Radio-frequency Power Graded Hydrogenated ...

Diamond-like carbon (DLC) films are increasingly used for optical and biological components. Yet the stability of the film, including adhesion and duration are still to be developed. Hydrogenated DLC films (hydrogenated amorphous carbon, a-C: H) were deposited onto transparent substrates by applying a graded radio-frequency (RF) power by plasma-enhanced chemical vapor deposition (PECVD). The a-C: H film, formed by constant RF power was synthesized for comparison. Raman spectra, X-ray photoelectron spectra (XPS), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) were used to characterize the film structure along with surface morphology and roughness on the diverse substrates. Tribological properties and adhesion were obtained by friction-wear experiment and scratch tests. Light transmittance was determined by UV/Vis spectra. The results have revealed that there were obvious residual stress relaxation and better adhesion for the graded a-C: H films.