Bochum 2015 – wissenschaftliches Programm

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P: Fachverband Plasmaphysik

P 18: Low Temperature Plasmas II

P 18.4: Vortrag

Mittwoch, 4. März 2015, 11:30–11:45, HZO 30

Influence of a phase-locked RF bias on the E-to-H mode transition in an inductively coupled plasma — •Philipp Ahr¹, Tsanko Vaskov Tsankov¹, Edmund Schüngel², Julian Schulze², and Uwe Czarnetzki¹ — ¹Institute for Plasma and Atomic Physics, Ruhr University Bochum, 44780 Bochum, Germany — ²Department of Physics, West Virginia University, 26506 West Virginia, USA

The cooupling mechanisms between inductive and capacitive power deposition in inductively coupled discharges (ICP) with a capacitive (CCP) rf bias in hydrogen are investigated. As a new feature the phases of the two power sources are synchronized, allowing for a defined phase difference. Two effects are observed: First, the electron density depends on the applied rf bias power. Second, the E-H-mode transition takes place at lower values of the inductive power with the rf bias power being present. The electron dynamics is observed by phase resolved optical emission spectroscopy. The observed effects are caused by the confinement (trapping) of the electron beams generated by the CCP. The efficiency of the trapping can be adjusted by the phase difference. In order for the coupling to be efficient, the penetration depth of the beam should be lager than the gap between the CCP and the ICP coil window. This sets a upper pressure value. In conclusion the performance of the ICP can be manipulated significantly by the CCP bias.