FABRICATION OF ARRAYED GLASSY-CARBON FIELD EMITTERS

Glassy carbon has desirable properties for electron field emission suc h as surface inertness, electrical conductivity, and thermal stability . In addition, a uniform thick substrate with a polished surface is ea sily obtainable. This enables one to apply large scale integrated circ uit processing for fabricating arrayed tips. By using oxygen reactive ion etching, cusps over 3.5 mu m in height and 2.5 mu m in base diamet er are fabricated with a tip radius of under 10 nm. The process is ass isted by the formation of a layer of etch products which protects the newly forming tip from bending and over etching. The field emission cu rrent up to 50 mu A from the glassy carbon tips is obtained by applyin g high voltage to a mesh anode. The current which passed through the m esh anode is collected at another electrode and measured. The Fowler-N ordheim plot suggests the existence of nm scale structure on the tip. This favorable result indicates glassy carbon substrate is a good subs trate for held emitter arrays. (C) 1997 American Vacuum Society.