Growth of hydrogen-free diamond-like carbon films by a particle-free hollow-cathode arc ion plating system

A hollow cathode arc (HCA) ion plating system was developed to deposit hydrogen-free diamond-like carbon (DLC) films. Unlike the conventional cold cathodic arc, a high-temperature hollow cathodic arc was employed to generate a high flux of carbon ions and carbon ion clusters producing no micro-particles for the depositions of hydrogen-free DLC films. The plasma density characterized by a Langmuir probe was around 1011 cm− 3 near the anode. The films were characterized by Raman, α-step, SEM, nano-indentation and TEM. The deposition rate was up to 0.6 μm/h. The DLC film with hardness around 19 G Pa was obtained at a substrate bias of − 250 V. The hardness of the DLC film containing no hydrogen was relatively low, and believed to be due to the high substrate temperature (∼ 400 °C) and the high flux of Ar ion bombardments.