Magnetic attenuation of the self-excitation of the plasma series resonance in low-pressure capacitively coupled discharges
Li Wang, Máté Vass, Zoltán Donkó, Péter Hartmann, Aranka Derzsi, Yuan‐Hong Song, Julian Schulze
Abstract
Abstract External magnetic fields impose diverse effects on low-temperature plasmas. We study these in a low-pressure capacitively coupled radio frequency plasma in argon via self-consistent kinetic simulations. The primary effect of the transversal magnetic field, that manifests itself in the trapping of electrons at lower excitation frequencies and, thus, in an increase of the plasma density as a function of the magnetic field, is overruled at higher excitation frequencies by the attenuation of the self-excitation of plasma series resonance oscillations and the attenuation of non-linear electron resonance heating, which lead to a reduced plasma density. At higher magnetic fields the plasma density increases again due to (i) a longer interaction time between the electrons and the edges of the expanding sheaths and (ii) the electric field reversals that develop at the collapsing sheath edges to overcome the trapping of electrons and accelerate them towards the electrodes.