Field emitter having source, channel, and drain layers

A field emission device having a three-dimensional emitter rising from a base fixed on a base member serving as a support member and adapted to emit cold electrons from an electric field concentration formed at a distal end thereof under application of an electric field produced by applying a voltage to an extractor gate provided near the distal end, the field emission device comprising:

• an n-type semiconductor source layer provided on the base side of the emitter;
• an n-type semiconductor drain layer provided on the distal end side of the emitter;
• a channel region layer provided between the source layer and the drain layer for controlling an amount of current passage in dependence on the magnitude of the applied electric field;
• and
• a second gate provided separately of the extractor gate, an electric field generated by the second gate in proportion to a voltage applied thereto being applied to the channel region layer for controlling the amount of current passage in the channel region layer;
• wherein:
• said electric field concentration comprises one of an electric field concentration tip and an electric field concentration edge.