| abstract |
A capacitor is formed between a lower wiring layer and an upper wiring layer in an interior of a circuit board. The capacitor comprises a lower metallic layer consisting of at least one valve metal selected from the group consisting of aluminum, tantalum, niobium, tungsten, vanadium, bismuth, titanium, zirconium and hafnium, a dielectric layer consisting of an oxide of the valve metal which may be the same as or different from the valve metal of the lower metallic layer, an intermediate layer consisting of a solid electrolyte, and an upper metallic layer consisting of an electrode metal, laminated in this order. |