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

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 Al
₂
O
₃
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 cm
²
/
$\text {V} \cdot \text {s}$
, 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 Al
₂
O
₃
/AlGaN normally-Off MOSFET signifies promising prospects for future high power and high voltage applications.