Ultrathin NbN films for superconducting single-photon detectors
Wojciech Słysz , Marek Guziewicz , Michał A. Borysiewicz , Jarosław Z. Domagala , Iwona Pasternak , K. Hejduk , Witold Rzodkiewicz , Jacek Ratajczak , Jan Bar , M. Wȩgrzecki , Piotr Grabiec , R. Grodecki , I. Wȩgrzecka , R. Sobolewski
We present our research on fabrication and structural and transport characterization of ultrathin superconducting NbN layers deposited on both single-crystal Al2O3 and Si wafers, and SiO2 and Si 3N4 buffer layers grown directly on Si wafers. The thicknesses of our films varied from 6 nm to 50 nm and they were grown using reactive RF magnetron sputtering on substrates maintained at the temperature 850°C. We have performed extensive morphology characterization of our films using the X-ray diffraction method and atomic force microscopy, and related the results to the type of the substrate used for the film deposition. Our transport measurements showed that even the thinnest, 6 nm thick NbN films had the superconducting critical temperature of 10-12 K, which was increased to 14 K for thicker films.
|Journal series||Acta Physica Polonica A, ISSN 0587-4246, e-ISSN 1898-794X, (A 15 pkt)|
|Publication indicators||= 10; = 10; : 2011 = 0.453; : 2011 = 0.444 (2) - 2011=0.404 (5)|
|Citation count*||16 (2020-01-29)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.