Continuous roller transfer-printing and automated metrology of >75,000 micro-LED pixels in a single shot

Abstract

A continuous, single shot roller transfer printing process is presented for the large-scale hybrid integration of semiconductor devices. Transfer of a 320 × 240 pixel micro-LED array, representing >75,000 individual devices in a single shot with sub-micron relative position accuracy is demonstrated. The transfer printing process preserves the array geometry with pixel spatial location error less than 1 µm deviation from the as-designed layout. An automated sub-micron precision metrology system based on simple optical microscopy was developed to asses such large device populations and allow the assessment of yield.