Chemical Composition and Microstructure of Metal Doped Graphite-Like Carbon Films by Closed Field Unbalanced Magnetron Sputtering

The addition of metal atoms within the matrix of the graphite-like carbon films lead to the improvement of their mechanical properties. In this paper, metal (Cr, Al, Zr, W) doped graphite-like carbon(GLC) films were deposited on silicon substrates by closed field unbalanced magnetron sputtering from pure metal target and pure graphite target. Chemical composition and chemical states of films were measured by X-ray photoelectron spectroscopy (XPS) and show that mainly sp2 bond existing in all the metal doped films, and sp2/sp3 ratios are not depend on the doped metal. Cross-section micrographs were observed by high resolution transmission electron microscopy (HRTEM) and revealed a structure of composite that metal or metal carbides embedded in amorphous carbon matrix. The relationship between microstructure and chemical composition was discussed.