Argon metastable densities in the GEC reference cell: a numerical study

Abstract

Summary form only given. The Gaseous Electronics Conference (GEC) reference cell was introduced several years ago as a standard parallel plate capacitively coupled experimental platform for comparing measurements from different research groups and providing reliable data for evaluating models. Recently, McMillin and Zachariah (1996) applied planar laser-induced fluorescence to construct two-dimensional profiles of argon metastable densities in argon, Ar, Ar/O/sub 2/ and Ar/CF/sub 4/ plasmas over a wide range of gas pressures and applied RF voltages. They observed systematic trends in the spatial distributions and magnitudes of the Ar densities. In this paper, we report on a numerical investigation of the GEC reference cell for the conditions of these experiments with the goals of identifying the processes responsible for the experimental observations. The numerical model used in this study is based on a previously described hybrid simulation originally developed for inductively coupled plasmas. In the model, ions and neutrals are simulated using fluid techniques, while a Monte Carlo (MC) simulation is used for computing the electron dynamics. The fluid and MC modules, coupled with a solution of Poisson's equation, are iterated until quasi-steady state conditions are obtained.