Emission statistics for HfC emitter arrays after residual gas exposure

Field emission arrays (FEAs) consisting of hafnium carbide (HfC)-coated silicon (Si) emitters (HfC emitters) have been fabricated. The FEA emission properties were measured in ultrahigh-vacuum conditions and after being subjected to Ar and O-2 residual gases with partial pressures in the range of 10(-6) to 10(-4) Pa. The influence of residual gases on the FEA field emission properties has been assessed using the model parameter extraction method. The array field emission model considers emitters with different radii and work functions. Fast and accurate results are obtained using a nonlinear parameter extraction procedure. HfC emitters achieve high emission currents, low noise levels and long-term emission stability.