Fabrication of Structured Nanogaps for Surface Conduction Electron Emitter

摘要

We explore the effect of geometric parameters on field emission characteristics in surface-conduction electron emitters. The structure of Pd thin-film emitter is fabricated on the SiO2 substrate and the nanometer scale gap is formed by the thermal shock technique. Different shapes of nanogaps due to the process variations are investigated by experiments. Three deformation structures are examined, and it is found that the type Ⅲ exhibits high emission efficiency due to a stronger electric field around the apex and larger emission current among structures. The electron emission current is dependent upon the angle of inclination of surface. Compare to the coplanar structure SCE fabricate by focus ion beam (FIB), for the nanogap with a separation of 90 nm, the turn-on voltage significantly reduces from 135V to 20V after the thermal shock treatment.