GaAs(100) (2×4) Surface Study by Molecular Beam Epitaxy and Field-Ion-Scanning-Tunneling-Microscopy

Abstract

The GaAs(100) (2×4) surface was studied by molecular beam epitaxy (MBE) and field-ion-scanning-tunneling-microscopy (FI-STM). The results showed that the GaAs(100) (2×4) surface unit cell consists of two dimers and two missing dimers of As. The c(2×8) reconstruction was observed to originate by the phase shift induced by the As vacancies. We also observed the domain boundaries on the GaAs(100) (2×4) surface and they were attributed to two dimensional island growth. A structural model was proposed to explain the observed surface reconstructions.