Al incorporation in AlGaN on (112¯2) and (0 0 0 1) surface orientation

Epitaxial lateral overgrowth of gallium nitride with (112¯2) facets was realized by metal organic chemical vapor deposition on GaN/sapphire (0 0 0 1) substrates with SiO2 stripe mask. Then AlGaN layers were grown on ELO GaN and on c  -plane GaN templates simultaneously. The variation of the aluminum compositions was studied by photoluminescence spectroscopy, secondary ion mass spectrometry (SIMS) and XRD. Different aluminum content of 0.07 and 0.11 were obtained on (112¯2) facet AlGaN layers and on (0 0 0 1) facet AlGaN layers, respectively. Compare to the c-plane AlGaN layer, it is found that polycrystalline AlGaN is grown on SiO2 layer and has higher Al content. These results indicate that aluminum incorporation depends significantly on the surface orientation.