INDIUM SURFACE SEGREGATION DURING CHEMICAL BEAM EPITAXY OF GA1-XINXASGAAS AND GA1-XINXP/GAAS HETEROSTRUCTURES/

We report on the investigation of In surface segregation in GaInP/GaAs and GaInAs/GaAs heterostructures grown by chemical beam epitaxy (CBE) . Owing to the peculiarities of CBE growth, it is shown that In segreg ation can be quantitatively evaluated in real-time by using reflection high-energy electron diffraction (RHEED). A segregation coefficient a nd its variation with the growth temperature is extracted from the RHE ED data. It is used to determine the In composition profiles at the in terfaces of GaInAs/GaAs quantum well (QW) structures as a function of the growth temperature. A good agreement is found between optical tran sition energies calculated from these profiles and the experimental ph otoluminescence (PL) energies. PL energy shifts observed in GaInP/GaAs QW's as a function of the growth temperature are qualitatively explai ned by In segregation.