MANUFACTURE OF JOSEPHSON JUNCTION ELEMENT

PURPOSE:To facilitate the manufacture of an element by a method wherein a barrier layer of an Nb oxide is formed by plasma ions of oxygen gas while a magnetic field is impressed, when a superconductor electrode layer and a tunnel barrier layer composed of Nb and another superconductor electrode layer are laminated on a substrate and thus turned into a Josephson element. CONSTITUTION:The superconductor electrode layer 2 in a fixed shape composed of Nb is formed on the substrate 1, the exposed surface thereof is covered with the tunnel barrier layer 3, and the other superconductor electrode layer 4 is adhered over the entire surface including it, resulting in the formation of the Josephson junction element. Next, for the purpose of manufacturing this element, the substrate 1 provided for the purpose of manufacturing this element, the substrate 1 provided with the electrode layer 2 is contained into the vessel 16; after evacuating the inside, the oxygen gas is fed from a gas introduction port 12 and then irradiated with a microwave M, the plasma ions of the oxygen gas are generated by impressing the magnetic field by a field giving means 17, and accordingly the tunnel barrier layer 3 composed of the No oixde is generated on the layer 2. Thereafter, the other electrode layer 4 is adhered over the entire surface including it by a normal method.