Layer-by-layer growth of AlN and GaN by molecular beam epitaxy

The conditions for obtaining layer-by-layer growth of (0 0 0 1) AlN and GaN with wurtzite structure in molecular beam epitaxy (MBE) have been determined by studying reflection high-energy electron diffraction (RHEED) oscillations. For both materials, the growth conditions are optimized when the metal/nitrogen ratio is close to unity. Atomic hydrogen has been found to enhance significantly the AlN growth rate. This effect is tentatively attributed to an increase in the nitrogen incorporation efficiency in the presence of hydrogen.