Copper film deposition rates by a hot refractory anode vacuum arc and magnetically filtered vacuum arc

Abstract

Two vacuum arc deposition techniques were compared for metal film deposition: 1) filtered vacuum arc deposition (FVAD), which applies a magnetic field to separate the plasma from macroparticles (MPs) generated in the cathode spots, and 2) hot refractory anode vacuum arc (HRAVA) deposition, in which anode plasma plume forms by re-evaporation of cathode material from the hot anode surface and MPs are vaporized in the hot interelectrode plasma. A Cu cathode and an arc current of 200 A were used in both systems. The FVAD film thickness was axially symmetric to within 10–20%. The focused plasma jet in the FVAD system covered a circular area, where the radius for half-thickness is ∼ 30 mm. The deposition rate was constant in time and maximal (about 0.25 μm/min) in the center of the circular area. The mass deposition rate was about 9.5 mg/min assuming bulk density. The HRAVA deposition rate initially increased with time and saturated at a maximum of ∼ 2.3 μm/min after 1 min. The plasma expanded radially, and was deposited on a cylindrical area of 100 cm 2 and height ∼ 20 mm, which was co-axial with the electrode axis. The thickness distribution was axially symmetric within 10%. The steady-state mass deposition rate was 400 mg/min. The HRAVA system produced an almost MP-free radially expanded mass throughput and cathode utilization efficiency ∼ 40 times greater than with the FVAD system.