Emission sensitivity to tip position of Spindt-type field emitters

Abstract

The emission characteristics of the Spindt-type field emitter are investigated as a function of the tip position with respect to the gate. The tip position is varied by either changing the hole diameter in the photomask or the dielectric layer thickness. Under low anode field, the measured emission current is sensitive to the tip position and drops quickly as the tip rises above the middle of the gate, which is consistent with the computer simulation result. Under high anode field, the computer simulation result shows that the emission increases for some distance above the gate electrode and then slowly falls off with increasing tip height. There is a “flat” region where emission is less sensitive to the tip position. The array with tall tips shows better emission uniformity. Two different types of emission patterns are observed for short and tall tips. The short tips show large blurry spots and the tall tips small sharp spots.