A fast turn-around time process for fabrication of qubit circuits

The authors describe a process for fabrication of Nb/AlO/sub x//Nb Josephson junction circuits for quantum computation. The process involves only one etch step and incorporates electron beam lithography and a self-aligned lift-off of the dielectric resulting in a short turn-around time of 4-5 days. Deep submicron junctions of size down to 0.15 /spl times/ 0.15 /spl mu/m/sup 2/ have been fabricated and tested. Results of junction quality measurements will be presented. In particular, a subgap resistance of /spl sim/1 G/spl Omega/ measured at /spl sim/0.4 K indicates that the junction's subgap leakage should not be a limitation for quantum computation.