HARDNESS, ELASTIC-MODULUS, AND STRUCTURE OF VERY HARD CARBON-FILMS PRODUCED BY CATHODIC-ARC DEPOSITION WITH SUBSTRATE PULSE BIASING

The hardness, elastic modulus, and structure of several amorphous carb on films on silicon prepared by cathodic-are deposition with substrate pulse biasing have been examined using nanoindentation, energy loss s pectroscopy (EELS), and cross-sectional transmission electron microsco py. EELS analysis shows that the highest sp(3) contents (85%) and dens ities (3.00 g/cm(3)) are achieved at incident ion energies of around 1 20 eV. The hardness and elastic modulus of the films with the highest sp(3) contents are at least 59 and 400 GPa, respectively. These values are conservative lower estimates due to substrate influences on the n anoindentation measurements. The films are predominantly amorphous wit h a similar to 20 nm surface layer which is structurally different and softer than the bulk. (C) 1996 American Institute of Physics.