Superlattice-like stacking fault and phase separation of InxGa1-xN grown on sapphire substrate by metalorganic chemical vapor deposition

InxGa1-xN alloys were directly grown on sapphire substrate with a GaN nucleation layer. The degree of phase separation in the InGaN layer on sapphire substrate is maximized at higher growth temperature than for an InGaN layer grown on a thick GaN layer. For high indium composition, a superlattice-like stacking fault in the InxGa1-xN grown on sapphire substrate was detected by the selected area diffraction pattern and high-resolution transmission electron microscopy. The superlattice-like arrangement of stacking faults leads to the formation of split spots and the distance of split spots corresponds to the distance between stacking faults. (C) 2000 American Institute of Physics. [S0003-6951(00)05628-X].