Thin film tantalum oxide capacitor

Claim 1

A thin film capacitor comprising a dielectric substrate, a first non-tantalum electrically conductive film electrode disposed on said substrate, a second electrically conductive film electrode, and a dielectric film consisting essentially of tantalum oxide disposed intermediate said first and second electrodes and being in contact with both said first and second electrodes, said dielectric film being characterized in that it is formed by the steps of providing the combination of said dielectric substrate having said nontantalum electrically conductive film thereon disposing said substrate and conductive film within a vacuum environment, applying a continuous film of tantalum oxide of desired thickness over said conductive film within said vacuum environment, removing the composite so formed from said vacuum environment, providing a liquid anodizing bath, thereafter disposing said composite in said liquid anodizing bath, passing an electrical current through said tantalum oxide film, said current being substantially constant until a predetermined desired voltage is reached, and removing said composite from said anodizing bath, whereby said capacitor exhibits a loss tangent less than 0.005, a breakdown voltage of at least 75 volts and a leakage current less than 10 -9 amp at 75 volts.