Modulation of IEADs by different bias waveforms in an ICP reactor: A fast hybrid simulation approach

In this work, a 2D fast hybrid model is developed to study the modulation of ion energy and angle distributions (IEADs) for a biased argon inductively coupled plasma. In the hybrid model, a numerical sheath module and an ion Monte Carlo module are coupled to a frequency domain electromagnetic module and a bulk fluid module to obtain the IEADs at different radial positions. In the bulk fluid module, the continuity equation and full momentum equation for ion and the energy conservation equation for electron are solved. The electron density is obtained by using the quasi-neutral condition, and the ambipolar electric field is obtained by using the no net current assumption. Since the inertial term is considered in the full momentum equation, the hybrid model is suitable for low pressure conditions. By using a single-frequency bias voltage source, the energy peak positions move to the high-energy region and the ion angle distribution moves to the small-angle region with the increasing bias voltage amplitude. Moreover, the width between two energy peaks is smaller at the edge of electrode than at the center. When a dual-frequency bias voltage source is used, the ion energy shows four peaks. The shape of IEADs can also be tuned by changing the phase between two frequencies.