A finFET device and methods of forming a finFET device are provided. The method includes depositing a dummy gate over and along sidewalls of a fin extending upwards from a semiconductor substrate, forming a first gate spacer along a sidewall of the dummy gate, and plasma-doping the first gate spacer with carbon to form a carbon-doped gate spacer. The method further includes forming a source/drain region adjacent a channel region of the fin and diffusing carbon from the carbon-doped gate spacer into a first region of the fin to provide a first carbon-doped region. The first carbon-doped region is disposed between at least a portion of the source/drain region and the channel region of the fin.