Investigation of In segregation in InAs/AlAs quantum-well structures

In this letter, we report the investigation of In segregation in InAs/AlAs heterostructures. InAs layers with different thicknesses were grown by molecular beam epitaxy on GaAs (001) substrates. The layers were investigated by transmission electron microscopy. Profiles of the chemical composition of the InAs layers in the [001] direction were deduced from high-resolution lattice fringe images using the composition evaluation by lattice fringe analysis method. The segregation efficiency was derived by fitting the measured In concentration profiles with the segregation model of Muraki [K. Muraki , Appl. Phys. Lett. 61, 557 (1992)]. We obtain efficiency of R=0.77 +/-0.03 for the segregation of In in AlAs/InAs at a temperature of 530 degreesC. (C) 2001 American Institute of Physics.