Superconducting routing platform for large-scale integration of spin qubits

We will report on the fabrication, using 200 mm silicon wafer technologies, of a multi-layer routing platform designed for the hybridization and three-dimensional integration of spin qubit arrays and control electronics chips. This interposer electrically couples the qubits and the control circuits using front-side superconducting routing layers made from standard microelectronics materials such as TiN and Al_0.995Cu_0.005 as well as Nb and NbN superconductors. These layers are connected between them by W-based vias. Electrical characterizations of this platform routing layers will be detailed. Wafer-level parametric tests at 300 K validate the high yield of these technologies. Low temperature electrical measurements in cryostat identify the superconducting regimes of Al_0.995Cu_0.005, TiN, Nb and NbN in terms of temperature, magnetic field and current, highlighting the compatibility of these materials with the Si spin qubit operating conditions. Based on these results, radio frequency passive components have been designed and integrated on the interposer to form reflectometry circuits, providing read-out alternatives. Preliminary low temperature high frequency measurements performed on superconducting embedded resistors, capacitors and inductors will be presented.