10-kV Ga₂O₃ Charge-Balance Schottky Rectifier Operational at 200 °C

Abstract

This work demonstrates a lateral Ga2O3 Schottky barrier diode (SBD) with a breakdown voltage (BV) over 10 kV, the highest BV reported in Ga2O3 devices to date. The 10 kV SBD shows good thermal stability up to 200°C, which is among the highest operational temperatures reported in multi-kilovolt Ga2O3 devices. The key device design for achieving such high BV is a reduced surface field (RESURF) structure based on the p-type nickel oxide (NiO), which balances the depletion charges in the n-Ga2O3 channel at high voltage. At BV, the charge-balanced Ga2O3 SBD shows an average lateral electric field (E-field) over 4.7 MV/cm at 25 °C and over 3.5 MV/cm at 200°C, both of which exceed the critical E-field of GaN and SiC. The 10 kV SBD shows a specific on-resistance of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.27~\Omega \cdot $ </tex-math></inline-formula> cm2 and a turn-on voltage of 1 V; at 200°C, the former doubles and the latter reduces to 0.7 V. These results suggest the good potential of Ga2O3 devices for medium- and high-voltage, high-temperature power applications.