Characterization of NbN/AlN/NbN tunnel junctions fabricated without intentional heating
We have fabricated by SNEP process Nb/Al/NbN/AlN/NbN Josephson junctions with the gap voltage V/sub g/=2/spl Delta//e/spl ap/4.0 mV, subgap leakage R/sub sg//R/sub n//spl ap/6.0, current density measured at the gap current rise J/sub g//spl ap/1.5 kA/cm/sup 2/. The (111)-textured NbN with transition...
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Published in | IEEE transactions on applied superconductivity Vol. 7; no. 2; pp. 2805 - 2808 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
IEEE
01.06.1997
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Subjects | |
Online Access | Get full text |
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Summary: | We have fabricated by SNEP process Nb/Al/NbN/AlN/NbN Josephson junctions with the gap voltage V/sub g/=2/spl Delta//e/spl ap/4.0 mV, subgap leakage R/sub sg//R/sub n//spl ap/6.0, current density measured at the gap current rise J/sub g//spl ap/1.5 kA/cm/sup 2/. The (111)-textured NbN with transition temperature T/sub c//spl ap/16 K have been deposited at ambient substrate temperature. Phase composition and structure of the NbN films were investigated by X-ray diffraction analysis (XRD). It was found that the films have a structure close to the cubic /spl delta/-NbN (JCPDS card N38-11556) and the phase composition and intrinsic stress in NbN depend on Ar and N/sub 2/ partial pressure during DC magnetron sputtering. Cross-sectional TEM analysis showed that in-situ deposition of thin Al layer in the base Nb/Al/NbN electrode provides effective planarization of its surface and the result in improvement of tunnel junction parameters. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 1051-8223 1558-2515 |
DOI: | 10.1109/77.621820 |