Coevaporated Bi-Sr-Ca-Cu Oxide Films and Their Patterning Film Fabrication of Artificial (BiO)/(SrCaCuO) Layered Structure
Initially, after the discovery of high Tc superconducting materials, most of the studies were confined to yttrium based 1-2-3 compounds. However, Bi and Tl based compounds are attracting the attention of many investigators recently because of their relatively lower sensitivity to oxygen and easy annealing1. In addition to a semiconducting phase2, these compounds have multiple superconducting phases with transition temperatures between 85 and 110 K. Various approaches to obtaining high T, superconducting BiCaSrCu oxide films have been reported. These include electron beam coevaporation3, ion and reactive ion beam deposition4–5, multisource magnetron sputtering6, spin—on coating7 and laser ablation8. For applications in electronics, another important aspect is the patterning of thin superconducting films. Numerous papers have been published regarding the patterning of yttrium based 1-2-3 films by wet chemical etching9, ion beam etching10 and laser ablation11, but there are only a few papers on the patterning of Bi based compounds. In this paper we report the results of the fabrication of BiSrCaCu oxide superconducting thin films by coevaporation of CaF2, SrF2, Bi and Cu followed by a post—deposition annealing in wet oxygen; and their patterning by wet chemical etching.
KeywordsOxide Film Etching Rate Zirconia Substrate Strontium Bismuth Tungsten Boat
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