Ultra-wide bandgap semiconductor Ga2O3 power diodes

TLDR

Ga2O3 is anticipated to surpass GaN and SiC in power device performance, yet its power figure‑of‑merit remains far below the material limit due to conflicting requirements for high breakdown voltage, low doping, PN junction termination, and simultaneous n‑ and p‑type doping. The study demonstrates that Ga2O3 heterojunction PN diodes can overcome these challenges. By injecting holes into Ga2O3, bipolar transport induces conductivity modulation and low resistance in a low‑doping material. The resulting diodes achieve 8.32 kV breakdown voltage, 5.24 mΩ·cm² on‑resistance, 13.2 GW/cm² power figure‑of‑merit, and 1.8 V turn‑on voltage, surpassing the 1‑D unipolar limits of GaN and SiC and indicating strong potential for next‑generation power electronics.

Abstract

Ultra-wide bandgap semiconductor Ga2O3 based electronic devices are expected to perform beyond wide bandgap counterparts GaN and SiC. However, the reported power figure-of-merit hardly can exceed, which is far below the projected Ga2O3 material limit. Major obstacles are high breakdown voltage requires low doping material and PN junction termination, contradicting with low specific on-resistance and simultaneous achieving of n- and p-type doping, respectively. In this work, we demonstrate that Ga2O3 heterojunction PN diodes can overcome above challenges. By implementing the holes injection in the Ga2O3, bipolar transport can induce conductivity modulation and low resistance in a low doping Ga2O3 material. Therefore, breakdown voltage of 8.32 kV, specific on-resistance of 5.24 mΩ⋅cm2, power figure-of-merit of 13.2 GW/cm2, and turn-on voltage of 1.8 V are achieved. The power figure-of-merit value surpasses the 1-D unipolar limit of GaN and SiC. Those Ga2O3 power diodes demonstrate their great potential for next-generation power electronics applications.