Formation of a Ba-Te Surface on GaAs

The formation of a Ba-Te surface on GaAs has been investigated. The surface was created using molecular beam epitaxy (MRS). A GaAs (100) surface was first exposed to Te and characterized using x-ray photoelectron spectroscopy (XPS), reflective high energy electron diffraction (RHEED) and low energy electron diffraction (LEED). The Te-reacted surface was then exposed to BaF 2 flux producing a second reaction. In this reaction, the BaF 2 dissociated leaving barium on the surface but no fluorine. This is in contrast to the clean (no tellurium) GaAs (100) surface in which BaF 2 has been shown to grow single crystal. Although high order exists during early stages of the Ba-Te growth, further exposure gives way to a polycrystalline form. This paper discusses the formation and analysis of the Ba-Te surface.