Light scattering and atomic force microscopy study of InAs island formation on InP

Some aspects of the morphology of InAs island formation on InP have been studied by atomic force microscopy, photoluminescence, photoluminescence excitation spectroscopy, and Raman scattering. The InAs layer is grown by chemical beam epitaxy on top of InP surfaces with sawtooth-like channels. The deposition of a thin InAs layer results in quantum dots strongly aligned along the InP channels. Subsequent annealing in an arsenic atmosphere produces growth and loss of coherency of the islands. Atomic force microscopy shows the changes in size and alignment of the islands. Optical measurements serve to give quantitative estimates of the strain distribution among the top of the InP buffer layer, the wetting layer and the islands for the differently treated samples.