Microfabrication of NdFeAs(O,F) thin films and evaluation of the transport properties

Submicron sized strip lines of NdFeAs(O,F) were fabricated and the transport properties were studied. By using laser lithography and dry etching, strip lines with a width as low as 0.84 μm were fabricated. The superconducting critical temperature was not seriously affected by the fabrication process, but a significant decrease of the critical current density (Jc) was observed for strip lines narrower than 2 μm when the sample was etched in Ar plasma. By employing a plasma free method on the other hand, the deterioration of Jc was largely prevented, and the yield of obtaining strip lines with a Jc higher than 5 MA cm−2 rose considerably.