In situ annealing effect on the structural properties of near-surface GaInNAs/GaAs quantum wells

Near-surface Ga1−xInxNyAs1−y/GaAs quantum well (QW) structures were grown and in situ annealed in a solid-source molecular beam epitaxy chamber equipped with a radio-frequency nitrogen (N2) plasma source. It was found that the surface desorption and indium out-diffusion from the surface QW took place under annealing condition by atomic force microscope and X-ray photoelectron spectroscope. Ga/In atoms interdiffusion across the QW hetero-junctions and the change of composition fluctuation within the QW have been observed at elevated annealing temperatures by using double crystal X-ray diffraction (XRD) θ/2θ scans and transmission electron microscopy. The best fitting for the XRD results reveals a diffusion length of δ=0.7 nm and 1.0 nm for 580°C and 680°C in situ annealing, respectively.