Surface diffusion and layer morphology of ((1122)) GaN grown by metal-organic vapor phase epitaxy

(1122) GaN layers were grown by metal-organic vapor phase epitaxy on (1122) bulk GaN substrates and (1010) sapphire substrates. The growth temperature was varied between 950 and 1050 °C and the total reactor pressure between 50 and 600 mbar. The growth conditions show a strong impact on the yellow band luminescence properties, while weak impact on the threading dislocation density was observed. The layer morphologies exhibit undulations with two periods along GaN [1100] and one period along [1123]. The different period lengths are connected to anisotropic adatom surface diffusion lengths. Arrow like features on the surface originate from the interference of the undulations along [1123] and [1100].