Global model of Ar, O[sub 2], Cl[sub 2], and Ar/O[sub 2] high-density plasma discharges

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)

DOI:https://doi.org/10.1116/1.579366· OSTI ID:6405597

Lee, C ^[1]; Lieberman, M A ^[2]

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1. Department of Chemical Engineering, University of California, Berkeley, California 94720 (United States)
2. Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, 94720 (United States)

We develop a global (volume averaged) model of high-density plasma discharges in molecular gases. For a specified discharge length and diameter, absorbed power, pressure, and feed gas composition, as well as the appropriate reaction rate coefficients and surface recombination constants, we solve the energy and particle balance equations to determine all species densities and the electron temperature. We use an expression for charged particle diffusive loss that is valid for low and high pressures and for electropositive and electronegative plasmas. We apply the model to Ar, O[sub 2], Cl[sub 2], and Ar/O[sub 2] discharges and compare with available experimental data. In Ar, we find that the ion density increases monotonically with increasing pressure, while for O[sub 2] and Cl[sub 2], the total positive ion density increases initially, then decreases as pressure is further increased. For a pure Cl[sub 2] discharge, we find that surface recombination processes are important in affecting the degree of dissociation and the negative-ion density of the system. For mixtures of Ar and O[sub 2], we find that at a fixed ratio of Ar to O[sub 2] flowrates, the dominant ionic species changes from Ar[sup +] to O[sup +] as pressure is increased. When a small amount of Ar is added to a pure O[sub 2] discharge, the overall positive-ion density increases, whereas the ratio of negative ion to electron density decreases.

• OSTI ID: 6405597
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States) Vol. 13:2; ISSN 0734-2101; ISSN JVTAD6
• Country of Publication: United States
• Language: English

Related Subjects

661300* -- Other Aspects of Physical Science-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ARGON
CHLORINE
ELECTRIC DISCHARGES
ELECTRON TEMPERATURE
ELEMENTS
FLUIDS
GASES
HALOGENS
MATHEMATICAL MODELS
NONMETALS
OXYGEN
PLASMA DENSITY
PRESSURE DEPENDENCE
RARE GASES
RECOMBINATION