Broadband Hetero-Integration of InP Chiplets on SiGe BiCMOS for mm-Wave MMICs up to 325GHz

We present a broadband flip-chip approach for the hetero-integration of indium phosphide based chiplets on a BiCMOS carrier. To accommodate for a limited temperature budget, the process temperatures are kept below 200°C in order to not degrade device performance. Using indium soldering together with a pillar-based approach instead of the common bump array technique ensures good scalability, repeatability and flexibility in terms of complex broadband transitions. The RF performance of this transitions was evaluated using standard 50Ω microstrip line test chips and carriers without any special interconnect optimization. The results show excellent broadband characteristics from DC up to 325GHz.