7.86 kV GaN-on-GaN PN power diode with BaTiO₃ for electrical field management.

This article focuses on the design, fabrication, and characterization of a vertical gallium nitride (GaN)-on-GaN power p-n diode incorporating a high dielectric constant material, barium titanate (BaTiO₃ or BTO), for enhanced electrical field management and increased breakdown voltage. The device, grown on a low-defect bulk GaN substrate with a 57 μm thick drift layer, demonstrated a breakdown voltage of 7.86 kV, an on-resistance of 2.8 mΩ·cm², and a Baliga figure of merit (BFOM) of 22 GW/cm². Numerical simulations and experimental results show that the inclusion of BTO and optimized guard-ring and field plate structures effectively mitigate peak electric fields, improving breakdown voltage by approximately 600 V compared to designs without high-k dielectrics. The study highlights the importance of high-quality epitaxial growth, advanced device design, and fabrication techniques in achieving high-performance GaN power devices suitable for high-power electronics applications.