Transport properties of SINIS junctions with high-current density
- Resource Type
- Periodical
- Authors
- Born, F.; Cassel, D.; Ilin, K.; Klushin, A.M.; Siegel, M.; Brinkman, A.; Golubov, A.A.; Kupriyanov, M.Yu.; Rogalla, H.
- Source
- IEEE Transactions on Applied Superconductivity IEEE Trans. Appl. Supercond. Applied Superconductivity, IEEE Transactions on. 13(2):1079-1084 Jun, 2003
- Subject
- Fields, Waves and Electromagnetics
Engineered Materials, Dielectrics and Plasmas
Niobium
Current density
Lithography
Voltage
Fabrication
Oxidation
Nonhomogeneous media
Temperature dependence
Tunneling
Electrostatic measurements
- Language
- ISSN
- 1051-8223
1558-2515
2378-7074
We have fabricated Nb/Al/sub 2/O/sub 3//Al/Al/sub 2/O/sub 3//Nb devices with different current densities using a conventional fabrication process, varying pressure and oxidation time. Patterning of the multilayers was done using standard photolithography and electron-beam lithography. The current density of SINIS junctions was changed in the range from 0.5 kA/cm/sup 2/ to 20 kA/cm/sup 2/. We achieved characteristic voltages up to 0.35 mV. By fabricating sub-/spl mu/m junction with a width from 0.1 /spl mu/m to 0.5 /spl mu/m, we have studied the influence of the asymmetry of barriers on transport properties. By comparing the experimental and theoretical temperature dependence of the characteristic voltage we estimated the barrier transparency and its asymmetry. The comparison shows a good agreement of experimental data with the theoretical model of tunnelling through double-barrier structures in the dirty limit. A new approach for determination of the asymmetry of both barriers based on the measurement of the electrostatic field distribution in the SINIS structure has been developed.