Ion Beam Induced Surface Modification of ta-C Thin Films

Thin film samples (d approximate to 40 nm) of tetrahedral amorphous carbon (ta-C), deposited by filtered cathodic vacuum arc, were implanted with Ga+ at ion energy E = 20 keV and ion fluences D = 3 x 10(14)-3 x 10(15) cm(-2) and N+ with the same energy and ion fluence D = 3 x 10(14) cm(-2). The Ga+ ion beam induced surface structural modification of the implanted material, displayed by formation of new phase at non-equilibrium condition, which could be accompanied by considerable changes in the optical properties of the ta-C films. The N+ implantation also results in modification of the surface structure. The induced structural modification of the implanted material results in a considerable change of its topography and optical properties. Nanoscale topography and structural properties characterisation of the Ga+ and N+ implanted films were performed using atomic spectroscopy analysis. The observed considerable surface structural properties modification in the case of the higher fluence Ga+ implanted samples results from the relatively high concentration of introduced Ga+ atoms, which is of the order of those for the host element.