TRANSFORMATION OF ALGAAS GAAS INTERFACE UNDER HYDROSTATIC-PRESSURE/

AlGaAs layers grown by molecular beam epitaxy on GaAs substrates were investigated before and after high hydrostatic pressure (1.2 GPa) at h igh temperature (770 K) treatment (RP-HT treatment). An influence of H P-HT treatment on the properties of the AlGaAs/GaAs system was studied by lattice parameter measurements using the high resolution diffracto meter and by X-ray topography. Observed changes in the lattice paramet er of the AlGaAs layers after HP-HT treatment are related to the strai n relaxation and explained by the creation of misfit dislocations and other extended defects which are visible on the topographs.