Al2O3/AlGaN Channel Normally-Off MOSFET on Silicon With High Breakdown Voltage

Abstract

A normally-Off metal-oxide-semiconductor field-effect transistor (MOS-FET) is proposed by using AlInN/AlGaN heterostructure grown on silicon. The AlGaN channel MOSFET with Al2O3 layer as gate insulator exhibits a drain current of 90 mA/mm at the gate bias of +8 V, an ON/OFF drain-current ratio of ${1.4} \times {10}^{8}$ , a peak field-effect mobility of 97 cm2/ $\text {V} \cdot \text {s}$ , and threshold voltage of +2.4 V, respectively. With significant reduction in leakage currents, the MOS-FET with a gate-to-drain spacing of 20 $\mu \text{m}$ delivers a high breakdown of 993 V. The present results of Al2O3/AlGaN normally-Off MOSFET signifies promising prospects for future high power and high voltage applications.