Patent ID: 8513724

Claim:
A semiconductor device comprising: a first gate insulating film formed on a first region of a semiconductor substrate; a first gate electrode formed on the first gate insulating film; a second gate insulating film formed on a second region of the semiconductor substrate; and a second gate electrode formed on the second gate insulating film, wherein the first gate insulating film includes a first oxygen-containing insulating film and a first high dielectric constant insulating film formed on the first oxygen-containing insulating film and containing a first metal, the first high dielectric constant insulating film further contains a second metal different from the first metal, part of the first high dielectric constant insulating film having a maximum composition ratio of the second metal is away from an interface between the first high dielectric constant insulating film and the first oxygen-containing insulating film and an interface between the first high dielectric constant insulating film and the first gate electrode, the second metal exists also in a portion of the first oxygen-containing insulating film near the interface between the first high dielectric constant insulating film and the first oxygen-containing insulating film, the second gate insulating film includes a second oxygen-containing insulating film and a second high dielectric constant insulating film formed on the second oxygen-containing insulating film and containing the first metal, the second high dielectric constant insulating film further contains a third metal different from the first metal and the second metal, and part of the second high dielectric constant insulating film having a maximum composition ratio of the third metal is away from an interface between the second high dielectric constant insulating film and the second oxygen-containing insulating film and an interface between the second high dielectric constant insulating film and the second gate electrode.