| 摘要 |
PURPOSE:To flatten the surface of an IC including the Josephson junction element by a method wherein a groove is cut on a substrate or an insulating layer, and an Nb superconductive thin film, which is the control wire for generation of magnetic field, of thickness the same as the depth of the groove is buried in the groove. CONSTITUTION:The pattern 2 of photoresist film is formed on the sapphire substrate 1, and using same as a mask, a wiring groove 3 of 200nm or thereabout in depth is cut by performing a reactiver plasma etching wherein a mixed gas of CF4 and O2 is used. Then, in the state wherein the pattern is left, an Nb film 4 of approximately 200nm is coated on the whole surface by preforming a sputtering, and the groove 3 is buried by the Nb4 film while isolating it from the pattern 2. Subsequently, the pattern 2 is removed together with the film 4 located above the pattern 2, a wiring 5 which will be used as a controlling wire or a superconductive wiring is left, and an SiO interlayer insulating film 6 is covered on the whole surface including the wiring 5. Subsequently, an Nb base electrode 7 is provided in the center part of the film 6, the circumference thereof is surrounded by an SiO, and a Pb upper electrode 10 is installed on the electrode 7 through the intermediary of a tunnel barrier layer 8 consisting of an Nb oxide. |
