Effect of reactive ion etching on amorphous carbon nitride films

Amorphous carbon nitride (a‐C : N) films have been deposited by reactive direct current magnetron sputtering of graphite using N 2 as the sputtering gas. In order to study the effects of dry etching on the deposited films, post‐treatment of the films has been performed by reactive ion etching in an argon plasma and an oxygen plasma, respectively. Fourier transform infrared (FTIR) spectroscopy and x‐ray photoelectron spectroscopy (XPS) have been used to study the chemical bonding structures in the films. We have found that although the FTIR results are very similar in all the samples, by comparing the XPS results from all the samples the relative ratio of the β‐C 3 N 4 ‐like phase over the graphite‐like carbon–nitrogen phase in the films increased significantly after oxygen bombardment. This indicates that an oxygen plasma works effectively as an etchant of the graphite‐like phase in a‐C : N films. This process is conducive to the production of CN films that have a higher concentration of the β‐C 3 N 4 ‐like phase. Copyright © 2002 John Wiley & Sons, Ltd.