The influence of different technological parameters on the production of GaN layers with homogeneous thickness and smooth surface by hydride vapor phase epitaxy in a vertical reactor have been investigated. The distance L from the GaCl introduction branch pipe to the substrate and the flow rate Q have been varied from 10 to 60 mm and from 2 to 200 l/hour, respectively, during the investigation. We show that both parameters exert essential influence on the thickness distribution profile along the diameter and the surface morphology. Parameter values have been suggested providing for the growth of epilayers with mirror smooth surfaces and uniform thickness distributions along the substrate diameter.

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