1-kV β-Ga2O3UMOSFET with Quasi-Inversion Nitrogen-Ion-Implanted Channel

In this work, 1-kV vertical enhancement-mode
$\beta- \text{Ga}_{2}\mathrm{O}_{3}$
U-shaped trench gate metal-oxide-semiconductor field-effect transistors (UMOSFETs) with nitrogen-ion-implanted channel have been successfully demonstrated. The nitrogen-ion-implanted region serves as a current blocking layer (CBL) and also allows a quasi-inversion channel to form at the trench sidewall. The activation annealing temperature of the nitrogen-ion-implanted CBL was optimized to suppress the leakage current. The CBL annealed at 1150 °C exhibits better current blocking capability than its 1100 °C annealed counterpart. Based on the CBL annealed at 1150 °C, the UMOSFET exhibits an improved on-off ratio of ~ 10
⁶
, an on-resistance of 87.6 mΩ-cm
²
and a remarkable breakdown voltage of 1028 V. This is the first 1-kV
$\beta-\text{Ga}_{2}\mathrm{O}_{3}$
MOSFET based on CBL, showing the potential
$\text{of}\beta-\text{Ga}_{2}\mathrm{O}_{3}$
UMOSFETs with N-implanted channel for kilovolt-class applications.