Power absorption in electrically asymmetric dual frequency capacitive radio frequency discharges

E. Schüngel, J. Schulze, Z. Donkó, U. Czarnetzki

Research output: Article

28 Citations (Scopus)

Abstract

The symmetry of capacitive radio frequency discharges can be controlled via the electrical asymmetry effect by driving one electrode with a fundamental frequency and its second harmonic. In such electrically asymmetric discharges, the mean ion energies at both electrodes are controlled separately from the ion flux by tuning the phase angle θ between the harmonics at fixed voltage amplitudes. Here, the question why the ion flux is nearly independent of θ is answered by investigating the power absorbed by the electrons Pe as a function of θ and time experimentally, by a particle in cell simulation, and an analytical model. The dynamics of Pe is understood by the model and is found to be strongly affected by the choice of θ. However, on time average, Pe is nearly constant, independently of θ. Thus, the ion flux remains approximately constant. In addition, it is shown that the absolute value of the individual voltages across the powered and grounded electrode sheath vary linearly with the dc self-bias. However, their sum remains constant. This yields, in combination with the constancy of the ion flux, a constant power absorbed by the ions and, in conclusion, a total power absorption that is independent of θ.

Original languageEnglish
Article number013503
JournalPhysics of Plasmas
Volume18
Issue number1
DOIs
Publication statusPublished - jan. 2011

Fingerprint

radio frequency discharge
ions
electrodes
harmonics
electric potential
sheaths
phase shift
tuning
asymmetry
symmetry
cells
electrons
simulation

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Power absorption in electrically asymmetric dual frequency capacitive radio frequency discharges. / Schüngel, E.; Schulze, J.; Donkó, Z.; Czarnetzki, U.

In: Physics of Plasmas, Vol. 18, No. 1, 013503, 01.2011.

Research output: Article

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