EDGE JUNCTION TYPE SINGLE CRYSTAL THIN FILM SUPERCONDUCTOR TUNNEL JUNCTION ELEMENT AND MANUFACTURE THEREOF

摘要

PURPOSE:To form a tunnel junction making use of a superconductor single crystal thin film so as to take advantage of a magnetic and electric anisotropic property of the single crystal by a method wherein a first superconductor single crystal thin film, an interlaminar insulating film, and a second superconductor single crystal thin film which is provided so as to form a step and junctioned with the first superconductor single crystal thin film through the intermediary of a thin insulating film are provided. CONSTITUTION:A first superconductor thin film 2 of La-Sr-Cu-O or the like is formed on a SrTiO2 (100) face of a cubic crystal perovskite structure through a sputtering evaporation. Next, the face vertical to the substrate is made to be a c axis when the first thin film 2 is subjected to a heat treatment at a temperature of 800 deg.C or higher so as to be a single crystal, then a SiO2 film 3 is formed thereon as an interlaminar insulating film through a CVD method after the single crystallization of the film 2 is completed. A process follows, where the SiO2 film 3 and the second superconductor layer 2 are etched through a resist employed as a mask for the formation of a pattern. Next, impurity ions are slantingly implanted so as to convert the composition of the superconductor for the formation of a thin film 4. Lastly, a second superconductor layer (La-Sr-Cu-O) 5 is evaporated through a sputtering and subjected to a heat treatment so as to be converted into a single crystal.