Semiconductor devices and methods of manufacturing thereof are disclosed. A preferred embodiment includes a semiconductor device comprising a workpiece, the workpiece including a first region and a second region proximate the first region. A first material is disposed in the first region, and at least one region of a second material is disposed within the first material in the first region, the second material comprising a different material than the first material. The at least one region of the second material increases a first stress of the first region.