MBE GROWTH OPTIMIZATION OF INYGA1-YAS/GAAS MULTIPLE-QUANTUM-WELL STRUCTURES

We have grown pseudomorphic InyGa1-yAs multiple quantum wells (MQWs) with y=0.20 and y=0.35, using four MBE and one migration-enhanced epitaxy (MEE) growth conditions. MQWs grown by MBE at 450-degrees-C had the narrowest photoluminescence (PL) linewidths and largest PL intensities. MQWs grown at 480-degrees-C had comparable integrated PL intensities, but larger linewidths. The growth stops in MQWs grown at 480-degrees-C improved the PL linewidths. The MEE MQWs had large PL linewidths and low PL intensities. High depth-resolution secondary ion mass spectrometry (SIMS) analysis was shown to be very sensitive to interface roughness. The lateral homogeneity of the In0.35Ga0.64As MQWs was investigated with scanning cathodoluminescence (CL) imaging. The SIMS and CL data corroborate the PL results, showing that lower temperatures and growth stops reduce interface roughness.