| 摘要 |
PURPOSE:To improve an energy voltage (Vg) and eliminate deviation of device characteristics by a method wherein a highly oriented magnesia thin film is employed as a foundation material and a tunnel barrier, composed of magnesia or aluminum oxide, and upper and lower electrodes, composed of niobium nitride, are made to grow by epitaxial growth to the same direction as the foundation material. CONSTITUTION:An MgO film 5 for epitaxial growth of NbN, which is to be a lower electrode 6 of a device, is formed. Successively, in the same vacuum, first the NbN 6 for the lower electrode of the device is deposited to the thickness of 100-150nm by reactive sputtering. Further, MgO 7 for a tunnel barrier is deposited to the thickness of 0.2-0.5mm which is several times of the coherence length of the NbN by sputtering. finally, NbN 8 for an upper electrode, is deposited to the thickness of 100-150nm. Then the upper electrode is processed by RIE after a resist stencil 9 is provided. Afther that, SiO2 10 for insulation is deposited by sputtering and the resist stencil 9 is lifted off. Finally, NbN 11 for wirings is deposited by sputtering and RIE and lifting-off are carried out to forme the device. |
