Effects of the excited states on electron kinetics and power absorption and dissipation in inductively coupled Ar plasmas

Abstract

The effects of the excited states on electron kinetics as well as plasma power absorption and dissipation are numerically studied in radio frequency low-pressure inductively coupled Ar plasmas. The model used in this work is based on the coupling of the kinetic module, the electromagnetic field module, and the global model module. The existence of excited states caused by the electron-impact excitations of the ground state of Ar decreases the electron temperature due to the significant depletion of the electron energy probability function in the inelastic energy range. The reduction in electron temperature decreases the power dissipation of an electron per unit volume and, therefore, increases the electron density for the fixed total power. The profile and maximum variations of the absorption power density indicate that the increased electron density suppresses the power deposition deeper into the plasma with inclusion of the electron-impact excitations of the ground state to excited states of Ar. However, the collision processes involving the excited states as reactants hardly affect the electron kinetics and electromagnetic field properties due to far lower densities of the excited states than that of the ground state of Ar.