The effect of the driving frequency on the confinement of beam electrons and plasma density in low-pressure capacitive discharges
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Tartalom: http://real.mtak.hu/51447/
Archívum: MTA Könyvtár
Gyűjtemény: Status = Published

Type = Article
Cím:
The effect of the driving frequency on the confinement of beam electrons and plasma density in low-pressure capacitive discharges
Létrehozó:
Wilczek, Sebastian
Trieschmann, Jan
Schulze, Julian
Schuengel, Edmund
Brinkmann, Ralf Peter
Derzsi, Aranka
Korolov, Ihor
Donkó, Zoltán
Mussenbrock, Thomas
Dátum:
2015-03-19
Téma:
QC04 Electricity. Magnetism. Electromagnetism / villamosság, mágnesesség, elektromágnessesség
Tartalmi leírás:
The effect of changing the driving frequency on the plasma density and the electron dynamics in a capacitive radio-frequency argon plasma operated at low pressures of a few Pa is investigated by particle-in-cell/Monte-Carlo collision simulations and analytical modeling. In contrast to previous assumptions, the plasma density does not follow a quadratic dependence on the driving frequency in this non-local collisionless regime. Instead, a step-like increase at a distinct driving frequency is observed. Based on an analytical power balance model, in combination with a detailed analysis of the electron kinetics, the density jump is found to be caused by an electron heating mode transition from the classical α-mode into a low-density resonant heating mode characterized by the generation of two energetic electron beams at each electrode per sheath expansion phase. These electron beams propagate through the bulk without collisions and interact with the opposing sheath. In the low-density mode, the second beam is found to hit the opposing sheath during its collapse. Consequently, a large number of energetic electrons is lost at the electrodes resulting in a poor confinement of beam electrons in contrast to the classical α-mode observed at higher driving frequencies. Based on the analytical model this modulated confinement quality and the related modulation of the energy lost per electron lost at the electrodes is demonstrated to cause the step-like change of the plasma density. The effects of a variation of the electrode gap, the neutral gas pressure, the electron sticking and secondary electron emission coefficients of the electrodes on this step-like increase of the plasma density are analyzed based on the simulation results.
Nyelv:
angol
Típus:
Article
PeerReviewed
info:eu-repo/semantics/article
Formátum:
text
Azonosító:
Wilczek, Sebastian and Trieschmann, Jan and Schulze, Julian and Schuengel, Edmund and Brinkmann, Ralf Peter and Derzsi, Aranka and Korolov, Ihor and Donkó, Zoltán and Mussenbrock, Thomas (2015) The effect of the driving frequency on the confinement of beam electrons and plasma density in low-pressure capacitive discharges. Plasma Sources Science and Technology, 24. 024002. ISSN 0963-0252 ; ESSN: 1361-6595
Kapcsolat:
https://doi.org/10.1088/0963-0252/24/2/024002
doi:10.1088/0963-0252/24/2/024002