X-RAY-DIFFRACTION STUDY OF ANNEALED ZNSE/GAAS SUPERLATTICES

We investigate the effect of annealing on the structural properties of ZnSe/GaAs superlattices by the x-ray double-crystal rocking-curve technique. A 6-period ZnSe/GaAs superlattice with 61-nm thick ZnSe layers and 6-nm thick GaAs layers is grown by a combination of migration-enhanced epitaxy and solid-phase epitaxy. X-ray diffraction is measured for the ZnSe/GaAs superlattice samples annealed at different temperatures for several annealing periods in flowing H-2 gas. From the change in the (004) and (115) rocking-curve profiles with increasing annealing temperature and annealing period, it was found that about 25% of the parallel strain in the ZnSe layers is relieved by misfit dislocations after annealing at 520-degrees-C for 20 min. The interface properties of the annealed ZnSe/GaAs superlattices are also examined by computer simulation of kinematical diffraction.