Double-Barrier β-Ga2O3 Schottky Barrier Diode With Low Turn-on Voltage and Leakage Current

This work reports a
$\beta $
-Ga
₂
O
₃
double-barrier Schottky barrier diode (DBSBD) with both low turn-on voltage and low reverse leakage current by using Ni and PtO
_x
as the anode electrode. The barrier height of PtO
_x
-based diode can be effectively modulated from 1.26 to 1.62 eV by adjusting oxygen pressure during sputtering processes. Combining the maximum work function of PtO
_x
electrode with the optimization of the electrode ratio of Ni and PtO
_x
, the DBSBD with an electrode diameter ratio of
$\text{D}_{\text {Ni}} /\text{D}_{\text {PtOx}}= {75}/{150} \mu \text{m}$
not only exhibits a high forward current of 470.9 A/cm
²
(at 3.5 V), a low on-resistance of 4.1
$\text{m}\Omega ~\cdot $
cm
²
and a low turn-on voltage of 1.13 V, but also possesses a relatively low reverse leakage current of
${1.2}\times {10}^{-{7}}$
A/cm
²
(at −100 V), which is more than one order of magnitude lower than that of the Ni-SBD. Silvaco TCAD simulation reveals that such optimization can be attributed to the suppression of edge leakage current due to the double-barrier contact. Therefore, the strategy of double-barrier design can balance the forward and reverse characteristics in SBD, providing a new device structure for advanced power electronics.