Nitrogen incorporation in thin oxides by constant current N2O plasma anodization of silicon and N-2 plasma nitridation of silicon oxides

A helical resonator plasma source was used to perform constant current N2O plasma anodization of silicon and N, plasma nitridation of silicon oxides. The nitrogen bonding structure and distribution in the oxides were studied using angle resolved x-ray photoelectron spectroscopy. Nitrogen corresponding to a N-Si-3 bonding structure was detected at the silicon side of the interface, the Si-SiO2 interfacial region, and the bulk oxide in a 4.5 nm N2O plasma grown oxide. The distribution profile of nitrogen in the oxide, determined from a normalized N 1s/Si 2p(ox) ratio, showed a continuous decrease from the silicon side of the interface towards the bulk oxide. Also, strong nitrogen peaks corresponding to either a N-Si-3 or a N-Si-2, bonding structure were detected throughout a 9.1 nm O-2 plasma grown oxide after postanodization constant current N-2 plasma nitridation. (C) 1996 American Institute of Physics.