Dense Array of Field Emitters Using Vertical Ballasting Structures

A field emitter array structure is provided. The field emitter array structure includes a plurality of vertical un-gated transistor structures formed on a semiconductor substrate. The semiconductor substrate includes a plurality of vertical pillar structures to define said un-gated transistor structures. A plurality of emitter structures are formed on said vertical un-gated transistor structures. Each of said emitter structures is positioned in a ballasting fashion on one of said vertical un-gated transistor structures so as to allow said vertical ungated transistor structure to effectively provide high dynamic resistance with large saturation currents.