In situ photoelectron spectroscopy of titanium-containing amorphous hydrogenated carbon films

Titanium-containing amorphous hydrogenated carbon films (a-C:H/Ti) have been deposited by a medium-frequency-driven physical vapor deposition plasma-enhanced chemical-vapor deposition process at 40 kHz. Core-level photoelectron spectroscopy and valence-band photoelectron spectroscopy have served as means for the characterization of these films. The spectroscopic data are interpreted by a structural model on the basis of a nanocomposite containing titanium carbide clusters embedded in an amorphous hydrogenated carbon matrix. Within this model parallel energy shifts in the measured positions of the Ti 2p core levels and of the Fermi edge can be explained by a one-electron charging effect of nanometer-sized TiC clusters due to the photoemission process.