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 epitaxy on InP(001) and characterized by atomic force microscopy and transmission electron microscopy. The growth temperature (450-600 degrees C), the InAs deposition time (3-12 s, using a growth rate of similar to 2.3 Angstrom/s), and the growth interruption time (8-240 s) were varied 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 islands vary widely with the growth conditions, ranging from very small (4-5 nm height, similar to 30-60 nm in diameter) coherent islands at low temperature (450-500 degrees C) to large (similar to 350 nm wide) plastically relaxed islands at high temperature (600 degrees C). For a given deposition time, the height of the coherent islands increases markedly with the growth temperature while their diameter shows only a moderate increase. The growth interruption time also affects the formation and the evolution of islands, which clearly shows that these processes are kinetically limited. Coherent islands with structural properties suitable for use in optoelectronic devices are obtained from similar to 2.4-4.8 monolayer thick InAs layers using a growth temperature of 500 degrees C and a 30 s interruption time.