| 摘要 |
PURPOSE:To obtain a magnetic thin film which is free from the variation of the uniaxial magnetic anisotropy and has high permeability in a high frequency band, by forming the magnetic thin film in a weak magnetic field and also applying the heat processing to the film in a state where an intensive magnetic field is applied in the direction rectangular to said weak magnetic field. CONSTITUTION:A weak magnetic field H or 10-20G is applied to the surface of a substrate 1, and a magnetic thin film is formed by a plating or sputtering process. Then the thin film is formed into a pattern by a lithographic method so that an easy axis EA of the thin film is coincident with the center axis Y of the magnetic core of the thin film. Then an intensive magnetic field of 200-600G is applied to the substrate in the direction rectangular to the axis Y, and the heat processing is applied to the substrate 1 at 200-250 deg.C and for 30-50min. As a result, the magnetic domain in the direction of the axis EA is inverted by 90 deg.. Thus the direction of a hard axis HA of the thin film is coincident with the axis Y. This improves greatly the permeability in a high in a high frequency band. |
