Influence of an electrical field on the macroparticle size distribution ina vacuum arc

The results of experimental study of macroparticle distribution in a vacuum are presented for Cu, Ti, Zr, and Cr cathodes. We have studied the macropa rticle contamination of the films deposited on the substrate having floatin g potential and biased up to -1000 V with respect to the anode. It has been found that the macroparticle number significantly decreases (by a factor o f 3-4) with substrate biasing for all examined cathode materials. A model o f macroparticle motion in the quasineutral plasma and near-substrate sheath was proposed. The model bases on analyses of the macroparticle charging an d motion in the quasineutral plasma and near substrate sheath. The model ca n qualitatively explain the macroparticle reduction in the coating due to n egatively charged macroparticle reflection in an electric field. (C) 1999 A merican Vacuum Society. [S0734-2101(99)04805-8].