Multichannel AlGaN/GaN Schottky barrier diode with low turn-on voltage and on-resistance

Herein, multichannel AlGaN/GaN Schottky barrier diodes (SBDs) with recess structure and tungsten (W) anode are proposed. The multichannel heterostructure improves the current drive capability of the devices and achieves a lower forward voltage (V${}_F$). W anode reduces the turn-on voltage (V${}_{ON}$) due to its lower work function and direct contact with all 2D electron gas (2DEG) channels in the recessed area. Post anode annealing is utilized to improve the interface between the metal and GaN etching surface. The fabricated devices with a 6.5 µm anode-cathode distance (L${}_{AC}$) achieve an ultralow V${}_{ON}$ of 0.29 V, V${}_F$ of 0.69 V, and a low on-resistance (R${}_{ON}$) of 2.39 Ω mm. The capacitance effect of multichannel heterostructures has been analyzed via the capacitance-voltage characteristics, showing the great potential of multichannel AlGaN/GaN SBDs for high-frequency applications. (© 2022 Wiley‐VCH GmbH)