Hard carbon nanocomposite films with low stress

Ti- and Al-containing carbon nanocomposite films were deposited by the filt ered cathode vacuum are technique. The influence of Ti and Al content in th e target on the surface morphology, structure, internal stress, hardness an d Young's modulus of the deposited films were studied. The surface of all c arbon nanocomposite films was atomically smooth. The incorporation of metal atoms In the films led to an increase in surface roughness and I-D/I-G rat io. The RMS and I-D/I-G ratio of ta-C:Al films was higher than that of ta-C :Ti films deposited from a target with the same metal content. The incorpor ation of both Ti and Al atoms in ta-C films resulted in a decrease in inter nal stress, hardness and Young's modulus. The effect of Al on the internal stress, hardness and Young's modulus of carbon nanocomposite films was more pronounced than that of Ti. For ta-C:Ti and ta-C:Al films deposited from a target with a metal content of 10 at.%, the internal stress was reduced to 4.29 and 1.94 GPa, respectively, whereas the hardness remained at a high l evel (24 and 18 GPa, respectively). Raman spectra clearly indicate that the Ti atoms in ta-C:Ti films exist as a TiC phase, which contributes to the h igher internal stress, hardness, and Young's modulus of ta-C:Ti films. (C) 2001 Elsevier Science B.V. All rights reserved.