Recessed AlGaN/GaN Schottky Barrier Diodes With TiN and NiN Dual Anodes

High-performance AlGaN/GaN lateral Schottky barrier diodes (SBDs) with recess structure and dual metal nitride anodes were demonstrated. With high work-function and nonrecess structure, a NiN anode enhances the breakdown voltage (BV), while a TiN anode reduces the turn-on voltage (Von) due to its low work-function and contact to the two-dimensional electron gas (2DEG) layer directly on a recess structure. As the length of the NiN anode (Lr) on the nonrecess region decreases from 75 to 3 μm, Von is reduced from 0.56 to 0.30 V, while the reverse leakage current slightly increases from 3 x 10⁻⁴ to 2 x 10⁻³ A/cm² at the bias of -10 V. The lateral AlGaN/GaN SBD with a Lr of 3 μm at a distance of cathode-anode (LAC) of 20 μm achieves a high BV of 1.62 kV, an ultralow Von of 0.30 V and a small capacitance of 6.0 pF at zero bias with little degradation on on-resistance, indicating superior potential application in high-frequency and high-power devices.