| 摘要 |
PURPOSE:To effectively connect first to second superconducting layers and to improve the integration of a Josephson circuit by sequentially depositing a thin film which becomes an etching stopper and can supply a large tunnel current and a third superconducting layer in this order. CONSTITUTION:A Josephson element and an insulating layer 5 made, for example, of silicon dioxide in which a counter electrode 4 is exposed and flattened are formed on a substrate 1. Then, a first superconducting layer 6 made, for example, of niobium, a thin aluminum film 10, and a third niobium superconducting layer 11 are sequentially deposited by sputtering. Thereafter, the region except the region of a contact window 8 of the layer 11 is removed by RIE, and the layer 11 is used as a contact unit 11. The film 10 becomes an etching stopper in this RIE. Subsequently, an insulating layer 7 of silicon dioxide in which the unit 11 is exposed and flattened is formed. Then, a control line 9 made of a second superconducting layer connected to the unit 11 is formed. Then, the layers 6 is connected through the window 8 to the second superconducting layer 9. |
