Spiral hollow cathode plasma-assisted diamond deposition

Abstract

High quality diamond films have been deposited on silicon and sapphire by means of a combined hot filament/electron beam/plasma-assisted chemical vapor deposition technique. A spiral tantalum foil is used as the hot cathode to generate a high-current dc discharge at a low sustaining voltage. Gas mixtures consisting of methane, hydrogen, and argon flowing through the spiral cathode towards the anode are effectively decomposed by the hot cathode and the high-density plasma. Diamond particles and films, grown at a rate between 0.5 and 5 μm/h, have been characterized by scanning electron microscopy, x-ray diffraction, and Raman spectroscopy.