摘要 |
A semiconductor device has a capacitor insulating film composed of a first and a second silicon nitride film. The surface of a lower electrode of impurity-doped polysilicon is transformed into the first silicon nitride film by thermal nitriding, and thereafter the second silicon nitride film is formed by chemical vapor deposition. An upper electrode is formed on the second silicon nitride film. A silicon oxide film may be formed on the second silicon nitride film by thermal oxidation. The capacitor insulating film which has a thickness of 5 nm or less in equivalent thickness of an oxide film reduces a leakage current and improves a long-term product reliability.
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