2.7 kV Low Leakage Vertical PtOx/β-Ga2O3 Schottky Barrier Diodes With Self-Aligned Mesa Termination

In this study, we fabricated superb
$\beta $
-Ga2O3 Schottky barrier diodes (SBDs) with high breakdown voltage (
${V}_{\text {br}}{)}$
and low leakage through combining platinum oxide (PtO
$_{\text {x}}{)}$
and anodic self-aligned mesa termination (SAMT). The PtOx that forms a high barrier with
$\beta $
-Ga2O3 enables the SAMT to function sufficiently. The in-situ annealing dry etch process repair the mesa sidewall and improve the Schottky contact well. SBDs with different mesa-etched depths (
${D}_{\text {ee}}{)}$
were systematically studied, including 0, 0.3, 0.6, 0.9, and
$1.2~\mu \text{m}$
. The results showed that the
${V}_{\text {br}}$
of the PtOx/
$\beta $
-Ga2O3 SBD increased from 1120 V to 2738 V, yielding a high power figure of merit (PFOM) of 1.02 GW/cm2. Meanwhile, the device maintained a less than
$10~\mu \text{A}$
/cm2 leakage current density until -2000 V. Devices with radii of 200, 100, and
$50~\mu \text{m}$
obtained highest
${V}_{\text {br}}$
of 2508, 2772, and 2738 V at a
${D}_{\text {ee}}$
of
$1.2~\mu \text{m}$
, respectively. The devices can be passivated by SU-8 without
${V}_{\text {br}}$
degradation. This work provides an effective method for further improving the performance of
$\beta $
-Ga2O3 SBDs and promotes the application of
$\beta $
-Ga2O3 power diodes.