A method for fabricating a semiconductor device includes forming a relaxed semiconductor layer on a substrate, the substrate comprising an n-type region and a p-type region. The method further includes forming a tensile strained semiconductor layer on the relaxed semiconductor layer, etching a portion of the tensile strained semiconductor layer in the p-type region, forming a compressive strained semiconductor layer on the tensile strained semiconductor layer in the p-type region, forming a first gate in the n-type region and a second gate in the p-type region, and forming a first set of source/drain features adjacent to the first gate and a second set of source/drain features adjacent to the second gate. The second set of source/drain features are deeper than the first set of source/drain features.