Discharge with a self-heated hollow cathode and a vaporizable anode in an inhomogeneous magnetic field

Abstract

This work is devoted to studying the conditions of the stable burning of discharge with self-heated hollow cathode and anode placed in an inhomogeneous magnetic field. Such a discharge generates dense plasma in Ar-O2 mixture, and compression of the discharge column by magnetic field allows efficient evaporation of the anode material. A new method of deposition of oxide coatings through reactive anode evaporation was implemented in such a system. The rate of this process, unlike the reactive magnetron sputtering, is not limited by the low-rate sputtering of oxidized target. In addition, this method provides intense ion bombardment of a coating surface. The terms of suppression of ion-sound oscillations have been determined, and a stable burning of discharge with current up to 40 A at a pressure of Ar-O2 mixtures 0.1 Pa has been achieved. The results of the probe diagnostic of discharge plasma parameters are presented. Nanocrystalline Al2O3 coatings have been deposited in the studied system on the area of 300-600 cm2 with rate 2-5 μm/h at temperatures of 400-600°C.