The interaction of nitric oxide (NO) on Si-rich beta-SiC(100) 3x2 surface reconstruction is investigated by photoemission spectroscopy using Al K alpha (1486.6 eV) and Zr M zeta (151.4 eV) x-ray lines at Si 2p, C 1s, N 1s and O 1s core levels. NO exposures are performed at sample temperatures ranging from 25 to 1000 degrees C. The initial sticking coefficient of the NO molecules is found to be already significant at room temperature, with a dissociative adsorption. resulting in Si oxynitride products as SiOxNy. The amount of oxynitride is significantly increased at surface temperatures of 500 degrees C and above. in addition, temperature is found to favor the formation nitrogen-rich SiOxNy oxynitride products. Thermal oxynitridation on the 3X2 reconstruction results in a SiOxNy/beta- SiC(100) interface.