Superconducting Thin-Film Interconnects for Cryogenic Photon Detector Arrays

Advanced imaging spectrometers for x-ray astronomy will require significant improvements in the high density interconnects between the detector arrays and the first stage electronics. These detectors operate at 50 to 100 mK, while the first stage is held between 1.3-1.5 K. Interconnects are needed that provide the required signal paths while imparting a thermal heat load on the detector stage of less than 0.5 microwatts. The innovation proposed to meet this need is a ribbon of ultra-thin polyimide supporting a high-density array of vacuum deposited superconducting traces. No such innovative high-density interconnects are available today. Phase I will test material properties of superconducting thin films fundamental to interconnect performance and prepare prototype devices that demonstrate the feasibility of this approach.