Kinetic calculation analysis of Ga deposition on the morphology evolution of GaAs quantum ring

GaAs Quantum Ring (QR) was gained on GaAs (001) by Droplet Epitaxy (DE), and the microscopic morphology of the GaAs samples was observed by Scanning Tunnel Microscope (STM). The kinetic model of Local Droplet Etching (LDE) was mainly used to study the influence of Ga deposition on the morphology evolution from Ga droplets to GaAs QR. Comparing experimental data with the theoretical value, it can be seen that the increase of Ga deposition will cause the reduction of surface density of Ga droplets, but the volume, height and diameter of Ga droplets will increase. Geometric dimension of GaAs QR increased also with the increase of Ga deposition. In addition, it found that the rate at which the substrate was etched was affected by Ga deposition and As pressure from experiment. The more Ga deposition, the deeper GaAs nano hole. However, GaAs nano hole became shallower under high As pressure. These results are consistent with theoretical calculation analysis. Under high substrate temperature, GaAs double rings finally evolved into a single ring. Above all results have certain guiding significance for the preparation of patterned GaAs substrates and the controlled growth of GaAs QR morphology. (paper)