InAs island-induced-strain driven adatom migration during GaAs overlayer growth

Abstract

The impact of the strain fields associated with partially strain relaxed InAs islands on GaAs (100) on the evolution of the growth front profile during subsequent GaAs capping layer growth as a function of the growth temperature is examined via placement of very thin AlGaAs marker layers. Transmission electron microscope studies reveal the presence of strain dominated atom migration away from the islands over dynamically evolving length scales of ∼100–400 Å at higher growth temperature whereas at lower growth temperature such an effect is minimal. Anisotropy in the length scale of impact between the [011] and [011̄] directions is observed. Estimates based upon a suitably adapted formulation of the classical theory of grain growth shows the mass transport to be dominantly strain rather than surface curvature driven.