Superconducting MoN thin films prepared by DC reactive magnetron sputtering for nanowire single-photon detectors

Abstract

We present a comprehensive study of molybdenum nitride (MoN) thin film deposition using direct current reactive magnetron sputtering. We have investigated the effect of various deposition conditions on the superconducting and electrical properties of the films. Furthermore, we have shown that meander-shaped single-photon detectors made from 5 nm MoN films have saturated quantum detection efficiency at the telecom wavelength of 1550 nm. Our results indicate that MoN may be a material of interest for practical applications of low-temperature superconductors, including single-photon detectors and transition-edge sensors.

Nanocrystalline superconducting γ-Mo2N ultra-thin films for single photon detectors

“…PQ values at low fields are up to ≈ 1300 m/s and decay as the magnetic field increases. For B > 0.1 T, PQ (7) decreases as 1/√7 (see dotted lines). The shift from the 1/√7 dependence at small fields is usually related to a low density of vortices and pinning inducing disorder at the vortex lattice (deviations from an Abrikosov vortex lattice) [25].…”

“…These systems present uniform superconductivity in films with thicknesses of a few nanometers and display a τ e shorter than the ns. An alternative material for applications in detectors of radiation is γ-Mo 2 N [7,8]. Nanocrystalline γ-Mo 2 N preserves superconductivity in ultra-thin films [9,10].…”

Magnetron Sputtered Thin Films Based on Transition Metal Nitride: Structure and Properties

“…Because of its outstanding features, MoN films find their applications in the fields such as hard coating in cutting tools, [233] microelectronics, [234] solar cells, [235] MEMS devices, [224] fuel cells, [236][237][238] super conductors, [239][240][241][242][243] diffusion barriers, [230,244] Li-ion batteries, [245] etc.…”

Stoichiometry Effects on the Chemical Ordering and Superconducting Properties in TiZrTaNbNx Refractory High Entropy Nitrides

“…[1] For sputter-deposited nitride thin films, the stoichiometry of nitrogen can be easily tuned by controlling the deposition condition DOI: 10.1002/andp.202300470 such as reactive gas partial pressure, thus allowing for the tailoring of their physical, chemical, and mechanical properties. Superconducting properties of nitride compounds with a NaCltype structure, such as TiN x , [2] NbN x , [3] VN x , [4] MoN x , [5] ZrN x , [6] and TiNbN, [7] have been widely studied by adjusting the nitrogen stoichiometry. These transitionmetal nitrides have been found in a broad range of device applications, including single phonon detectors, [8,9] accelerator cavities, [10] superconducting resonators, [11] and qubit computers.…”