Epitaxial Growth and Properties of Al x Ga1 − x N by MOVPE

Abstract

Epitaxial layers of AlxGa1-x N alloys are grown on sapphire (0001) and silicon (111) substrates by MOVPE in an ambient H2 gas at atmospheric pressure. By optimizing the reactor design and the growth conditions, parasitic reactions of metalorganic compounds with gaseous NH3 are remarkably reduced and the composition of AlxGa1-x N layers can be controlled fairly well for the first time. The vapor-solid distribution coefficient for A1 is found to be approximately unity. At respective substrate temperatures of 1020°C for sapphire and 1050°C for silicon, single-crystal layers of AlxGa1-x N with x up to 0.40 are obtained. The lattice constant is proportional to the molar fraction of AIN following Vegard's law. The electrical resistivity, carrier concentration, and Hall mobility of the layers are studied as a function of the composition. © 1986, The Electrochemical Society, Inc. All rights reserved.