Plasma deposition of thin films utilizing the anodic vacuum arc

• Published in: IEEE transactions on plasma science 1990-12, Vol.18 (6), p.895-903
• Main Authors: Ehrich, H., Hasse, B., Mausbach, M., Muller, K.G.
• Format: Article
• Language: English
• Subjects: Anodes; Coatings; Conducting materials; Cross-disciplinary physics: materials science; rheology; Electrons; Exact sciences and technology; Inorganic materials; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical materials; Physics; Plasma density; Plasma sources; Sputtering; Vacuum arcs; Vacuum deposition
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/27.61500

Anodic vacuum arcs operating with cold cathodes in the spot mode and hot evaporating anodes are investigated to explore their technical potential as a plasma deposition technique. This discharge provides a unique source of a highly ionized, metal vapor plasma by autogeneration of the working gas to evaporation of the anode. This gas-free and droplet-free metal vapor plasma expands into the ambient vacuum (10/sup -4/ mbar) and produces thin metallic films at the surface of substrates. An analysis of Al and Cu plasmas at the position of a possible substrate for arc currents between 20 and 200 A leads to the following results: electron densities, 10/sup 15/-10/sup 18//m/sup 3/; degree of ionization, 0.5-25%; directed ion energy, 5 eV; and electron temperatures, 0.2-1 eV. Metallic coatings generated with deposition rates between 0.1 and 100 nm/s show the following properties: purity, 99.9%; polycrystalline structure with grain sizes between a few and a few hundred nm, same mass density as the respective bulk material, electrical conductivity rather close to that of the bulk material, and excellent optical properties. The coatings show good adhesion, which can be enhanced by a plasma-supported pretreatment of the substrate surface and by an acceleration of the ions towards the substrate.< >