Carbon nitride films deposited by three different methods have been analyzed using in situ Auger electron spectroscopy and ex situ x-ray photoelectron spectroscopy (XPS) and Rutherford backscattering spectrometry. The XPS data for all 27 samples indicate that these films have a similar composition consisting of two phases. One phase has a stoichiometry near ${\mathrm{C}}_3$${\mathrm{N}}_4$ and is identified as a tetrahedral component. The other phase has a variable stoichiometry from ${\mathrm{C}}_5$N to ${\mathrm{C}}_2$N and is identified as predominantly an $s{p}^2$ bonded structure. For a film composition of [N]/[C] < 1, the tetrahedrally bonded component grows only moderately as the nitrogen content of the films is increased.

• Received 7 March 1994

DOI:https://doi.org/10.1103/PhysRevLett.73.118