Hybrid HiPIMS + controlled pulsed arc for deposition of hard coatings

A new hybrid PVD deposition system was developed based on the combination of HiPIMS pulsed glow discharge and pulsed cathodic arc discharge (HiPIMS+ARC). The presence of cathodic arc discharge in the HiPIMS is a typical situation when the glow discharge randomly transits to an arc discharge during the active part of the pulse cycle. In these typical cases, the transition appears randomly and cannot be controlled. The new hybrid HiPIMS+ARC discharge works with modified pulsed high power supplies which allow the initiation of pulsed arc discharge during HiPIMS pulse at the defined time. The initiated arc during the active part of the HiPIMS pulse is quenched at the end of this active part of the pulse when the magnetron cathode is disconnected from the negative voltage of the power supply. Several modifications with HiPIMS sequence of active pulses with arc were tested as well. The hybrid HiPIMS+ARC was applied for the deposition of ta-C thin films by use of a graphite magnetron target. Carbon ta-C films were deposited on silicon substrates at different pulse configurations. Deposited films were analyzed by DUV Raman scattering and the ratio of sp3/sp2 bonds was qualitatively determined. Microhardness and modified Young's modulus was analyzed by microindenter. The surface morphology was observed by optical microscopy and the presence of microdroplets was analyzed for particular conditions. Achieved ta-C film parameters for this deposition source were compared with other deposition methods.