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A unique field termination structure combining a three-step field plate with nitrogen ion implantation to enhance the reverse breakdown performance of Pt/β-Ga₂O₃Schottky barrier diodes (SBDs) and NiO/β-Ga₂O₃heterojunction diodes (HJDs) is reported. The fabricated devices showed a lowR_on,spof 6.2 mΩ cm²for SBDs and 6.8 mΩ cm²for HJDs. HJDs showed a 0.8 V turn-on voltage along with an ideality factor of 1.1 leading to a low effective on-resistance of 18 mΩ cm². The devices also showed low reverse leakage current (<1 mA cm⁻²) and a breakdown voltage of ∼1.4 kV. These results offer an alternative, simpler route for fabricating high-performance kilovolt-classβ-Ga₂O₃diodes.

Superlattices composed of either monoclinic μ-Fe2O3 or β-(AlxGa1−x)2O3 with β-Ga2O3 spacers are grown on (010) β-Ga2O3 substrates using plasma-assisted molecular beam epitaxy. High-resolution x-ray diffraction data are quantitatively fit using commercial dynamical x-ray diffraction software (LEPTOS) to obtain layer thicknesses, strain, and compositions. The strain state of β-(AlxGa1−x)2O3 and μ-Fe2O3 superlattices as characterized using reciprocal space maps in the symmetric (020) and asymmetric (420) diffraction conditions indicates coherent growths that are strained to the (010) β-Ga2O3 lattice. β-(AlxGa1−x)2O3 and μ-Fe2O3 superlattices grown at hotter substrate temperatures result in crystal structures with better coherency and reduced defects compared to colder growths. The growth rate of μ-Fe2O3 is ∼2.6 nm/min at Tsub = 700 °C and drops to ∼1.6 nm/min at Tsub = 800 °C due to increased Fe interdiffusion at hotter substrate temperatures. Scanning transmission electron microscopy data of a μ-Fe2O3 superlattice grown at Tsub = 700 °C confirm that there is significant diffusion of Fe atoms into β-Ga2O3 layers.