Chemical Bonding in Composite SiNx/Diamond-Like Carbon Films Prepared by Filter Cathodic Arc Deposition of Graphite Incorporated with Radio Frequency Sputtering of Silicon Nitride

SiNx and diamond-like carbon (DLC) films were prepared simultaneously on Si substrates by the RF magnetron sputtering of a silicon nitride (Si3N4) target and the filtered cathodic arc (FCA) deposition of graphite, respectively. The RF power was fixed at 100 W, while the arc current of graphite for the FCA deposition was varied from 20 to 80 A. The structure of composite SiNx/DLC films was investigated by Raman spectroscopy. The chemical composition and chemical state of the films were analyzed by X-ray photoelectron spectroscopy (XPS). Results revealed that the atomic concentration of carbon (C) increased, while those of silicon (Si) and nitrogen (N) decreased with increasing arc current. In addition, the sp(3) content in the composite films was found to increase with the arc current. This result indicates that the structure and property of the composite films can be controlled according to their required applications by varying the arc current. (C) 2013 The Japan Society of Applied Physics