Breaking the Back-Attraction by Bipolar Bursts in BiPIMS
Abstract: Limiting the back-attraction of ions is crucial to increase the deposition rate in HiPIMS processing. Back-attraction can be considerably limited by bipolar plasma bursts in which a positive voltage pulse is applied instantaneously after the negative voltage pulse. Energy-resolved mass spectroscopy confirms that, in addition to the increased flux, the energy of the target metal ions travelling from the target to the substrate is also increased, as a function of positive pulse length. Amorphous carbon coatings have been deposited by bipolar HiPIMS (BiPIMS) as a case study. The increased energy of the depositing flux led to a higher density of the carbon coatings and a significant reduction in the incorporation of the sputter gas atom, argon, was observed in the coatings. Langmuir probe measurements suggests the optimum plasma density window to minimize arc generation and reduce the probability of generated arcs moving away from target racetrack, which results in smoother coatings. BiPIMS voltage pulses of optimized length and magnitude help to coat high quality amorphous carbon coatings with excellent machining functionalities.
Bio: Dr. Rajesh Ganesan is presently working in Nuclear, Plasma, and Radiological Engineering at the University of Illinois at Urbana-Champaign as a research scientist. Prior to this, he worked in Australia, Germany, Switzerland, and the Netherlands. He has been working in High power impulse magnetron sputtering (HiPIMS) related research with Prof. Marcela Bilek and Prof. David McKenzie since 2013.
Dr. Ganesan has gained vast experience in working in the coating process development for HiPIMS and design modifications with HiPIMS machine building companies in Switzerland, Germany and in Netherlands.