Novel method of patterning YBaCuO superconducting thin films

A unique method of patterning YBaCuO thin films based on the inhibition of superconductivity by Si-YBaCuO intermixing has been developed. In the experiment, a thin Si film was first evaporated on a MgO substrate and subsequently patterned using laser direct-write etching. Multilayered YBaCuO thin films were then deposited by e-beam evaporation and annealed in a rapid thermal annealing system for 30--90 s at 980 degree C. The YBaCuO film deposited on the silicon regions became insulating. Auger depth profiling measurements indicate that Si-YBaCuO intermixing had occurred in these areas. Between the insulating regions, narrow YBaCuO superconducting lines were formed. For both 10-μm-wide, 1-mm-long and 2.5-μm-wide, 80-μm-long lines, the Tc was observed above 76 K. The critical current density of the lines was measured to be 300 A/cm2 at 75 K. This patterning technique may be useful for fabrication of high Tc superconducting interconnects and devices