Electric field non-linearity in very high frequency capacitive discharges at constant electron plasma frequency

Abstract

A self-consistent particle-in-cell simulation study is performed to investigate the effect of driving frequency on the electric field non-linearity, electron heating mechanism and electron energy distribution function (EEDF) in a low pressure symmetric capacitively coupled plasma (CCP) discharge at a constant electron plasma frequency. The driving frequency is varied from 27.12 MHz to 100 MHz for a discharge gap of 3.2 cm in argon at a gas pressure of 1 Pa. The simulation results provide insight of higher harmonic generations in a CCP system for a constant electron response time. The spatio-temporal evolution and spatial time averaged electron heating is presented for different driving frequencies. The simulation results predict that the electric field non-linearity increases with a rise in driving frequency along with a concurrent increase in higher harmonic contents. In addition to the electron heating and cooling near to the sheath edge a positive <J.E> is observed in to the bulk plasma at higher driving frequencies. The EEDF illustrate enhancement in the population of mid-energy range electrons as driving frequency increases thereby changing the shape of EEDF from bi-Maxwellian to nearly Maxwellian. For the constant ion flux on the electrode surface, a decrease in the ion energy by more than half is observed with an increase in driving frequency.

13 pages, 6 figures

References in corpus (6)

• Simulation benchmarks for low-pressure plasmas: capacitive discharges
• Anomalous Capacitive Sheath with Deep Radio Frequency Electric Field Penetration
• The effect of the driving frequency on the confinement of beam electrons and plasma density in low pressure capacitive discharges
• Kinetic Interpretation of Resonance Phenomena in Low Pressure Capacitively Coupled Radio Frequency Plasmas
• Influence of driving frequency on the metastable atoms and electron energy distribution function in a capacitively coupled argon discharge
• Plasma density and ion energy control via driving frequency and applied voltage in a low pressure capacitively coupled plasma discharge

Cited by in corpus (6)

• Plasma asymmetry, electron and ion energy distribution function in capacitive discharges excited by tailored waveforms
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• Driving frequency effect on discharge parameters and higher harmonic generation in capacitive discharges at constant power densities
• High frequency sheath modulation and higher harmonic generation in a low pressure very high frequency capacitively coupled plasma excited by sawtooth waveform
• Ion energy distribution function in very high frequency capacitive discharges excited by sawtooth waveform
• Flux and energy asymmetry in a low pressure capacitively coupled plasma discharge excited by sawtooth-like waveform -- a harmonic study