Pulsed Vacuum-Arc Plasma Source Operating in the Reflective-Discharge Mode

Plasma sources based on vacuum arc discharge have an important disadvantage that is a high share of droplets exists in the cathode erosion material. To "cut off" droplets, various kind of bended magnetic filters are used. We have suggested one more approach to reduce droplet content in arc discharge plasma which Is intense evaporation of droplets in a discharge cell, caused by ignition of "droplet spots". Penning-type arc discharge cell was recognized to be providing favourable conditions for Ignition of droplet spots. At such a cell, a uniform plasma column is formed, which temperature and concentration are much higher than those of a routine vacuum arc of the same discharge current. Further increase in energy density in plasma of a reflective-discharge cell could he achieved by means of the both increase in discharge current and B-field optimisation. The present paper presents results of development and characterisation of a plasma source combining well-known high-current vacuum arc evaporator with a Penning discharge cell. It has been recognized that ion current density amplitude at the source output is as high as 800 A/cm(2), plasma density up to 10(14) cm(.3), and electron temperature 6-8 cV. Those conditions lead to intensive evaporation of droplets in fly. Copper film deposition rate was measured to be of 1.5 nm per pulse, which corresponds to instantaneous deposition rate of 2000 nm/s.