Over 2 GW/cm2 Low Leakage Vertical β-Ga2O3 Schottky Barrier Diode With Multizone JTE via Self-Aligned NiO/β-Ga2O3 Co-Etching

Abstract

In this work, a vertical $\beta $ -Ga2O3 Schottky barrier diode (SBD) featuring a self-aligned mesa and multizone junction termination extension (MZ-MJTE) is proposed. Enabled by a simple fabrication process, the MZ-MJTE SBD reduces the sensitivity of conventional single-zone JTE (SZ-JTE) to effective p-type charge density, broadens the process window, and achieves efficient electric field management. Process optimization identified a BCl3/Ar gas mixture of 35:5 as the optimal condition for etching $\beta $ -Ga2O3 and NiO simultaneously. With structure parameters optimized via TCAD simulations, the MZ-MJTE SBD achieves a lowest ${R}_{\text {on, {sp}}}$ of 4.41 m $\Omega \cdot $ cm2 and a breakdown voltage ( ${V}_{\text {br}}\text {)}$ exceeding 3000 V, yielding a highest power figure-of-merit (PFOM) of 2.04 GW/cm2. Statistically, the devices exhibit an average ${R}_{\text {on, {sp}}}$ of 4.86 m $\Omega \cdot $ cm2 and an average ${V}_{\text {br}}$ of 2718 V, corresponding to an average PFOM of 1.52 GW/cm2, which ranks among the best reported values for vertical $\beta $ -Ga2O3 SBDs. Moreover, the MZ-MJTE SBD maintains a low leakage current below 0.0002 A/cm2 even at −2500 V and demonstrates stable operation up to 448 K, indicating excellent thermal stability and promising potential for high temperature applications. This work provides a novel multizone JTE termination with a simple fabrication scheme and effective electric field management, offering a practical pathway toward high-performance $\beta $ -Ga2O3 power devices.