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Langmuir Probe Measurements in an Inductively Coupled Ar/CF4 PlasmasTechnological advancement in the microelectronics industry requires an understanding of the physical and chemical processes occurring in plasmas of fluorocarbon gases, such as carbon tetrafluoride (CF4) which is commonly used as an etchant, and their mixtures to optimize various operating parameters. In this paper we report data on electron number density (ne), electron temperature'(Te), electron energy distribution function (EEDF), mean electron energy, ion number density (ni), and plasma potential (Vp) measured by using Langmuir probe in an inductively coupled 13.56 MHz radio frequency plasmas generated in 50%Ar:50%CF4 mixture in the GEC cell. The probe data were recorded at various radial positions providing radial profiles of these plasma parameters at 10-50 mTorr pressures and 200 W and 300 W of RF power. Present measurements indicate that the electron and ion number densities increase with increase in pressure and power. Whereas the plasma potential and electron temperature decrease with increase in pressure, and they weakly depend on RF power. The radial profiles exhibit that the electron and ion number densities and the plasma potential peak at the center of the plasma with an exponential fall away from it, while the electron temperature has a minimum at the center and it increases steadily towards the electrode edge. The EEDFs have a characteristic drop near the low energy end at all pressures and pressures and their shapes represent non-Maxwellian plasma and exhibit more like Druyvesteyn energy distribution.v
Document ID
20010067453
Acquisition Source
Ames Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Rao, M. V. V. S.
(NASA Ames Research Center Moffett Field, CA United States)
Meyyappan, M.
(NASA Ames Research Center Moffett Field, CA United States)
Sharma, S. P.
(NASA Ames Research Center Moffett Field, CA United States)
Arnold, James O.
Date Acquired
August 20, 2013
Publication Date
January 1, 2000
Subject Category
Plasma Physics
Funding Number(s)
PROJECT: RTOP 632-10-01
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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