Patent ID: 8575677

Claim:
A semiconductor device, comprising: a gate insulating film and a gate electrode stacked in this order; wherein said gate insulating film and said gate electrode are in contact with each other; and wherein said gate insulating film comprises a silicon oxide film formed on a silicon substrate so as to be in contact therewith, and a nitrogen containing high-dielectric-constant insulating film formed on said silicon oxide film so as to be in contact therewith; and wherein said nitrogen containing high-dielectric-constant insulating film which has a structure in which nitrogen is introduced into metal oxide or metal silicate; and wherein a nitrogen concentration in said nitrogen containing high-dielectric-constant insulating film has a distribution in a direction of a film thickness; and a position at which the nitrogen concentration in said nitrogen containing high-dielectric-constant insulating film reaches a maximum in the direction of the film thickness is present in a region at a distance from the silicon substrate such that a maximum impurity concentration of the nitrogen concentration is greater than a nitrogen concentration at an interface between the silicon oxide film and the nitrogen containing high-dielectric-constant insulating film.