Flip Chip Packaging for Superconducting Qubit: Design Methodology and Simulation

This paper presents the design, simulation, and fabrication process of a superconducting single qubit utilizing Josephson junctions in both planar and flip-chip architectures. The Xmon qubit, characterized by its cross-shaped coplanar waveguide structure and high scalability, is employed to demonstrate the enhancement in coherence, connectivity, and control speed. The Xmon qubit was modeled and validated using Python, Ansys HFSS, and Sonnet software. The fabrication process, including the transmission line and Josephson junction, is also introduced.