A Study of Field Electron Emission in a Nanoscale Air-Channel Silicon Diode

Over the past few years, the rapid progress in the field of vacuum nanoelectronics is mainly associated with the emergence of technological methods for the formation of quasi-vacuum (air) nanoscale gap between the emitter and collector (less than 100 nm). Since the probability of ionization of gas molecules on such scales is negligible, it opens up the attractive prospects of creating field-emission devices with an air channel which operate in a THz range under atmospheric conditions. In this work, we experimentally demonstrate the field-emission behavior of a silicon diode with a nanoscale air channel of about 60 nm, which was fabricated on a sapphire substrate by means of focused ion beam (FIB) etching. Based on the density functional theory (DFT) formalism, we also perform the first-principles calculations of the field-emission current in a such diode for ultra-small air-channel lengths (up to the de Broglie wavelength), where a noticeable deviation of the current-voltage (I-V) characteristics from the classical Fowler-Nordheim equation was found. The results obtained can be used for the development of high-speed solid-state nanoelectronic devices with a nanoscale air channel.