High performance AlGaN/GaN power diode with edge-terminated hybrid anode

In this work, an AlGaN/GaN power diode with edge-terminated Schottky/ohmic hybrid (ETH) anode is proposed. 2-D simulation is carried out to study the characteristics of the ETH-diode. The forward onset voltage V_on of the device can be modulated by thinning the barrier thickness beneath the Schottky gate region of the hybrid anode. With remaining AlGaN-barrier of 5 nm the V_on as low as 0.25 V is achieved in ETH-Diode. Comparing with the reference device the edge-termination (ET) integrated into the ETH-Diode enabling more than 5-order and 2-order leakage current reduction at -100 V and -300 V, respectively. Correspondingly, even using a more stringent criterion the breakdown voltage (BV) is improved from 400 V at I_leakage=10 μA/mm to 510 V at I_leakage=1 μA/mm in a device with anode-cathode spacing of 5 μm due to the employment of the edge-termination. By using a 2 μm field plate the BV of the ETH-Diode can be further improved to 800 V.