High κ dielectric single-crystal monoclinic Gd2O3 on GaN with excellent thermal, structural, and electrical properties

Abstract: MBE-grown single-crystal Gd2O3 epitaxially on GaN has exhibited excellent thermal stability, withstanding rapid thermal annealing (RTA) at 1100°C. The high-κ dielectric Gd2O3 thin film 10nm thick has a monoclinic phase with a high degree of crystallinity, characterized by X-ray diffraction using synchrotron radiation. The orientation relationship is and . Interface between Gd2O3 and GaN remains atomically sharp after the RTA, as demonstrated using X-ray reflectivity and high-resolution transmission electron microscopy. Gd2O3/GaN metal-oxide-semiconductor capacitors show well-behaved capacitance–voltage characteristics with small dispersion and hysterisis, a high dielectric constant of ∼17, and a low electrical leakage current density of 4.6×10−9 A/cm2 at 1MV/cm. [Copyright &y& Elsevier]