Characterization of diamond-like carbon (DLC) films deposited by filtered cathodic vacuum arc technique

Diamond-like carbon (DLC) films were prepared on AISI H13 hot-work tool steel substrates by filtered cathodic vacuum arc (FCVA) technique under variable substrate DC biasing. The atomic structures of the films were investigated by Raman spectroscopy, X-ray photoelectron spectroscopy, and near edge x-ray absorption fine structure spectroscopy. The Raman spectra revealed that when the magnitude of the bias voltage increased, the G peak was shifted toward lower wave numbers, and indicated that the sp 3 content in the DLC films increased. The ratios between the sp 3 and sp 2 bonds in the films were verified by X-ray photoelectron spectroscopy, and the analyses from near-edge x-ray absorption fine structure measurements demonstrated the mixture of the sp 3 , sp 2 bonds together with C-O, C-H bonds, and the amorphous structure in the DLC films.