Characterization of the self-assembled InP structure grown on the GaInP epitaxial layer mismatched to GaAs substrate by near-field scanning optical microscopy (NSOM)

InP self-assembled structure were grown by MOCVD method on GaInP epitaxial layer mismatched to the GaAs substrate and were measured by employing the Near-field Scanning Optical Microscopy (NSOM) and SEM. The distribution of self-assembled islands was analyzed from the NSOM images and SEM results based on the scaling theories. It is found the distribution periodicity of the islands along [110] direction is improved and 1μm separation is obtained. The regular distribution was found along [1-10] direction. It shows and the mismatched epitaxial layer could improve the distribution periodicity of the islands along [110] and [1-10] direction. The experiment gives a potential way to realize the ordered two-dimensional distribution of the self-assembled structure. A mode, based on the shear force boundary and QD sphere, was established to explain the difference of our results between the topography and NPC. The size of islands could be evaluated by NSOM if the diameter of the probe has been taken account on.