3D Integration of Superconducting Qubits in a Three-Tiered Quantum Processor*

Heterogeneous 3D integration is an enabling technology for the construction of a quantum processor with a large number of superconducting qubits and a high degree of qubit interconnectivity. Our approach entails the construction of a three-tiered quantum processor where the high-coherence superconducting qubits are controlled and read-out through superconducting through silicon vias (TSVs) in an interposer which is bump bonded to a superconducting multichip module using indium microbumps. We will discuss our work on the fabrication and integration of the interposer with superconducting TSVs as well as the superconducting multichip module and the electrical data measured from test structures.