oxides which build the interface between SiC and the oxynitride layers.