Structural properties of amorphous carbon nitride films prepared by reactive rf-magnetron sputtering

Highly nitrogenated amorphous carbon films have been prepared by reactive rf-magnetron sputtering using pure N2 or Ar/N2 mixed gases. The nitrogen content measured by Rutherford backscattering spectrometry was 40 at% for pure N2 gas and 35 at% for Ar75%-N225% mixed gas. Oxygen atoms of about 7 at% were also detected. Infrared spectra showed a broad absorption band in the range from 1200 to 1600 cm-1 assigned to the N atoms incorporated in the bonding network of amorphous carbon. They showed an absorption band near 2200 cm-1 assigned to the C=N or N = C = 0 bond, but no trace of the N-H or C-H bond was seen.