GaN Film Growth by a Supersonic Arcjet Plasma

Abstract

This paper reports on preliminary studies of GaN growth obtained using a supersonic nitrogen arcjet plasma expanding into low pressure. A hydrogen-free and carbon-free growth environment was achieved by use of a Ga vapor source positioned downstream of the expanding plume. GaN growth rates of around 8 μm/hour were obtained in these preliminary studies. We believe these growth rates are the highest reported for a non-chemical decomposition process. The growth rates are attributed to the very high nitrogen atom fluxes estimated to be on the order of 1019 atoms/cm2/sec. The initial growth rates are believed to be well below those possible with a fully optimized system. The GaN films are characterized by Raman spectroscopy, visible-IR transmission, and x-ray diffraction. The deposited films appear to be single crystal and epitaxial on basal plane sapphire substrates.