Fabrication of high quality Nb/AlO/sub x/-Al/Nb Josephson junctions. I. Sputtered Nb films for junction electrodes

Author

Imamura, T. ; Shiota, T. ; Hasuo, S.

Author_Institution

Fujitsu Lab. Ltd., Atsugi, Japan

Volume

2

Issue

1

fYear

1992

fDate

3/1/1992 12:00:00 AM

Firstpage

1

Lastpage

14

Abstract

The stress, surface morphology, superconducting characteristics, and crystal structure of sputtered Nb films were evaluated to judge their applicability to Josephson-junction electrodes. The film qualities were compared between Nb films deposited by DC and RF magnetron sputtering. The authors concluded that DC-sputtered Nb films are more suitable for junction electrodes and studied the relationship between their film quality and sputtering parameters. They observed that the Nb film characteristics were determined solely by the cathode voltage during sputtering regardless of the other parameters. The authors discuss the changes in film characteristics during Josephson integrated circuit processing.<>

Keywords

Josephson effect; internal stresses; niobium; scanning electron microscope examination of materials; sputtered coatings; superconducting integrated circuits; superconducting junction devices; superconducting thin films; surface structure; type II superconductors; DC sputtering; Josephson integrated circuit processing; Josephson junctions; Nb-AlO/sub x/-Al-Nb; RF magnetron sputtering; SEM; cathode voltage; crystal structure; film quality; junction electrodes; sputtered Nb films; stress; superconducting characteristics; surface morphology; Electrodes; Fabrication; Josephson junctions; Niobium; Radio frequency; Sputtering; Stress; Superconducting films; Superconducting magnets; Surface morphology;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.124922

Filename

124922