Abstract
Powder formation studies in deposition plasmas are motivated by the need to reduce contamination in the plasma and films. Models for the force acting upon particles in rf discharges suffer from a lack of quantitative experimental data for comparison in the case of silane-containing plasmas. In this work, a cross-section of the parallel-plate capacitor discharge is illuminated with a polarized beam-expanded laser and global spatio-temporal scattered light and extinction are recorded by CCD cameras. Spatially-regular periodic bright/dark zones due to constructive/destructive Mie interference are visible over large regions of the powder layers, which shows the uniform nature of particle growth in silane plasmas. For particles trapped in an argon plasma, as for steady-state conditions in silane, spatial size segregation is demonstrated by fringes which reverse according to the polarisation of scattered light. The method allow a self-consistent estimation of particle size and number density throughout the discharge volume from which strong particle Coulomb coupling ({Gamma}>40) is suggested to influence powder dynamics. Correction must be made to the plasma emission profile for the extinction by powder. In conclusion, this global diagnostics improves understanding of particle growth and dynamics in silane rf discharges and provides experimental input for testing the validity of
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Dorier, J L;
Hollenstein, C;
Howling, A A
[1]
- Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)
Citation Formats
Dorier, J L, Hollenstein, C, and Howling, A A.
Spatio-temporal powder formation and trapping in RF silane plasmas using 2-D polarization-sensitive laser scattering.
Switzerland: N. p.,
1994.
Web.
Dorier, J L, Hollenstein, C, & Howling, A A.
Spatio-temporal powder formation and trapping in RF silane plasmas using 2-D polarization-sensitive laser scattering.
Switzerland.
Dorier, J L, Hollenstein, C, and Howling, A A.
1994.
"Spatio-temporal powder formation and trapping in RF silane plasmas using 2-D polarization-sensitive laser scattering."
Switzerland.
@misc{etde_10104005,
title = {Spatio-temporal powder formation and trapping in RF silane plasmas using 2-D polarization-sensitive laser scattering}
author = {Dorier, J L, Hollenstein, C, and Howling, A A}
abstractNote = {Powder formation studies in deposition plasmas are motivated by the need to reduce contamination in the plasma and films. Models for the force acting upon particles in rf discharges suffer from a lack of quantitative experimental data for comparison in the case of silane-containing plasmas. In this work, a cross-section of the parallel-plate capacitor discharge is illuminated with a polarized beam-expanded laser and global spatio-temporal scattered light and extinction are recorded by CCD cameras. Spatially-regular periodic bright/dark zones due to constructive/destructive Mie interference are visible over large regions of the powder layers, which shows the uniform nature of particle growth in silane plasmas. For particles trapped in an argon plasma, as for steady-state conditions in silane, spatial size segregation is demonstrated by fringes which reverse according to the polarisation of scattered light. The method allow a self-consistent estimation of particle size and number density throughout the discharge volume from which strong particle Coulomb coupling ({Gamma}>40) is suggested to influence powder dynamics. Correction must be made to the plasma emission profile for the extinction by powder. In conclusion, this global diagnostics improves understanding of particle growth and dynamics in silane rf discharges and provides experimental input for testing the validity of models. (author) 6 figs., 43 refs.}
place = {Switzerland}
year = {1994}
month = {Sep}
}
title = {Spatio-temporal powder formation and trapping in RF silane plasmas using 2-D polarization-sensitive laser scattering}
author = {Dorier, J L, Hollenstein, C, and Howling, A A}
abstractNote = {Powder formation studies in deposition plasmas are motivated by the need to reduce contamination in the plasma and films. Models for the force acting upon particles in rf discharges suffer from a lack of quantitative experimental data for comparison in the case of silane-containing plasmas. In this work, a cross-section of the parallel-plate capacitor discharge is illuminated with a polarized beam-expanded laser and global spatio-temporal scattered light and extinction are recorded by CCD cameras. Spatially-regular periodic bright/dark zones due to constructive/destructive Mie interference are visible over large regions of the powder layers, which shows the uniform nature of particle growth in silane plasmas. For particles trapped in an argon plasma, as for steady-state conditions in silane, spatial size segregation is demonstrated by fringes which reverse according to the polarisation of scattered light. The method allow a self-consistent estimation of particle size and number density throughout the discharge volume from which strong particle Coulomb coupling ({Gamma}>40) is suggested to influence powder dynamics. Correction must be made to the plasma emission profile for the extinction by powder. In conclusion, this global diagnostics improves understanding of particle growth and dynamics in silane rf discharges and provides experimental input for testing the validity of models. (author) 6 figs., 43 refs.}
place = {Switzerland}
year = {1994}
month = {Sep}
}