Abstract

We present a β-Ga 2 O 3 Trench Schottky Barrier Diode (SBD) featuring a high-permittivity (high-k) dielectric RESURF and an atomic layer-deposited (ALD) Ru anode contact to engineer the trade-off between forward voltage drop and reverse leakage current. We created 1 µm deep trenches on the lightly doped β-Ga 2 O 3 drift layer and deposited a high-permittivity BaTiO 3 as the RESURF dielectric. By encircling the trenches with the anode metal, the electric field at the metal/semiconductor junction is effectively reduced. Consequently, we were able to utilize a low work-function metal like Ru without inducing a significant increase in reverse leakage current. The high-k RESURF trench SBD, spanning an area of 200×200 µm 2 , demonstrated a low turn-on voltage of 0.5 V and a reverse breakdown voltage exceeding 3 kV, with a leakage current density of 2 mA/cm 2 at 3kV. The larger area 1×1 mm 2 and 2×2 mm 2 devices exhibited breakdown voltages of 1.74kV and 1.42kV, respectively, while accommodating maximum pulsed forward currents of 6A and 20A, respectively. The devices presented here exhibit record low product of stored charge and forward voltage drop (Q C V F) for > 1 A, 1 kV device, indicating promising switching and conduction loss trade-off for multi-kilovolt class applications.