OBSERVATIONS OF PARTICLE LAYERS LEVITATED IN A RADIOFREQUENCY SPUTTERING PLASMA

Citation
G. Praburam et J. Goree, OBSERVATIONS OF PARTICLE LAYERS LEVITATED IN A RADIOFREQUENCY SPUTTERING PLASMA, Journal of vacuum science & technology. A. Vacuum, surfaces, and films, 12(6), 1994, pp. 3137-3145
Citations number
18
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics, Applied","Materials Science, Coatings & Films
ISSN journal
0734-2101
Volume
12
Issue
6
Year of publication
1994
Pages
3137 - 3145
Database
ISI
SICI code
0734-2101(1994)12:6<3137:OOPLLI>2.0.ZU;2-F
Abstract
Submicron carbon particles are grown in an argon radio-frequency (rf) sputtering plasma with graphite electrodes. In situ laser light scatte ring revealed particles levitated in the plasma in stratified layers, which were often thinner than 0.5 mm. Under some conditions, the numbe r of layers was very large. These layers are grouped into clouds. In a pure argon plasma, there is one cloud near the sheath edge above the lower electrode, while adding SF6 results in additional particle cloud s near the upper electrode and in the glow region. The different layer s appear to separate particles according to size, with the heaviest in the lowest layer. During several hours of plasma operation, the layer s collapsed and grew again into more stratified layers. The influence of parameters, such as gas pressure, rf power, electrode separation, a nd gas mixture was investigated. Scanning electron microscopy revealed that the particles were multisized spheres with a cauliflowerlike sur face. Some of the particles were found to be coagulated, due to collis ions within the plasma.