METALORGANIC VAPOR-PHASE EPITAXIAL-GROWTH AND STRUCTURAL CHARACTERIZATION OF GAAS INP HETEROSTRUCTURES/

Highly mismatched GaAs epitaxial layers with thickness ranging from 15 nm to 7 mum have been grown on InP substrates by atomospheric pressur e metalorganic vapor phase epitaxy. Layers thinner than 30 nm exhibite d 3-D growth mechanism; in the thicker layers, the islands coalesced a nd then the growth followed the layer by layer mechanism. The elastic strain and the extended defects have been studied by high resolution x -ray diffraction and transmission electron microscopy, respectively. T he common observation of planar defects, misfit, and threading disloca tions in the layers has been confirmed. The results on the elastic str ain release have been discussed on the basis of the equilibrium theory .