High-throughput photoluminescence-based optical inspection for MicroLED wafers

Yield management plays a pivotal role in reaching high-volume microLED manufacturing capability. Yield is a key element in manufacturing cost and its control requires full-wafer inspection, where each microLED device is individually measured. On the other hand, the display industry is driving for an ever-decreasing device size. Current GaN/InGaN microLEDs have typical characteristic dimensions of 1-10 micrometer. These two requirements mean that there is a need for fast and accurate inspection metrologies for microLED characterization.