Growth and characterization of single-crystalline gallium nitride using (1Â 0Â 0) LiAlO2 substrates

Self-separating single-crystalline gallium nitride films were grown by hydride-metalorganic vapor-phase epitaxy (H-MOVPE) on LiAlO2 (LAO) substrates. Nitridation of the LAO substrate leads to the reconstruction of the surface and to the formation of a thin layer of nitrided material. Free-standing films of 35-40 μm thick were grown by a succession of techniques using both MOVPE and hydride vapor-phase epitaxy (HVPE) growth steps. The films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), and micro-Raman spectroscopy to investigate the effect of the initial MOVPE step.