Integrated fabrication of a high strain InGaAs/GaAs quantum well structure under variable temperature and improvement of properties using MOCVD technology

Abstract

An InGaAs/GaAs quantum well (QW) structure was prepared by metal-organic chemical vapor deposition (MOCVD) via a new growth method, where the InGaAs well layer and the GaAs barrier layer were grown under a variable temperature. A GaAs protection layer was employed to avoid indium atom evaporation on the InGaAs surface during the temperature change. Room and low-temperature photoluminescence (RT/LT-PL), atomic force microscopy (AFM), and high-resolution X-ray diffraction (HRXRD) were carried out to investigate the effect of the variable temperature growth method. The theoretical and experimental results indicated that it could erase the 2D islands and rebuild the surface morphology to a step-flow mode surface. The quality of the InGaAs crystal layer was also improved because of the annealing-like treatment. In addition, the study found that when the thickness of the GaAs protection layer was 2 nm and the growth temperature of the InGaAs layer was 560°C, the maximal properties of the InGaAs/GaAs QW were achieved. Moreover, high-quality multiple QWs with five periods were grown with the tailored structure. The growth method will improve the properties of strained InGaAs/GaAs QW materials and provide technical support for a semiconductor laser's performance optimization.