Patent ID: 8349695

Claim:
A method of forming a semiconductor device, the method comprising: forming a material layer stack above a first device region and a second device region, said material layer stack comprising a dielectric base layer, a high-k dielectric material formed on said dielectric base layer and metal-containing material formed on said high-k dielectric material; performing a heat treatment so as to diffuse a metal species from said metal-containing material to an interface formed by said dielectric base layer and said high-k dielectric material; forming a dielectric layer selectively above said second device region after performing said heat treatment; and forming a first gate electrode structure above said first device region and a second gate electrode structure above said second device region, said first gate electrode structure comprising said dielectric base layer and said high-k dielectric material as a first gate dielectric and said second gate electrode structure comprising said dielectric base layer, said high-k dielectric material and said dielectric layer as a second gate dielectric.