702.3 A·cm⁻²/10.4 mΩ·cm² β-Ga₂O₃ U-Shape Trench Gate MOSFET With N-Ion Implantation

High-performance $\beta $ -Ga2O3 U-shaped trench-gate metal-oxide-semiconductor field-effect transistor (UMOSFET) has been demonstrated. Nitrogen ions implantation was employed to form current blocking layer. Electrons in the blocking layer can accumulate in the area near the U-shaped groove and form a conductive channel to promote current generation at a positive gate bias. The UMOSFET with an applicable threshold voltage of 4.2 V was achieved by modulating the concentration of implanted nitrogen ions. A high current density of 702.3 A/cm2, a low on-resistance of 10.4 $\text{m}\Omega \cdot $ cm2, and a decent breakdown voltage of 455 V (at ${V}_{\text {G}}=0$ V) were obtained for UMOSFET with N ions concentration of ${5}\times {10} ^{{18}}$ cm $^{-{3}}$ . The UMOSFET in this work offers exceptional advantages in fabrication of high-performance E-mode vertical $\beta $ -Ga2O3 MOSFETs, facilitating the development of $\beta $ -Ga2O3 power electronics devices.