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

Abstract

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 (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> ) 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 ( L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> ) on the nonrecess region decreases from 75 to 3 μm, V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> is reduced from 0.56 to 0.30 V, while the reverse leakage current slightly increases from 3 ×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> to 2 ×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at the bias of -10 V. The lateral AlGaN/GaN SBD with a L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> of 3 μm at a distance of cathode-anode ( L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">AC</sub> ) of 20 μm achieves a high BV of 1.62 kV, an ultralow V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> 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.