Embodiments of the present invention are directed to dual threshold voltage (VT) channel devices and their methods of fabrication. In an example, a semiconductor device includes a gate stack disposed on a substrate, the substrate having a first lattice constant. A source region and a drain region are formed on opposite sides of the gate electrode. A channel region is disposed beneath the gate stack and between the source region and the drain region. The source region is disposed in a first recess having a first depth and the drain region disposed in a second recess having a second depth. The first recess is deeper than the second recess. A semiconductor material having a second lattice constant different than the first lattice constant is disposed in the first recess and the second recess.