Electronic device comprising a gate electrode including a metal-containing layer having one or more impurities

One or more impurities may be incorporated within a metal-containing layer of a metal-containing gate electrode to modify the work function of the metal-containing gate electrode of a transistor can affect the threshold voltage of the transistor. In one embodiment, the impurity can be used in a p-channel transistor to allow the work function of a metal-containing gate electrode to be closer to the valence band for silicon. In another embodiment, the impurity can be used in an n-channel transistor to allow the work function of a metal-containing gate electrode to be closer to the conduction band for silicon. In a particular embodiment, a boron-containing species is implanted into a metal-containing layer within the metal-containing gate electrode within a p-channel transistor, so that the metal-containing gate electrode has a work function closer to the valence band for silicon as compared to the metal-containing gate electrode without the boron-containing species.