A COMPARISON OF PARTICLE-IN-CELL AND FLUID MODEL SIMULATIONS OF LOW-PRESSURE RADIO-FREQUENCY DISCHARGES

A comparison is made between particle-in-cell model (PIC) and fluid mo del simulations of a radio frequency (rf) gaseous discharge containing a helium model gas. The agreement in the discharge properties predict ed by the two models is examined over a range of pressures and applied voltages. It is found that there is quantitative agreement in the ove rall discharge behavior predicted by the PIC and fluid simulations at pressures above 100 mTorr and applied voltages up to 800 V. With the e xception of the ion energy at the electrodes, the two models also agre e in their prediction of the scaling of discharge properties as a func tion of the applied voltage. Below 100 mTorr, disagreement in the peri od-averaged electron heating predicted by each model leads to differen ces in the predicted discharge properties. The estimate for the electr on power input prediction can be improved in the fluid simulation by i ncluding an analytic expression for stochastic heating in the electron energy balance equation.