Bonding structure analysis of carbon nitride films by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS)

Carbon nitride films were prepared by an opposed-target DC reactive sputtering system and the bonding behaviors were investigated according to the nitrogen content and annealing temperature. Annealing leads to a loss of nitrogen from the films and the C equivalent toN is totally removed at 600 degreesC. Due to annealing at 600 degreesC, the C-C out-of-plane vibrational band intensity at similar to 700 cm(-1) becomes very low and also the C equivalent toN band at similar to 2200 cm(-1) disappears completely. The sp(2) bonding in a CN compound is the most stable phase. Due to carbon's atypical nature in having its p orbital snore compact and tightly bound compared to s states, the C=N sp(2) phase is more stable than the C-C spa phase. As the C=N spl phase dominates the structure, the film is mainly graphite-like with some proportion of C-C, C equivalent toN and N=N bonds. (C) 2001 Elsevier Science B.V. All rights reserved.