A device includes a first semiconductor fin, a second semiconductor fin, a source/drain epitaxial structure, a semiconductive cap, and a contact. The first semiconductor fin and the second semiconductor fin are over a substrate. The source/drain epitaxial structure is connected to the first semiconductor fin and the second semiconductor fin. The source/drain epitaxial structure includes a first protruding portion and a second protruding portion aligned with the first semiconductor fin and the second semiconductor fin, respectively. The semiconductive cap is on and in contact with the first protruding portion and the second protruding portion. A top surface of the semiconductive cap is lower than a top surface of the first protruding portion of the source/drain epitaxial structure. The contact is electrically connected to the source/drain epitaxial structure and covers the semiconductive cap.