The effect of target power density on physical and structural properties of amorphous carbon films prepared by CFUBM sputtering

비대칭 마그네트론 스퍼터링으로 합성된 비정질 탄소박막의 물리적, 구조적 특성에서 타겟 파워 밀도의 영향

Amorphous carbon (a-C) is an interesting materials and its characteristics can be varied by tuning it $sp^3$ fractions. The $sp^3$ fraction in a-C films depends on the kinetic energy of the deposited carbon ions. In this work, a-C films was synthesized on Si(100) and glass substrates at room temperature by closed-field unbalanced magnetron (CFUBM) sputtering with the increase of graphite target power density. The structural and physical properties of films were investigated by using Raman spectroscopy, X-ray photoelectron spectrometer (XPS), nano- indentation, atomic force microscope (AFM) and contact-angle measurement. We obtained the good tribological properties, such as high hardness up to 26 GPa., friction coefficient lower than 0.1 and the smooth surface (rms roughness: 0.12 nm). The increase of the physical properties with the increase of target power density are related to the increase of nano-clusters in the carbon network. Also, these results might be due to the increase of the subplantation and resputtering by the increase of ions density in the plasma.