Effects of nitrogenmonoxide on 4H–SiC(0 0 0 1)

Effects induced by nitrogenmonoxide (NO) exposures on the √3×√3 R30° reconstructed 4H–SiC(0 0 0 1) surface are reported. NO exposures from 0.3 to 1 × 106 L at a substrate temperature of 800 °C are investigated. Recorded Si 2p spectra show three shifted components, besides the bulk SiC peak. These are assigned to originate from SiO2, N–Si–O and Si3N4/Si+1 (since we cannot distinguish between Si3N4 and an Si+1 oxidation state). It can be concluded that SiO2 does grow on top of N–Si–O and that Si3N4/Si+1 is located at the interface. Two N 1s components are observed after NO exposures. A main one, located at around 398.05 eV, assigned to originate from Si3N4 and a weaker one suggested to correspond to N–Si–O bonding. The assignments are made using Si 2p and N 1s spectra collected after NH3 and O2 exposures under similar conditions. No graphite like carbon or carbon by-product at the interface can be detected after large NO or O2 exposures.