A tantalum film capacitor has an .alpha.-tantalum as a lower electrode, a chemical conversion layer of .alpha.-tantalum as a dielectric and an upper electrode, an improvement involving forming a highly nitrogen-doped tantalum film between the .alpha.-tantalum and a substrate, and also, another improvement...http://www.google.de/patents/US4364099?utm_source=gb-gplus-sharePatent US4364099 - Tantalum thin film capacitor
