Over 1.2 GW cm⁻² <i>β</i>-Ga₂O₃ SBD with <i>V</i> _br of 1.93 kV realized by O₂ plasma and annealing

Abstract In this study, the electrical performance of β -Ga 2 O 3 Schottky barrier diode (SBD) has been significantly enhanced through the application of O 2 plasma and annealing treatment (OPAT). Compared to the control device, the OPAT β -Ga 2 O 3 SBD exhibits superior turn-on voltage ( V on ), specific on-resistance ( R on,sp ) and breakdown voltage ( V br ). Moreover, by incorporating electron-beam evaporated Al 2 O 3 as the field plate oxide, the surface breakdown electric field increases from 2.19 MV cm −1 to 4.09 MV cm −1 , as extracted by TCAD simulation. The OPAT field-plated β -Ga 2 O 3 SBD achieves V on of 0.52 V at the current density of 1 A cm −2 , R on,sp of 3.10 mΩ·cm 2 , and V br of 1.93 kV. Its power figure of merit reaches 1.2 GW cm −2 . X-ray Photoelectron Spectroscopy measurements indicate that OPAT reduces the concentration of oxygen vacancy, which in turn decreases the Schottky barrier height of the device, consequently enhancing the performance of β -Ga 2 O 3 SBD. These results demonstrate the enormous potential of β -Ga 2 O 3 in low V on and high V br applications.