Copper film deposition by a hot refractory anode vacuum arc

Copper films, deposited by radially expanding plasma plume from a hot refractory anode vacuum arc, were studied. The arc was sustained between a consumed, water-cooled Cu cathode, and a non-consumed Mo anode, which was heated by the arc. The plasma plume was created by re-evaporation of the cathode material from the hot anode. Arc currents of 175–300 A were sustained for periods of up to 120 s. The coatings were deposited on glass substrates. A shutter controlled when and how long the substrate was exposed to the plasma. Macroparticle (MP) presence on the coating surface was examined by optical microscopy and the coating thickness was measured by profilometry. The MPs size distribution function was determined. It was found that the morphology of the film in the region facing the anode (anode region) differed from that on the region facing the cathode (cathode region). The cathode region had a matt appearance, and the surface contained many MPs, while in the anode region, a mirror-like film was obtained. The film thickness in the anode region increased linearly with current. Film deposition rate in a 200 A arc in the anode region on a substrate positioned 11 cm from the electrodes initially increased linearly with time and in 1 min reached 0.5 μm/min.