High breakdown voltage InAlN/AlN/GaN HEMTs achieved by Schottky-Source technology

Abstract

In this paper, we demonstrate 253% improvement in the off-state breakdown voltage (BV) of the lattice-matched In_0.17Al_0.83N/GaN high-electron-mobility transistors (HEMTs) by using a new Schottky-Source technology. Based on this concept, the Schottky-Source (SS) InAlN/GaN HEMTs are proposed. The SS HEMTs with a L_GD of 15 μm showed a three-terminal BV of 650 V, while conventional InAlN/GaN HEMTs of the same geometry showed a maximum BV of 184 V. Without using any field-plate the result measured in the proposed device is the highest BV ever achieved on InAlN/GaN HEMTs. The corresponding specific on-resistance (R_{sp, on}) is as low as 3.4 mΩ·cm². A BV of 118 V was also obtained in an SS InAlN/GaN HEMTs with L_GD=1 μm, which is the highest BV in GaN-based HEMTs featuring such a short L_GD with GaN buffer.