GaN epitaxial layers at low-doping concentrations around 1016/cm3 for power devices were grown onto low-dislocation-density GaN substrates. The epitaxial layers have shown much less-compensated behavior in net doping concentration, which arose from their much high-purity nature than those on sapphire substrates. Schottky barrier diode fabricated on the layer have shown extremely low leakage current and high breakdown voltage of 580V, and low specific on-resistance of 1.3mΩcm2, as expected from its high-quality epitaxial layer.

High-Purity GaN Epitaxial Layers for Power Devices on Low-Dislocation-Density GaN Substrates. S.Hashimoto, Y.Yoshizumi, T.Tanabe, M.Kiyama: Journal of Crystal Growth, 2007, 298, 871-87