High-voltage Schottky barrier diode on silicon substrate

New GaN Schottky barrier diodes (SBDs) on Si substrates are proposed to achieve a high-breakdown voltage. We have fabricated GaN SBDs using doped GaN/unintentionally doped (UID) GaN because doped GaN with the thickness of 200 nm is suitable for high-current operation. The 1-μm-deep mesa and low-temperature annealing of ohmic contacts suppress the leakage current of GaN SBDs. Annealing of Schottky contacts also improves the interface between a Schottky contact and GaN. Annealing of ohmic contacts at 670 °C yields the low leakage current of 2.8 nA through the surface and the buffer. When the anode-cathode distance is 5μm, the fabricated GaN SBD successfully achieves a low forward voltage drop of 1.3V at 100A/cm², low on-resistance of 4.00mΩcm², and the low leakage current of 0.6A/cm² at-100V. The measured breakdown voltage of GaN SBDs is approximately 400 V.