Effect of substrate temperature on properties of diamond-like films deposited by combined DC impulse vacuum-arc method

DLC thin films have been deposited using a combined DC and high power impulse vacuum-arc process. Hardness and adhesion of the obtained films deposited at different substrate temperature were studied using nanohardness testing and the scratch tester REVETEST®. The bonding structure of as-deposited films was analyzed by Raman scattering and X-ray photoelectron spectroscopy. The results show that the substrate temperature is one of the main parameters influencing the sp3-to-sp2 ratio of carbon atom bonds in the coatings, which in turn affects the film's mechanical properties. XRD analysis shows that a CrxCy interfacial layer forms at 280 °С, which reduces the adhesion properties of the DLC coatings. High quality DLC coatings are obtained by control of the specimen temperature below 280 °C using a sensor that is in direct contact with the substrate.