Calculated sheath dynamics under the influence of an asymmetrically pulsed dc bias

A one-dimensional model is used to describe the evolution of charged particles in a plasma sheath driven by an asymmetrically pulsed dc bias in the frequency range of 100 kHz to 10 MHz. The temporal-spatial evolution of the sheath is obtained through the simultaneous solution of Poisson's equations, the ionic fluid equations and a Boltzmann treatment of the electrons. Calculations are performed to demonstrate the effects ionic inertia and sheath restructuring have on the temporal dependence of current and energy of the ions arriving at the driven electrode. The temporal scale is observed to depend on the bulk density of the plasma. The pulse frequency, the pulse duty, and the capacitive coupling of the pulse to the driving electrode are varied to demonstrate the influence of these factors on the energy distribution of the ions extracted from the plasma to the electrode.