Influence of consumed power on structural and nano-mechanical properties of nano-structured diamond-like carbon thin films

Mixed Ar-C2H2 plasma was characterized by VI probe for estimating the actual consumed power (CP) in the plasma and its effect on diamond-like carbon (DLC) thin films deposited at different CPs in the range 16-85 W. The structural properties of the films were examined using variety of spectroscopic and microscopic techniques, such as Fourier Transform Infrared spectroscopy, X-ray Photoelectron Spectroscopy, Micro-Raman Spectroscopy and Atomic Force Microscopy. The film deposited at 36 W CP showed the formation of nano-structure, creation of optimum sp3/sp2 bonding ratio and excellent nano-mechanical properties with the maximum hardness of ∼28.2 GPa. However, the nano-mechanical properties of the films got altered with the variation of CP, which is attributed to the changes seen in the structural properties. These findings show that high quality DLC films with higher hardness can be deposited by monitoring and controlling the process parameters of the plasma.