Breakdown voltage enhancement in p-GaAs/n-Ga₂O₃ heterojunction diodes with advanced termination designs

Abstract A vertical p-GaAs/n-Ga 2 O 3 heterojunction diode (HJD) is proposed, achieving a high breakdown voltage ( V br ) of 1210 V, a Baliga’s figure of merit (BFOM) of 15.1 MW cm −2 , and a specific on-resistance ( R on,sp ) of 96.9 mΩ·cm 2 . To further enhance the breakdown voltage and mitigate electric field crowding, a three-step junction termination extension (JTE) and a beveled edge termination are introduced. The three-step JTE effectively disperses the peak electric field, alleviates field concentration at the anode edge, and improves the overall field distribution, leading to an increase in V br to 1408 V. Meanwhile, the beveled edge termination efficiently reduces localized field stress and suppresses crowding effects at the anode edge and structural weak points. Among the proposed termination techniques, the beveled edge design offers the most effective field control, significantly lowering the electric field gradient at the device periphery and enabling the highest breakdown voltage of 1475 V. These findings pave the way for advanced Ga 2 O 3 device structures and reaffirm the critical role of edge termination in Ga 2 O 3 power devices.