Behavior of macroparticles near and on a substrate immersed in a vacuum arc plasma at negative high-frequency short-pulsed biasing

Abstract

It was found that the negative repetitive pulsed biasing of a substrate with respect to the adjacent plasma significantly reduce the macroparticles (MPs) content on surface. The decrease of MPs on the negative potential substrate surface is caused by several different physical mechanisms. Up to 10% of macroparticles can be repulsed from the plasma-substrate voltage drop after being negatively charged in plasma. The MPs surface density on substrate can be significantly reduced after MPs interaction with negatively biased metal surface. This physical mechanism of negatively charged MPs electrostatic repulsion disappears when tungsten grid is used to create a sheath near the substrate surface. Reduction of MPs surface density almost by half takes a place due to ion sputtering. The decrease of MPs surface density by factor of 12 was achieved after the treatment of substrate for 2 min.