| 摘要 |
PURPOSE:To reduce a leakage current by crystallizing oxide or suboxide of an intermediate layer by heat treating in a nonoxidative atmosphere, and then oxidizing it in an oxidative atmosphere to sufficiently oxidize the metal, metal nitride or suboxide of the layer. CONSTITUTION:An Si substrate 11 is RF sputtered by a target made of tantalum nitride (TaN) and tantalum oxide (Ta2O5) to form an intermediate layer 12. It is heat treated at 700 deg.C for 1 hour in an Ar gas atmosphere to crystallize the Ta2O5 film, and then oxidized at 650 deg.C for 30min in an oxidative atmosphere. It 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, and a capacitor in which the layer 12 is interposed between electrodes 11 and 13 made of the Ta2O5 films is completed. The capacitor is connected to the source of a MOS transistor to be used as a memory capacitor.
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