Tungsten pedestal structure for nanotriode devices

The nanotriode is a vacuum nanoelectronic device with a turn-on voltage for a field emission of similar to8 V, in which electrons are emitted from a metal nanotip with a radius similar to1 nm in an integrated vacuum chamber, over a distance of similar to100 nm. However, surface breakdown Of the gate-cathode dielectric within the device chamber occurs similar to2 V outside of its operating range, limiting the reliable range of field-emission observation. To increase this surface breakdown voltage, while maintaining the operating voltage range, a pedestal structure has been developed that can be incorporated into the nanotriode. This structure has a thicker dielectric layer, while maintaining a gate-cathode separation similar to that used previously. Measurements on vacuum-encapsulated two-terminal devices show field emission in the same voltage range and with similar characteristics to those previously observed; in consequence of the pedestal, higher surface breakdown voltages are achieved and the significance of the leakage current is reduced. (C) 2004 American Vacuum Society.