AVS 45th International Symposium
    Plasma Science and Technology Division Monday Sessions
       Session PS-MoP

Paper PS-MoP1
Plasma-CVD with a Pulsed DC Glow-Discharge: A Time Resolved Experimental Investigation@footnote 1@

Monday, November 2, 1998, 5:30 pm, Room Hall A

Session: Plasma Science and Technology Poster Session
Presenter: T.A. Beer, Technische Universität Wien, Austria
Authors: T.A. Beer, Technische Universität Wien, Austria
J. Laimer, Technische Universität Wien, Austria
H. Störi, Technische Universität Wien, Austria
Correspondent: Click to Email
Pulsed direct-current (d.c.) glow discharges are commonly used in systems for plasma-assisted chemical vapour deposition (PACVD). In the present work we investigate the development of plasmas relevant for the production of TiN coatings. A videocamera with gateable image-intensifier is used to study the spatial and temporal evolution of the development of the plasma. Additionally, we use a single electrostatic probe to determine a time resolved charged particle distribution. Measurements are performed on a commercially available Plasma-CVD. Different steel-cylinders have been used as substrates. The typical shutter-speed used in our experiments is 100 ns. The pictures taken were used to generate MPEGmovies@footnote 3@ showing the plasma developement. Our investigations reveal large differences between plasmas with and without TiCl@sub 4@. In the absence of TiCl@sub 4@, the plasma ignites within the first 500 ns. In the presence of TiCl@sub 4@, the formation of the plasma along the substrates occurs with a certain delay, which has also been reported by Mogensen@footnote 2@. Our experiments show that the plasma ignites at the beginning of each pulse at one spot, where a positive column is observed, and spreads from there across the substrate surface. The pattern of the spatialtemporal evolution is quite complex and the evolution of the negative glow depends on various parameter, including geometry. The observed delays in the plasma formation are in the range of 10 us to 130 us. Detailed investigations of the time-dependent density of electrons and negative ions with our Langmuirprobe-setup are still in progress, first measurements show a high concentration of negative ions in the afterglow. @FootnoteText@ @footnote 1@ Supported by the Austrian Science Foundation FWF under Project No. P10794 @footnote 2@ K Mogensen, C Mathiasen, S Eskildsen, H Stöori, Surf. Coat. Technol.(in press) @footnote 3@ http://www.iap.tuwien.ac.at/www/plasma/mp_plasma/