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Title: Effects of feedstock availability on the negative ion behavior in a C{sub 4}F{sub 8} inductively coupled plasma

In this paper, the negative ion behavior in a C{sub 4}F{sub 8} inductively coupled plasma (ICP) is investigated using a hybrid model. The model predicts a non-monotonic variation of the total negative ion density with power at low pressure (10–30 mTorr), and this trend agrees well with experiments that were carried out in many fluorocarbon (fc) ICP sources, like C{sub 2}F{sub 6}, CHF{sub 3}, and C{sub 4}F{sub 8}. This behavior is explained by the availability of feedstock C{sub 4}F{sub 8} gas as a source of the negative ions, as well as by the presence of low energy electrons due to vibrational excitation at low power. The maximum of the negative ion density shifts to low power values upon decreasing pressure, because of the more pronounced depletion of C{sub 4}F{sub 8} molecules, and at high pressure (∼50 mTorr), the anion density continuously increases with power, which is similar to fc CCP sources. Furthermore, the negative ion composition is identified in this paper. Our work demonstrates that for a clear understanding of the negative ion behavior in radio frequency C{sub 4}F{sub 8} plasma sources, one needs to take into account many factors, like the attachment characteristics, the anion composition, the spatial profiles,more » and the reactor configuration. Finally, a detailed comparison of our simulation results with experiments is conducted.« less
Authors:
 [1] ;  [2] ; ; ;  [1] ;  [3]
  1. School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China)
  2. (Belgium)
  3. Research group PLASMANT, Dept. Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium)
Publication Date:
OSTI Identifier:
22489523
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANIONS; AVAILABILITY; FLUOROFORM; ION DENSITY; PLASMA; PRESSURE RANGE KILO PA; PRESSURE RANGE MEGA PA 10-100; RADIOWAVE RADIATION; SIMULATION; VARIATIONS