Suppression of hexagonal GaN mixing by As4 molecular beam in cubic GaN growth on GaAs (001) substrates

A mechanism of hexagonal GaN crystal-phase mixing in cubic GaN growth under As, molecular beam irradiation on GaAs (0 0 1) substrates has been investigated. it is found that the As, beam irradiation during growth of the GaN is effective for the suppression of the hexagonal GaN mixing on the (1 1 1) A planes, although it is not so effective for the (1 1 1) B planes. The results strongly indicate that the high-quality cubic GaN layers will be obtained in the MBE growth by the As, beam irradiation combined with the formation techniques of the atomically flat surfaces such as the high-temperature atomic hydrogen treatment. (C) 1999 Elsevier Science B.V. All rights reserved.