Establishing an end-to-end workflow for SNSPD fabrication and characterization

The outstanding performance of superconducting nanowire single-photon detectors (SNSPDs) has expanded their application areas from quantum technologies to astronomy, space communication, imaging, and LiDAR. As a result, there has been a surge in demand for these devices, that commercial products cannot readily meet. Consequently, more research and development efforts are being directed towards establishing in-house SNSPD manufacturing, leveraging existing nano-fabrication capabilities that can be customized and fine-tuned for specific needs. We report on the implementation of an end-to-end workflow for SNSPD fabrication and characterization, from superconducting film growth to meander nanowire fabrication and their integration with electrical readout circuits and optical testbeds. An essential aspect of this research involved identifying the key parameters of our workflow and developing reliable procedures for their optimization. As an outcome, the ab initio development of SNSPD technology yielded devices with characteristics comparable to commercial devices at a wavelength of 1550 nm, making them well-suited for telecommunication and integrated quantum systems. This report aims to provide useful insights to those entering the field and accelerate the establishment of superconducting detector technology and its application across various domains.