Laser patterning of metal oxide superconductor films by reactive solid-state transformation

A planar submicrometer-resolution patterning method has been developed for fabrication of thin-film Ba/sub 2/YCu/sub 3/O/sub x/ devices without photoresist, water, or solvent exposure. The method is based on a rapid transformation from the superconductive to a dielectric phase. The phase change is induced by controlled changes in the oxygen stoichiometry which are induced thermally by local-area laser irradiation of the thin film in a gaseous ambient. Both extended-area pattern projection and scanned-beam direct writing have been demonstrated with a spatial resolution in the submicrometer range and are presently limited by the grain size of available films. Negligible thickness loss is observed in patterning. The method circumvents lithographic techniques which tend to degrade the electronic quality of Ba/sub 2/YCu/sub 3/O/sub x/ superconductors.<
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