Kinetic Interpretation of Resonance Phenomena in Low Pressure Capacitively Coupled Radio Frequency Plasmas

TL;DR

This paper uncovers the kinetic mechanisms behind resonance phenomena in low-pressure capacitively coupled RF plasmas, highlighting how electron beam interactions excite current harmonics through particle-based simulations.

Contribution

It introduces a kinetic interpretation of resonance phenomena, revealing the role of electron beams and their interactions during sheath expansion in RF plasmas.

Findings

Multiple electron beams form during sheath expansion.

Interaction between energetic and bulk electrons excites current harmonics.

Kinetic origin of resonance phenomena is established.

Abstract

The kinetic origin of resonance phenomena in capacitively coupled radio frequency plasmas is discovered based on particle-based numerical simulations. The analysis of the spatio-temporal distributions of plasma parameters such as the densities of hot and cold electrons, as well as the conduction and displacement currents reveals the mechanism of the formation of multiple electron beams during sheath expansion. The interplay between highly energetic beam electrons and low energetic bulk electrons is identified as the physical origin of the excitation of harmonics in the current.