Cryogenic Microwave Wafer-Scale Characterization of Superconducting Resonators for Improved Fabrication Yield

Superconducting resonators are used for the readout of superconducting transmon qubits. As quantum computers scale, fabrication yield becomes a critical component for success. Errors during the fabrication process results in larger distributions and offsets from designed parameters. For superconducting devices, this can lead to issues with frequency crowding and weak coupling to the qubit. We used a 4 K wafer prober to form a statistical data set for the center frequency of superconducting readout resonators across an entire wafer. The resonators were measured with a single port probe in hanger-mode configuration. We were able to produce wafer maps showing frequency variation which can be used to inform fabrication process.