Nanocrystalline diamond thin films deposited from C-60 monoenergetic fullerene ion beam

Abstract

Carbon films 250 divided by 500 nm in thickness deposited on Si wafers from mass-selected flow of accelerated C-60 ions with energies of 5.0 +/- 0.1 keV at temperatures of 300 K and 673 K are characterized by TEM and nanoinclentation. On the TEM images of the films deposited at 673 K, nanocrystalline graphite with the typical grain size of similar to 6 nm is observed. The films deposited at 300 K are transparent in visible light. TEM study of these films has revealed structural elements with lattice spacing close to that of diamond and the grain size of about 4 nm. Nanohardness and elastic modulus of the films prepared at a substrate temperature of 300 K were 23.1 +/- 0.2 GPa and 200 +/- 1 GPa, respectively. Possible mechanisms of the carbon films structure formation are suggested in the framework of a hydrodynamic shock wave model.