A growth model of cubic GaN microstripes grown by MOVPE: Vapour phase diffusion model including surface migration effects

Growth features of c-GaN stripes grown by selective area metalorganic vapour phase epitaxy (SA-MOVPE) on GaAs (001) substrates with stripe patterns aligned along [110] direction were analysed by vapour phase diffusion (VPD) model including surface migration effects from (111) facets. An addition of surface migration effects was found to improve the correlation between the simulation and experiment for the fill factors smaller than 0.5. The effects of the surface migration length (L) and the weight of surface migration contribution on the surface profile and the growth rate of the c-GaN stripes were also analysed. An increase of L was found to strongly enhance the growth rate at the centre of c-GaN stripes, while increasing the weight of contribution leads to the growth rate enhancement at the edges of the stripes. Our simulation demonstrated that the most probable values of L and the weight of contribution were 0.8 mu m and 0.13, respectively. According to our simulation, mechanism of cubic-to-hexagonal structural phase transition is suggested as an incentive of the surface concentration profiles. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim