Circular‐Gate Nanoscale Air Channel Transistors: Achieving ultralow Subthreshold Swing and Working Voltage

Abstract As electronics advance toward higher performance and adaptability in extreme environments, traditional metal‐oxide‐semiconductor field‐effect transistors (MOSFETs) face challenges due to physical constraints such as Boltzmann's law and short‐channel effects. Nanoscale air channel transistors (NACTs) present a promising alternative, leveraging their vacuum‐like channel and Fowler–Nordheim tunneling characteristics. In this study, a novel circular gate NACT (CG‐NACT) is purposed, fabricated on a 4‐inch silicon‐based wafer using a CMOS‐compatible process. By employing an innovative gate control mechanism, the transistors achieve an ultralow SS of only 0.15 mV dec⁻¹ and maintain the average SS remained at 1.5 mV dec⁻¹ over three decades of drain current. Additionally, our CG‐NACTs deliver milliamper‐level drain current at a low drain voltage of 0.7 V, with a maximum on/off ratio of 7.82×10⁶. Notably, CG‐NACTs remain highly stable even at high temperatures of up to 150 °C and under irradiation. Furthermore, the practical application of CG‐NACTs is successfully implemented by designing an inverter circuit for the first time.