Radio-frequency magnetron-sputtered thin films on p-type Si substrates were studied as a function of rapid thermal annealing temperatures of between 800 and 1000C. This revealed that higher rapid thermal annealing temperatures caused the GaN films to recrystallize in the stable hexagonal form, and enhanced the near-bandedge emission in the photoluminescence spectrum. A deep electron trap with an activation energy of 0.39eV, which was detected at the surfaces of films which had been rapidly thermally annealed at higher temperatures, was suggested to be a N-vacancy related defect that played a defect-assisted tunnelling role in the forward conduction of Au/GaN Schottky diodes.

Effect of Rapid Thermal Annealing on Radio-Frequency Magnetron-Sputtered GaN Thin Films and Au/GaN Schottky Diodes. C.W.Wang, J.Y.Liao, C.L.Chen, W.K.Lin, Y.K.Su, M.Yokoyama: Journal of Vacuum Science and Technology B, 1999, 17[4], 1545-8