Fabrication of matrix-addressable InGaN-based microdisplays of high array density

Abstract

We describe the fabrication and characterization of matrix-addressable microlight-emitting diode (micro-LED) arrays based on InGaN, having elemental diameter of 20 μm and array size of up to 128 × 96 elements. The introduction of a planar topology prior to contact metallization is an important processing step in advancing the performance of these devices. Planarization is achieved by chemical-mechanical polishing of the SiO2-deposited surface. In this way, the need for a single contact pad for each individual element can be eliminated. The resulting significant simplification in the addressing of the pixels opens the way to scaling to devices with large numbers of elements. Compared to conventional broad-area LEDs, the micrometer-scale devices exhibit superior light output and current handling capabilities, making them excellent candidates for a range of uses including high efficiency and robust microdisplays.