| 초록 |
GaN films were grown on (0001) sapphire substrates by using direct reaction of gaseous gallium and ammonia. The GaN films grown at 1070℃ including the (101) plane, which appeared at 2θ=36.7°in the XRD pattern. Growth of the (100) and (101) planes was detected in the GaN films grown at 1070 ℃. The SEM observation showed that the GaN films containing the (101) plane had very rough V-shape surface due to the growth of GaN crystals in the shape of a triangle. The inclusion of the (100), (101), and (102) planes in the GaN films resulted inplate-like crystals with hexagonal shapes and flat-top surfaces. The crystal and the optical qualities of the GaN films improved with increasing NH3 flow rate. The intensity of the yellow emission increased with increasing (100) peak intensity. The growth rate of the GaN thick films increased with the growth temperature, but decreased at 1270 ℃ due to the decomposition of GaN into elementary Ga and N. The growth rate of the GaN films increased with the NH3 flow rate.
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