Numerical and experimental diagnostics of rf discharges in pure and dusty argon

Journal Article · Tue Dec 15 00:00:00 EST 1992 · Physical Review A. General Physics; (United States)

DOI:https://doi.org/10.1103/PhysRevA.46.7923· OSTI ID:6988641

Belenguer, P ^[1]; Blondeau, J P; Boufendi, L; Toogood, M; Plain, A; Bouchoule, A; Laure, C ^[2]; Boeuf, J P ^[1]

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1. Centre de Physique Atomique de Toulouse, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse CEDEX (France)
2. Groupe de Recherche sur l'Energetique des Milieux Ionises, UFR Sciences-Universite d'Orleans, Boite Postale 6759, 45067 Orleans CEDEX 02 (France)

Self-consistent fluid and particle-in-cell Monte Carlo (PIC-MC) models in conjunction with experimental measurements have been used to study the electrical characteristics of rf discharges in pure argon and in argon contaminated with dust particles (at 0.11 torr argon, 13.56 MHz). In the experiments, the dust particles were first created in a silane-argon rf discharge and subsequently trapped in an argon discharge in order to stop the growth process. The concentration and radius of the dust particles were measured experimentally and found equal to 10[sup 8] cm[sup [minus]3] and 0.05 [mu]m, respectively. The PIC-MC discharge model has been used to check the validity of the fluid model in pure argon. The discharge in dusty argon has been described with a fluid model modified to account for the presence of dust particles. This model uses as input data the number of negative charges carried by the dust particles and the frequency of electron loss to the particles deduced from a two-dimensional particle-in-cell Monte Carlo simulation of a dusty dc plasma. The results show good agreement between experiments and models within the whole range of rf voltages considered and for the pure and dusty argon plasmas. The presence of dust particles in the plasma modifies considerably the discharge impedance, which becomes much more resistive. The electron number density in the plasma is much smaller than the positive ion density and than the number density of negative charges carried by the dust particles. It appears that the phase shift between current and voltage is very sensitive to the presence of powders. This property could be useful for the detection of powder formation in a processing plasma.

• OSTI ID: 6988641
• Journal Information: Physical Review A. General Physics; (United States), Vol. 46:12; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ARGON
HIGH-FREQUENCY DISCHARGES
PLASMA
DUSTS
ELECTRIC IMPEDANCE
ELECTRON DENSITY
ION DENSITY
MONTE CARLO METHOD
CALCULATION METHODS
ELECTRIC DISCHARGES
ELEMENTS
FLUIDS
GASES
IMPEDANCE
NONMETALS
RARE GASES
700330* - Plasma Kinetics
Transport
& Impurities- (1992-)