Novel Superconductive Delay Line Process Using High-Tc Superconducting Films

This letter reports a novel process for fabricating long and large-area superconductive delay lines. This process makes it possible to repattern easily without degrading superconducting properties and to obtain low contact resistance. A contact resistance of less than 3×10-5 Ω·cm2 can be obtained at a relatively low baking temperature in air. The process was used to fabricate a practical superconductive delay line 160 µm wide and 40 cm long. This line had a low insertion loss of 0.068 dB/ns at 1 GHz and 77 K.