Effect of variable temperature growth on the crystal quality and surface morphology characteristics of InGaAs/GaAs MQWs obtained via MOCVD

In this paper, a variable temperature growth method was proposed and adopted for InGaAs/GaAs multiple quantum wells (MQWs) grown by MOCVD, where the InGaAs well layer and the GaAs barrier were grown under different temperature. A new structure with protection layer was also presented to protect the indium atoms on InGaAs surface from the evaporation during temperature change. The effect of new growth method was investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), and Photoluminescence (PL). Compared to the conventional constant temperature growth, the surface morphology and crystal quality were improved due to the protection layer and high temperature growth of GaAs. The growth temperature of InGaAs well layer was also optimized in detail, it is found that when the temperature was too high, the surface will be deteriorated, as well the optical properties. The new growth method and tailored structure will help to impro9ve the properties of strained InGaAs/GaAs MQWs materials, and provide the technical support for the performance optimization of semiconductor laser.