The 'nanotriode:' A nanoscale field-emission tube

A nanoscale electron tube with a field-emission cathode and a control gate (nanotriode) has been fabricated and characterized. Electrons are field emitted from metal nanopillars with radii of about 1 nm into a vacuum nanochamber, collected at the anode, and controlled by a gate electrode. The nanochamber is sealed by an integrated anode and has vertical and horizontal dimensions of 100 nm. The turn-on voltage is less than 10 V and is independent of ambient temperature. Currents of 10 nA and transconductances of up to 6 nS per device have been observed; this would yield a transconductance of 60 S cm−2 at the maximum packing density of 1010 nanotriodes cm−2 for these devices. The emission stability is better than 3% at room temperature and improves to 0.1% at 20 K.