X-ray photoemission spectroscopic study of ultrananocrystalline diamond/hydrogenated amorphous carbon composite films prepared by pulsed laser deposition

Chemical bonding configurations of ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon (a-C:H) composite films prepared by pulsed laser ablation of graphite were investigated by X-ray photoemission spectroscopy using synchrotron radiation. The spectra were decomposed using a Voigt function after the backgrounds were subtracted by Shirley's method. A narrow full-width half-maximum of the sp³ peak is specific, which might be attributed to existence of a large number of UNCD crystallites in the film. The width was immediately broadened by an argon ion bombardment. Its value became equivalent to that of the a-C:H film after the ion bombardment in the same manner. This implies that UNCD crystallites were easily damaged and destroyed by the ion bombardment.