Sputtered NbN Films for Ultrahigh Performance Superconducting Nanowire Single-Photon Detectors

Abstract

Nowadays ultrahigh performance superconducting nanowire single-photon detectors are the key elements in a variety of devices from biological research to quantum communications and computing. Accurate tuning of superconducting material properties is a powerful resource for fabricating single-photon detectors with a desired properties. Here, we report on the major theoretical relations between ultrathin niobium nitride (NbN) films properties and superconducting nanowire single-photon detectors characteristics, as well as ultrathin NbN films properties dependence on reactive magnetron sputtering recipes. Based on this study we formulate the exact requirements to ultrathin NbN films for ultrahigh performance superconducting nanowire single-photon detectors. Then, we experimentally study ultrathin NbN films properties (morphology, crystalline structure, critical temperature, sheet resistance) on silicon, sapphire, silicon dioxide and silicon nitride substrates sputtered with various recipes. We demonstrate ultrathin NbN films (obtained with more than 100 films deposition) with a wide range of critical temperature from 2.5 to 12.1 K and sheet resistance from 285 to 2000 ~$\Omega$/sq, as well as investigate a sheet resistance evolution over for more than 40\% within two years. Finally, we found out that one should use ultrathin NbN films with specific critical temperature near 9 K and sheet resistance of 400 ~$\Omega$/sq for ultrahigh performance SNSPD.

The following article has been submitted to APL Materials. After it is published, it will be found at https://pubs.aip.org/aip/apm. Copyright 2023 Author(s). This article is distributed under a Creative Commons Attribution (CC BY) License

References in corpus (13)

• Superconducting nanowire single-photon detectors: physics and applications
• Ultimate low system dark count rate for superconducting nanowire single-photon detector
• Superconducting nanowire detector jitters limited by detector geometry
• Universal scaling of the critical temperature for thin films near the superconducting-to-insulating transition
• GHz detection rates and dynamic photon-number resolution with superconducting nanowire arrays
• Greatly Enhanced Emission from Spin Defects in Hexagonal Boron Nitride Enabled by a Low-Loss Plasmonic Nano-Cavity
• Dark counts of superconducting nanowire single-photon detector under illumination
• Broadband polarization insensitivity and high detection efficiency in high-fill-factor superconducting microwire single-photon detectors
• Current dependence of the hot-spot response spectrum of superconducting single-photon detectors with different layouts
• Demultiplexed Single-Photon Source with a Quantum Dot Coupled to Microresonator
• High-resistivity niobium nitride films for unity-efficiency SMSPDs at telecom wavelengths and beyond
• Superconducting detector of IR single-photons based on thin WSi films
• Site-Selective Enhancement of Superconducting Nanowire Single-Photon Detectors via Local Helium Ion Irradiation

Cited by in corpus (2)

• Atomic layer etching of niobium nitride using sequential exposures of O${}_2$ and H${}_2$/SF${}_6$ plasmas
• Investigation of tantalum films growth for coplanar resonators with internal quality factors above ten million