METALORGANIC VAPOR-PHASE EPITAXIAL-GROWTH AND STRUCTURAL CHARACTERIZATION OF SELF-ASSEMBLED INAS NANOMETER-SIZED ISLANDS ON INP(001)

Self-assembled InAs islands were grown by metalorganic vapor phase epi taxy on InP(001) and characterized by atomic force microscopy and tran smission electron microscopy. The growth temperature (450-600 degrees C), the InAs deposition time (3-12 s, using a growth rate of similar t o 2.3 Angstrom/s), and the growth interruption time (8-240 s) were var ied systematically in order to investigate the effect of thermodynamic and kinetic factors on the structural properties of InAs/InP and InP/ InAs/InP structures. It is found that the structural properties of isl ands vary widely with the growth conditions, ranging from very small ( 4-5 nm height, similar to 30-60 nm in diameter) coherent islands at lo w temperature (450-500 degrees C) to large (similar to 350 nm wide) pl astically relaxed islands at high temperature (600 degrees C). For a g iven deposition time, the height of the coherent islands increases mar kedly with the growth temperature while their diameter shows only a mo derate increase. The growth interruption time also affects the formati on and the evolution of islands, which clearly shows that these proces ses are kinetically limited. Coherent islands with structural properti es suitable for use in optoelectronic devices are obtained from simila r to 2.4-4.8 monolayer thick InAs layers using a growth temperature of 500 degrees C and a 30 s interruption time.