Scannable light emitting diode array and method

Abstract

Abstract There is disclosed a monolithic light display comprising a matrix of light emitting diodes in an integral structure which is scannable to produce an alpha numeric character display. Groups of the light emitting diodes are electrically isolated from other groups of diodes by a supporting carrier and an isolation channel with the cathode of the diodes connected in a series of groups by address or row lines and anodes connected in an orthagonal plurality of groups by bit or column lines. A conductive bus in the isolation channel forms the connection for either the row or column lines. A strobing format logic address system is provided for lighting the individual diodes to emission for producing an alpha numeric character. There is also disclosed a method of manufacturing the foregoing which comprises placing an epitaxial layer of a first conductivity type semiconductor material upon a substrate of semiconductor material having an intrinsic or semi insulating conductivity. Then channels are etched through the epitaxial layer to the semi insulating semiconductor substrate, thereby forming the epitaxial material into a plurality of parallel ribs or ridges. After coating the entire surface of the channels and the ridges with a dielectric layer, a conductive material is deposited over the substrate to fill the channels with the conductive material which may be either a metal or polycrystalline silicon doped to have sufficient conductivity. The surface of the substrate is then lapped to remove the conductive material and the dielectric material from the ridges to expose the first semiconductor material, and following diffusion of a dopant to convert the first semiconductor material to a second conductivity type material thereby forming a PN junction in each of the ridges in spaced locations therealong, suitable metallization is placed on the substrate to connect the first conductivity material to the conductive material in the channels to form column lines and metallization is placed on top a dielectric layer to connect the other conductivity material in a plurality of row lines.

Inventors

• 👤 L Grenon
• 👤 M Coleman

Bibliographic Details