GaN Nano Air Channel Diodes with Ultralow Turn-On Voltages for NAND Logic Circuits

Nano air channel transistors (NACTs) have gained attention as promising alternatives to traditional solid-state devices due to their near-ballistic electron transport in air and resistance to harsh conditions. However, their applications in logic circuits remain limited by high operating voltages, low output currents, and integration challenges. This paper introduces a GaN-based nano air channel diode (NACD) featuring a planar tip-to-edge structure with a sub-10 nm tip radius, fabricated by focused ion beam (FIB) technology. This device demonstrates an ultralow turn-on voltage down to 0.2 V, a current density exceeding 1 × 10⁶ A cm^-2, and a rectification ratio of over 1000. In addition, the electrical performance and current noise behavior of NACDs with different channel lengths are also investigated. Notably, two rectifying GaN NACDs with a common anode are prepared to enable NAND logic circuits. Remarkably, the device exhibits high stability and reliability, maintaining its performance after more than 34 months. Our findings address key challenges in NACTs for logic circuits and present a practical approach to constructing high-performance, integrated circuits and systems based on NACTs.