Surface properties of copper-incorporated diamond-like carbon films deposited by hybrid magnetron sputtering

In an effort to improve the surface properties of surgical instruments in terms of corrosion resistance, mechanical strength, anti-sticking property, and anti-bacterial performance, bioactive films of hydrogenated diamond-like carbon containing different fractions of Cu were synthesized using the radio frequency plasma enhanced chemical vapor deposition with a magnetron Cu electrode in different atmospheres comprising different proportions of Ar/CH₄ mixture. The influence of the methane fraction and plasma power on the Cu content, microstructure and surface properties of the deposited films was investigated. The results show that the films included stacked nano-clusters and domains of Cu and that the size of the nano-clusters slightly increased with the Cu content and deposition time. The Cu content in the films increased with the plasma power and argon flow ratio. In addition, increasing the Cu content not only improved hardness but also roughened the surface, and consequently, increased the water contact angle of the film surface. All films exhibited a hydrophobic surface that is expected to be useful for synthesizing minimally invasive instruments.