X-ray photoelectron spectroscopy studies of the effects of plasma etching on amorphous carbon nitride films

The effects of post-treated oxygen plasma etching procedures have been investigated for amorphous carbon nitride (a-C:N) films deposited by dc magnetron sputtering. X-ray photoelectron spectroscopy (XPS) has been used to study the microstructure of these films. It has been found that the relative concentration of the β-C3N4-like phase in the a-C:N films is enhanced significantly by oxygen plasma etching and by increasing the dc bias voltages during the etch experiments. This study reveals that an oxygen plasma can work as an effective chemical etchant for the graphite-like carbon-nitrogen phase in a-C:N films. This suggests a very promising way of obtaining harder a-C:N films.