Oxynitrides on 4H–SiC(0 0 0 1)

It will be reported on the growth of oxynitride ultra-thin layers (<2 nm) on (0 0 0 1)-oriented 4H–SiC surfaces. The oxynitride layers were grown by a thermal treatment of the samples in low pressure (up to 1000 Pa) N2O ambient. By varying the growth conditions (N2O pressure, sample temperature, growth time) different layers were made. The highest nitrogen incorporation was found to be at high temperatures and low N2O pressures. own layers were investigated by photoelectron spectroscopy (XPS) for chemical analysis. Concerning the chemical analysis, the general nitrogen content of the samples is compared at different preparation conditions. The films are found to consist mainly of SiO2 and small fraction of silicon nitride. Only a tenth of the nitrogen was incorporated as oxynitride. The results obtained for oxynitride thin films on 4H–SiC are compared to similarly prepared oxynitride layers on Si(1 1 1) investigated in the past. Furthermore, an additional source of nitrogen due to dopand diffusion in the SiC single crystal is reported.