Effect of Residual Gas Pressure on the Characteristics of a Nanoscale Field-Emission Diode
Abstract
The fabrication and experimental study of a nanoscale field-emission diode based on tantalum are described. The cathode and anode with an interelectrode gap were shaped using a focused ion beam in an SEM/FIB system. Current–voltage measurements were carried out in a pressure range from 10−6 mbar to atmospheric pressure. At pressures above 1 mbar, a sharp decrease in emission current was observed, which may be explained by the adsorption of residual atmosphere gases onto the cathode upon vacuum degradation and removal of the anode voltage, leading to a local change in the work function of the emission centers. At atmospheric pressure, cathode destruction was observed, presumably caused by a microplasma discharge and subsequent ion bombardment.