THE ROLE OF ZINC PREEXPOSURE IN LOW-DEFECT ZNSE GROWTH ON AS-STABILIZED GAAS(001)

Zinc coverage and the structures of Zn-exposed As-stabilized GaAs(001) -(2x4) and -c(4x4) surfaces have been studied using x-ray photoelectro n spectroscopy and scanning tunneling microscopy in order to clarify t he role of the Zn pre-exposure process in ZnSe growth on GaAs(001), Si nce Zn atoms stick on the GaAs-(2x4) surface even though their interac tion is very weak, Zn may act as a balancer to form a neutral ZnSe/GaA s interface. Zn can also remove excess As atoms and make a ''pure'' (2 x4) structure that is the only possible starting surface for low-defec t ZnSe heteroexpitaxy on a GaAs(001) surface, (C) 1998 American Instit ute of Physics.