Effect of thermal treatment on structure of GaN self-assembled quantum dots grown by MOCVD

We report the effect of thermal annealing on the formation of GaN self-assembled quantum dots (QDs) grown by low-pressure metalorganic chemical vapor deposition (MOCVD). Atomic force microscopy (AFM) analysis shows that the density of the QDs rapidly increases and then decreases with increasing the growth interruption time. This is due to the combined effect of the QD formation process and the ripening process. The flow rate of NH3 during the growth interruption also strongly influences the formation of the QDs. These results show that the growth interruption at growth temperature plays an important role in the formation of the QDs.