Sheath voltage ratio for asymmetric rf discharges

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.348436· OSTI ID:5651808

Alves, M V; Lieberman, M A; Vahedi, V; Birdsall, C K ^[1]

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1. Department of Electrical Engineering and the Electronics Research Laboratory, University of California, Berkeley, California 94720 (USA) Department of Computer Sciences and the Electronics Research Laboratory, University of California, Berkeley, California 94720 (USA)

Spherical and cylindrical many-particle models are used to simulate rf (radio frequency) discharges in which the rf powered and the grounded electrodes have different areas. This asymmetry determines the magnitude of the average plasma-to-electrode voltage {ital V}{sub {ital a}} (the ion bombarding energy) at the smaller powered electrode, which is a critical process parameter. A collisionless uniform ionization discharge model predicts that the voltage ratio {ital V}{sub {ital a}}/{ital V}{sub {ital b}} scales as the fourth power of the electrode area ratio {ital A}{sub {ital b}}/{ital A}{sub {ital a}}, where {ital V}{sub {ital b}} is the potential drop at the other electrode. However, measurements indicate a much weaker dependence of {ital V}{sub {ital a}}/{ital V}{sub {ital b}} on the area ratio, which is also observed in our simulations. Over a limited range of area ratios it was found that the power dependence was close to one, in agreement with a local ionization discharge model. The simulation codes used are PDC1 (plasma device cylindrical one-dimensional) and PDS1 (plasma device spherical one-dimensional).

• DOE Contract Number: FG03-87ER13727
• OSTI ID: 5651808
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 69:7; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

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