THE CVD OF SUPERCONDUCTORS

The discovery of high-temperature superconductivity in mixed oxides, such as the lanthanum-barium-copper oxide complexes, has created a great deal of interest in these materials. Superconductivity, that is, the absence of any resistance to the flow of electric current, is now possible at temperatures above the temperature of liquid nitrogen (77K). Many problems remain in the development of practical processes for these materials and commercialization is not likely to occur until these problems are solved. Among the several processing techniques now used, CVD appears one of the most successful. 

The most likely CVD applications of these superconductors to reach the practical stage are coatings for semiconductor and other electronic-related applications. For 1 arger current-carrying applications, a superconductor coating over a metallic conductor such as copper may also become a practical design because of its advantage over a monolithic superconductor wire. It is able to handle current excursions and has better mechanical properties. 

The metal alloy, niobium germanium (Nb3Ge), is another superconductor with a much lower transition temperature (20K) with well-established characteristics and good strength. It is deposited by CVD on an experimental basis by the reaction described in Ch. 6. 

Applications of CVD superconductors now being considered include the following  

Singer, P., Filling Contacts and Vias, A Progress Report, Semiconductor International, pp. 89-94 (Feb. 1996) 

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