Indium nitride and indium gallium nitride layers grown on nanorods

Molecular beam epitaxy has been used to grow InN layers on both Si and SiC substrates and In_0.5Ga_0.5N layers on Si substrates using a nanorod precursor array. Transmission electron microscopy (TEM) studies show that nanorods grown first under N-rich conditions, and then under more metal-rich conditions to promote lateral growth are free of dislocations until coalescence occurs. At coalescence, dislocations are introduced at grain boundaries. These are predominantly twist boundaries, with better epitaxial alignment seen on SiC substrates. The lateral growth of In_0.5Ga _0.5N is shown to be cubic, tentatively ascribed to the growth of basal plane stacking faults at the start of the lateral growth and the low growth temperatures used.