Fabrication of high quality Nb/AlO/sub x/-Al/Nb Josephson junctions. II. Deposition of thin Al layers on Nb films

Author

Imamura, T. ; Hasuo, S.

Author_Institution

Fujitsu Lab. Ltd., Atsugi, Japan

Volume

2

Issue

2

fYear

1992

fDate

6/1/1992 12:00:00 AM

Firstpage

84

Lastpage

94

Abstract

The surface of thin Al layers deposited on Nb films with different sputtering parameters was studied. The anodization profile and X-ray photoelectron spectroscopy (XPS) confirmed that the underlying Nb layer is wet by a thin 2.9-nm Al layer, and the oxide formation on the Nb layer is completely suppressed. The excellent surface coverage is due to the affinity of Al for Nb and is quite different from the degraded coverage of Al on Si. It was observed that the surface coverage of Al on Nb depends on the film characteristics of the underlying Nb layers. Nb/AlO/sub x/-Al/Nb junctions with lower Nb layers deposited with different sputtering parameters were fabricated. The authors verified that the quality of the junction is closely related to the surface coverage as analyzed by the anodization profiles and XPS.<>

Keywords

X-ray photoelectron spectra; aluminium; aluminium compounds; anodisation; niobium; sputtered coatings; superconducting junction devices; Josephson junctions; Nb-AlO/sub x/-Al-Nb junctions; XPS; anodization profiles; surface coverage; Argon; Artificial intelligence; Cathodes; Fabrication; Insulation; Josephson junctions; Niobium; Semiconductor films; Substrates; Voltage;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.139224

Filename

139224