Laser patterning of YBaCuO weak link bridges

A laser ablation process was developed to pattern thin-film superconducting devices with 1- mu m resolution. The process was utilized to fabricate bridge structures in high T/sub c/(>90 K) YBaCuO superconducting thin films sputtered on various substrates. For bridges patterned on thin films with a high degree of polycrystallinity, the authors observed weak-link Josephson behaviour, from 4.2 K up to T/sub c/. The weak-link behaviour was attributed to grain-boundary superconducting tunneling. The results suggest that direct laser patterning can be a powerful technique for evaluation and optimization of prototype superconducting devices.< >