Abnormal InGaN growth behavior in indium-desorption regime in metalorganic chemical vapor deposition

• This work reported the growth behavior of InGaN.
• Two growth regimes, mass-transport limited regime and indium desorption regime, were examined for InGaN growth.
• In the indium desorption regime, we found an abnormally enhanced GaN growth rate, which was indium source and temperature dependent.
• The source of the gallium was possible from GaN template or residual gallium on reactor walls and/or showerhead surface.
• Due to the enhanced growth rate, the optical quality of In0.16Ga0.84N layers degraded significantly in the indium desorption region.

InGaN strained bulk layers were grown by low-pressure metalorganic chemical vapor deposition on c-plane GaN/sapphire templates. Two growth regimes, mass-transport limited regime and indium desorption regime, were examined for InGaN growth. In the indium desorption regime, more indium source must be fed to keep a constant indium content. In the indium desorption regime, we found an abnormally enhanced GaN growth rate, which was proved to be related to the indium desorption and dependent on the growth temperature and the indium source flow. Due to the enhanced growth rate, the optical quality of In0.16Ga0.84N layers degraded significantly.