X-ray diffraction investigation of GaN layers on Si(111) and Al₂O₃ (0001) substrates

Abstract

Methodical approaches to the analysis of X-ray data for GaN films grown on various buffer layers and different substrates are presented in this work. Justification of dislocation structure investigation by various methods was analyzed and approaches for evaluation of deformation level and relaxation are discussed. Clarity and accuracy of obtained structure characteristics of nitride films are under discussion. Optimization methods for experimental data processing are shown. Structural properties were obtained using high resolution X-ray diffraction with two types of scans and reciprocal space maps. Microscopic nature of spatial inhomogeneities in these structures (deformations and dislocation density) and influence of the buffer layer thickness on properties of GaN layer were discussed with account of obtained results.