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

摘要

Diamond-like carbon films were deposited on Si substrate using direct negative carbon ion (C-) beam source at various C- ion beam energy and then the effect of ion beam energy on the crystal structure, sp(3)/sp(2) ratio, hardness and surface roughness of DLC film was investigated. As ion beam energy increased from 25 to 150 eV, the sp(3)/sp(2) ratio of DLC films increased from 32% to 67%. 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 (111) 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. (c) 2006 Elsevier B.V. All rights reserved.