Proximity effects in superconducting wire bonding

Author

Tsukada, K. ; Yamasaki, S. ; Mizutani, N. ; Uehara, G. ; Kado, H. ; Akimoto, H. ; Ogashiwa, T.

Author_Institution

Superconducting Sensor Lab., Chiba, Japan

Volume

3

Issue

1

fYear

1993

fDate

3/1/1993 12:00:00 AM

Firstpage

2965

Lastpage

2967

Abstract

To investigate the superconducting characteristics of a superconducting wire bonding connection, a series of Nb electrodes consisting of an Au pad formed on a Si chip were made, and the pads were connected in series with a superconducting wire (Pb/sub 76/In/sub 20/Au/sub 4/). The I-V characteristics of the superconducting connection reflect the typical characteristics of a superconductor-normal-metal-superconductor (SNS) sandwich structure, with normal resistance on the order of mu Omega when a critical current (I/sub c/) level is exceeded. The dependence of I/sub c/ on the thickness of Au is an exponential decrement, and I/sub c/ is over a hundred mA when the Au thickness is between 20 nm and 230 nm. Auger analysis is applied to obtain the depth profile of the bonded part, revealing mutual Au and In atomic diffusion at the interface between the Au intermediate layer and the PbInAu wire.<>

Keywords

SQUIDs; lead bonding; packaging; proximity effect; superconducting junction devices; Au pad; Auger analysis; I-V characteristics; Nb electrodes; PbInAu wire; SQUID; Si chip; critical current; depth profile; packaging; proximity effects; superconducting wire bonding; superconductor-normal metal-superconductor sandwich; Atomic layer deposition; Critical current; Diffusion bonding; Electrodes; Gold; Niobium; Proximity effect; Sandwich structures; Superconducting devices; Superconducting filaments and wires;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.234024

Filename

234024