Chemical bonding in carbon nitride films studied by X-ray spectroscopies

Carbon nitride films are deposited using dc magnetron sputtering in a N-2 d ischarge. The nature of chemical bonding of the films is investigated using X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structur e, and X-ray emission spectroscopy. X-Ray photoelectron spectroscopy spectr a show that Nls binding states depend on substrate temperature, in which tw o pronounced peaks can be observed. The near edge X-ray absorption fine str ucture at Cls and Nls exhibits a similar absorption profile in the pi* reso nance region, but the sigma* resonance is sharper in the Nls spectra. Reson ant N K-emission spectra show a strong dependence on excitation photo energ ies. Compared XPS Nls spectra with recent theoretical calculations by Johan sson and Stafstrom, two main nitrogen sites are assigned in which N bound t o sp(3) hybridized C and Sp(2) hybridized C, respectively. The correlation of X-ray photoelectron, X-ray absorption, and X-ray emission spectra for N in carbon nitride films is also discussed. (C) 2001 Elsevier Science B.V. A ll rights reserved.