Augsburg 2006 – scientific programme
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P: Plasmaphysik
P 8: Hauptvortrag 3: Niedertemperaturplasmen
P 8.1: Invited Talk
Tuesday, March 28, 2006, 10:30–11:10, 1002
Numerical characterization of dual frequency capacitively coupled hydrogen plasmas — •Aurel Salabas — Theoretical Electrical Engineering, Ruhr-University Bochum,Universitätsstr. 150, D-44801 Bochum, Germany
In this work we report on results from a numerical investigation of dual frequency capacitively coupled plasmas. The calculations simulate H2 discharges produced by a combination of two rf sources with the frequency in the domain 2−60 MHz, at pressures p=150−500 mTorr and for Vrf=25−1000 V applied voltages. A recently developed two-dimensional fluid model is used to provide information about the space-time evolution of the main physical quantities: electron density, electron mean energy, plasma potential,ionization rate; other parameters such as the self-bias voltages and the coupled electrical power are also calculated. For single frequency discharges, the model has been tested against measurements; and a good agreement has been found.
Here we provide a comparative analysis between single and dual frequency discharges. For dual frequency discharges, the influence of geometry, frequency, pressure, and applied voltages on the plasma parameters is discussed. The results reproduce well the behavior of the physical quantities (e.g. the modulation of the plasma potential) and are in agreement with other analytical and numerical studies. The model predictions indicate also that the combination of the two frequencies leads to a space-time modulated structure of the ionization maxima, with considerable ionization processes occurring within the bulk region.