| 摘要 |
PROBLEM TO BE SOLVED: To provide a thin-film capacitor, and more particularly, a low-cost thin-film capacitor with large capacitance density and low impedance, which is suitable for using as an electrode foil of an electrolytic capacitor for a substrate with built-in components. SOLUTION: A lower electrode 2 which consists of a conductive material is formed on an insulating substrate 1. A dense layer 3 of a valve metal is formed on the lower electrode 2. A composite metal thin film 4, in which the valve metal and a different phase component which is incompatible with the valve metal are homogeneously distributed within a grain size range of 1 nm to 1μm, is formed on the dense layer 3. Heat treatment is performed. Thus, the grains of the valve metal and the different phase component of the compound metal thin film are grown, and the different phase component is selectively dissolved and removed from a composite metal thin film 5, after adjusting the grain size. Thus, a porous layer 6 of the valve metal is formed. COPYRIGHT: (C)2009,JPO&INPIT
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