C-axis microbridges for rapid single flux quantum logic

Author

Hirst, P.J. ; Henrici, T.G. ; Atkin, I.L. ; Satchell, J.S. ; Moxey, J. ; Exon, N.J. ; Wooliscoft, M.J. ; Horton, T.J. ; Humphreys, R.G.

Author_Institution

DERA, Malvern, UK

Volume

9

Issue

2

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

3833

Lastpage

3836

Abstract

The c-axis microbridge (CAM) junction technology has an inherently low inductance due to its groundplaned geometry which should be well suited to SFQ logic applications. However, the critical currents of the conventional (2 /spl mu/m diameter) CAM technology are too high. Experiments with optical lithography have shown that junctions of /spl sim/0.5 micron dimension are required. A new process using electron beam lithography has been developed. The junction statistics even at this early stage of development look promising. To confirm the validity of the rest of the design and fabrication technology a CAM based RS Flip-Flop has been fabricated which shows the correct traversal of the state graph at 45 K.

Keywords

electron beam lithography; flip-flops; superconducting logic circuits; superconducting microbridges; 45 K; RS flip-flop; c-axis microbridge junction technology; critical current; electron beam lithography; inductance; rapid single flux quantum logic; state graph; CADCAM; Computer aided manufacturing; Critical current; Electron beams; Electron optics; Geometrical optics; Inductance; Lithography; Logic; Statistics;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.783863

Filename

783863