Kinetics of oxynitridation of 6H-SiC(112¯0) and the interface structure analyzed by ion scattering and photoelectron spectroscopy

Clean and pre-oxidized 6H-SiC(112¯0) surfaces were annealed in NO at temperatures ranging from 800 to 1000 °C under a pressure of 1 × 10−3 Torr. The growing surface and interface structures were analyzed in situ by high-resolution medium energy ion scattering (MEIS) and photoelectron spectroscopy using synchrotron-radiation-light. The present result reveals growth of double-layered structure of SiO2/SiOxNy on SiC for the samples annealed at 1000 °C in NO with and without pre-oxidation in O2. Oxynitridation takes place only at SiO2/SiC interfaces. The thickness of growing layers is saturated at ∼0.2 nm of SiO2 and 0.3-0.4 nm of SiOxNy layers with the elemental compositions unchanged. For the samples pre-oxidized in 18O2 followed by annealing in N16O, the exchange reaction between 18O and 16O occurs at the surface and interface. No nitrogen removal was observed by annealing the oxy-nitrided sample in O2 at 1000 °C and 1 × 10−3 Torr. We also observed the C 1s, N 1s and Si 2p spectra and identified the N 1s and Si 2p components originating from Si-oxynitride layers.