Manuela Junghaehnel, Steffen Bickel, Kay Viehweger, Fraunhofer IZM-ASSID, Moritzburg, Germany
Within the the 5-year joint BMBF funded project “Quantum computer in the solid state – QSolid” the central goal is the development of a fault-tolerant quantum computer based on superconducting qubits and its early integration into the exist-ent super-computing environment at Forschungszentrum Jülich. In this project, a quantum computer demonstrator with processor generations of different perfor-mance profiles (size, precision, application reference) based on superconducting circuits will be created.
Fraunhofer IZM-ASSID is involved in the subproject “technology for hardware inte-gration”, in which it works on the task “cryogenic packaging solutions” in coopera-tion with Globalfoundries, Fraunhofer IPMS and FZJ regarding the co-integration of qubits and adapted control- and readout-electronics into a scalable packaging solu-tion. The main challenge is given by a combination of an effective thermal decou-pling and highly dense superconducting wires between the quantum-processing unit and the control electronic devices at cryogenic conditions. Therefore, the silicon-flex-interposer approach developed at IZM-ASSID is of special interest. In detail, the realization of thin-film TiN based superconducting wiring and Indium bump bonds including an optimization of interface materials and associated processes on 300 mm wafer level are the key aspects. We report about the current status of the research activities.