High quality GaAs/AlGaAs quantum wells grown on (111)A substrates by metalorganic vapor phase epitaxy

Abstract

Growth of GaAs and AlGaAs epitaxial layers on both (111)A and (111)13 faces of GaAs substrates was studied by the atmospheric metalorganic vapor phase epitaxy (MOVPE) technique. We show that GaAs and AlGaAs layers with excellent surface quality can be grown at relatively low temperatures and V/III ratios (600°C, 15) on the (111)A face, whereas for layers on the (111)13 face a higher growth temperature (720°C) was required. GaAs/AlGaAs quantum well (QW) structures were successfully grown for the first time on the (111)A GaAs face by the MOVPE technique. The effects of various growth conditions on the surface morphology of the epilayers were studied. For the (111)A surface a wide growth window with temperatures in the range 600°-660°C and V/III ratios varying from 15 to 45 was established for obtaining excellent surface morphology. The properties of the QWs were investigated by high resolution X-ray diffractometry, photoluminenscence and photoreflectance measurements. These measurements indicate that the QWs are of very high structural and optical quality.