Micro-Transfer Printing of SiGe BiCMOS Electronic Chiplets on Silicon

We demonstrate micro-transfer printing ($\mu$TP) and post-printing metallization of thin electronic chiplets on silicon, with a view to heterogeneously integrate electronic integrated circuits (EICs) with photonic integrated circuits (PICs).$\mu$TP decouples the fabrication of EICs and PICs, and simultaneously enables their tight integration with high-throughput, small form-factor and on wafer-scale. In this study, we successfully established the process flow for releasing and printing 300$\mu$m × 200$\mu$m SiGe BiCMOS electronic driver chiplets and electrically connecting these chiplets using a polymer ramp to overcome the 20-$\mu$m chiplet thickness, providing a gain of 14 dB and bandwidth of over 35 GHz with low-parasitic interconnections. The proposed methodology provides a practical and mass-producible solution to realize the stacking of EICs on silicon photonic wafers for emerging applications such as co-packaged optics (CPO).