Growth of GaN on lattice matched AlInN substrates

Abstract: This project was planed in order to study the effect of growth and crystalline quality of GaN on lattice matched Al1-xInxN seed layer. The GaN lattice matched Al0.81Ino.19N seed layer was grown by co-sputtering of Al and In target using only N2 as a sputtering gas in a direct current (DC) reactive magnetron sputter deposition chamber under UHV conditions at low temperature (230 oC) on different substrates. The Indium composition was calculated using vegards law from lattice parameters determined by XRD. The Indium composition was determined by Rutherford Backscattering Spectroscopy (RBS) as well. X-rays diffraction (XRD) showed high crystalline quality wurtzite hexagonal Al1-xInxN seed layers grown at this temperature. The GaN was grown on top of Al0.81Ino.19N seed layer by halide vapour phase epitaxy (HVPE) using a mixture of N2 and H2 and only N2 as a carrier gas in order to study the effect of carrier gas on crystalline quality of GaN. The GaN films were characterised by high resolution X-rays diffraction (HRXRD), scanning electron microscopy (SEM), cathode luminescence (CL) and high resolution transmission electron microscopy (HRTEM) in order to study stress, strain, crystalline quality, surface morphology and optoelectronic properties in relation with the defect density and the microstructure of grown GaN films.