Raman Spectroscopy of GaN Epitaxial Layers Synthesized on Si(111) by Molecular Beam Epitaxy with Nitridation

Abstract

Investigation of GaN epitaxial layers on silicon substrates is driven by high potential for fabrication of high efficiency and relatively low-cost electronic devises. Growth process of GaN layers on Si by molecular-beam epitaxy is complicated by mutual diffusion of Si and Ga and differences in thermal expansion coefficients and lattice parameters causing large number of defects. To improve the quality of GaN layers high temperature nitridation of silicon substrates was applied leading to stress relaxation and decrease of diffusion.