Fabrication of arrayed glassy carbon field emitters

Glassy carbon has desirable properties for electron field emission such as surface inertness, electrical conductivity, and thermal stability. In addition, a uniform thick substrate with a polished surface is easily obtainable. This enables one to apply large scale integrated circuit processing for fabricating arrayed tips. By using oxygen reactive ion etching, cusps over 3.5 μm in height and 2.5 μm in base diameter are fabricated with a tip radius of under 10 nm. The process is assisted by the formation of a layer of etch products which protects the newly forming tip from bending and over etching. The field emission current up to 50 μA from the glassy carbon tips is obtained by applying high voltage to a mesh anode. The current which passed through the mesh anode is collected at another electrode and measured. The Fowler-Nordheim plot suggests the existence of nm scale structure on the tip. This favorable result indicates glassy carbon substrate is a good substrate for field emitter arrays.