CHARACTERIZATION OF HIGH-QUALITY MOLECULAR-BEAM EPITAXIAL GROWN INXALZGA1-X-ZAS INYALUGA1-U-YAS/INP HETEROSTRUCTURES/

We focus on molecular beam epitaxy (MBE) growth and characterization o f InAlGaAs/InP heterostructure layers by photoluminescence (PL) and X- ray diffraction (XRD) measurement. The epitaxial quality is demonstrat ed by very narrow XRD linewidths just above the theoretical limits ind ependent of various quaternary compositions. In contrast to the XRD li newidths showing no dependence on the aluminum content for a fixed lay er thickness, we observe PL linewidths decreasing with increasing band gap wavelength and decreasing aluminum content. This may be explained by an interplay of alloy disorder fluctuations and defect formation wh ich both strongly vary with composition. Multiple quantum well structu res were grown for all possible combinations of ternary and quaternary materials in the wells and the barriers. Measured and simulated rocki ng curves show excellent agreement and the PL studies reveal low linew idths.