Semiconductor devices, transistors, and methods of manufacture thereof are disclosed. In one embodiment, a semiconductor device includes a gate dielectric disposed over a workpiece, a gate disposed over the gate dielectric, and a spacer disposed over sidewalls of the gate and the gate dielectric. A source region is disposed proximate the spacer on a first side of the gate, and a drain region is disposed proximate the spacer on a second side of the gate. A metal layer is disposed over the source region and the drain region. The metal layer extends beneath the spacers by about 25% or greater than a width of the spacers.