HIGH-QUALITY GAAS ALGAAS QUANTUM-WELLS GOWN ON (111)A SUBSTRATES BY METALORGANIC VAPOR-PHASE EPITAXY/

Growth of GaAs and AlGaAs epitaxial layers on both (111)A and (111)B f aces of GaAs substrates was studied by the atmospheric metalorganic va por phase epitaxy (MOVPE) technique. We show that GaAs and AlGaAs laye rs with excellent surface quality can be grown at relatively low tempe ratures and V/III ratios (600 degrees C, 15) on the (111)A face, where as for layers on the (111)B face a higher growth temperature (720 degr ees C) was required. GaAs/AlGaAs quantum well (QW) structures were suc cessfully grown for the first time on the (111)A GaAs face by the MOVP E technique. The effects of various growth conditions on the surface m orphology of the epilayers were studied. For the (111)A surface a wide growth window with temperatures in the range 600-660 degrees C and V/ III ratios varying from 15 to 45 was established for obtaining excelle nt surface morphology. The properties of the QWs were investigated by high resolution X-ray diffractometry, photoluminenscence and photorefl ectance measurements. These measurements indicate that the QWs are of very high structural and optical quality. (C) 1997 Published by Elsevi er Science Ltd.