A particle-in-cell/Monte Carlo simulation of a capacitively coupled chlorine discharge

Abstract

Here we demonstrate the oopd1 (object-oriented plasma device for one dimension) particle-in-cell/Monte Carlo simulation tool for a capacitively coupled chlorine discharge with a comprehensive reaction set. We apply a hybrid approach where a global model determines the dissociation fraction of the discharge. The simulation results are compared with available experimental measurements and good agreement is achieved. We explore a typical capacitively coupled chlorine discharge using oopd1 and obtain key plasma parameters, including particle density, effective electron temperature, electron energy probability function and ion energy and angular distributions for both Cl+ and ions. The dependence of the plasma parameters on the discharge pressure is systematically investigated. As the pressure increases from 5 to 100 mTorr, the heating mechanism evolves from both stochastic and Ohmic heating to predominantly Ohmic heating and the electron heating outweighs the ion heating at high pressures. Also, the density profile for and Cl− ions becomes flat in the bulk region and the electronegativity increases with increasing pressure. The creation of Cl+ ions in the sheath region is mainly due to conversion from ions to Cl+ ions through non-resonant charge exchange, while in the bulk region the creation of Cl+ ions is mainly ascribed to electron impact ionization processes.