JOSEPHSON JUNCTION INCLUDING SUPERCONDUCTING MGB2 THIN FILM AND METHOD FOR MANUFACTURING THE SAME

摘要

PURPOSE: Josephson junction including a superconducting MgB2 thin film is provided to not only have such a uniform junction so as to be applied in an integrated circuit but also be used to make a circuit with a common refrigerator under low temperature ranging 15 to 20 K. CONSTITUTION: A bottom superconductor thin film(12) made up of MgB2 is formed on a substrate(10). A metal barrier layer(20a) is formed on the bottom superconductor thin film. A top superconductor thin film(22a) is formed on the metal barrier layer. The first capping layer is formed on the superconductor thin film to prevent diffusion of Mg. After exposing the product in the air, the first capping layer, A top superconductor thin film and barrier layer are patterned in sequence. The second capping layer(32) is formed to isolate the bottom superconductor thin film from the top superconductor thin film electrically. After patterning the first capping layer again so as to expose the top superconductor thin film, electric pads(40) and wires(42) are formed on the exposed surface of it.