Selenium-treated GaAs(001)-2×3 surface studied by scanning tunneling microscopy

Abstract
An Se‐passivated GaAs(001) surface was found to be stabilized by 2×3 reconstruction, previously reported as an intermediate structure, under the condition of a low Se chemical potential. Ordered elliptical protrusions with ∼0.6‐nm periodicity in the [110] direction were observed by scanning tunneling microscopy, the structure of which was in good agreement with a double‐layered dimer model. A comprehensive model to explain the 2×3 structure together with the formation of a Ga2Se3‐like structure with ordered 1/3 ML Ga vacancies was proposed.