X‐ray photoelectron spectroscopy study of carbon nitride coatings deposited by IR laser ablation in a remote nitrogen plasma atmosphere

The reactive pulsed laser deposition technique was used to deposit carbon nitride (CN x ) coatings on a silicon substrate. In this process, an infrared transversely excited atmospheric pressure CO 2 laser ablation of a graphite target in a remote nitrogen plasma afterglow was used to provide simultaneously both carbon and nitrogen‐containing species. Evidence of different CN bonding configurations has been observed in the deposited coatings. For nitrogen pressures ( P   N   2) of ≥700 Pa there is an increase in the contribution of sp 2 carbon atoms that is associated with graphitization of the CN x coatings. For P   N   2increasing from zero to 100 Pa, the comparison between XPS core‐level and valence band spectra of the CN x coatings shows good correlation between the p‐derived states (C 2p electrons) of C–C π bonds in the valence band and the sp 2 carbon atom concentration deduced from the C 1s spectra. The progressive positive contribution of nitrogen lone pair electrons to the valence band is consistent with the increase of the N–C sp 3 contribution with P   N   2. The decrease in the sp 2 carbon atom contribution is associated with the increase of the nitrogen concentration in the coatings. Copyright © 2001 John Wiley & Sons, Ltd.