【Device Papers】TCAD investigation of β-Ga₂O₃ junction barrier Schottky diode with p-Cr₂O₃ heterojunction wells

      Researchers from Duy Tan University (DTU) have published a dissertation titled " TCAD investigation of β-Ga₂O₃ junction barrier Schottky diode with p-Cr₂O₃ heterojunction wells " in RSC Advances.

Abstract

      Although β-Ga₂O₃ Schottky barrier diodes (SBDs) are promising for high-voltage power applications, the lack of effective p-type doping severely limits the realization of junction-based devices. In this paper, TCAD simulations are employed to numerically investigate a vertical β-Ga₂O₃ junction barrier Schottky (JBS) diode incorporating an interconnected grid of p-type chromium oxide (p-Cr₂O₃) wells. The wide-bandgap p-Cr₂O₃, which exhibits a favorable valence-band offset of 2.65 eV and a reported ideality factor as low as 1.07 at the Cr₂O₃/Ga₂O₃ heterojunction, enables the formation of effective p-type regions without requiring p-type doping in β-Ga₂O₃. The simulated β-Ga₂O₃ JBS diode exhibits a turn-on voltage of approximately 0.8 V, a forward current density of 52.8 A cm⁻² at a forward voltage of 3.0 V, and a low reverse leakage current density of 2.0 mA cm⁻² at 800 V. Compared with a conventional SBD, the simulated JBS diode shows an increase in breakdown voltage from 390 V to 950 V with only a slight increase in specific on-resistance (from 45.4 to 47.8 mΩ cm²), resulting in a Baliga's figure of merit of 18.88 MW cm⁻². The simulation results further indicate that optimal device performance is achieved at a p-Cr₂O₃ acceptor concentration of N_A = 5.0 × 10¹⁶ cm⁻³ and a p-well spacing of W_S = 4 µm, for which the electric field distribution becomes more uniform within the drift region. Temperature-dependent simulations predict stable unipolar operation up to 450 K. This predictive design framework provides valuable physical insights and design guidelines for the experimental realization of Cr₂O₃/β-Ga₂O₃ JBS rectifiers, demonstrating that the proposed heterojunction architecture effectively bypasses the p-type doping bottleneck and offers a viable pathway toward next-generation high-voltage and high-temperature β-Ga₂O₃ power rectifiers.

DOI：

https://doi.org/10.1039/d6ra02684b