Effect of silicon impurity on carbon nitride films prepared by microwave plasma chemical vapor deposition

Carbon nitride thin films have been synthesized on polycrystalline Pt subst rates using microwave plasma chemical vapor deposition (MPCVD) technique. T he effect of Si on the composition and structure of carbon nitride films wa s investigated using scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis. X-ray diffraction (XRD) patterns, Fourier transform i nfrared (FTIR) and Raman spectra. Small amounts of Si can increase the [N]/ ([C] + [Si]) atomic ratio and promote the crystallization of carbon nitride films. The N/([C] + [Si]) atomic ratio of carbon nitride film containing 5 .52% Si can reach 1.35 which, is close to the stoichiometric value 1.33 of C3N4. The experimental XRD pattern contains all the strong peaks of alpha - C3N4 and beta -C3N4. The films are mixtures of alpha -C3N4 and beta -C3N4. The observed Raman and FT-IR spectra support the existence of C-N covalent bond in carbon nitride compound. (C) 2001 Elsevier Science B.V. All rights reserved.