Characterization of metal-containing amorphous hydrogenated carbon films

Metal-containing amorphous hydrogenated carbon (Me–C: H) films were prepared on silicon substrates. Two kinds of metals (Ti, Ta) were incorporated in the process of reactive rf diode— (13.56 MHz) and DC-magnetron sputtering, respectively. Elastic recoil detection (ERD) and Rutherford backscattering (RBS) of MeV He⁺ ions were used to determine the hydrogen content and mass density of Me–C: H films. The mechanical properties, i.e., microhardness, Young's modulus, and adhesion, were measured with the help of a nanoindenter and scratch tester. Results show that (1) the mechanical properties of Me–C: H films depend mainly on metal concentrations. At a certain metal concentration, optimal hardness, Young's modulus, and critical load were obtained; (2) the M–C: H films with an optimal metal concentration possess similar hardness, Young's modulus, and higher critical load compared with the corresponding values of diamond-like carbon (a–C: H) films, due to the improvement of the toughness of the films by the incorporation of metals. Therefore, Me–C: H films show high promise of being wear-resistant protective coatings.