AVS 49th International Symposium
    Plasma Science Tuesday Sessions
       Session PS1-TuA

Paper PS1-TuA5
One-dimensional Simulation of Glow-like Plasma Phenomena in Parallel-plate Microdischarge Geometries

Tuesday, November 5, 2002, 3:20 pm, Room C-103

Session: Microdischarges
Presenter: P. Kothnur, University of Texas at Austin
Authors: X. Yuan, University of Texas at Austin
P. Kothnur, University of Texas at Austin
L. Raja, University of Texas at Austin
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Recently, microdischarges have gained much attention in the plasma process community for a variety of applications. Proposed applications range from generation of intense UV radiation to maskless etching of thin films. While some estimates of properties of microdischarge plasmas are available, a detailed understanding of the plasma dynamics and chemistry is completely lacking. This talk presents results from a self-consistent, one-dimensional computational study of the glow-like phenomena in microdischarges. A dc microdischarge in a parallel-plate geometry with gap distances of the order of 10's-100's of microns is modeled. Results for a noble gas (helium) microdischarge indicates the formation of a relatively large cathode sheath that occupies a significant fraction (~ 50 %) of the micron-sized geometry with the remaining region being the bulk plasma. The electron temperatures attain significantly high peak values (~ 50 eV) in the cathode sheath with relatively low (~ 1 eV) temperatures in the bulk plasma. Gas temperatures of ~ 1000 K and electron densities in excess of 1e14 /cm^3 are predicted. The results indicate that microdischarge plasmas are quite unique with properties that are somewhat intermediate between classical glow-discharges and thermal arc discharges.