Semiconductor device and manufacturing method

The present invention provides a semiconductor device manufacturing method, comprising: providing a semiconductor substrate having a first region and a second region; forming a high-k dielectric layer on the substrate; a metal layer is formed on the high-k dielectric layer, the metal layer having a first work function; protective metal layer of the first region, performing a decoupled plasma containing carbon and nitrogen to the metal layer in the second region processing, performing an annealing process, and forming a first gate structure in the first region and a second gate structure is formed in the second region. The first gate structure comprises a high k dielectric layer and a metal layer is untreated. The second gate structure comprises a high-k dielectric layer and the layer of the treated metal. The present method provides a simple and cost-effective with a single metal layer, is applied to the prior art CMOS process, and therefore can be easily integrated with existing manufacturing equipment and technical means.