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) t he growth by molecular-beam epitaxy of the II-VI compound-semiconducto r BeTe on GaAs substrates. Long lasting RHEED oscillations reveal that BeTe nucleates on GaAs buffer layers in a two-dimensional mode when t he GaAs surface is not Te reacted. The growth temperatures of BeTe and ZnSe are only marginally compatible. We show that the Te- and Be- ter minated BeTe surfaces are (2x1) and (3X1) reconstructed, respectively. The transition from (2X1) to (3X1) surface occurs via the formation o f a faint (4X1) reconstruction. We determine the surface phase diagram under static as well as growing conditions. (C) 1998 American Institu te of Physics.