Vertical metal–dielectric–semiconductor diode on (001) β-Ga2O3 with high-κ TiO2 interlayer exhibiting reduced turn-on voltage and leakage current and improved breakdown

We demonstrate vertical Pt/TiO2/β-Ga2O3 metal–dielectric–semiconductor (MDS) diodes and compare performance with co-fabricated Pt/β-Ga2O3 Schottky diodes (SBDs). The MDS diode exhibits a lower turn-on voltage and leakage current. In addition, the breakdown voltage increased from 548 V for an SBD to 1380 V for a MDS diode. The improvement in the off-state characteristics compared to a SBD while simultaneously reducing on-state losses leads to lower power dissipation at all duty cycles, indicating the great promise of this device architecture for advancing low-loss β-Ga2O3 rectifiers toward material limits.