Ultrathin NbTiN Films With High Ti Composition for Superconducting Nanowire Single Photon Detectors

Author

Jia, X.Q. ; Kang, L. ; Yang, X.Z. ; Wang, Z.H. ; Ren, T.K. ; Jin, B.B. ; Chen, Jiann-Jong ; Xu, W.W. ; Wu, P.H.

Author_Institution

Res. Inst. of Supercond. Electron. (RISE), Nanjing Univ., Nanjing, China

Volume

25

Issue

3

fYear

2015

fDate

Jun-15

Firstpage

1

Lastpage

4

Abstract

We have fabricated and characterized ultrathin NbTiN films with high Titanium (Ti) composition for applications of superconducting nanowire single photon detectors (SNSPD). An alloy with 47 wt. % Ti and 53 wt. % Nb as the target material is employed. NbTiN thin films with thicknesses ranging from 5 nm to 20 nm are grown onto MgO (100), Si (100) and SiO_X-Si substrates by DC magnetron sputtering. The zero resistance superconducting transition temperature (T_C0) of about 8.8 K has been obtained for the NbTiN film of 8 nm thick on MgO substrate. With twice Ti composition than usual NbTiN film, the lattice mismatch and low resistivity are further improved, which will be more favorable for the performance of SNSPD. The results of the films´ structural characterizations by AES, AFM, TEM and XRD are also presented.

Keywords

Auger electron spectra; X-ray diffraction; atomic force microscopy; electrical resistivity; nanosensors; nanowires; niobium compounds; sputter deposition; superconducting photodetectors; superconducting thin films; superconducting transition temperature; thin film sensors; titanium compounds; transmission electron microscopy; AES; AFM; DC magnetron sputtering; MgO; MgO(100) substrates; NbTiN; SNSPD; Si; Si(100) substrates; SiO_X-Si; SiO_X-Si substrates; TEM; XRD; lattice mismatch; size 5 nm to 20 nm; structural characterization; superconducting nanowire single photon detectors; titanium composition; ultrathin films; zero resistance superconducting transition temperature; Detectors; Films; Lattices; Photonics; Silicon; Substrates; Superconducting transition temperature; Magnetron sputtering; Niobium nitride; Niobium titanium nitride; magnetron sputtering; niobium nitride; superconducting ultra-thin film;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2014.2373818

Filename

6963351