High pressure solution growth of GaN

Abstract

An internally heated pressure vessel was used to study the decomposition reaction of GaN at temperatures above 900°C and the phase equilibria in the system Ga-N 2. As a consequence of these studies we have undertaken the crystal growth of GaN free crystals and epitaxial layers on sapphire by a VLS process. We have succeeded in the synthesis of high quality epitaxial layers showing the terrace structure typical of LPE. As a function of the growth conditions both n and p type gallium nitride were obtained, the latter only in polycrystalline form.