Electron and ion kinetics in magnetized capacitively coupled plasma source
Abstract
Onedimensional particleincell Monte Carlo collision simulations of magnetized argon plasmas in an asymmetric capacitively coupled plasma reactor are presented. At low pressure (10 mTorr), electron kinetics are strongly affected by the magnetic field and transitions from nonlocal to local kinetic property occur with increasing magnetic field which are reflected in spatially resolved calculations of the electronenergy probability function. For highenergy electrons, the transition takes place when the energyrelaxation length is smaller than the system length. For lowenergy electrons, however, the transition occurs when the electrondiffusion time scale in the energy space is shorter than the spatialdiffusion time scale in coordinate space. These observations are in agreement with experimental data and theoretical calculations deduced from the Boltzmann equation. The ion energy distribution function (IEDF) on the driven electrode changes from the ionneutral collisional type to the ionneutral collisionless type with increasing magnetic field strength. The maximum ion energy in the IEDF decreases and the angular spread in the ion angle distribution function slightly increases with increasing magnetic field strength. These changes are explained in terms of the ratio of the iontransit time to rf frequency, the sheath length, and the mean potential difference between the driven electrode and the plasma. Atmore »
 Authors:
 Department of Electronics and Electrical Engineering, Pohang University of Science and Technology, Pohang 790784 (Korea, Republic of)
 Publication Date:
 OSTI Identifier:
 20979365
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films; Journal Volume: 25; Journal Issue: 3; Other Information: DOI: 10.1116/1.2713408; (c) 2007 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ARGON; BOLTZMANN EQUATION; DISTRIBUTION FUNCTIONS; ELECTRONS; IONS; KINETICS; MAGNETIC FIELDS; MONTE CARLO METHOD; ONEDIMENSIONAL CALCULATIONS; PLASMA; PLASMA SHEATH; PLASMA SIMULATION; PRESSURE RANGE MEGA PA 10100
Citation Formats
Lee, S. H., You, S. J., Chang, H. Y., and Lee, J. K. Electron and ion kinetics in magnetized capacitively coupled plasma source. United States: N. p., 2007.
Web. doi:10.1116/1.2713408.
Lee, S. H., You, S. J., Chang, H. Y., & Lee, J. K. Electron and ion kinetics in magnetized capacitively coupled plasma source. United States. doi:10.1116/1.2713408.
Lee, S. H., You, S. J., Chang, H. Y., and Lee, J. K. Tue .
"Electron and ion kinetics in magnetized capacitively coupled plasma source". United States.
doi:10.1116/1.2713408.
@article{osti_20979365,
title = {Electron and ion kinetics in magnetized capacitively coupled plasma source},
author = {Lee, S. H. and You, S. J. and Chang, H. Y. and Lee, J. K.},
abstractNote = {Onedimensional particleincell Monte Carlo collision simulations of magnetized argon plasmas in an asymmetric capacitively coupled plasma reactor are presented. At low pressure (10 mTorr), electron kinetics are strongly affected by the magnetic field and transitions from nonlocal to local kinetic property occur with increasing magnetic field which are reflected in spatially resolved calculations of the electronenergy probability function. For highenergy electrons, the transition takes place when the energyrelaxation length is smaller than the system length. For lowenergy electrons, however, the transition occurs when the electrondiffusion time scale in the energy space is shorter than the spatialdiffusion time scale in coordinate space. These observations are in agreement with experimental data and theoretical calculations deduced from the Boltzmann equation. The ion energy distribution function (IEDF) on the driven electrode changes from the ionneutral collisional type to the ionneutral collisionless type with increasing magnetic field strength. The maximum ion energy in the IEDF decreases and the angular spread in the ion angle distribution function slightly increases with increasing magnetic field strength. These changes are explained in terms of the ratio of the iontransit time to rf frequency, the sheath length, and the mean potential difference between the driven electrode and the plasma. At high pressure (218 mTorr), electronneutral collisions disrupt electron gyromotion so that the effects of the magnetic field on electron and ion kinetics are greatly reduced.},
doi = {10.1116/1.2713408},
journal = {Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films},
number = 3,
volume = 25,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}

With the energy resolved quadrupole mass spectrometer and hybrid simulation, the influence of lowfrequency (LF) source parameters on the ion energy distributions (IEDs) of argon ions impinging on the grounded electrode was studied, both experimentally and numerically, in a dual frequency capacitively coupled plasma. It was shown that for decreasing LF or increasing LF power, the high energy peak in IEDs shifts toward the high energy region significantly. The simulation results were in general agreement with the experimental data.

Ion species and electron behavior in capacitively coupled Ar and O{sub 2} plasma
We investigated the change in electron density using the plasma frequency by the wave cutoff method, and the behavior of ion species with a quadrupole mass spectrometer (QMS) in pure Ar and O{sub 2} and mixed O{sub 2}/Ar plasmas. The change in electron and ion density in pure Ar and O{sub 2} plasmas was evaluated while varying such process conditions as rf power and pressure. We found that electron density in a pure Ar and O{sub 2} discharge is closely correlated to loss and generation of ions. The electron densities in both pure Ar and O{sub 2} plasmas increase withmore » 
Spatially resolved measurements of ion density and electron temperature in a dualfrequency capacitively coupled plasma by complete floating double probe technique
Spatially resolved measurements of the ion density and electron temperature in a dualfrequency capacitively coupled Ar discharge plasma are performed with a newly developed complete floating double probe. Axial and radial distributions of the ion density and electron temperature under various highfrequency (HF) power and gas pressure were studied in detail. Both the ion density and the electron temperature increased with increasing HF power. With increasing gas pressure from 1.3 to 9.3 Pa, the radial profile of ion density below the driven electrode experienced a change from ''bimodal'' to ''unimodal'' shape, with better uniformity being achieved at the optimal pressuremore » 
Capacitively Coupled Radio Frequency Discharge Plasmas In Hydrogen: Particle Modeling and Negative Ion Kinetics
We present a 1D(r)2D(v) particle code for capacitively coupled radio frequency discharge plasmas in hydrogen, which includes a rigorous kinetic modeling of ion transport and several solutions to speed up the convergence. In a test case the effect of surface atom recombination and molecule vibrational deactivation on H concentration is investigated. 
Numerical investigation of ion energy distribution and ion angle distribution in a dualfrequency capacitively coupled plasma with a hybrid model
A onedimensional hybrid model is developed to study the characteristics of energy and angular distributions of the ions and fast neutrals impinging on the rfbiased electrode in a dualfrequency capacitively coupled Ar discharge. The hybrid model consists of a fluid model that determines the spatiotemporal evolution of the discharge, and a MonteCarlo model that, including the electronneutral, ionneutral, and fast neutralneutral collisions, predicts the energy and angular distributions of the ions and fast neutrals on the rfbiased electrode. The influence of pressure, voltage amplitude, and frequencies of the two rf sources on the energy and angular distributions is discussed. Themore »