Growth temperature optimization of GaAs-based In0.83Ga0.17As on InxAl1−xAs buffers

Abstract Improved quality of gas source molecular beam epitaxy grown In 0.83 Ga 0.17 As layer on GaAs substrate was achieved by adopting a two-step In x Al 1−x As metamorphic buffer at different temperatures. With a high-temperature In 0.83 Al 0.17 As template following a low-temperature composition continuously graded In x Al 1−x As (x = 0.05–0.86) buffer, better structural, optical and electrical properties of succeeding In 0.83 Ga 0.17 As were confirmed by atomic force microscopy, photoluminescence and Hall-effect measurements. Cross-sectional transmission electron microscopy revealed significant effect of the two-step temperature grown InAlAs buffer layers on the inhibition of threading dislocations due to the deposition of high density nuclei on GaAs substrate at the low growth temperature. The limited reduction for the dark current of GaAs-based In 0.83 Ga 0.17 As photodetectors on the two-step temperature grown In x Al 1−x As buffer layers was ascribed to the contribution of impurities caused by the low growth temperature of InAlAs buffers.