Suppression of composition modulation in In-rich In x Ga1−x N layer with high In content (x ∼ 0.67)

The composition modulation of in In-rich InxGa1−xN layers with an indium content as high as ∼67% was suppressed in plasma-assisted molecular beam epitaxy on c-sapphire substrates. It was found that the higher nitrogen plasma flow rate was very effective in suppression of composition modulation in In-rich InGaN layers. X-ray diffraction, X-ray energy dispersive spectroscopy, and transmission electron microscopic images clearly showed disappearance of composition modulation with increasing the nitrogen flow rate.