Research on the surface morphology of AlxGa1−xAs in molecular beam epitaxy

The influence of deposition of aluminum on adatoms diffusion and evaporation during the growth of AlGaAs alloy layer on GaAs (001) surface is investigated. The real space scanning tunneling microscopy (STM) images showed the obvious changes on different AlGaAs surface morphology; reflection high-energy electron diffraction (RHEED) is also used to estimate the deposition. STM images and RHEED patterns showed the pits coverage and roughness of deposition surfaces caused by stronger Al–As bonds and slower surface migration rate of aluminum; Ehrlich–Schwoebel potential is considered as possible explanation of steps forming on the surface morphology. A conjecture for the formation of surfaces morphology and its influence on subsequent growth is proposed.