Nonlinear Plasma Dynamics in Electron Heating of Asymmetric Capacitive Discharges with a Fluid Sheath Model

Abstract

A fluid radio-frequency (rf) sheath model coupled to an equivalent circuit method is adopted to describe the nonlinear series resonance effects due to nonlinear interaction of plasma bulk and sheath in asymmetric capacitive discharges. With the fluid sheath model, we can determine self-consistently the relationship between the instantaneous potential drop across the rf sheath and the instantaneous sheath thickness. The numerical results demonstrate that the self-excitation of the plasma series resonance significantly enhances both ohmic heating and stochastic heating. Also, we observe that the effects of nonlinear series resonance increases the total power dissipation by factors of 2–5 for low pressure capacitive plasmas. Furthermore, we find that the largest harmonic is about 13 for the plasma current.