Substrate bias effect on amorphous hydrogenated carbon films deposited by filtered cathodic arc deposition

Abstract

In the present study, we briefly describe the 45 degrees angle magnetic filtered arc deposition (FAD) process and investigate the effect of substrate bias on the hardness of amorphous carbon (a-C) films. An attempt is made to correlate the microstructure. chemical composition and chemical bonding states with the hardness of the corresponding films. After deposition. the film properties v,ere analyzed by Raman spectroscopy and nanoindentation system (NIS). It was found that amorphous carbon films possess highest hardness when deposited at substrate biases ranging from -50 V to -100 V. The hardness values do not show good correlation with Raman I(D)/I(G) ratio. Hydrogen additions to the system help prevent the nucleation of the graphite phase, and stabilize the sp(3) bonding of amorphous hydrogenated carbon films. Hydrogen affected on the small graphitic crystalline growth. Films have higher hardness when they have higher fraction of sp(3) content.