Ion and Probe Measurements in rf Capacitive Discharges in Argon and Nitrogen
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Year of publication | 2004 |
Type | Article in Proceedings |
Conference | WDS'04 Proceedings of Contributed papers, Part II |
MU Faculty or unit | |
Citation | |
Field | Plasma physics |
Keywords | Langmuir probe; Ion energy distribution; concentration profiles |
Description | We used Langmuir probe and Balzers PPM to determine electron concentration, energy of ions and plasma potential in Ar and N2 discharge. Both diagnostic devices were oriented parallel. The movable electrodes allow a perpendicular spatially resolved measurements. The ion energy distribution (IED) measured at the high power is the same as at the grounded electrode. It exhibited only one peak which was typically found for low voltage modulated r.f. sheaths (the case of grounded electrode). The mean energy of Ar+ and N2+ ions was about 92~\% of the energy related to the plasma potential. Moreover, low energy electron tail appeared in their IEDs. These both facts are explained by collisions in the sheath. Not observed effect of collisions in N+ ions IEDs. The ion mean energies decreased towards the grounded electrodes in agreement with the plasma potential. The ion and electron concentrations showed similar profiles (maximum about 12~mm above the grounded electrode). |
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