Emission characteristics of a GaAs wedge emitter monolithically fabricated with an air bridge and a cantilever anode

GaAs wedge emitters with an air bridge anode and a cantilever anode were monolithically fabricated using a micromachining technique. The threshold voltage of electron emission is about 8 V for the diode between the emitter and the air bridge anode, while only 1.5 V for the diode between the emitter and the cantilever anode. The current–voltage characteristic of the air bridge diode is due to a field emission, on the other hand, that of the cantilever diode is recognized as a direct tunneling of electrons through the reduced air gap between the emitter and the cantilever by electrostatic force.