Effect of InxGa1-xAs underlying layer and growth mode on the surface morphology of In0.5Ga0.5As/GaAs quantum dots

Abstract

Single layer of In0.5Ga0.5AsIn0.5Ga0.5As quantum dots (QDs) was grown using self‐assembled Stranski‐Krastanow on a thin InxGa1−xAsInxGa1−xAs underlying layer and on a reference GaAs wafer by metal‐organic chemical vapour deposition (MOCVD). The effect of different indium composition in the underlying layer and the duration of arsine (AsH3)(AsH3) flow during cooling‐down period of the growth process were investigated and characterized using atomic force microscopy (AFM). The growth of the thin underlying layer has significant influence on the formation of the QDs on the top surface. The dots density increases with increasing indium composition in the underlying layer. AsH3AsH3 flow during the period was found to influence the nucleation process of In0.5Ga0.5AsIn0.5Ga0.5As QDs. A shorter period of AsH3AsH3 flow promotes smaller dots size and therefore increases the dots density.