GaN Growth

Abstract

As the melting point of GaN is approximately 1700°C the growth of GaN crystals from a liquid melt is difficult and GaN is instead normally grown using the halide vapor phase epitaxy (HVPE) method using an equilibrium mixture of nitrogen and Ga-containing gas. In practice, this is achieved by depositing GaN on a sapphire crystal at 1000°C using a mixture of GaCl3 and ammonia as the Ga and nitrogen source gases, respectively. However, the growth speed using this method is too high (several µm/min) to control the thickness of thin epitaxial layers with precision, whilst high purity crystal is not easily achieved due to the interaction of the hydrogen chloride product gas with the reaction vessel [125, 126] .