Role of C{sub 2}F{sub 4}, CF{sub 2}, and ions in C{sub 4}F{sub 8}/Ar plasma discharges under active oxide etch conditions in an inductively coupled GEC cell reactor

Journal Article · Sun May 01 00:00:00 EDT 2005 · Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films

DOI:https://doi.org/10.1116/1.1874173· OSTI ID:20637085

Barela, Marcos J; Anderson, Harold M; Oehrlein, Gottlieb S ^[1]

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1. Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

Utilizing infrared diode-laser absorption spectroscopy (IRDLAS) and UV-Visible absorption spectroscopy (UV-Vis), we show that it is possible to make a near complete mass balance of etch reactants and products in a GEC inductively coupled fluorocarbon discharge while actively etching SiO{sub 2} substrates. Langmuir probe measurements were performed to measure the total ion current density. C{sub 2}F{sub 4} and CF{sub 2} are shown to be the main dissociation products in a C{sub 4}F{sub 8} plasma discharge. The C{sub 2}F{sub 4} concentration decreases as the SiO{sub 2} etching rate increases, along with CF{sub 2} and CF radicals, suggesting a role in the SiO{sub 2} etching process. The addition of Ar to the C{sub 4}F{sub 8} discharge increased the ion flux at the wafer surface, and the consumption rate of C{sub 2}F{sub 4} relative to CF{sub 2}. The increased ion flux enhanced the SiO{sub 2} etching rate, until at a very high degree of Ar dilution of C{sub 4}F{sub 8}/Ar the etching rate became neutral limited. We also monitored SiF{sub 2} using UV-Vis absorption and CO by IRDLAS. In our work we found SiF{sub 2} and CO to be the prevalent Si and C gas phase etch products for the SiO{sub 2} etching process.

• OSTI ID: 20637085
• Journal Information: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films, Vol. 23, Issue 3; Other Information: DOI: 10.1116/1.1874173; (c) 2005 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0734-2101
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTROSCOPY
ARGON
CARBON FLUORIDES
CARBON MONOXIDE
CURRENT DENSITY
DILUTION
DISSOCIATION
ETCHING
LANGMUIR PROBE
LASERS
MASS BALANCE
PLASMA
RADICALS
SILICON OXIDES
SURFACES
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA