Hardnes and resistivity of amorphous carbon thin films deposited by laser ablation

Amorphous carbon thin films were deposited by laser ablation of a graphite target, using the fundamental line of a 5 ns Nd:YAG laser. Deposition was carried out as a function of the plasma parameters (mean kinetic ion energy and plasma density), determined by means of a planar probe. In the selected working regimes the optical emission from the plasma is mainly due to atomic species, namely C+ (426.5 nm); however, there is also emission from other atomic species and molecular carbon. The hardness and resistivity could be varied in the range between 10 and 25 GPa, and 10(8) and 10(11) Omega cm, respectively. The maximum values were obtained at a 200 eV ion energy and 6x10(13) cm(-3) plasma density, where the maximum quantity of C-C sp(3) bonds was formed, as confirmed by Raman spectroscopy.