Direct lateral epitaxy overgrowth of GaN on sapphire substrates based on a sparse GaN nucleation technique
نویسندگان
چکیده
A sparse nucleation process on sapphire ~0001! substrates has been developed for the growth of GaN thin films. The density of nucleation sites is reduced to only 4310 cm. Based on this process, we performed direct lateral epitaxial overgrowth ~LEO! of GaN by metalorganic chemical vapor deposition on patterned SiO2/sapphire ~0001! substrates. An aggregate lateral to vertical growth rate ratio of around 2:1 was achieved after the coalescence of the GaN stripes. Cathodoluminescence imaging shows strong and uniform near-band gap luminescence from LEO regions and confirms the improved quality of LEO GaN, which is further supported by atomic force microscopy analysis. © 2000 American Institute of Physics. @S0003-6951~00!02039-8#
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