Theoretical and experimental study of ion flux formation in an asymmetric high-frequency capacitive discharge

TL;DR

This paper combines experimental and kinetic modeling to analyze ion flux formation in asymmetric high-frequency capacitive discharges, revealing how electrode area ratios influence ion energy and plasma parameters.

Contribution

It provides a comprehensive study of ion flux formation using both experiments and two-dimensional Particle-in-Cell modeling, highlighting the impact of electrode geometry on plasma characteristics.

Findings

Increasing electrode area ratio boosts ion energy without affecting plasma parameters.

Self-bias voltage and ion distribution are significantly affected by electrode asymmetry.

Model results align well with experimental measurements across various pressures.

Abstract

Parameters of a high frequency capacitive discharge in argon in axially symmetric chambers of different geometries are studied in experiments and by means of two-dimensional kinetic modeling by the Particle-in-Cell method. It is demonstrated that a change in the ratio of the areas of the driven and grounded electrodes can substantially increase the ion energy on the electrode practically without disturbing the plasma parameters. Particular attention is paid to studying the self-bias voltage and the ion distribution function on the electrode for gas pressures ranging from 15 to 70 mTorr. The results of self-consistent calculations are in good agreement with experimental data.