ABSTRACT
The relationship between the structural and optical properties of the GaN layers grown using hydride vapor phase epitaxy and epitaxial lateral overgrowth is investigated using cathodoluminescence in transmission electron microscope. The optical properties of the different GaN regions are correlated with their growth facets indicating that the optical properties are dominated by the point defect concentration. One of the limiting factors of GaN-based device performance is the high density of dislocations formed during the GaN growth. Dislocations are formed due to the lattice and thermal mismatches between GaN and substrates. The reduction of the dislocation density using epitaxial lateral overgrowth (ELO) has shown to significantly improve device performances. The ELO GaN films are advantageous for the investigation of defect-induced optical processes in GaN. The lateral and the vertical growth rates of ELO GaN are investigated as a function of the hydrogen flow rate.
