Asymmetrical FIB junctions as components for HTS SFQ circuits

Author

Mizuno, Y. ; Miyahara, K. ; Wen, J.G. ; Utagawa, T. ; Enomoto, Y.

Author_Institution

Supercond. Res. Lab., ISTEC, Tokyo, Japan

Volume

9

Issue

2

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

2882

Lastpage

2885

Abstract

High-temperature superconductor (HTS) Josephson junctions have been formed on asymmetrical V-shape grooves etched by a Ga focused-ion beam (FIB). The asymmetrical groove is made by tilting the substrate during FIB etching. Transmission electron microscopy (TEM) shows a tilted V-shape groove and two clear grain boundaries in the NBCO film. The I-V characteristics of the junctions are controlled by the dose amount of Ga ions and the NdBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (NBCO) film thickness. The inductance of the lines was estimated to be 0.5 pH//spl mu/m for the film thickness of 200 nm for the characteristics of a SQUID fabricated with the asymmetrical FIB junctions.

Keywords

Josephson effect; SQUIDs; barium compounds; focused ion beam technology; grain boundaries; high-temperature superconductors; inductance; neodymium compounds; sputter etching; superconducting thin films; transmission electron microscopy; I-V characteristics; Josephson junction; NdBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// thin film; NdBa/sub 2/Cu/sub 3/O/sub 7/; SFQ circuit; SQUID; asymmetrical V-shape groove; focused ion beam etching; grain boundary; high temperature superconductor; inductance; transmission electron microscopy; Circuits; Etching; Grain boundaries; High temperature superconductors; Inductance; Josephson junctions; Substrates; Superconducting films; Thickness control; Transmission electron microscopy;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.783631

Filename

783631