| 摘要 |
PURPOSE:To facilitate controlling and regulating the maximum Josephson current and normal conducting tunnel resistance simultaneously in liquid helium by a method wherein a junction barrier made of magnesia or aluminum oxide and upper and lower electrodes made of niobium nitride are made to grow in the same direction as a substrate by epitaxial growth to form a junction and micro-short is provided in the junction. CONSTITUTION:After four layers of films, i.e. a magnesium oxide film 6, a niobium nitride film 7 as a lower electrode, a magnesium oxide film 8 as an insulating barrier and further a niobium nitride film 9 as an upper electrode are formed on an insulating substrate 5, a normal SNEP method is carried out to complete a junction device. In other words, after the resist pattern 11 of the device is formed, the upper electrode 9 is etched by reactive ion etching. Further, after an insulating silicon oxide film 12 is formed by sputtering, the resist pattern 11 is removed by lifting-off. Then, after trimming is carried out in liquid helium by a burn-in method to control so as to obtain required characteristics, a niobium nitride film 13 for wiring pattern is formed by reactive sputtering. Then the wiring is completed by processing in the same way as processing the upper electrode 9. |
