Metal–Air Transistors: Semiconductor-Free Field-Emission Air-Channel Nanoelectronics

Abstract

Scattering-free transport in vacuum tubes has always been superior to solid-state transistors. It is the advanced fabrication with mass production capability at low cost which drove solid-state nano-electronics. Here, we combine the best of vacuum tubes with advanced nanofabrication technology. We present nano-scale, metal-based, field emission air channel transistors. Comparative analysis of tungsten, gold, and platinum based devices is presented. Devices are fabricated with electron beam lithography, achieving channel lengths less than 35 nm. With this small channel length, vacuum-like carrier transport is possible in air under room temperature and pressure. Source and drain electrodes have planar, symmetric and sharp geometry. Due to this, devices operate in bi-direction with voltages <2 V. The experimental data shows that influential operation mechanism is Fowler–Nordheim tunnelling in tungsten and gold devices, while Schottky emission in platinum device. The presented work enables a technology where metal-based switchable nanoelectronics can be created on any dielectric surface.