Physical mechanisms of macroparticles number density decreasing on a substrate immersed in vacuum arc plasma at negative high-frequency short-pulsed biasing

The objective of this investigation was to study the physical mechanisms of macroparticles (MPs) number density decreasing on a substrate immersed in a vacuum arc plasma. It was found that negative repetitively pulsed biasing of the substrate significantly reduced the MPs content on surface. Several different physical mechanisms for the MPs decreasing have been identified. It was established that up to 10% of the MPs are repelled by the sheath electric field. Reduction of MPs density by almost 20% is attributable to ion sputtering after 2 min of processing. It was found that enhanced ion sputtering, MPs evaporation on substrate surface, and even evaporation of MPs in a sheath, can take place depending on the cathode material and the irradiation parameters.