Fabrication of petal-shaped vertical field emitter arrays

We have invented a novel field emitter array (FEA) with a petal-shaped design. The emitter has a metal-disk fitted into a silicon (III) pyramidal hole; viewed from an angle it resembles the petal of a flower, We have elucidated the relationships between the detailed structure and the emission characteristics and have achieved the threshold voltage of 60 V, the emission current of 20 mu A at the gate voltage of 150 V and the anode current fraction of 90% in this new structure. We could fabricate the present FEA as easily as the disk-shaped lateral FEA, and it gives a much higher anode current fraction than does the latter. We have also investigated the improvement of the surface condition of the emitter, and obtained the lowest threshold voltage of 17V with metal-coated FEAs.