Theoretical and experimental investigations of sheath dynamics during plasma ion implantation

Summary form only given, as follows. In this paper we study theoretically and experimentally the characteristics of the transient sheath which surrounds a target immersed in a plasma and biased by negative high-voltage pulses. The plasma is produced by the UTK Microwave Plasma Facility (MPF), which is an approximately 200 liter steady-state, uniform plasma generated by 2 kW, 2.45 GHz microwave power. The steady state sheath thickness is determined for various plasma parameters. Our theoretical model takes into account the initial ion Bohm velocity and the matrix sheath thickness. The ion transit time through the sheath is also determined and plotted as function of the sheath thickness. The propagation velocity of the edge of the sheath is determined experimentally.