Berlin 2005 – scientific programme

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P: Plasmaphysik

P 14: Poster: Niedertemperaturplasmen / Plasmatechnologie 6, Diagnostik 4

P 14.7: Poster

Saturday, March 5, 2005, 14:45–16:45, Poster HU

Temporal evolution of atomic oxygen density profiles in a pulsed rf plasma — •Silke Peters, Kristian Dittmann, Bert Krames und Jürgen Meichsner — Institute of Physics, University of Greifswald, Domstr. 10a, 17489 Greifswald, Germany

Atomic oxygen represents an important reactant in plasma surface treatment of materials. The knowledge about spatio-temporal density distributions of such species is of great interest for better understanding of elementary processes involved, and comparison with results from simulation. In the used capacitively coupled rf-discharge the atomic oxygen density distributions are determined by diffusion as well as by generation and loss processes in plasma chemical reactions. For various plasma parameters the axial and radial profiles were studied by two photon absorption laser induced fluorescence spectroscopy (TALIF) at different time delays after plasma ignition and during the afterglow. The results from pulsed plasmas are compared with previous measurements under continuous discharge conditions. Both, the investigations of plasma-on and the plasma-off phase provide results about the radial profiles which confirm very well the explanation in the case of continuous plasma. On the other hand, the time-evolution of the axial profiles shows different behaviour compared with continuous discharge mode.