CHARACTERIZATION OF IN-SITU CL-2-ETCHED GAAS BUFFER LAYERS AND REGROWN GAAS ALGAAS QUANTUM-WELLS/

We studied the interface between an in situ Cl-2-gas-etched GaAs buffe r layer and a regrown AlGaAs layer, as a function of the etching tempe rature, together with the optical properties of etched buffer layers a nd GaAs/AlGaAs quantum wells (QWs) which were regrown on the buffer la yers. In the case of etching at 70 degrees C, degradation of the photo luminescence (PL) was observed for the etched GaAs buffer layer and th e regrown QWs, which extended 100 nm from the interface. With increasi ng etching temperature up to 200 degrees C, on the other hand, the PL was greatly improved for both the etched GaAs buffer layer and the reg rown QWs This was due to the reduced C and O impurity accumulation at the etched/regrown interface, which was confirmed by secondary ion mas s spectroscopy measurements.