Microminiature thermionic vacuum tube

Abstract

An integrated circuit vacuum tube array includes an insulating or highly resistive substrate, electrically conductive materials disposed on the substrate to define and surround a plurality of first voids extending from the substrate upwardly through the material, a plurality of cathodes disposed on the material to bridge over the respective first voids, for emitting electrons when heated by circuitry that selectively heats the cathodes, first electrically resistive material disposed on the electrically conductive material to surround the cathodes and define a plurality of second voids thereabove, an electrically conductive grid disposed on the electrically resistive material to project partially into the second voids to define an opening in the grid above each cathode, for allowing the passage of electrons therethrough, circuitry to selectively apply a voltage to the grid to control electron flow and thereby control the electrical current produced at the anodes, second electrically resistive material disposed on the grid to define a plurality of third voids above the openings in the grid, and a plurality of electrically conductive anodes disposed on the second electrically resistive material over the third voids to receive electrons emitted by the cathodes and thereby produce an electrical current.