ANGULAR-DISTRIBUTION OF MASS FLUX FROM ARC-LIKE TI VAPOR PLASMA

Arc-like Ti vapor plasma that appears symmetrical is formed on the ele ctron beam evaporation source in high vacuum by applying similar to 20 V dc voltage to the anode set diagonally above the source. Angular di stributions of both ion and mass fluxes from the plasma at the longitu dinal section, including the anode, are investigated. The angular dist ribution of Ti ion flux from the plasma with 40 V-80 A discharge is un symmetric (maximum ion current density is 16 Am-2 at theta = 0 degrees and source-to-Faraday cup distance 460 mm): the ion current at the an ode side (back side) is much higher than that at the front side. Howev er, the ion current decreases near the anode direction. Angular distri bution of mass flux from the plasma agrees largely with that of ion fl ux, but disagrees with that of mass flux from the vacuum evaporation s ource (cos(3) theta distribution). Therefore, ionization efficiency of Ti vapor in the plasma is considered to be high. Rough surface and sm all Voids are seen at vacuum evaporation, but not at the are-like disc harge evaporation. The cross section fractured in liquid nitrogen is b rittle in the former, but ductile in the latter. This shows that self- ion bombardment greatly affects Ti film densification. Copyright (C) 1 996 Elsevier Science Ltd.