In as a surfactant for the growth of GaN (0001) by plasma-assisted molecular-beam epitaxy

The influence of indium on the surface morphology of GaN (0001) grown by plasma-assisted molecular-beam epitaxy (MBE) has been investigated. The rough and grain-like surface under nitrogen-rich growth conditions becomes smoother and similar to surfaces grown under gallium-rich conditions when a sufficiently high indium flux is used. However, the use of indium instead of gallium-rich conditions prevents the formation of gallium droplets on the surface which are associated with voids at their edges. Since indium is not incorporated into GaN for growth temperatures above 700 °C, it can be used as a surfactant in MBE growth of GaN.