Evolution of nanomicro structures on GaAs (001) surface under high temperature evaporation

Protuberant mounds and micro-nanoholes are prepared on the GaAs surface under Langmuir evaporation. It is demonstrated that mounds are oxidised Ga-rich droplets with minute As. Through analysis of the experimental conditions of samples forming holes and mounds, the correlation between the two phenomena is presented. It is concluded that annealing time is the key factor in controlling the size of mounds and holes and that the annealing temperature is one predominant factor in deciding the evolution direction of the structure on GaAs-forming holes or protuberant mounds. The tuning over the GaAs surface morphology will be potentially applied in the preparation of quantum dots used for optical and electronic devices.