A fin field effect transistor (FinFET) comprises a substrate; a fin over the substrate, the fin having a channel region; a gate structure engaging the fin adjacent to the channel region; and a spacer on sidewalls of the gate structure. The FinFET further includes first and second heavily doped source/drain (HDD) features at least partially in the fin, on opposing sides of the gate structure, and adjacent to the spacer. The FinFET further includes first and second lightly doped source/drain (LDD) regions in the fin between the first and second HDD features, respectively, and the channel region. A sidewall of the first HDD feature and a sidewall of the first LDD region have substantially a same shape.