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

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.