Ultra-Low On-Resistance W/β-Ga2O3 Junction Barrier Schottky Rectifiers

Abstract

The on-resistance of Ga2O3 rectifiers with different metal anodes was measured from the forward current-voltage characteristics. The use of W anode metal produces low on-resistance of 0.34 mΩ.cm2 for W/Au/ β-Ga2O3 Schottky Barrier Diode (SBD) rectifiers and 0.22 mΩ.cm2 for heterojunction Diode (HJD) NiO/β-Ga2O3 rectifiers, overcoming the generally much larger values obtained using Ni or Pt metal. These are the lowest on-resistances reported for Ga2O3 rectifiers. The turn-on voltage was 0.22 V for SBD and 1.69 V for HJDs. By changing the anode metal, we varied the effective barrier height, which also affects reverse breakdown voltage. The switching characteristics were measured for the different device types, with reverse recovery times of 30.6 ns for SBDs and 33.0 ns for HJDs and slew rates of 2 A.μs−1 for both types of devices. Using a simple change of anode metal allows the achievement of a broad range of breakdown voltage and on-resistance, which allows for tailoring the rectifier performance depending on the application.