Field-emission element having a cathode with a small radius

摘要

The invention is a field-emission element that is fabricated by forming an elevated surface and a base surface on a conductive substrate or a semiconductor substrate by applying a photolithographic process and an etching process, and making these surfaces cross at a step with an acute angle between the two surfaces. The intersection of the elevated surface with the step form a cathode having a radius of curvature of less than 20 nm. A gate electrode formed on the base electrode but insulated therefrom is disposed at a distance less than 1 mu m from said cathode by controlling the distance by the thickness of an etching protection mask. The field-emission element enables electrons to be emitted from the cathode when a voltage less than 150V is applied between the cathode and the gate electrode.