Isotropic Lateral Ordering of III-V Quantum Dots Over GaAs (001) By Self-Assembly

摘要

Lateral ordering of InGaAs quantum dots over GaAs (001) has been achieved in earlier reports resembling anisotropic pattern. We present in this letter a method of breaking the anisotropy of ordered QDs by changing the growth environment. We do show experimentally that using As{sub}2 molecules instead of As{sub}4 as a background flux is effective in controlling the diffusion of Ga adatoms in away to make it possible to produce isotropic ordering of InGaAs QDs over GaAs (001). Our results are consistent with reported experimental and theoretical studies on surface structure and diffusion mechanism over GaAs.