THE BUILDING UP OF TERRACE PERIODICITY BY MBE GROWTH ON (001)GAAS VICINAL SURFACES

The morphology of MBE grown GaAs vicinal surfaces is studied using ex situ AFM. Analysing the statistical distribution of terrace width. we succeed in explaining our measurements either by a thermodynamical equ ilibrium model taking into account the step by step interaction of by a 2D Monte Carlo simulation of the growth. In the latter case, an anis otropic Schwoebel barrier at the step edge has to be introduced in ord er to get a good agreement. We argue that growth is the efficient proc ess to get a low disordered step array at the usual time scale and tem perature range of MBE. In addition the effect of a GaAs/AlAs buffer su perlattice. or of pure AlAs layer, or of Si doping in GaAs is also dis cussed.