Design and Implement of Notched Tether for Large-Volume Micro-Transfer-Printing Technique

This study leverages MEMS technology to realize notched oxide tethers and mechanical supports/stoppers on silicon substrate to enable large-volume micro-transfer-printing (µTP). The proposed concept incorporates several key design features, and has been demonstrated on the SOI wafer. The suspended oxide layer on the source substrate is utilized to form the tethers, while a notch is designed to concentrate stress, facilitating controlled fracture of the oxide tether during transfer. The sidewall of substrate cavity provides mechanical support to the oxide tether, improving contact between the stamp and the microdevices. It also functions as a mechanical stopper, preventing excessive bending of the microdevice during the preload stage. Together, these features significantly enhance the yield of large-volume microdevice transfer. Experimental results validate the effectiveness of the proposed approach.