Instabilities in Inductively Coupled Oxygen Plasma
Abstract
In inductively coupled plasma, instabilities are observed when operating with electronegative gases, because the transition between capacitive and inductive modes does not occur at fixed power but on a range of power. We observed instabilities in oxygen for pressure between 5 and 20mTorr. Time resolved Langmuir probe has been used to record plasma parameters (ne, Te, Vp, eedf) during instability. For pure O2, O2-Ar (10variations are observed. Typically, electronic density varies by almost two orders of magnitude during the instability period. This confirms the oscillation between the E-mode with low densities, and the H-mode with higher densities. The electronic temperature presents also important variations. Electron energy distribution functions have been obtained. We studied the influence of pressure and source power on plasma parameters. Complementary measurements with planar probe are presently carried out to measure the exact time resolved positive ion flux. Negative ion fractions could then be determined.
- Publication:
-
APS Annual Gaseous Electronics Meeting Abstracts
- Pub Date:
- September 2004
- Bibcode:
- 2004APS..GECKM1003R