Field-emission cold-cathode electron gun having emitter tips between the top surface of gate electrode and focusing electrode

摘要

A field-emission cathode comprises a substrate having a conductive surface, a gate electrode and a focusing electrode overlying the substrate with insulation layers interposed therebetween, a plurality of cavities formed by penetrating the gate electrode, focusing electrode and insulation layers, and an emitter formed in each of the cavities on the substrate for emission of an electron beam. The emitter has tip located at a level between the gate electrode and the focusing electrode, which receive therebetween a signal for modulating the electron beam at a high frequency.