1.5 kV Vertical Ga2O3 Trench-MIS Schottky Barrier Diodes

β-Ga
₂
O
₃
electronic devices for high power applications have seen rapid development over the recent years, due to the excellent material properties including an extremely large band-gap, high critical electric field, decent electron mobility and the availability of low-cost bulk substrates. As unipolar devices, Ga
₂
O
₃
vertical Schottky barrier diodes (SBDs) have fast switching capability, while enjoying all the superior properties of Ga
₂
O
₃
. With the development of halide vapor phase epitaxy (HVPE) capable of delivering high quality thick n
^-
epitaxial layers [1], Ga
₂
O
₃
vertical SBDs have shown promising results with up to 1 kV breakdown voltage (BV) together with decent on-resistance (R
_on
) of 2-6 mΩ·cm
²
[1-3]. However, the results are still far from the projected performance which surpasses GaN and SiC [4]. One important reason is the high reverse leakage current due to the high surface electric field, which causes thermionic-field emission and barrier height lowering, especially at the device edge where field crowding occurs. The leakage current can be much reduced by edge termination techniques such as field-plating [3]. More effectively, a trench-metal-insulator-semiconductor (MIS) structure can be utilized to reduce the leakage current [5], taking advantage of the reduced surface field (RESURF) effect [6]. In this work, we demonstrate Ga
₂
O
₃
trench-MIS SBDs with a record-high 1.5 kV breakdown voltage without edge termination, together with a ~10
⁴
times reduction in reverse leakage current compared with regular SBDs.