A FinFET device and method for fabricating a FinFET device is disclosed. An exemplary device includes a fin structure formed over a semiconductor substrate. The fin structure includes a source region and a drain region that include a first material layer disposed over the semiconductor substrate, a second material layer disposed over the first material layer, and a third material layer disposed over the second material layer. The first, second, and third material layers are different from each other. The fin structure also has a channel defined between the source and drain regions. The channel includes the first material layer disposed over the semiconductor substrate and the second semiconductor material layer disposed over the first material layer.