PRIMARY STUDY ON THE IRRADIATION EFFECTS OF HIGH-ENERGY C+ AND H+ ON DIAMOND-LIKE CARBON-FILMS

Diamond-like carbon films, prepared by the dual-ion beam sputtering method on glass substrate, were irradiated by both carbon ions (C+) and hydrogen ions (H+) under the dose of 1 X 10(17) ion/cm2 and the energy of 114 and 112 keV, respectively. The as-deposited and the irradiated films were characterized by electrical resistivity, infrared transmittance, and Raman spectroscopy. It showed that the irradiation of both the C+ and the H+ can lead to the decrease or even the removal of bond-angle disorder and the increase of the sp2 C-C bond dominated crystallite size and/or number. The irradiation can also break the sp3 C-H bond. But the irradiation of C+ can lead to a bigger decrease of sp3 bonds, forming a film containing more sp2 bonds, and the induced film was then more graphite-like. In irradiation of H+, however, the decrease degree of sp3 bonds is smaller and the irradiated film still showed evident diamond-like characteristics in electrical and optical properties. The different irradiation mechanisms of the two ions on the diamond-like carbon films are briefly discussed.