SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREFOR

摘要

A gate electrode achieves a desired work function in a semiconductor device including a field-effect transistor equipped with a gate electrode composed of a metal nitride layer. The semiconductor device includes a silicon substrate and a field-effect transistor provided on the silicon substrate and having a gate insulating film and a gate electrode provided on the gate insulating film. The gate insulating film includes a high-permittivity insulating film formed of a metal oxide, a metal silicate, a metal oxide introduced with nitrogen, or a metal silicate introduced with nitrogen, and the gate electrode includes at least a metal nitride layer containing Ti and N. At least a part which is in contact with the gate insulating film of the metal nitride layer has a molar ratio between Ti and N (N/Ti ratio) of not less than 1.15 and a film density of not less than 4.7 g/cc.