Patterning of Tl-based superconducting films using new etching solution

Tl-based cuprate superconducting films were prepared in a two-step process by RF magnetron sputtering of an amorphous precursor and ex situ thallination in open system. The films prepared on LaAlO3 and CeO2 buffered R-plane sapphire substrates consisted from c-axis oriented Tl-2212 superconducting phase. The zero resistance critical temperature TC0 exhibited values up to 94 K. Subsequently, superconducting structures were prepared from the Tl-based thin films using photolithography process and wet etching. A new etchant based on potassium iodide was used for the Tl-based film patterning. The prepared structures had sharp edges, unchanged phase composition and critical temperature values. Such a way of the Tl-based film patterning is very simple, fast and easy to realize.