One-dimensional hybrid simulation of the electrical asymmetry effectcaused by the fourth-order harmonic in dual-frequencycapacitively coupled plasma

A one-dimensional hybrid model was developed to study the electrical asymmetry effect (EAE) caused by the fourth-order harmonic in a dual-frequency capacitively coupled Ar plasma. The self-bias voltage caused by the fourth-order frequency changes periodically with the phase angle, and the cycle of self-bias with the phase angle is π/2, which is half of that in the second-order case. The influence of the phase angle between the fundamental and its fourth-order frequency on the ion density profiles and the ion energy distributions (IEDs) were studied. Both the ion density profile and the IEDs can be controlled by the phase angle, which provides a convenient way to adjust the sheath characters without changing the main discharge parameters.