A method is for making a semiconductor device. The method may include forming fins above a substrate, each fin having an upper fin portion including a first semiconductor material and a lower fin portion including a dielectric material. The method may include forming recesses into sidewalls of each lower fin portion to expose a lower surface of a respective upper fin portion, and forming a second semiconductor layer surrounding the fins including the exposed lower surfaces of the upper fin portions. The second semiconductor layer may include a second semiconductor material to generate stress in the first semiconductor material.