A novel in situ vacuum encapsulated lateral field emitter triode

We have designed and fabricated a novel lateral field emitter triode, which is in situ vacuum encapsulated so that any troublesome additional vacuum sealing process is not required. The device exhibits low turn-on voltage of 7 V, stable current density of 2 μA per tip, and high transconductance of 1.7 μS per 100 tips field emitter array at V/sub AC/=22 V. An in situ vacuum encapsulation employing recessed cavities by isotropic RIE (reactive ion etch) method and an electron beam evaporated molybdenum vacuum seal are implemented to fabricate the new field emitter triode. The superb field emitter characteristics are probably due to sub-micron dimension device structure and the pencil type lateral cathode tip employing upper and lower LOCOS oxidation.