AVS 45th International Symposium
    Vacuum Metallurgy Division Monday Sessions
       Session VM+TF-MoM

Paper VM+TF-MoM3
Transport of a Cathodic-Arc Plasma Through a Linear-Solenoid Macroparticle Filter

Monday, November 2, 1998, 9:00 am, Room 328

Session: Ionized-PVD: Processes, Properties, and Applications
Presenter: B.P. Cluggish, Los Alamos National Laboratory
Authors: B.P. Cluggish, Los Alamos National Laboratory
B.P. Wood, Los Alamos National Laboratory
Correspondent: Click to Email
A long standing problem in the use of cathodic arcs for deposition of coatings is the production of micron sized droplets, or "macroparticles," of the cathode material. These macroparticles hit and stick to the substrate, causing defects in the coating. One widely used method for "filtering out" the macroparticles is to guide the arc plasma through a solenoidal "magnetic duct" (a metal tube with an axial magnetic field.) The macroparticles travel in straight lines and thus hit and stick to the walls of the duct, rather than reaching the substrate. Unfortunately, most of the plasma ions are lost as well. For this reason, we are performing measurements to understand the transport of the plasma through a duct. The ion flux is found to decay exponentially along the length of the duct, and the magnetic field is crucial for reducing the ion losses. However, increasing the field strength above 50 G has no effect on the ion losses. Furthermore, unlike previous researchers @footnote 1@, we find that applying a positive voltage to the duct has little effect on the ion losses. We have developed a computer simulation which reproduces our results, and predicts that the injection conditions at the entrance to the duct are crucial in determining the ion losses. This work supported by the U.S. D.O.E. @FootnoteText@ @footnote 1@ A. Anders, S. Anders, and I. G. Brown, J. Appl. Phys., vol. 75, pp. 4900-4905, 1994