Non-Neutral/Quasi-Neutral Plasma Edge Definition for Discharge Models: A Numerical Example for Dual Frequency Hydrogen Capacitively Coupled Plasmas

Aurel Salabas, Ralf Peter Brinkmann

J. Appl. Phys. 45 (2006) pp. 5203-5206


A practical definition for the non-neutral/quasi-neutral plasma edge region is proposed and tested with the help of a fluid model. The numerical calculations show that the definition reproduce well the space-time behavior of the plasma sheath for single and dual frequency capacitively coupled discharges. The simulation results indicate that the velocity of the sheath expansion for a H2 discharge sustained at 13.56 MHz frequency, 0.5 Torr pressure and 200 V applied rf voltage is about 2.5 ×107 cm s-1. For dual frequency discharges, the modulation of the sheath is stronger when the sheath thickness assumes its minimum.


Tags: fluid model, non-neutral/quasi-neutral plasma edge region, plasma sheath, sheath thickness, sheath-modulation