VIRTUAL-SURFACTANT-INDUCED WETTING IN STRAINED-LAYER HETEROEPITAXY

We show that surface stoichiometry and growth mode are intimately related for heteroepitaxy of InAs on GaO0.47In0.53As. Under As-stable conditions during molecular beam epitaxy, the high strain of the InAs film induces a morphological phase-transition from layer-by-layer to island nucleation. In contrast, under In-stable conditions without direct As4 flux, islanding is inhibited. The In-stabilized surface imposes limitations to the migration of both As and In adatoms and forces layer-by-layer nucleation, thus acting as a virtual surfactant.