Minimal lateral damage fabrication of high-temperature superconducting nanowires via focused helium ion beam irradiation

Abstract Low-temperature superconducting nanowire single-photon detectors have become a key infrared photon counting technology in communication and astronomy applications. However, the constrained physical space of devices demands high-performance superconducting detectors capable of operation at higher temperatures. To date, high-temperature superconductor nanowires still face seriously uneven lateral damage in the ion etching process during fabrication. In this work, we report a promising fabrication method for high-temperature superconducting YBa 2 Cu 3 O 7− x (YBCO) nanowires, using a focused helium ion beam to minimize the lateral damage of the cut. Based on simulations, we designed tangent circles and adjacent isosceles triangles to replace lines in cutting nanowires to reduce the superimposed damage by He + ions. The lateral damage of a single helium ion cut has been reduced with a decrease in superimposed damage width from 58.8 nm to 29.7 nm. This work provides a platform for boosting YBCO nanowires to achieve single photon detection.