Nanostructured copper/hydrogenated amorphous carbon composite films prepared by microwave plasma-assisted deposition process from acetylene-argon gas mixtures

Copper/carbon composite films have been deposited on Si substrates from argonacetylene mixtures using a hybrid technique combining sputter-deposition and plasma-assisted chemical vapor deposition. The carbon content in these films determined by Rutherford backscattering spectroscopy was varied in the range 5-99 at.%. The crystallographic structure was determined by X-ray diffraction techniques. The microstructure of films was examined by transmission electron microscopy. The magnitude of compressive residual stresses increased up to 0.5 GPa with increasing carbon content in the films. The hardness and elastic recovery of films determined by nanoindentation measurements were studied as functions of the composition of the gas phase. Low friction coefficient values were obtained from films containing more than 50 at.% of carbon in room air with a relative humidity of 50%. The wear resistance of films containing 23 to 29 at.% of carbon was higher by a factor of 2 than that of pure Cu films.