Fluorine negative ion density measurement in a dual frequency capacitive plasma etch reactor by cavity ring-down spectroscopy

Journal Article · Mon Apr 10 00:00:00 EDT 2006 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.2194823· OSTI ID:20778890

Booth, Jean-Paul; Corr, Cormac S; Curley, Garrett A; Jolly, Jacques; Guillon, Jean; Foeldes, Tomas ^[1]

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1. Laboratoire de Physique et Technologie des Plasmas, CNRS UMR 7648, Ecole Polytechnique, 91128 Palaiseau (France)

F{sup -} negative ions were detected by direct observation of the weak photodetachment absorption continuum below 364.5 nm by cavity ring-down spectroscopy. The negative ions were generated in a modified industrial dielectric plasma etch reactor, with 2+27 MHz dual frequency capacitive excitation in Ar/CF{sub 4}/O{sub 2} and Ar/C{sub 4}F{sub 8}/O{sub 2} gas mixtures. The F{sup -} signal was superimposed on an unidentified absorption continuum, which was diminished by O{sub 2} addition. The F{sup -} densities were in the range of (0.5-3)x10{sup 11} cm{sup -3}, and were not significantly different for single (27 MHz) or dual (2+27 MHz) frequency excitation, not confirming recent modeling predictions.

• OSTI ID: 20778890
• Journal Information: Applied Physics Letters, Vol. 88, Issue 15; Other Information: DOI: 10.1063/1.2194823; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ABSORPTION
ANIONS
ARGON
CARBON TETRAFLUORIDE
ELECTRON DETACHMENT
EXCITATION
FLUORINE IONS
MHZ RANGE 01-100
MIXTURES
OXYGEN
PLASMA
PLASMA DENSITY
PLASMA DIAGNOSTICS
SIMULATION
SPECTROSCOPY