| abstract |
A tantalum film capacitor has an α-tantalum as a lower electrode, a chemical conversion layer of α-tantalum as a dielectric and an upper electrode, an improvement involving forming a highly nitrogen-doped tantalum film between the α-tantalum and a substrate, and also, another improvement involving forming a transitional thin tantalum layer between said highly nitrogen-doped tantalum film and said α-tantalum. The nitrogen concentration of the highly nitrogen-doped tantalum film is from 14 to 30 atomic %. The electrical properties, especially leakage current, are improved over those of the prior art. A disadvantage of the conventional α-tantalum thin film capacitor, that is the necessity of using an expensive partial glazed Al 2 O 3 substrate, is eliminated, and a non-glazed Al 2 O 3 substrate can be used in the present invention. |