Patent attributes
A semiconductor device includes a structure of a gate electrode/a high-k dielectric insulating film containing aluminum and having a dielectric constant greater than that of a silicon oxide film/the silicon oxide film/a silicon substrate, and is provided with a diffusion layer formed by diffusing an aluminum atom or an aluminum ion to the silicon oxide film or an interface between the silicon oxide film and the silicon substrate by a heat treatment. A laminated film or a mixed film of hafnium oxide and aluminum oxide having a ratio of hafnium and aluminum ranging from about 2:8 to 8:2 is used as the high-k dielectric film. The heat treatment is performed at any temperature from about 500 to 1000° C. for any period of time from about 1 to 100 seconds.