Shunting arc plasma generation and ion extraction

This article reviews the generation and time evolution of shunting arc plasma, which is an alternating pulsed discharge through a solid-state material and contains mainly ions of a metal or a solid-state material. The material is provided into the plasma as a rod that connects electrodes for the discharge. Optimization of the discharge condition has made it possible for the arc discharge to be self ignited with relatively low input power to the rod, which leads to a long lifetime of the rod. Because the principal of its generation is ohmically heating the rod, the droplets are not emitted. The material is deposited from the surface by the heating at the initial stage and an arc discharge is generated via a glow-like discharge and surface discharge along a rod. The shunting plasma flows towards the vacuum chamber wall due to the voltage bias of the plasma to the grounded chamber and induces a new plasma. This brings a hybrid usage of the shunting arc plasma and its induced plasma for synthesizing a new compound of the materials. As another hybrid plasma generation, the shunting arc discharge can be produced in a stationary RF (13.56 MHz)-plasma. The possibility of the shunting pulse plasma as a pulsed ion source for plasma based ion implantation is also described.