Sub-10-nm Air Channel Field Emission Device With Ultra-Low Operating Voltage

In this letter, sub-10-nm air channel devices were fabricated with the aid of photolithography and focused ion beam (FIB) etching. Field emission (FE) properties of the device were measured under ambient conditions. The operation mechanism was discussed by means of current-voltage (I-V) curve fitting and energy band diagram analysis. On account of the extremely shrinking of nano-gap, record-high emission currents of $355.6~\mu \text{A}$ at 1 V were realized in air with a threshold voltage as low as 0.588 V. A cycle test of 200 times was also performed to verify and analyze the stability of the device. Importantly, the temporal response performance of the device was also measured. It demonstrated a high-speed and repeatable output waveform with a rise/fall time of $\sim 100$ ns. This study demonstrates a practical nano-fabrication technology to fabricate sub-10-nm air channel devices with ultra-low operating voltage, which can be utilized as an electrical element in high-speed and low-power integrated circuits.