Dislocation Structure of Epitaxial Layers of AlGaN/GaN/α-Al2O3 Heterostructures Containing a GaN Layer Doped with Carbon and Iron

The aim of this work is to study the effect that the process of iron and carbon doping of a GaN epitaxial layer on sapphire can influence (affects) on the features of growth of epitaxial films and their dislocation structure. The following research methods are used in the study: secondary ion mass spectroscopy (SIMS), selective chemical etching of spherical sections, and single-crystal diffractometry. It is shown that carbon doping of a GaN epitaxial layer during growth can lead to a significant decrease in the dislocation density of the epitaxial layers. It is also demonstrated that, for samples doped with iron, a decrease in the number of short dislocations in the bulk of the structure is characteristic; however, a large number of extended dislocations are generated, encouraging iron diffusion into the working regions of the heterostructures, which is confirmed by the iron depth distribution of the layers, measured by the SIMS method.