US 10,652,963 B2 · LED display structures and fabrication of same

Abstract

LED structures (e.g., LED arrays) and fabrication methods can reduce or even eliminate deep etching, and associated defect formation, proximate sites of individual LEDs. Such approaches can achieve desired electrical isolation without deep etching, provide a high conductivity current spreading layer, and, or reduce losses otherwise associated with conventional fabrication approaches. Some implementations advantageously lift off or separate an insulating substrate from a wafer to expose a bottom surface of the epitaxial LED layer and forms a backside contact (e.g., ground plane) overlying the bottom surface. Other implementations isolate deep etching away from sensitive regions and locate the backside contact on a top surface of the epitaxial LED layer. Some implementations form light extraction features (e.g., photonic crystals) on the exposed bottom surface. The top surface of the epitaxial LED layer may be undoped to improve electrical isolation. The bottom surface of may be shallow etched to improve light extraction.

Claims19

Dependent claims

A method of fabricating a light emitting diode structure, the method comprising:

forming a set of contacts overlying a front surface of an epitaxial LED layer of a wafer, the wafer comprising a substrate and the epitaxial LED layer carried by the substrate;
forming an insulator overlying the set of contacts;
forming a plurality of throughholes that extend through the insulator to the contacts;
integrating a set of drive circuits;
connecting respective ones of the drive circuits to respective ones of the contacts by way of respective ones of a set of vias formed by the throughholes;
separating a structure resulting from the previous operations from the substrate to expose a back surface of the epitaxial LED layer;
and
forming at least one backside contact overlying the back surface of the epitaxial LED layer exposed by the separation of the substrate therefrom.

5 more elements

Dependencies are inferred from the claim text.

LED display structures and fabrication of same

Life of this patent

LED display structures and fabrication of same

Life of this patent

Abstract

Claims19