Schottky Source/Drain InAlN/AlN/GaN MISHEMT With Enhanced Breakdown Voltage

In this letter, we present the deployment of Schottky source/drain (SSD) in InAlN/GaN metal-insulator-semiconductor high-electron-mobility transistors (MISHEMTs) for off-state breakdown voltage improvement. The improved breakdown voltage relies on the suppression of electron injection into the buffer under the Schottky source contact. A V_BD of 460 V is obtained in an SSD MISHEMT with an L_GD = 10 μm, at a 170% improvement compared with that of the control MISHEMT featuring ohmic source/drain. Despite the SSD contacts, an SSD MISHEMT with a gate length of 1 μm exhibits a respectable drain current density of 416 mA/mm and a transconductance of 113 mS/mm.