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Indexed by:期刊论文

Date of Publication:2008-03-01

Journal:PHYSICS OF PLASMAS

Included Journals:SCIE、EI

Volume:15

Issue:3

ISSN No.:1070-664X

Abstract:Heating mechanisms and particle flow balancing of capacitively coupled plasmas driven by combined dc/rf sources have been investigated by particle-in-cell/Monte Carlo simulations. At low pressure, Ohmic heating will be suppressed and stochastic heating will be enhanced while increasing dc voltage. But the overall heating power will decrease. No heating mode transitions are observed. At high pressure, bulk plasma density decreases at low dc and rf voltage, and the one- side alpha-gamma transition will occur while increasing dc voltage. After the transition, the plasma density abruptly increases and average electron energy drops. As the result of that, the plasma is sustained by secondary electrons instead of the Ohmic heating of the bulk electrons. The dc source will reduce, or even eliminate at high voltage, the electron charge flowing into the dc powered electrode. Therefore the ratio of electron-to-ion charge flowing into the rf powered electrode over one period increases from -1.0 to -2.0- -2.3 for low pressure and -2.2- -5.0 for high pressure. (C) 2008 American Institute of Physics.