Josephson LSI fabrication technology using NbN/MgO/NbN tunnel junctions

Author

Aoyagi, M. ; Nakagawa, H. ; Kurosawa, I. ; Takada, S.

Author_Institution

Electrotech. Lab., Ibaraki, Japan

Volume

27

Issue

2

fYear

1991

fDate

3/1/1991 12:00:00 AM

Firstpage

3180

Lastpage

3183

Abstract

Josephson LSI fabrication technology using NbN/MgO/NbN tunnel junctions has been developed. The deposition process of the NbN electrode was investigated to obtain high uniformity of the electrical properties. The deposition process of the MgO tunnel barrier was investigated to obtain high reproducibility of the Josephson critical current density. The NbN film with high T_c of 15 K was obtained. The reproducibility of the MgO deposition rate was improved. The 10-b instruction 128-word ROM unit chip was successfully fabricated using the NbN/MgO/NbN junction LSI technology with the 3-μm design rule. The READ operation test was performed for a few 10-b words. The total access time was measured to be 710 ps. The uniformity and reproducibility of the critical current density in the LSI chip were improved

Keywords

integrated circuit technology; large scale integration; magnesium compounds; niobium compounds; read-only storage; superconducting memory circuits; 10 bit; 1280 bit; 15 K; 3 micron; 710 ps; Josephson LSI fabrication technology; Josephson junctions; LSI chip; MgO tunnel barrier; NbN-MgO-NbN; READ operation test; ROM chip; access time; critical current density; deposition process; reproducibility; uniformity; Critical current density; Electrodes; Fabrication; Large scale integration; Performance evaluation; Read only memory; Reproducibility of results; Semiconductor device measurement; Testing; Time measurement;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.133887

Filename

133887