Gas source molecular beam epitaxy of wurtzite GaN on sapphire substrates using GaN buffer layers
Wurtzite GaN was grown by gas source molecular beam epitaxy on (0001) sapphire substrates. Taking advantage of the catalytic decomposition of ammonia on the growing surface, high growth rates (>1 mu m/h) were achieved for substrate temperatures ranging between 800 and 850 degrees C. Surface morphology, structural, and optical properties of thick (2-4 mu m) GaN films were investigated versus the growth temperature of the GaN buffer layer. It is shown that this parameter has a drastic influence on the GaN properties. (C) 1997 American Institute of Physics.