Rapid growth of bulk GaN crystal using GaN powder as source material

Abstract

Using a novel gallium (Ga) vapor transport technique, thick gallium nitride (GaN) layers have been grown using GaN powder as the source material. In this technique, GaN powder decomposes at 1100oC into gallium and nitrogen vapors. The Ga vapors are transported to the seed substrate and reacted with ammonia to form a crystalline GaN layer. The seed was composed of a sapphire substrate with a 2 μm Hydride Vapor Phase Epitaxy (HVPE) GaN layer on it. The growth temperature was set at 1180oC. Using this technique, growth rates as high as 500 μm/hr were achieved. The grown GaN layers were single crystal and were characterized by X-ray diffraction and scanning electron microscopy.