Structure modelling and reciprocal space maps simulation of the (Ga,Al)N epitaxial layers deposited on the sapphire substrate

This paper presents the computer simulation of the reciprocal lattice maps (RLM) on the base of the disordered epitaxial layer structure model. The following crystallographic defects are taken into account: limited lateral block sizes, tilt mosaicity and gradients of the lattice parameters. The influence of these structural factors on the RLM shape and position in the reciprocal lattice space is analysed. Only geometrical aspects of the diffraction phenomena are taken into account in proposed model, so the intensity of the simulated maps is not considered. The theoretical results are compared with the measured maps for the GaN and AlN layers deposited on the sapphire substrate, chosen as examples.