High Reverse Blocking and Low Onset Voltage AlGaN/GaN-on-Si Lateral Power Diode With MIS-Gated Hybrid Anode

An AlGaN/GaN-on-Si lateral power diode with recessed metal/Al₂O₃/III-nitride (MIS)-gated ohmic anode for improved forward conduction and reverse blocking has been realized. The low onset voltage of ~0.6 V with good uniformity for the fabricated 189 devices is obtained. In comparison with the conventional Schottky diode the specific ON-resistance (R_ON,SP) was reduced by 51% in a device with anode-to-cathode spacing (L_AC) of 5 μm. The incorporation of high-k dielectric in the recessed gate region enabling two-order lower reverse leakage comparing with the conventional device, leading to a high breakdown voltage over 1.1 kV at leakage current as low as 10 μA/mm in device with L_AC=20μm. The strong reverse blocking over 600 V was still achieved at 150°C. The proposed diode is compatible with GaN normally OFF MIS high-electron-mobility transistors, revealing its potential for highly efficient GaN-on-Si power ICs.