| 摘要 |
PURPOSE:To reduce a leakage current by forming an intermediate layer made of metal to become by oxidizing high dielectric or high dielectric, then oxidizing it in an oxidative atmosphere to convert part of a lower electrode into an insulator, and then forming an upper electrode on the intermediate layer. CONSTITUTION:A tantalum nitride film (TaN) is formed as a lower electrode 11 by RF sputtering on an Si substrate 10. Then, a tantalum oxide film (Ta2O5) is deposited as an intermediate layer on the electrode 11. This sample is heat treated at 750 deg.C for 1 hour in an Ar atmosphere, and then oxidized at 750 deg.C for 10min in an oxidative atmosphere. This is further heat treated at 950 deg.C for 30min in a nonoxidative atmosphere. An aluminum film is deposited as an upper electrode 13 on the layer 12. Thus, the layer 12 made of the Ta2O5 film is interposed between electrodes 11 and 13 to complete a capacitor. The capacitor is connected, for example, to the source of a MOS transistor to be used as a memory capacitor.
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