Sustainment of Plasma Density by a Low Magnetic Field in a Dual-Frequency Capacitively Coupled Plasma

Abstract

Dual-frequency capacitively coupled plasmas (DF-CCPs) have been used to control the ion flux by the high-frequency source and the ion bombardment energy onto the electrode by the low-frequency (LF) source separately. However, an increase in the LF voltage, which extends the maximum ion energy to a higher value, causes the reduction of the bulk plasma length with a subsequent decrease of the plasma density. By using a one-dimensional particle-in-cell/Monte Carlo simulation code, the effect of the magnetic field on a DF-CCP is investigated to find whether the plasma can be sustained during the LF voltage increase. It is found that a low magnetic field can effectively maintain the plasma density and electron temperature constant with respect to the variation of the LF voltage.