MBE grown high κ dielectrics Ga 2O 3(Gd 2O 3) on GaN

Abstract

High κ Ga 2O 3(Gd 2O 3) dielectric was deposited on n-type GaN (0 0 0 1) using molecular beam epitaxy (MBE). TiN/Ga 2O 3(Gd 2O 3)/GaN metal–oxide–semiconductor (MOS) diodes have exhibited a negligible frequency dispersion, low leakage currents (∼10 −8 A/cm 2), and a low interfacial density of states ( D it) of 10 11 cm −2 eV −1 at the midgap. Well-behaved capacitance–voltage ( C V) curves with accumulation and depletion behaviors were shown, with a dielectric constant of 14.7. Forming gas annealing at 600 °C has reduced the frequency dispersion in the C V curves. A sharp oxide/semiconductor interface was shown by high-resolution transmission electron microscopy (HR-TEM).