Magnetically enhanced hollow cathode - a new plasma source for high-rate deposition processes

Hollow cathode arc discharges have been studied for some decades in basic research and different fields of practical application. Especially in the field of physical vapor deposition (PVD) they are often used for metal evaporation and the generation of plasma. Problematical aspects were found in the high throughput of working gas necessary for stable operation and in the inhomogeneous, locally concentrated ionization efficiency. A promising way out of this dilemma was found in a special arrangement of hollow cathode and annular anode in an axial magnetic field. This configuration allows a drastic reduction of working gas flow without loss of discharge stability. Moreover, with reduction of gas flow a strong increase in ion current density was observed together with a highly expanded volume of plasma plume.