6 kV/3.4 mΩ·cm2 Vertical β-Ga2O3 Schottky Barrier Diode With BV2/Ron,sp Performance Exceeding 1-D Unipolar Limit of GaN and SiC

In this work, we show that the
$\beta $
-Ga
₂
O
₃
Schottky Barrier Diode (SBD) can perform beyond the 1-D unipolar limit of the SiC and GaN by employing a deep trench with filled thick SiO
₂
layer structure to enhance the breakdown voltage (BV). By doing so, BV and specific on- resistance (
$\text{R}_{\text {on},\text {sp}}$
) of 5–6 kV and 3.4
$\text{m}\boldsymbol {\Omega } \cdot \text {cm}^{{2}}$
are simultaneously derived on the SBDs with
$\beta $
-Ga
₂
O
₃
epi-layer thickness of 10
$\boldsymbol {\mu } \text{m}$
and diode radius of 90
$\boldsymbol {\mu }\text{m}$
. Therefore, the Baliga’s power figure of merit (P-FOM = BV
$^{{2}} /\text{R}_{\text {on,sp}}$
) is yielded to be 7.4-10.6 GW
$/$
cm
²
. To the best of all authors’ knowledge, those P-FOMs are the highest values among all types of SBDs, which is a significant step towards the Ga
₂
O
₃
SBD performance improvement. Combined with negligible forward hysteresis and low reverse leakage current, vertical
$\beta $
-Ga
₂
O
₃
SBDs with state-of-the-art BV and P-FOM show its great promise for next generation high voltage and high power applications.