Amorphous thin nitrogen-containing layers, whose stoichiometry is close to SiC(x)N(1-x), where x is variable in depth, have been obtained by SiC surface treatment with a nitrogen plasma. X-ray photoelectron spectroscopy (XPS) with layer-by-layer analysis was used for the study of the composition and the chemical bonding; in depth of nitrogen-containing layers. Both the process of etching in the nitrogen plasma and the process of introducing nitrogen ions in the SIC surface in relation to the time of treatment in the nitrogen plasma were investigated. The surface profile mesurement showed a very smooth surface morphology after the nitrogen plasma treatment.