A novel low-voltage ballistic-electron-emission source

Abstract

A novel tunnel junction emitter based on ballistic electron transmission through ultra-thin metal foils is proposed as an electron source. From a simple planar tunneling model and Monte-Carlo simulations, we show that either a high-brightness monochromatic electron source can be obtained or a high-current source with energy spread comparable with a field emission source. Freestanding 5 nm thick Pt films were successfully fabricated for the construction of a tunnel junction electron source, in which a UHV-STM is used as a tip-emitter positioning device.