Over 400 V Field‐Plate Enhanced Vertical Diamond Schottky Diodes With Near‐Ideal Behavior and Over 2700 A/cm 2 Current Density

Abstract

Vertical diamond Schottky barrier diodes with field‐plate edge termination were fabricated on 1.5 μm low‐doped () epilayers grown on heavily boron‐doped substrates. Devices with Schottky radii of 25–350 μm and FP lengths of 0–20 μm were systematically characterized. Temperature‐dependent I – V (298–448 K) revealed near‐ideal ideality factors (∼1) and apparent barrier heights of ∼1.8 eV, with Gaussian inhomogeneity modeling yielding mean barrier heights ∼ 2.1 eV (near‐theoretical 2.2 eV for Mo/O‐terminated diamond) and low standard deviation (0.11 eV). Specific on‐resistance reached 1.78 mΩ.cm 2 with current densities 2700 A.cm −2 at 10 V for small devices and 1.5 A total current for large‐area diodes. Reverse characteristics showed breakdown voltages exceeding 400 V (max 449 V, 66% parallel‐plane efficiency), with FP termination improving BV across all Schottky contact radii compared to non‐FP devices, while BV showed no significant dependence on FP length among FP devices. Benchmarking yields a Baliga figure‐of‐merit of 113 MW.cm −2 , surpassing most prior diamond SBDs.