Current sensitivity of the Spindt-type field emitter

The emission current has been found to be strongly dependent on the distance from the tip of an emitter to the gate. The tip height was varied by either adjusting the aluminum lift-off layer thickness, which in turn changes the well diameter during tip deposition or by varying the fabrication process. In this study, the dependence of emission current on tip height for Spindt-type field emitters is investigated over a range varying from below the gate surface to well above the gate surface. The tip height is varied by adjusting the well diameter in the photo mask or the thickness of dielectric layer between the gate and base.