Role Of Growth Parameters In Equalizing Simultaneous Growth Of N- And Ga-Polar Gan By Mocvd

In preparing periodically-oriented gallium nitride (PO GaN) samples for optical applications, smooth surfaces are essential. Although post-growth processing of these surfaces is possible, it is challenged by significantly different reactivity of the two polar surfaces. To this end, it would be highly desirable to grow PO GaN structures with smooth surfaces. In this paper, the influence of growth parameters on the morphology of PO GaN structures is investigated. The three primary parameters investigated include the V/III ratio of the gas phase precursors, the nature of the carrier gas, and the geometry of the structure. The V/III ratio was varied from 1100 to 5500. Substitution of N-2 for the standard H-2 carrier gas is investigated. Finally, the effects of changing the structure periodicity from 2 to 100 mu m are studied. Smoother structures (resulting from more equal growth rates of the two polarities) are achieved with increases in V/III ratio, substitution of H-2 with N-2, and by reducing the stripe width. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim