| 摘要 |
PURPOSE:To obtain excellent insulation film by depositing a metal thin film which may be anode-oxidized on the surface of metal whose surface is mirror polished and by anode-oxidizing the thin film. CONSTITUTION:A disk of niobium Nb with purity of 99% is obtained in the thickness of 1mm. and diameter of 4cm and its surface is mirror polished with diamond paste. Thereby, a substrate 1 can be obtained. In order to cover crystal defect or the like, a thin film 2 of Nb is vacuum-deposited in the thickness of 2,000Angstrom on the surface. This metal thin film 2 is placed under the anode-oxidation process using a mixing solution of ethylene glycol and ammonium borate, thereby Nb2O3 film as been formed in the thickness of about 2,000Angstrom , thereafter the surface is insulated. In case a Josephson element integrated circuit utilizing Pb alloy is formed thereon, it is resistive to a temperature cycle of 10 times of that for the element using Si substrate. As described above, a satisfactory insulating film can be obtained by executing the anode oxidation to a metal plate of which surface is coated with thin film of Al, Ta, Nb, Ti etc. which can be anode-oxidized. |
