Effect of high voltage stress on the DC performance of the Al2O3/AlN GaN metal–insulator–semiconductor high-electron mobility transistor for power applications

Abstract

We demonstrate an Al2O3/AlN/AlGaN/GaN metal–insulator–semiconductor high-electron mobility transistor (MIS-HEMT) device with stable electrical properties under high-voltage stress, by using an Al2O3/AlN stack layer as the gate dielectric layer. Excellent quality AlN/Al2O3 GaN interface was obtained by using plasma-enhanced ALD (PE-ALD), resulting in a very low interface trap density (Dit) of ∼1.8 × 1011 eV−1 cm−2, obtained by using the conductance method. The device exhibits a small threshold voltage hysteresis of ∼200 mV and a lower gate–source leakage current. No obvious changes in the drain–source current and ON-resistance were observed for the device that was subject to the drain–source voltage stress of 100 V for 15 h.