Technology of Ultrathin NbN and NbTiN Films for Superconducting Photodetectors
M. Guziewicza, W. Slysza, M. Borysiewicza, R. Kruszkaa, Z. Sidora, M. Juchniewicza, K. Golaszewskaa, J.Z. Domagalaa, b, W. Rzodkiewicza, J. Ratajczaka, J. Bara, M. Wegrzeckia and R. Sobolewskia, c
aInstitute of Electron Technology, al. Lotników 32/46, 02-668 Warsaw, Poland
bInstitute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
cDepartments of Electrical and Computer Engineering and Physics and Astronomy, Materials Science Program, and Laboratory for Laser Energetics, University of Rochester, Rochester, NY-14627-0231, USA
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We report fabrication and characterization of ultrathin NbN and NbTiN films designed for superconducting photodetectors. Our NbN and NbTiN films were deposited on Al2O3 and Si single-crystal wafers by a high-temperature, reactive magnetron sputtering method and, subsequently, annealed at 1000°C. The best, 18 nm thick NbN films deposited on sapphire exhibited the critical temperature of 15.0 K and the critical current density as high as ≈ 8 × 106 A/cm2 at 4.8 K.
DOI: 10.12693/APhysPolA.120.A-76
PACS numbers: 74.62.Bf, 74.78.-w, 81.15.Cd, 81.15.Jj