| 摘要 |
PROBLEM TO BE SOLVED: To provide two types of gate structures which are suitable, when a part of a gate insulating film is formed of a high dielectric film.SOLUTION: After the high dielectric film having a relative permittivity larger than a silicon nitride film, for example, a titanium oxide film 6 (a gate insulating film of an internal circuit) is formed on a substrate 1, a silicon nitride film 7 is deposited over the titanium oxide film 6. The silicon nitride film 7 serves as an oxidation preventive film which prevents the titanium oxide film 6 from becoming oxidized, when the surface of the substrate 1 is thermally oxidized in a next process. After the silicon nitride film 7 and titanium oxide film 6 in an I/O circuit region are removed, while the silicon nitride film 7 and titanium oxide film 6 are left in an internal circuit region, by thermally oxiidizing the substrate 1, a silicon oxide film 8 (a gate insulating film of an I/O circuit) is formed on a surface of the substrate 1 in the I/O circuit region. |
