High-quality AlN/Al2O3 Dielectric in AlGaN/GaN MIS-HEMTs

In GaN-based power devices, a broader gate voltage swing is required to match practical circuit applications [1-3]. In this paper, novel AlGaN/GaN MIS-high electron mobility transistors (HEMTs) with AlN/Al2O3 stack layer as dielectric are proposed. The developed MIS-HEMTs exhibit a maximum drain current of 614.7 mA/mm and high ON/OFF ratio of 1.6×10⁸, while associated low ON-resistance of 8.57 Ω·mm. Furthermore, small threshold voltage shifts are observed under positive and negative gate bias conditions, specifically less than 0.3 V under VGS= 1 V with a stress time of 10⁴ seconds and less than 0.1 V under VGS= -16 V with a stress time of 10⁴ seconds. This result indicate the AlN/Al2O3 stack layer realize high-performance MIS-HEMTs.