Patent ID: 6157044
Filing Date: 2000-12-05
Classification: H01L

Abstract:
A stacked SIS tunnel junction type Josephson device including a pair of superconductor layers formed of a Y--Ba--Cu--O type compound oxide superconductor material and an insulator layer sandwiched between the pair of superconductor layers so as to form a three-layer laminated structure, wherein said pair of superconductor layers comprises a lower superconductor layer and an upper superconductor layer, said upper superconductor layer being deposited on said insulator layer, wherein said insulator layer is formed of a Y--Ba--Cu--O type compound oxide which is composed of the same constituent elements as those of the compound oxide superconductor material of said superconductor layers but with an atomic ratio of Y.sub.2 Ba.sub.1 Cu.sub.1 O.sub.5--y which is an insulator at least at the operating temperature of the SIS tunnel junction type Josephson device and wherein said upper superconductor layer is an epitaxial layer formed on said insulator layer.