Title :
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
fDate :
6/1/1999 12:00:00 AM
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;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
