Fabrication and I-V Characteristics of High-Tc Nb3Ge Microbridges

High-T c Nb3Ge microbridges are fabricated by electron-beam lithography combined with CF4 reactive sputter etching. The bridges are 0.48 µm wide and 0.36–0.6 µm long. The temperature dependence of I c is found to be proportional to (1-t)5/2 at t>0.8 (t=T/T c). This result means that the bridge region behaves like an inhomogeneous type-II superconductor film. 9.75 GHz microwave induced steps are observed throughout a wide temperature range. The steps are observed above 20 K in some bridges.