KINETIC-MODEL FOR PLASMA-BASED ION-IMPLANTATION OF A SHORT, CYLINDRICAL TUBE WITH AUXILIARY ELECTRODE

Plasma-based ion implantation of the inner surface of a short, cylindr ical tube is modeled using a two-dimensional particle-in-cell simulati on. An auxiliary electrode, hen a coaxial anode, is used to increase t he ion impact energy. Initially, ions inside the tube impact the inner surface at approximately normal angles, At later times, ions enter th e tube from the exterior plasma and impact predominantly near its cent er at glancing angles, Ions are found to cross the midplane of the tub e and in some cases to pass completely through the tube, in contrast t o the predictions of the ''collisionless'' fluid model. The total inci dent dose is greatest around the center of the tube, and least at its ends. (C) 1998 American Institute of Physics.