Microstructure and mechanical properties of cu-containing amorphous carbon nanocomposite thin films by a hybrid deposition technique

Cu-containing amorphous carbon (a-C:Cu) films were deposited on Si (100) substrate by a hybrid process where co-operating of a filter cathodic vacuum arc (FCVA) and a magnetron sputtering (MS). Cu content was tuned by changing the Cu MS power density from 0 to 4.93 W/cm². The results show that metallic Cu exists in crystal with grain size 4-8 nm and there is no carbide formation. Incorporation Cu promotes graphitization of amorphous carbon matrix where C C (sp²) increases from 56% to 64%, whilst C-C (sp³) decreases from 42% to 31%. Raman results show I_d/I_g ratio increases from 0.71 to 1.45. Incorporation Cu from 0 to 16.86 at.% decreases hardness from 45.84 to 17.29 GPa. Toughness indicated by plasticity, with increase of Cu from 0 to 13.48 at.%, the plasticity increases from 21% to 43%, further increase Cu to 16.86 at.% results in a plasticity decrease to 33%. The coefficient of friction increases from 0.120 to 0.140 with increase of Cu content from 0 to 16.86 at.%. All the as-prepared films show a high H/E ratio of ≥0.1 and high elastic recovery ≥0.57.