NbTiN thin films for superconducting photon detectors on photonic and two-dimensional materials

Steinhauer, Stephan; Yang, Lily; Gyger, Samuel; Lettner, Thomas; Errando-Herranz, Carlos; Jöns, Klaus D.; Baghban, Mohammad Amin; Gallo, Katia; Zichi, Julien; Zwiller, Val

doi:10.1063/1.5143986

Cited by 30 publications

(23 citation statements)

References 38 publications

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“…NbTiN films with thicknesses of 6 and 9 nm (samples L135 and L134, respectively, in Table I) were deposited on 270-nmthick SiO 2 layers thermally grown on Si substrates. Details of the deposition process were reported elsewhere [17]. According to studies of films prepared under the same sputtering conditions [18], the compositions of our Nb x Ti 1−x N films had a Nb fraction of approximately x = 0.6 and a polycrystalline granular structure with diameters of most grains in the range from 4 to 5 nm.…”

Section: Experiments and Resultsmentioning

confidence: 99%

Magnetoconductance and photoresponse properties of disordered NbTiN films

et al. 2021

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We report on the experimental study of phonon properties and electron-phonon scattering in thin superconducting NbTiN films, which are intensively exploited in various applications. Studied NbTiN films with sub-10-nm thicknesses are disordered with respect to electron transport, the Ioffe-Regel parameter of kFle=2.5-3.0 (kF is the Fermi wave vector, and le is the electron mean free path), the inelastic electron-phonon interaction, and the product qTle1 (qT is the wave vector of a thermal phonon). By means of magnetoconductance and photoresponse techniques, we derive the inelastic electron-phonon scattering rate 1/e-ph and determine sound velocities and phonon heat capacities. In the temperature range from 12 to 20 K, the scattering rate varies with temperature as 1/e-phT3.45±0.05; its value extrapolated to 10 K amounts to approximately 1/16 ps. Making a comparative analysis of our films and other films used in superconducting devices, such as polycrystalline granular NbN and amorphous WSi, we find a systematic reduction of the sound velocity in all these films by about 50% compared to the corresponding bulk crystalline materials. A corresponding increase in the phonon heat capacities in all these films is, however, less than the Debye model predicts. We attribute these findings to reduced film dimensionality and film morphology.

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Section: Experiments and Resultsmentioning

confidence: 99%

Magnetoconductance and photoresponse properties of disordered NbTiN films

et al. 2021

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“…70 nm wide, 10 nm thick), respectively. Lower DCR values of few cps and below can be achieved in detectors with significantly shorter [21], [22] and wider nanowires [4], [18], [19]. The trade-off of reducing DCR in such ways leads to reduced ability of detecting low-energy particles and the overall detection efficiency.…”

Section: A Dark Count Rate and Critical Currentmentioning

confidence: 99%

X-Ray Induced Secondary Particle Counting With Thin NbTiN Nanowire Superconducting Detector

Branny

Didier

Zichi

et al. 2021

IEEE Trans. Appl. Supercond.

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We characterized the performance of a biased superconducting nanowire to detect X-ray photons. The device, made of a 10 nm thin NbTiN film and fabricated on a dielectric substrate (SiO2, Nb3O5) detected 1000 times larger signal than anticipated from direct X-ray absorption. We attributed this effect to X-ray induced generation of secondary particles in the substrate. The enhancement corresponds to an increase in the flux by the factor of 3.6, relative to a state-of-the-art commercial Xray silicon drift detector. The detector exhibited 8.25 ns temporal recovery time and 82 ps timing resolution, measured using optical photons. Our results emphasise the importance of the substrate in superconducting X-ray single photon detectors.

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“…NbTiN films with thicknesses 6 and 9 nm (samples #L135 and #L134, respectively, in Table I) were deposited on 270 nm-thick SiO 2 layers thermally grown on Si substrates. Details of the deposition process have been reported elsewhere [11]. According to studies of films prepared under the same sputtering conditions [12], the compositions of our Nb x Ti 1−x N films had a Nb/Ti fraction of approximately x = 0.6 and polycrystalline granular structure with diameters of most grains in the range from 4 to 5 nm.…”

Section: Experiments and Resultsmentioning

confidence: 99%

Magnetoconductance and photoresponse properties of disordered NbTiN films

Sidorova,

Semenov,

Huebers

et al. 2021

Preprint

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We report on the study of phonon properties and electron-phonon coupling in thin NbTiN films, which are intensively exploited in superconducting devices. Studied NbTiN films with thicknesses less than 10 nm are disordered with respect to electron transport, the Ioffe-Regel parameter of kF le = 2.5 − 3.0 (kF is the Fermi wave vector and le is the electron mean free path), and inelastic electron-phonon interaction, the product qT le 1 (qT is the wave vector of a thermal phonon). By means of magnetoconductance and photoresponse techniques, we derived the inelastic electronphonon scattering rate 1/τ e−ph and determined sound velocities and phonon heat capacities. In the temperature range from 12 to 20 K, the scattering rate varies with temperature as 1/τ e−ph ∝ T 3.45±0.05 ; its value extrapolated to 10 K amounts to approximately 16 ps. Making a comparative analysis of our films and other films used in superconducting devices, such as polycrystalline granular NbN and amorphous WSi, we found a systematic reduction of the sound velocity in all these films by about 50% as compared to the corresponding bulk crystalline materials. A corresponding increase in the phonon heat capacities in all these films is, however, less than the Debye model predicts. We attribute these findings to reduced film dimensionality and film morphology.

show abstract

NbTiN thin films for superconducting photon detectors on photonic and two-dimensional materials

Cited by 30 publications

References 38 publications

Magnetoconductance and photoresponse properties of disordered NbTiN films

Magnetoconductance and photoresponse properties of disordered NbTiN films

X-Ray Induced Secondary Particle Counting With Thin NbTiN Nanowire Superconducting Detector

Magnetoconductance and photoresponse properties of disordered NbTiN films

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