| abstract |
A semiconductor device of the present invention includes a plurality of active regions defined on a semiconductor substrate, a plurality of gate structures formed on the active regions, respectively, and source / drain regions formed on the semiconductor substrate on both sides of the gate structures do. Wherein the plurality of gate structures are formed on the semiconductor substrate such that at least one of the high dielectric constant layers, the first work function metal layers having different thicknesses, the second work function metal layers having a lower work function than the first work function metal layers, And sequentially stacked structures. The gate structure including the thickest first work function metal layer among the first work function metal layers further includes a capping layer including an impurity element on the high dielectric constant layer. |