An Increase of Threading Dislocations Filtering Efficiency in Al2O3 Templates with Faceted Surface Morphology During a Growth by Molecular Beam Epitaxy

We present the results of a transmission electron microscopy and X-ray diffractometry investigation of AlN/c-Al2O3 templates with GaN ultrathin insertions grown by plasma-assisted molecular beam epitaxy. It has been shown that AlN buffer layers with faceted surface morphology provide a greater threading dislocation density reduction than smooth layers. The filtering effect of GaN ultrathin insertions has been confirmed.