Effects induced by nitrogenmonoxide (NO) exposures on the v3 × v3 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 Si2p 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 N1s 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 Si2p and N1s 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. © 2003 Elsevier Science B.V. All rights reserved.