Examination of intermediate species in GaN metal‐organic vapor‐phase epitaxy by selective‐area growth

Abstract

AbstractThe major reactive intermediate species of GaN has been deduced and its surface reaction rate constant has been obtained through the analysis of multi‐scale growth‐rate profiles both in the reactor‐scale and in the micrometer‐scale that were obtained by selective‐area growth. Usually, it is difficult to explore surface reaction kinetics, especially for metal‐organic vapour phase epitaxy (MOVPE), because of mass‐transfer‐limited kinetics. This multi‐scale analysis, however, has clarified that a single precursor, a gas‐phase reaction product between (CH3)3Ga and NH3, leads to the growth of GaN with a surface reaction probability of approximately 0.4 at 1400 K which is a typical growth temperature of GaN. Contribution of higher‐order polymers was not significant in growth rate, but they seemed to be a cause of degraded surface morphology. A lumped reaction model of GaN MOVPE was proposed that led to reasonable agreement between a simulated growth‐rate profile in the reactor‐scale and a corresponding measured profile, which would lead to improved design of reactors and growth conditions. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)