Field emission cold cathode and method for manufacturing the same

Abstract

A field emission cold cathode includes a conductive substrate, an insulating layer formed on the substrate and having plural cavities each for receiving an emitter, a gate electrode for applying a high electric field to the tips of emitters. An annular portion of the gate electrode defines an opening of a corresponding cavity is located at a distance from the substrate smaller than the distance between an elevated middle portion of the gate electrode and the substrate. Parasitic capacitance between the gate electrode and the cold cathode including the substrate and the emitter is reduced due to the large distance between the elevated middle portion of the gate electrode and the substrate. Between the elevated middle portion and the substrate, a second insulating layer or a gap is disposed. The field emission cold cathode can function in a high frequency range while fabricating conical emitters with a small height due to the small distance between the annular portions and the substrate.

Dependencies are inferred from the claim text.