Structural Properties of Free-Standing 50 mm Diameter GaN Wafers with (1010) Orientation Grown on LiAlO_2

摘要

(1010) GaN wafers grown on (100) face of γ-LiAlO_2 were studied using transmission electron microscopy. Despite good lattice matching in this heteroepitaxial system, high densities of planar structural defects in the form of stacking faults on the basal plane and networks of boundaries located on prism planes inclined to the layer/substrate interface were present in these GaN layers. In addition, significant numbers of threading dislocations were observed. High-resolution electron microscopy indicates that stacking faults present on the basal plane in these layers are of low-energy intrinsic I_1 type. This is consistent with diffraction contrast experiments.