FABRICATION AND CHARACTERIZATION OF VOLCANO-SHAPED FIELD EMITTERS SURROUNDED BY PLANAR GATES

Micron-sized volcano field emitters have been developed and demonstrat ed using a new fabrication process. The key element of the process is the formation of the volcano-shaped thin-film emitter by sputtering te chnique, which results in very thin emission sites due to the shadowin g effect of the masking oxide disk. For the emitter array with 1.5-mu m-diam gate apertures, an anode current of 0.1 mu A per emitter was ob tained at the gate voltage of about 88 V. The emission performance is comparable to that of the cone-like held emitter with the same gate ho le size. Since the field conversion factor of an off-axis rim must be much smaller than that of the apex of a cone emitter with the same eff ective emission radius, the comparable operating voltage between two t ypes implies the formation of the rim emitters with extremely thin emi ssion sites by the new process. (C) 1997 American Vacuum Society.