Reaction mechanism for the ammonolysis of β-gallium oxide to gallium nitride

Abstract

The reaction mechanism for the ammonolysis of β-gallium oxide (β-Ga2O3) to gallium nitride (GaN) was elucidated by observing the morphology of microsized β-Ga2O3 single crystals with a distinct shape under a flow of ammonia (NH3) and hydrogen (H2) at elevated temperatures. The morphology of the microsized β-Ga2O3 single crystals grown on the c-plane sapphire by the thermal annealing of gallium sulfide, was not retained after calcination under a flow of NH3 and H2. These microstructural observations strongly support that the ammonolysis of β-Ga2O3 to GaN proceeds through gaseous Ga 2O, and that the rate of the reduction of β-Ga2O 3 to Ga2O is slower than that of the nitridation of Ga2O to GaN. © 2013 The Ceramic Society of Japan. All rights reserved.