Design, Fabrication and Characterization of Molybdenum Field Emitter Arrays (Mo-FEAs)

We report on the fabrication of highly uniform field emitter arrays (FEAs) with an integrated self-aligned extraction gate from bulk molybdenum. All critical dimensions of the emitter tip were determined by a single process step of Inductively Coupled Plasma (ICP) etching. In addition, the height difference between the emitter tip and the gate plane was controlled by the thickness of the SiO2 dielectric layer. A 10 μm gate aperture molybdenum-FEAs (Mo-FEAs) at a typical 20 μm pitch with 6 μm height was achieved with 8.4 mA/cm2 current density at gate voltages of 110 V and the turn-on field of 1.4 V/μm. These self-aligned Mo-FEAs could be expanded to active larger areas to increase the emission current.