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Title: Argon–oxygen dc magnetron discharge plasma probed with ion acoustic waves

Journal Article · · Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films
DOI:https://doi.org/10.1116/1.4871081· OSTI ID:22258568
; ;  [1];  [2]
  1. Centre of Plasma Physics, Institute for Plasma Research, Nazirakhat, Sonapur, Kamrup, Assam 782 402 (India)
  2. Madhabdev College, Narayanpur, Lakhimpur, Assam 784164 (India)

The precise determination of the relative concentration of negative ions is very important for the optimization of magnetron sputtering processes, especially for those undertaken in a multicomponent background produced by adding electronegative gases, such as oxygen, to the discharge. The temporal behavior of an ion acoustic wave excited from a stainless steel grid inside the plasma chamber is used to determine the relative negative ion concentration in the magnetron discharge plasma. The phase velocity of the ion acoustic wave in the presence of negative ions is found to be faster than in a pure argon plasma, and the phase velocity increases with the oxygen partial pressure. Optical emission spectroscopy further confirms the increase in the oxygen negative ion density, along with a decrease in the argon positive ion density under the same discharge conditions. The relative negative ion concentration values measured by ion acoustic waves are compared with those measured by a single Langmuir probe, and a similarity in the results obtained by both techniques is observed.

OSTI ID:
22258568
Journal Information:
Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films, Vol. 32, Issue 3; Other Information: (c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0734-2101
Country of Publication:
United States
Language:
English