Strongly adhering and thick highly tetrahedral amorphous carbon (ta-C) thin films via surface modification by implantation

Highly tetrahedral amorphous carbon thin films have exceptional mechanical properties that make them ideal for many challenging wear applications such as protective overcoats for orthopaedic prostheses and aerospace components. However, the use of ta-C in many wear applications is limited due to the poor adhesion and the inability to grow thick films because of the large compressive stress. Here we report on a simple modification of the substrate growth surface by 1-keV ion bombardment using a cathodic vacuum arc (CVA) plasma prior to deposition of ta-C films at 100 eV. The 1-keV C⁺ ion bombardment created a thin intermixed layer consisting of substrate and carbon atoms. The generation of the intermixed carbide layer improved the adhesion and allowed the growth of thick (several μm) ta-C layers on metallic substrates.