Growth and characteristics of diamond-like carbon (DLC) films deposited by direct negative carbon ion beam deposition

The films prepared at 150 eV showed the more flat surface morphology of the film than that of the film prepared under another ion beam energy conditions and diamond structure also obtained at 150 eV. Surface roughness of DLC film varied from 0.62 to 0.22 nm with depositing carbon ion beam energy. The film prepared at 50 eV shows the typical amorphous phase, while the films prepared at 150 eV exhibited (1 1 1) plane of diamond. Nanohardness increased from 12 to 57 GPa when increasing the negative carbon ion beam energy from 25 to 150 eV and then decreased above 150 eV.