Synthesis of hard hydrogenated amorphous carbon films by atmospheric pressure filamentary dielectric barrier discharge

In this study, the authors synthesized a-C:H films by filamentary dielectric barrier discharge (FDBD) to improve their mechanical properties compared to the films synthesized by glow DBD (GDBD), which is generally used for atmospheric pressure plasma enhanced chemical vapor deposition. The discharge type was transited from GDBD to FDBD by increasing the gap between the electrodes from 1 to 4mm. The hydrogen concentration of the a-C:H films synthesized by FDBD was reduced compared to that of the films synthesized by GDBD. The hardness of the films increased from 3.7 to 11.9GPa by using FDBD. These results show that the hard a-C:H films can be synthesized at room temperature in a large area by FDBD.