Fast simulation of the E–H mode transition in Ar/O2 inductively coupled plasmas

Abstract

In this work, an analytical hybrid model, which consists of an analytical electromagnetic model and a global model, is developed to investigate the E to H mode transition in a planer inductively coupled plasma. By employing the hybrid model, the effect of discharge frequency, oxygen content, and gas pressure on the E to H mode transition is investigated. The results show that the electron density increases rapidly with coil current when the discharge shifts to the H mode, and the mode transition becomes smoother and occurs at lower current when the driving frequency is higher. As oxygen content increases, the electron density declines, and the threshold current for the mode transition exhibits a rising trend. The evolution of the threshold current with pressure is nonlinear; i.e., it decreases first and then increases, and the minimum value varies with discharge frequency. In addition, the plasma composition also changes during the E to H mode transition; i.e., all the charged species densities increase with coil current, except the O− density, which varies nonlinearly, and this indicates the decreasing electronegativity in the H mode. The results obtained in this work are helpful for understanding the effect of different discharAr/O2ge parameters on the E to H mode transition in Ar/O2 inductive discharges.