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 which to introduce metallic ions into the plasma for metallic ion implantation and/or thin film deposition. The power supply of a metal vacuum arc plasma 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. These restrictions make process optimization and synchronization with the sample high voltage modulator complicated in pulsed-mode PIII operation. In this work, we experimentally investigate the voltage-current characteristics of our metal vacuum arc plasma source. Our results suggest two different power supply designs. By adopting the design incorporating a gradual voltage-current decline, we successfully construct a simple and reliable power supply that works in a stable manner for a prolonged period of time.