Influence of growth conditions on the quality of strained InAlGaAs/AlGaAs quantum wells grown by MOCVD

Abstract

Compressive-strained InAlGaAs quantum wells (QWs) were grown on GaAs substrates by metal organic chemical vapor deposition (MOCVD). The influences of reactor pressure, V/III ratio, growth temperature, and substrate orientation on the quality of InAlGaAs QWs were studied using high resolution X-ray diffraction (HR-XRD), photoluminescence (PL) and atomic force microscope (AFM) measurements. The PL results indicate that the PL intensity and full width at the half-maximum (FWHM) of QWs are very sensitive to the growth conditions such as reactor pressure, growth temperature, and substrate orientation. The AFM results demonstrate that the growth mode of epilayer is dominated by the orientation of substrate. The growth mode of samples grown on 0.5° miscut and 2° miscut substrates is step flow and step bunching, respectively. The samples grown on 0.5° miscut substrates have higher PL intensity comparison with the samples grown on 2° miscut substrates at the same growth conditions. The PL and AFM results of sample grown at 700 °C and a pressure of 50 mbar with a V/III ratio of 100 indicated that these growth parameters are close to the optimum growth conditions for InAlGaAs QWs.