Analysis of the electron emission characteristics and working mechanism of a planar bottom gate vacuum field emission triode with a nanoscale channel

Abstract

A planar lateral vacuum field emission triode (VFET) with a nanoscale channel of 80–90 nm was fabricated on a silicon wafer. The nanoscale channel of this vacuum triode was generated by via the electro-forming process (EFP). With the use of a wedge-waist-type conductive film, the distribution of Joule heat during EFP could be guided, which helped to realize the controllable preparation of a nanoscale fissure that served as the vacuum channel. Experimental results revealed that the fabricated device demonstrated good emission characteristics in vacuum and could be operated normally under atmospheric conditions. The triode emission characteristics under atmospheric pressure were preliminarily realized. The field-assisted thermal electron emission for low operating voltage and the Fowler–Nordheim tunneling emission mechanism for voltages greater than the turn-on voltage were used to explain the emission mechanism of the proposed VFET.