ABSTRACT
Low-temperature GaN layers have been grown on (0001) sapphire substrates by metalorganic chemical vapor deposition at 600°C and the effects of in-situ annealing (1000°C) have been investigated using DXRD, SEM, RBS, and SIMS. DXRD measurements indicate that the crystal quality of these low-temperature GaN layers improve with decreasing thickness in the range of 200Å to 5500Å. RBS in channeling condition also indicates crystallinity improvement after annealing. The surface of the layers grown at low temperature were rough and upon annealing they exhibited columnar structures. RBS and SIMS revealed considerable interdiftusion between GaN and sapphire.
