Independent Variables to Control a Time-Varying Energy Distribution of Charged Species in a Capacitively Coupled Plasma

Abstract

Currently, most experimental plasma diagnostics have commonly used a physical approach based on the time-invariant energy distribution function, and the effect of time-varying parameters is underestimated. It is helpful to analyze the spatio-temporal evolution of charged particle dynamics using a particle-in-cell Monte Carlo Collision (PIC-MCC) simulation for advanced plasma control. Driving voltage, pressure, gap length, driving frequency, gas mixture, and gas pressure are the external variables to control the plasma kinetics. The control of the electron energy distribution functions in helium or argon discharges is investigated with the variation of these parameters at a specific pressure regime from 50 mTorr to 200 Torr. Additionally, the energy relaxation mechanism is investigated to verify the kinetic approach in this study. It was found that the spatio-temporal energy relaxation process dominantly determines not only the energy distribution but also macroscopic plasma properties including the electric field, velocity, plasma potential, and so on <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> .