Radio frequency glow discharge source with integrated voltage and current probes used for evaluation of discharge parameters

Journal Article · Wed Mar 15 04:00:00 EST 2006 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2182077· OSTI ID:20787972

Wilken, L; Hoffmann, V; Wetzig, K ^[1]

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1. Leibniz Institute for Solid State and Materials Research Dresden, P.O. Box 270116, D-01171, Dresden (Germany)

A radio frequency (rf) Grimm-type glow discharge source for the chemical analysis of solid samples, with integrated voltage and current probes, was developed. All elements of a plasma equivalent circuit are determined from the measured current-voltage characteristics. The procedure is based on the independent evaluation of the ion current and electron current region. The physical meaning of the parameters is investigated by comparisons with measurements from dc glow discharges. We found that the reduced rf current of the powered electrode is comparable to the reduced current in dc discharges. A formula is developed that corrects the reduced current due to gas heating. The sheath thickness at the powered rf electrode is evaluated and is between 75 and 1100 {mu}m. The voltage of the bulk plasma is in the range 2-15 V, and the resistance is between 30 and 400 {omega}. The bulk plasma consumes about 3% of the total power, and the reduced voltage is comparable to the reduced electrical field in the positive column of direct current discharges. The sheath voltage at the grounded electrode is in the range 25-100 V, the capacities are between 10 and 400 pF, and the resistances are in the range 100 {omega}-5000 {omega}. We also found invariants for the evaluated sheath parameters.

• OSTI ID: 20787972
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 99; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CAPACITY
CHEMICAL ANALYSIS
DIRECT CURRENT
ELECTRIC FIELDS
ELECTRIC POTENTIAL
ELECTRODES
ELECTRONS
EQUIVALENT CIRCUITS
GLOW DISCHARGES
HIGH-FREQUENCY DISCHARGES
PLASMA
PLASMA SHEATH
POSITIVE COLUMN
RADIOWAVE RADIATION
THICKNESS