Continuous Roller Transfer-Printing and Automated Metrology of >75,000 Micro-Led Pixels in a Single Shot

A continuous, single shot roller transfer printing process is presented for the large-scale hybrid integration of semiconductor devices. Transfer of a 320 x 240 pixel micro-LED array, representing >75,000 individual devices 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 microscopy-based metrology system was developed to assess such large device populations with sub-micron accuracy and allow the assessment of yield.