Synthesis of nanostructured amorphous carbon-copper composite films by plasma-enhanced chemical vapour deposition

• Nanostructured amorphous carbon-copper composite films were deposited.
• Effect of temperature on the composition, refractive index and surface roughness was determined.
• The nanohardness of the composite films varied in the range of 0.2–3 GPa.

Nanostructured amorphous carbon-copper composite films were formed by plasma-enhanced chemical vapour deposition. The formation was done on copper-silicon substrates at 25 °C, 300 °C, 520 °C, and 700 °C temperatures using an acetylene gas at 40–70 Pa pressure. The heating of the CuSi substrate induced formation of Cu nanospheres with 50–500 nm size depending on the substrate temperature. The microstructure and composition of nanostructured carbon-copper composite films were investigated. The SEM views showed formation of amorphous carbon films with the randomly distributed nanostructures. The oxygen concentration in the composite films decreased with the increased heating temperature. The surface roughness measurements indicated that the surface roughness values increased with the increase of the temperature. The increase of the substrate temperature stimulated to the graphitization, enhanced the fraction of sp2 CC sites and lead to the formation of the nanocrystaline graphite clusters in composite films. The nanohardness values of the formed nanostructured amorphous carbon-Cu films varied in the range of 0.2–3 GPa.