APPLICATION OF THE FOCUSED ION-BEAM TECHNIQUE TO THE DIRECT FABRICATION OF VERTICAL-TYPE FIELD EMITTERS

The focused ion beam (FIB) technique has been applied to the direct fabrication of vertical-type field emitters for vacuum microelectronics. A gate and emitter can be formed directly by etching metal/insulator/semiconductor (MIS) structure with an FIB. A rotationally deflected FIB erodes the metal surface to produce a ring-shaped groove, and finally produces a small protrusion made of semiconductor (field emitter). The present process is simple, self-aligned, and a direct process which does not require the electrode material to have a specified chemical property. In the present study, sputter etched structures have been evaluated with a dynamical simulation, and compared with those fabricated under the similar condition. The calculated structure agreed with the fabricated structure, which means the present simulation gives a reasonable estimation of the FIB fabricated structures. Also, attempts have been made to optimize fabrication conditions and emitter materials.