Chemical and microstructural characterisation of silicon-containing carbon films

The chemical and microstructural modifications of carbon films, induced by silicon incorporation during the film growth, were studied on films deposited by rf magnetron sputtering of a graphite-silicon target. Silicon incorporation produced Si–C bondings in the films and an increased defect density in the carbon matrix structure. Besides, increasing the silicon content resulted in a significant decrease of the π-plasmon loss peak intensity in the C1s binding energy region in the X-ray photoelectron spectra, along with a lineshape sharpening for the σ–s component of the valence band spectra. This specific electronic structure is best discussed in terms of σ–π system perturbations rather than in terms of an increased sp3/sp2 hybridisation ratio in the films.