Semiconductor device and manufacturing method thereof

摘要

Disclosed is a method of improving smoothness on a surface of a gate dielectric composed of a high dielectric film made of metal oxide. A dielectric film with a high permittivity made of metal oxide such as a TiO2 film or a ZrO2 film having an amorphous structure is deposited over a silicon substrate by the plasma enhanced chemical vapor deposition method, and the film is used as a gate dielectric. Since the gate dielectric has good surface smoothness, simultaneous reductions of both the film thickness of a gate dielectric and the gate leakage current can be achieved. In addition, it is also possible to reduce the variation in the characteristics of the devices.