HYDRIDE VAPOR-PHASE EPITAXY OF GAN ON MOLECULAR-BEAM EPITAXIAL GAN SUBSTRATES

We have studied the growth by hydride vapour phase epitaxy (HVPE) of G aN on GaN layers grown by molecular beam epitaxy (MBE) on sapphire and GaAs(1 1 1)B substrates. For growth on the GaN/sapphire composite sub strates, the properties of the HVPE GaN are significantly improved as evidenced from X-ray studies. Growth on GaAs has enabled us to produce thick Gee-standing layers of GaN which may be suitable as substrates for further epitaxy. (C) 1998 Elsevier Science B.V. All rights reserve d.