Physical Features of the Functioning of a Planar Magnetron Sputter with a Thermally Insulated, Discharge-Heated Target for Boron Coating Deposition

The design, the principle of operation, and the characteristics of a planar magnetron sputter for pure boron coatings are presented. A feature of this device is the use of a thermally insulated target (cathode) made from pure crystalline boron, which is heated by an auxiliary low-current discharge to provide an electrical conductivity sufficient for the stable functioning of the magnetron discharge. This makes it possible to realize a DC mode and a pulsed self-sputtering mode in the magnetron, where boron ions in the discharge plasma dominate over the working gas ions. Another feature of the magnetron is the use of a slotted anode of a special design, which ensures stable and long-term operation of the device when a non-conductive boron film is applied to the anode surface. When using a pulsed discharge with a peak current of 40 A, a pulse duration of 400 μs, and a pulse repetition rate of 25 pps, the deposition rate of pure boron coatings on a substrate installed at a distance of 10 cm from the cathode is comparable with the deposition rate of the coatings in a DC magnetron discharge with a current of 300 mA and is found to be about 20−30 nm/min.