Easy process for fabrication of high-reliability DC-SQUIDs

Author

Chinone, K. ; Ataka, T. ; Shimizu, N.

Author_Institution

Seiko Instrum. Inc., Chiba, Japan

Volume

29

Issue

6

fYear

1993

fDate

11/1/1993 12:00:00 AM

Firstpage

3562

Lastpage

3564

Abstract

A process to fabricate high-reliability DC-SQUIDs for the study of biomagnetism on 4-in silicon wafers by minimizing the steps of the fabrication process is discussed. Al films were used for the shunt and damping resistors to decrease the number of materials used in the fabrication. The large βL DC-SQUID device was adopted to increase the reliability of the process because of the small number of input coil turns needed. The reliability of the fabricated devices was tested by examining their current-voltage and flux-voltage characteristics. These characteristics were in close agreement with the calculated values. The critical current and the modulation depth of about 200 DC-SQUIDs across a single wafer agreed within ±5%

Keywords

SQUIDs; alumina; critical currents; niobium; sputter deposition; Al; Al films; Nb-AlO_x-Nb; Si; biomagnetism; critical current; current-voltage characteristics; damping resistors; fabrication; flux-voltage characteristics; high-reliability DC-SQUIDs; input coil turns; large βL DC-SQUID device; modulation depth; reliability; shunt; sputter deposition; Fabrication; Magnetic devices; Magnetic films; Magnetic materials; Niobium; Rough surfaces; SQUIDs; Surface morphology; Surface roughness; Voltage;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.281230

Filename

281230