REAL-TIME ANALYSIS OF SI MONOLAYER FORMATION ON GAAS(001) DURING MBE

The kinetics of structure formation during Si deposition on GaAs(001) and the underlying atomic configurations have been studied in real-tim e simultaneously by reflectance difference spectroscopy (RDS) and refl ection high-energy electron diffraction (RHEED). Using a difference fu nction approach, Si dimers and As dimers on Si are directly detected i n addition to As and Ga dimers. A number of differently terminated (3 x 2) structures of the missing atom row type, that cannot distinguishe d by RHEED alone, are identified. RDS transients recorded at photon en ergies characteristic for different dimers reveal the evolution of ord ered structures at well-defined coverages that clearly depend on the s tructure of the initial GaAs(001) surface. (C) 1998 Elsevier Science B .V. All rights reserved.