Silicon Field Emitter Arrays With Current Densities Exceeding 100 A/cm2 at Gate Voltages Below 75 V

We report silicon field emitter arrays (FEAs) that demonstrate current densities >100 A/cm² at gate–emitter voltages <75 V. These are the highest current densities reported for a semiconductor FEA, and approach the current densities of Spindt-type metal cathodes. We achieved these results using a new device structure that employs high-aspect-ratio silicon nanowire current limiters in series with each emitter tip to address the major failure mechanisms in FEAs. These current limiters mitigate emitter tip failure due to joule heating thus allowing for higher reliability. We employed a novel fabrication process to produce small gate apertures ( $\approx 350$ nm) that are self-aligned to the field emitter tip enabling device operation at >100 A/cm² with gate-to-emitter voltages that are less than 75 V. These FEAs demonstrate performance that has the potential to enable smaller, more efficient, and high-power vacuum electronics.