A non-planar gate all-around device and method of fabrication thereby are described. In one embodiment, the device includes a substrate having a top surface with a first lattice constant. Embedded epi source and drain regions are formed on the top surface of the substrate. The embedded epi source and drain regions have a second lattice constant that is different from the first lattice constant. Channel nanowires having a third lattice are formed between and are coupled to the embedded epi source and drain regions. In an embodiment, the second lattice constant and the third lattice constant are different from the first lattice constant. The channel nanowires include a bottom-most channel nanowire and a bottom gate isolation is formed on the top surface of the substrate under the bottom-most channel nanowire. A gate dielectric layer is formed on and all-around each channel nanowire. A gate electrode is formed on the gate dielectric layer and surrounding each channel nanowire.