manufacturing method of a superconducting device with extremely thin superconducting channel supraleitendem oxidmaterial

摘要

A superconducting device comprises a substrate, a projecting insulating region formed in a principal surface of the substrate, and a first thin film portion of an oxide superconductor formed on the projecting insulating region. Second and third thin film portions of an oxide superconductor are positioned at opposite sides of the projecting insulating region to be continuous to the first thin film portion, respectively, so that a superconducting current can flow through the first thin film portion between the second thin film portion and the third thin film portion. The second thin film portion and the third thin film portion has a thickness larger than, that of the first thin film portion. The projecting insulating region is formed of an oxide which is composed of the same constituent elements of the oxide superconductor but which has the oxygen content smaller than that of said oxide superconductor. The superconducting device can be manufactured by forming on a surface of a substrate a compound oxide layer which is composed of the same constituent elements as those of an oxide superconductor but includes the oxygen amount less than that of the oxide superconductor, and which will be brought into an oxide superconductor when oxygen ions are injected, injecting oxygen ions into two separated portions of the compound oxide layer, so that the two separated portions of the compound oxide layer are converted into a pair of thick superconducting regions composed of the oxide superconductor, and heat-treating the layered structure in an oxygen atmosphere so that the oxygen is diffused into a portion of the compound oxide layer between the two separated portions of the compound oxide layer so as to constitute an extremely thin superconducting region. IMAGE