ISLAND FORMATION OF INAS GROWN ON GAAS

We observe the initial growth layer of InAs on a GaAs substrate by ato mic force microscopy (AFM), transmission electron microscopy (TEM), an d photoluminescence (PL) spectroscopy. The layer grows two-dimensional ly until about 1.8 ML, and small islands which have a certain size are formed around 1.8 ML. Then, they grow to large sized islands after 2. 0 ML, and the density of the small islands decreases. The sizes of lar ge islands are not similar to each other. The plan-view TEM image reve als that the misfit dislocations are generated in the large islands. T he growth mode of InAs on GaAs is explained by considering the surface energy and strain energy. Variations in the size and shape of the lar ge islands are also interpreted.