INAS ISLAND-INDUCED-STRAIN DRIVEN ADATOM MIGRATION DURING GAAS OVERLAYER GROWTH

The impact of the strain fields associated with partially strain relax ed InAs islands on GaAs (100) on the evolution of the growth front pro file during subsequent GaAs capping layer growth as a function of the growth temperature is examined via placement of very thin AlGaAs marke r layers. Transmission electron microscope studies reveal the presence of strain dominated atom migration away from the islands over dynamic ally evolving length scales of approximately 100-400 angstrom at highe r growth temperature whereas at lower growth temperature such an effec t is minimal. Anisotropy in the length scale of impact between the [01 1] and [011BAR] directions is observed. Estimates based upon a suitabl y adapted formulation of the classical theory of grain growth shows th e mass transport to be dominantly strain rather than surface curvature driven. (C) 1994 American Institute of Physics.