XPS and XAS preliminary studies of diamond-like carbon films prepared by HiPIMS technique

Abstract

X-ray photoelectron spectroscopy (XPS) and x-ray absorption spectroscopy (XAS) were employed for the investigations of diamond-like carbon (DLC) films prepared by highpower impulse magnetron sputtering technique (HiPIMS). The measurements were done ex-situ, i.e. the prepared DLC samples were exposed to air during transferring from the deposition to analysis chambers. It is inevitable that the surface of the samples was contaminated by absorbed air molecules. XPS analyses revealed that the main surface contaminants are carbon and oxygen, which introduce the difficulties for the determination of carbon species in the DLC films. In this work, a complementary XAS technique was used for analyzing carbon species in the DLC films. It was found that the DLC film contain more sp2 than sp3 carbon. The discrepancy in the sp2/sp3 ratio from the two techniques is different as a result of the difference in depth/surface sensitivity.