A semiconductor device having a semiconductor substrate with a dielectric layer disposed thereon. A trench is defined in the dielectric layer. A metal gate structure is disposed in the trench. The metal gate structure includes a first layer and a second layer disposed on the first layer. The first layer extends to a first height in the trench and the second layer extends to a second height in the trench; the second height is greater than the first height. In some embodiments, the second layer is a work function metal and the first layer is a dielectric. In some embodiments, the second layer is a barrier layer.