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

In the present study, we briefly describe the 45 degrees angle magnetic fil tered 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 st ates with the hardness of the corresponding films. After deposition. the fi lm properties v,ere analyzed by Raman spectroscopy and nanoindentation syst em (NIS). It was found that amorphous carbon films possess highest hardness when deposited at substrate biases ranging from -50 V to -100 V. The hardn ess values do not show good correlation with Raman I(D)/I(G) ratio. Hydroge n additions to the system help prevent the nucleation of the graphite phase , and stabilize the sp(3) bonding of amorphous hydrogenated carbon films. H ydrogen affected on the small graphitic crystalline growth. Films have high er hardness when they have higher fraction of sp(3) content.