Characteristics and design of metal vacuum arc plasma source power supply for pulsed-mode plasma immersion ion implantation

Metal vacuum arc plasma sources enhance the capability of plasma immersion ion implantation (PIII) by providing a convenient and efficient means by wh ich to introduce metallic ions into the plasma for metallic ion implantatio n and/or thin film deposition. The power supply of a metal vacuum arc plasm a source is usually based on the artificial transformation line design, but it has several drawbacks. For instance, the pulse width cannot be adjusted conveniently and the pulsing frequency cannot exceed a predefined value. T hese restrictions make process optimization and synchronization with the sa mple high voltage modulator complicated in pulsed-mode PIII operation. In t his work, we experimentally investigate the voltage-current characteristics of our metal vacuum arc plasma source. Our results suggest two different p ower supply designs. By adopting the design incorporating a gradual voltage -current decline, we successfully construct a simple and reliable power sup ply that works in a stable manner for a prolonged period of time. (C) 2000 American Institute of Physics. [S0034- 6748(00)02001-9].