Molecular-beam epitaxy of BeTe layers on GaAs substrates studied via reflection high-energy electron diffraction

We study through reflection high-energy electron diffraction (RHEED) the growth by molecular-beam epitaxy of the II-VI compound-semiconductor BeTe on GaAs substrates. Long lasting RHEED oscillations reveal that BeTe nucleates on GaAs buffer layers in a two-dimensional mode when the GaAs surface is not Te reacted. The growth temperatures of BeTe and ZnSe are only marginally compatible. We show that the Te- and Be- terminated BeTe surfaces are (2×1) and (3×1) reconstructed, respectively. The transition from (2×1) to (3×1) surface occurs via the formation of a faint (4×1) reconstruction. We determine the surface phase diagram under static as well as growing conditions.