Gallium pollution in an AIXTRON close coupled showerhead reactor and its serious effect on the growth process stability of InGaN layers for optoelectronic applications (Conference Presentation)

InGaN-based devices have attracted a lot of attention, thanks to versatile optoelectronic applications. We show that the growth of these layers in an AIXTRON Close Coupled Showerhead is complicated due to the presence of gallium pollution in the chamber after the growth of GaN buffer layers. This pollution reacts with the TMIn precursor in the growth chamber to give thicker InGaN layers with reduced indium incorporation. We overcame this problem by limiting the presence of the metallic gallium in the growth chamber, resulting in more stable and predictable growth of InGaN layers.