Nitridation interfacial-layer technology: Enabling low interface trap density and high stability in III-nitride MIS-HEMTs

We present an interface enhancement technology featuring in situ low-damage NH3/Ar/N2 pre-gate plasma treatment prior to the ALD-Al2O3 deposition for high-performance III-nitride MIS-HEMTs. It is manifest that this technology can effectively remove the native oxide while forming a monocrystal-like nitridation interfical-layer (NIL) on III-nitride surface. The Al2O3(NIL)/GaN/AlGaN/GaN MIS-heterostructures with high-quality interface exhibit well-behaved electrical characteristics, including a small subthreshold swing of ∼64 mV/dec, a small hysteresis of ∼0.09 V, tiny f/T-dispersions in the C-V characteristics, and low interface trap density of ∼10¹²–10¹³ cm⁻²eV⁻¹.