Growth behavior of nonpolar GaN on the nearly lattice-matched (1 0 0) γ-LiAlO2 substrate by chemical vapor deposition

Nonpolar gallium nitride (GaN) epitaxial film was grown on a nearly lattice-matched (1 0 0) γ-LiAlO2 substrate by a versatile chemical vapor deposition (CVD) method. LiAlO2 single crystal was grown by the Czochralski (Cz) method. Epi-ready LiAlO2 single-crystal substrate with RMS roughness of 0.24–0.32 nm were used for all experiments. The dependence of growth characteristics on the growth temperatures and deposition time was investigated. The orientation of GaN film was identified as (1 0 1¯ 0) m-plane by X-ray diffraction pattern. The characterization of detailed structure of the nonpolar GaN epilayer was done by transmission electron microscopy (TEM). Optical properties examined by photoluminescence spectra exhibit a strong near-band-edge emission peak at 3.37 eV and a weak yellow band emission.