Simulation Study of Hollow Cathode Enhanced Radio Frequency Capacitively Coupled Plasma Discharges

Fluid model simulation analysis was employed in this work to investigate the effect of a trench on the grounded electrode of a radio frequency capacitively coupled plasma (CCP) discharge, by using commercial available code, CFD-ACE+ (ESI corp.). The analysis was carried for Ar plasma driven by 27 MHz rf power. Effects of trench dimensions, such as width and depth were investigated. Simulation results demonstrate that, although the trench is on the grounded electrode, it still exhibits hollow cathode effect if the trench width is wider than twice the sheath thickness, approximately. Simulation results also show that local plasma density is significantly enhanced due to the hollow cathode effect and the spatial distribution of the plasmas can also be tailored by this local density enhancement effect. The effect of different voltage waveforms on the discharge characteristics of this ground electrode hollow cathode CCPs are also investigated. The detailed simulation results will be presented.