CNx films deposited on Si substrates with microwave plasma chemical vapor deposition method are measured and analyzed using Raman scattering,X-ray photoelectron spectrum,X-ray diffraction and scanning electron microscopy techniques.The result of Raman spectrum shows the amorphous graphite peak around 1600cm-1 with the flow ratio of CH4 and N2 below 1∶8.As the flow ratio is equal to 1∶8,a characteristic peak around 2190cm-1 exists,which represents C≡N bond.According to the XPS results,the binding pattern of C and N are seen to be of C—N bond and C≡N bond.There is no diffraction peaks corresponding to β-C3N4 phase in the XRD pattern.The gas pressure has influence on the deposited rate of the film.