The influence of growth and annealing conditions on the structural quality of LT-GaAs layers grown on [111]B substrate by molecular beam epitaxy

Abstract

The structural quality of the layers grown at low temperature on (111)B GaAs is investigated by Raman spectroscopy and transmission electron microscopy. It is shown that both the amorphous layers grown at 150/spl deg/C and the defect-rich layers (mostly based on multiple twinning) grown at 250/spl deg/C can recover perfect crystalline quality upon annealing provided, (i) they are not too thick (<350 nm) and, (ii) the annealing temperature is high enough. Both conditions are necessary to allow the reordering of the layer initiated at the interface to propagate towards the surface without being stopped at dislocation nodes.