Nitridation interfacial-layer technology for enhanced stability in GaN-based power devices

Abstract

Effective interface engineering technology in GaN-based insulated-gate heteroj unction transistors are of critical significance to enhance device stability and suppress current collapse. In this paper, we present an interface engineering approach featuring in situ low-damage remote plasma treatment prior to the dielectric deposition, to realize high-performance and high-stability GaN-based metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs). This technology can remove the native oxide while forming a monocrystal-like nitridation interfacial-layer (NIL) on the GaN surface. The Al2O3(NIL)/GaN/AlGaN/GaN MIS heterostructures with high-quality interface exhibit well-behaved electrical characteristics, including suppressed gate leakage current, a steep subthreshold swing of ~64 mV/dec, a small hysteresis of ~0.09 V, tiny frequency/temperature-dispersions in the capacitance-voltage characteristics, and low interface trap density of ~6×1011 - 6×1012 cm-2eV-1.