In situ, atomic force microscope studies of the evolution of InAs three-dimensional islands on GaAs(001)

The size evolution of molecular beam epitaxy-grown strained InAs three-dimensional (3D) islands on GaAs(001) is examined using in situ ultrahigh vacuum atomic force microscopy. Remarkably, just after the initiation of well-formed 3D islands at similar to 1.57 ML InAs deposition, the lateral size dispersion and average value are found to first increase drastically with the smallest amount (similar to 0.05 ML) of additional InAs deposition and then decrease and saturate, indicating the onset of a natural tendency for size equalization, including through loss of material from the initially formed largest islands. These observations are found to be consistent with the previously suggested island-separation dependent influence of the evolving island-induced substrate strain fields on the adatom migration and incorporation/detachment kinetics that control the evolution of the islands. (C) 1996 American Institute of Physics.