| Autor: |
J Du, A D M Charles, K D Petersson, E W Preston |
| Předmět: |
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| Zdroj: |
Superconductor Science & Technology; Nov2007, Vol. 20 Issue 11, pS350-S355, 6p |
| Abstrakt: |
In this work, we investigate the influence of the Nb film surface roughness on the microstructure of Nb/AlOx-Al/Nb trilayers and the current-voltage (I-V) characteristics of the trilayer junctions. The surface morphology of the base-Nb film was found to directly affect the Al layer coverage of the base-Nb and the quality of the Al/Nb interface. Diffusion of Al at the Al/Nb interface increases with increasing roughness of the base-Nb layer, which results in micro-shorts or pinholes in the insulating barrier layer and increases the sub-gap leakage current of the junctions. We correlate the I-V characteristics of the junctions to their microstructures and show that Nb surface roughness and Nb/Al interface quality play critical roles in determining the sub-gap leakage characteristics of the trilayer junctions. High-quality Nb/Al-AlOx/Nb trilayer junctions with very low sub-gap leakage currents were obtained after optimizing the Nb film surface morphology. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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