| 摘要 |
PURPOSE:To prevent the fall of superconductive transfer temperature by heating an Mo thin film as masked with other material in a mixture gas of H2 and N2 and nitriding the Mo. CONSTITUTION:The Mo thin film 1 and an SiO2 mask 12 are laminated on an SiO2 film 11 on a P type Si substrate 10, and are heat treated, for example, at 500- 800 deg.C for 15-20min in an N2 gas (of 1 atm.) containing 5-10vol% of H2. N2 and H2 adsorbed upon the Mo film react to form NH3 and Mo is nitrified. Further, the H2 removes the adverse affect of the impurities such as H2O or O2 in the gas. According to this method, the N2 content in the formed film can be controlled by the temperature, and the N2 content becomes maximum in the vicinity of the center of the above temperature range. In the range that the N2 content varies, the formed film is a mixture of Mo, MoN and MoN2, but when the ratio (nitriding temperature) is suitably determined, the transition transfer temperature of the superconductivity can be controlled. |
