Publication
Title
Effects of feedstock availability on the negative ion behavior in a $C_{4}F_{8}$ inductively coupled plasma
Author
Abstract
 In this paper, the negative ion behavior in a C4F8 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 (1030 mTorr), and this trend agrees well with experiments that were carried out in many fluorocarbon (fc) ICP sources, like C2F6, CHF3, and C4F8. This behavior is explained by the availability of feedstock C4F8 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 C4F8 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 C4F8 plasma sources, one needs to take into account many factors, like the attachment characteristics, the anion composition, the spatial profiles, and the reactor configuration. Finally, a detailed comparison of our simulation results with experiments is conducted.
Language
English
Source (journal)
Journal of applied physics / American Institute of Physics. - New York, N.Y., 1937, currens
Publication
New York, N.Y. : American Institute of Physics, 2015
ISSN
0021-8979 [print]
1089-7550 [online]
Volume/pages
118:3(2015), 18 p.
Article Reference
033301
ISI
000358429200004
Medium
E-only publicatie
Full text (Publisher's DOI)
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UAntwerpen
 Faculty/Department Research group Project info Computer modeling and experimental validation for plasmas used for etching in the microelectronics industry. Publication type Subject Affiliation Publications with a UAntwerp address