Initial Growth Conditions of GaAs on (100) Si Grown by Migration-Enhanced Epitaxy

This paper investigates the effect of initial growth conditions on the structural and optical properties of GaAs and (AlGa)As/GaAs quantum well heterostructures (QWH) on (100)Si. Samples are grown by migration-enhanced epitaxy (MEE) at 300°C. Only the growth conditions of the first GaAs monolayer on Si substrates are varied. Optimization requires: 1) no exposure of the hot Si surface to As, and 2) Ga-dominated initial growth conditions. Sharp low-temperature excitonic luminescence (8.0 meV (FWHM) for L z =2 nm) confirms the smooth heterointerfaces of the MEE-grown layers. Samples grown by conventional MBE at 300°C show a clearly poorer crystal quality.