AVS 45th International Symposium
    Plasma Science and Technology Division Thursday Sessions
       Session PS-ThP

Paper PS-ThP5
Negative Ions in Inductively Coupled Plasmas@footnote 1@

Thursday, November 5, 1998, 5:30 pm, Room Hall A

Session: Plasma Science and Technology Division Poster Session
Presenter: J.L. Kleber, University of Texas, Dallas
Authors: J.L. Kleber, University of Texas, Dallas
L.J. Overzet, University of Texas, Dallas
Correspondent: Click to Email
The effects of negative ions on continuous wave and pulsed low pressure inductively coupled plasmas (ICP's) are being investigated using a Langmuir probe and a microwave interferometer. The sheath resistance (R@sub sh@) can cause the plasma potential to rise when a Langmuir probe in the plasma is biased above floating potential.@footnote 2@ This can lead to errors in calculating plasma parameters such as electron density (n@sub e@), electron temperature, and the electron energy probability function (EEPF). We have measured R@sub sh@ for continuous wave ICP's in the Gaseous Electronics Conference (GEC) reactor in argon and nitrogen and will measure it in a mixture of argon and chlorine all at or under 50 mTorr. We found that R@sub sh@ had a power law dependence on n@sub e@ and will demonstrate how this arises. We have also investigated the spatial and temporal behavior of plasma parameters in pulsed pure argon ICP's and will investigate them in a mixture of argon and chlorine. We focus on the afterglow when it is possible for the negative ions to influence more the chemistry of the plasma as the electron density decays. @FootnoteText@ @footnote 1@This material is based upon work supported by a National Science Foundation under a Graduate Research Fellowship and Grant No. CTS-9713262 and by the State of Texas Advanced Research Program under Grant No. 009741-043. @footnote 2@M. B. Hopkins, J. Res. NIST 100, 415-425 (1995)