Next, in FIG. 4, upper portions of the epitaxial material 52 (e.g., an epitaxial silicon layer) in the region 50C (e.g., a p-type device region) are removed, and an epitaxial material 53, which may be suitable for forming p-type devices, is formed over the remaining portions of the epitaxial material 52 in the region 50C. In the illustrated embodiment, the epitaxial material 52 is an epitaxial silicon layer, and the epitaxial material 53 is an epitaxial silicon germanium layer. To form the epitaxial material 53, a mask layer may be formed to cover the epitaxial material 52 in the region 50B and to expose the epitaxial material 52 in the region 50C, then an etching process may be performed to remove the upper portions of the epitaxial material 52 in the region 50C. After the upper portions of the epitaxial material 52 are removed, an epitaxy process is performed to grow the epitaxial material 53 over the remaining portions of the epitaxial material 52 in the region 50C. After the epitaxial process, the mask layer is removed.
