ICP argon discharge simulation: The role of ion inertia and additional RF bias

Abstract

Inductively coupled plasma (ICP) argon discharge with additional RF bias on the electrode is studied numerically and compared with experimental data. The role of ion inertia is shown by comparing the two numerical approaches: drift-diffusion approximation and a separate equation for ion momentum in the model. Two different discharge geometries are studied: simple cylindrical geometry and two chambers geometry with a downstream plasma. The difference in the calculated plasma density is shown for lower pressure values. Two approaches give similar results at a pressure of 100 mTorr. The downstream ICP discharge with an additional 12 MHz bias was calculated for the range of voltage amplitude from 20 to 215 V. The ion energy distribution function at the RF-biased electrode is calculated by the kinetic model. The results are compared with experimentally measured plasma density and ion energy spectra in the two-chamber discharge geometry. A good agreement was obtained between the calculated and experimental data.