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Effect of oxygen on filament activity in diamond chemical vapor deposition

Journal Article · · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (USA)
DOI:https://doi.org/10.1116/1.577590· OSTI ID:5690412
;  [1]
  1. Department of Physics, The City College of the City University of New York, New York, New York 10031 (US)

Previous studies that have focused on the interactions of CH{sub 4}/H{sub 2} and C{sub 2}H{sub 2}/H{sub 2} mixtures with the hot W filaments used for diamond chemical vapor deposition have been extended in order to determine the effect of oxygen on filament activity. The behavior of W filaments has now been studied up to 2300 {degree}C in mixtures of 3% CH{sub 4}/H{sub 2}, with 0.5, 1.0, and 1.5% O{sub 2}, at a pressure of 25 Torr. The effects of the addition of O{sub 2} on filament resistance, emissivity, and power consumption, as well as on the partial pressures of the gases (CH{sub 4}, C{sub 2}H{sub 2}, O{sub 2}, CO, and H{sub 2}O ) in the reaction chamber, have been determined. The significant improvements in filament activity that are observed are shown to be due to removal of carbon from the filament surface by formation of CO. These results can be understood on the basis of our quasi-equilibrium thermodynamic model for the C--H--O system.

DOE Contract Number:
FG02-87ER45317
OSTI ID:
5690412
Journal Information:
Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (USA), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (USA) Vol. 9:3; ISSN JVTAD; ISSN 0734-2101
Country of Publication:
United States
Language:
English