Diamond deposition by hollow cathode arc discharge

Abstract We have studied the influence of various discharge and deposition parameters on the operation of an HCA discharge as well as on the formation of polycrystalline diamond films, using this rarely investigated CVD method. Obvious changes and dependencies of the growth of diamond particles and films were observed with variation of the distance between hollow cathode tip and substrate, deposition temperature, working pressure, methane concentration in hydrogen, total gas flow and deposition time. With our improved HCA discharge system, which can be used for deposition with mainly thermal, mainly kinetic or combined activation of the gas mixture, diamond films have been obtained with a growth rate up to 3 μm h −1 . From the various methods of investigation we can conclude that the electron current to the substrate, a characteristic feature of the HCA discharge method, is actually a main influence factor for plasma-activated deposition of diamond and not only for substrate heating. Increasing the substrate current results in higher growth rates, improved film uniformity and changed surface morphologies of the diamond deposits.